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  → /programs/develop/libraries/cairo/src/cairo.c @ 1891

  → /programs/develop/libraries/cairo/src/cairo.c @ 1892

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/programs/develop/libraries/cairo/src/cairo.c
0,0 → 1,4173
/* -*- Mode: c; c-basic-offset: 4; indent-tabs-mode: t; tab-width: 8; -*- */
/* cairo - a vector graphics library with display and print output
*
* Copyright © 2002 University of Southern California
* Copyright © 2005 Red Hat, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it either under the terms of the GNU Lesser General Public
* License version 2.1 as published by the Free Software Foundation
* (the "LGPL") or, at your option, under the terms of the Mozilla
* Public License Version 1.1 (the "MPL"). If you do not alter this
* notice, a recipient may use your version of this file under either
* the MPL or the LGPL.
*
* You should have received a copy of the LGPL along with this library
* in the file COPYING-LGPL-2.1; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Suite 500, Boston, MA 02110-1335, USA
* You should have received a copy of the MPL along with this library
* in the file COPYING-MPL-1.1
*
* The contents of this file are subject to the Mozilla Public License
* Version 1.1 (the "License"); you may not use this file except in
* compliance with the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY
* OF ANY KIND, either express or implied. See the LGPL or the MPL for
* the specific language governing rights and limitations.
*
* The Original Code is the cairo graphics library.
*
* The Initial Developer of the Original Code is University of Southern
* California.
*
* Contributor(s):
* Carl D. Worth <cworth@cworth.org>
*/
#include "cairoint.h"
#include "cairo-private.h"
#include "cairo-arc-private.h"
#include "cairo-error-private.h"
#include "cairo-path-private.h"
/**
* SECTION:cairo
* @Title: cairo_t
* @Short_Description: The cairo drawing context
* @See_Also: #cairo_surface_t
*
* #cairo_t is the main object used when drawing with cairo. To
* draw with cairo, you create a #cairo_t, set the target surface,
* and drawing options for the #cairo_t, create shapes with
* functions like cairo_move_to() and cairo_line_to(), and then
* draw shapes with cairo_stroke() or cairo_fill().
*
* #cairo_t<!-- -->'s can be pushed to a stack via cairo_save().
* They may then safely be changed, without loosing the current state.
* Use cairo_restore() to restore to the saved state.
*/
/**
* SECTION:cairo-text
* @Title: text
* @Short_Description: Rendering text and glyphs
* @See_Also: #cairo_font_face_t, #cairo_scaled_font_t, cairo_text_path(),
* cairo_glyph_path()
*
* The functions with <emphasis>text</emphasis> in their name form cairo's
* <firstterm>toy</firstterm> text API. The toy API takes UTF-8 encoded
* text and is limited in its functionality to rendering simple
* left-to-right text with no advanced features. That means for example
* that most complex scripts like Hebrew, Arabic, and Indic scripts are
* out of question. No kerning or correct positioning of diacritical marks
* either. The font selection is pretty limited too and doesn't handle the
* case that the selected font does not cover the characters in the text.
* This set of functions are really that, a toy text API, for testing and
* demonstration purposes. Any serious application should avoid them.
*
* The functions with <emphasis>glyphs</emphasis> in their name form cairo's
* <firstterm>low-level</firstterm> text API. The low-level API relies on
* the user to convert text to a set of glyph indexes and positions. This
* is a very hard problem and is best handled by external libraries, like
* the pangocairo that is part of the Pango text layout and rendering library.
* Pango is available from <ulink
* url="http://www.pango.org/">http://www.pango.org/</ulink>.
*/
/**
* SECTION:cairo-transforms
* @Title: Transformations
* @Short_Description: Manipulating the current transformation matrix
* @See_Also: #cairo_matrix_t
*
* The current transformation matrix, <firstterm>ctm</firstterm>, is a
* two-dimensional affine transformation that maps all coordinates and other
* drawing instruments from the <firstterm>user space</firstterm> into the
* surface's canonical coordinate system, also known as the <firstterm>device
* space</firstterm>.
*/
#define CAIRO_TOLERANCE_MINIMUM _cairo_fixed_to_double(1)
#if !defined(INFINITY)
#define INFINITY HUGE_VAL
#endif
static const cairo_t _cairo_nil = {
CAIRO_REFERENCE_COUNT_INVALID, /* ref_count */
CAIRO_STATUS_NO_MEMORY, /* status */
{ 0, 0, 0, NULL }, /* user_data */
NULL, /* gstate */
{{ 0 }, { 0 }}, /* gstate_tail */
NULL, /* gstate_freelist */
{{ /* path */
{ 0, 0 }, /* last_move_point */
{ 0, 0 }, /* current point */
FALSE, /* has_current_point */
FALSE, /* has_last_move_point */
FALSE, /* has_curve_to */
FALSE, /* is_box */
FALSE, /* maybe_fill_region */
TRUE, /* is_empty_fill */
{ {0, 0}, {0, 0}}, /* extents */
{{{NULL,NULL}}} /* link */
}}
};
static const cairo_t _cairo_nil__null_pointer = {
CAIRO_REFERENCE_COUNT_INVALID, /* ref_count */
CAIRO_STATUS_NULL_POINTER, /* status */
{ 0, 0, 0, NULL }, /* user_data */
NULL, /* gstate */
{{ 0 }, { 0 }}, /* gstate_tail */
NULL, /* gstate_freelist */
{{ /* path */
{ 0, 0 }, /* last_move_point */
{ 0, 0 }, /* current point */
FALSE, /* has_current_point */
FALSE, /* has_last_move_point */
FALSE, /* has_curve_to */
FALSE, /* is_box */
FALSE, /* maybe_fill_region */
TRUE, /* is_empty_fill */
{ {0, 0}, {0, 0}}, /* extents */
{{{NULL,NULL}}} /* link */
}}
};
#include <assert.h>
/**
* _cairo_error:
* @status: a status value indicating an error, (eg. not
* %CAIRO_STATUS_SUCCESS)
*
* Checks that status is an error status, but does nothing else.
*
* All assignments of an error status to any user-visible object
* within the cairo application should result in a call to
* _cairo_error().
*
* The purpose of this function is to allow the user to set a
* breakpoint in _cairo_error() to generate a stack trace for when the
* user causes cairo to detect an error.
*
* Return value: the error status.
**/
cairo_status_t
_cairo_error (cairo_status_t status)
{
CAIRO_ENSURE_UNIQUE;
assert (_cairo_status_is_error (status));
return status;
}
/**
* _cairo_set_error:
* @cr: a cairo context
* @status: a status value indicating an error
*
* Atomically sets cr->status to @status and calls _cairo_error;
* Does nothing if status is %CAIRO_STATUS_SUCCESS.
*
* All assignments of an error status to cr->status should happen
* through _cairo_set_error(). Note that due to the nature of the atomic
* operation, it is not safe to call this function on the nil objects.
*
* The purpose of this function is to allow the user to set a
* breakpoint in _cairo_error() to generate a stack trace for when the
* user causes cairo to detect an error.
**/
static void
_cairo_set_error (cairo_t *cr, cairo_status_t status)
{
/* Don't overwrite an existing error. This preserves the first
* error, which is the most significant. */
_cairo_status_set_error (&cr->status, _cairo_error (status));
}
/* We keep a small stash of contexts to reduce malloc pressure */
#define CAIRO_STASH_SIZE 4
#if CAIRO_NO_MUTEX
static struct {
cairo_t pool[CAIRO_STASH_SIZE];
int occupied;
} _context_stash;
static cairo_t *
_context_get (void)
{
int avail;
avail = ffs (~_context_stash.occupied) - 1;
if (avail >= CAIRO_STASH_SIZE)
return malloc (sizeof (cairo_t));
_context_stash.occupied |= 1 << avail;
return &_context_stash.pool[avail];
}
static void
_context_put (cairo_t *cr)
{
if (cr < &_context_stash.pool[0] ||
cr >= &_context_stash.pool[CAIRO_STASH_SIZE])
{
free (cr);
return;
}
_context_stash.occupied &= ~(1 << (cr - &_context_stash.pool[0]));
}
#elif HAS_ATOMIC_OPS
static struct {
cairo_t pool[CAIRO_STASH_SIZE];
cairo_atomic_int_t occupied;
} _context_stash;
static cairo_t *
_context_get (void)
{
cairo_atomic_int_t avail, old, new;
do {
old = _cairo_atomic_int_get (&_context_stash.occupied);
avail = ffs (~old) - 1;
if (avail >= CAIRO_STASH_SIZE)
return malloc (sizeof (cairo_t));
new = old | (1 << avail);
} while (! _cairo_atomic_int_cmpxchg (&_context_stash.occupied, old, new));
return &_context_stash.pool[avail];
}
static void
_context_put (cairo_t *cr)
{
cairo_atomic_int_t old, new, avail;
if (cr < &_context_stash.pool[0] ||
cr >= &_context_stash.pool[CAIRO_STASH_SIZE])
{
free (cr);
return;
}
avail = ~(1 << (cr - &_context_stash.pool[0]));
do {
old = _cairo_atomic_int_get (&_context_stash.occupied);
new = old & avail;
} while (! _cairo_atomic_int_cmpxchg (&_context_stash.occupied, old, new));
}
#else
#define _context_get() malloc (sizeof (cairo_t))
#define _context_put(cr) free (cr)
#endif
/* XXX This should disappear in favour of a common pool of error objects. */
static cairo_t *_cairo_nil__objects[CAIRO_STATUS_LAST_STATUS + 1];
static cairo_t *
_cairo_create_in_error (cairo_status_t status)
{
cairo_t *cr;
assert (status != CAIRO_STATUS_SUCCESS);
/* special case OOM in order to avoid another allocation */
switch ((int) status) {
case CAIRO_STATUS_NO_MEMORY:
return (cairo_t *) &_cairo_nil;
case CAIRO_STATUS_NULL_POINTER:
return (cairo_t *) &_cairo_nil__null_pointer;
}
CAIRO_MUTEX_LOCK (_cairo_error_mutex);
cr = _cairo_nil__objects[status];
if (cr == NULL) {
cr = malloc (sizeof (cairo_t));
if (unlikely (cr == NULL)) {
CAIRO_MUTEX_UNLOCK (_cairo_error_mutex);
_cairo_error_throw (CAIRO_STATUS_NO_MEMORY);
return (cairo_t *) &_cairo_nil;
}
*cr = _cairo_nil;
cr->status = status;
_cairo_nil__objects[status] = cr;
}
CAIRO_MUTEX_UNLOCK (_cairo_error_mutex);
return cr;
}
void
_cairo_reset_static_data (void)
{
int status;
CAIRO_MUTEX_LOCK (_cairo_error_mutex);
for (status = CAIRO_STATUS_SUCCESS;
status <= CAIRO_STATUS_LAST_STATUS;
status++)
{
if (_cairo_nil__objects[status] != NULL) {
free (_cairo_nil__objects[status]);
_cairo_nil__objects[status] = NULL;
}
}
CAIRO_MUTEX_UNLOCK (_cairo_error_mutex);
}
/**
* cairo_create:
* @target: target surface for the context
*
* Creates a new #cairo_t with all graphics state parameters set to
* default values and with @target as a target surface. The target
* surface should be constructed with a backend-specific function such
* as cairo_image_surface_create() (or any other
* cairo_<emphasis>backend</emphasis>_surface_create() variant).
*
* This function references @target, so you can immediately
* call cairo_surface_destroy() on it if you don't need to
* maintain a separate reference to it.
*
* Return value: a newly allocated #cairo_t with a reference
* count of 1. The initial reference count should be released
* with cairo_destroy() when you are done using the #cairo_t.
* This function never returns %NULL. If memory cannot be
* allocated, a special #cairo_t object will be returned on
* which cairo_status() returns %CAIRO_STATUS_NO_MEMORY.
* You can use this object normally, but no drawing will
* be done.
**/
cairo_t *
cairo_create (cairo_surface_t *target)
{
cairo_t *cr;
cairo_status_t status;
if (unlikely (target == NULL))
return _cairo_create_in_error (_cairo_error (CAIRO_STATUS_NULL_POINTER));
if (unlikely (target->status))
return _cairo_create_in_error (target->status);
cr = _context_get ();
if (unlikely (cr == NULL))
return _cairo_create_in_error (_cairo_error (CAIRO_STATUS_NO_MEMORY));
CAIRO_REFERENCE_COUNT_INIT (&cr->ref_count, 1);
cr->status = CAIRO_STATUS_SUCCESS;
_cairo_user_data_array_init (&cr->user_data);
_cairo_path_fixed_init (cr->path);
cr->gstate = &cr->gstate_tail[0];
cr->gstate_freelist = &cr->gstate_tail[1];
cr->gstate_tail[1].next = NULL;
status = _cairo_gstate_init (cr->gstate, target);
if (unlikely (status)) {
_context_put (cr);
cr = _cairo_create_in_error (status);
}
return cr;
}
slim_hidden_def (cairo_create);
/**
* cairo_reference:
* @cr: a #cairo_t
*
* Increases the reference count on @cr by one. This prevents
* @cr from being destroyed until a matching call to cairo_destroy()
* is made.
*
* The number of references to a #cairo_t can be get using
* cairo_get_reference_count().
*
* Return value: the referenced #cairo_t.
**/
cairo_t *
cairo_reference (cairo_t *cr)
{
if (cr == NULL || CAIRO_REFERENCE_COUNT_IS_INVALID (&cr->ref_count))
return cr;
assert (CAIRO_REFERENCE_COUNT_HAS_REFERENCE (&cr->ref_count));
_cairo_reference_count_inc (&cr->ref_count);
return cr;
}
/**
* cairo_destroy:
* @cr: a #cairo_t
*
* Decreases the reference count on @cr by one. If the result
* is zero, then @cr and all associated resources are freed.
* See cairo_reference().
**/
void
cairo_destroy (cairo_t *cr)
{
if (cr == NULL || CAIRO_REFERENCE_COUNT_IS_INVALID (&cr->ref_count))
return;
assert (CAIRO_REFERENCE_COUNT_HAS_REFERENCE (&cr->ref_count));
if (! _cairo_reference_count_dec_and_test (&cr->ref_count))
return;
while (cr->gstate != &cr->gstate_tail[0]) {
if (_cairo_gstate_restore (&cr->gstate, &cr->gstate_freelist))
break;
}
_cairo_gstate_fini (cr->gstate);
cr->gstate_freelist = cr->gstate_freelist->next; /* skip over tail[1] */
while (cr->gstate_freelist != NULL) {
cairo_gstate_t *gstate = cr->gstate_freelist;
cr->gstate_freelist = gstate->next;
free (gstate);
}
_cairo_path_fixed_fini (cr->path);
_cairo_user_data_array_fini (&cr->user_data);
/* mark the context as invalid to protect against misuse */
cr->status = CAIRO_STATUS_NULL_POINTER;
_context_put (cr);
}
slim_hidden_def (cairo_destroy);
/**
* cairo_get_user_data:
* @cr: a #cairo_t
* @key: the address of the #cairo_user_data_key_t the user data was
* attached to
*
* Return user data previously attached to @cr using the specified
* key. If no user data has been attached with the given key this
* function returns %NULL.
*
* Return value: the user data previously attached or %NULL.
*
* Since: 1.4
**/
void *
cairo_get_user_data (cairo_t *cr,
const cairo_user_data_key_t *key)
{
return _cairo_user_data_array_get_data (&cr->user_data,
key);
}
/**
* cairo_set_user_data:
* @cr: a #cairo_t
* @key: the address of a #cairo_user_data_key_t to attach the user data to
* @user_data: the user data to attach to the #cairo_t
* @destroy: a #cairo_destroy_func_t which will be called when the
* #cairo_t is destroyed or when new user data is attached using the
* same key.
*
* Attach user data to @cr. To remove user data from a surface,
* call this function with the key that was used to set it and %NULL
* for @data.
*
* Return value: %CAIRO_STATUS_SUCCESS or %CAIRO_STATUS_NO_MEMORY if a
* slot could not be allocated for the user data.
*
* Since: 1.4
**/
cairo_status_t
cairo_set_user_data (cairo_t *cr,
const cairo_user_data_key_t *key,
void *user_data,
cairo_destroy_func_t destroy)
{
if (CAIRO_REFERENCE_COUNT_IS_INVALID (&cr->ref_count))
return cr->status;
return _cairo_user_data_array_set_data (&cr->user_data,
key, user_data, destroy);
}
/**
* cairo_get_reference_count:
* @cr: a #cairo_t
*
* Returns the current reference count of @cr.
*
* Return value: the current reference count of @cr. If the
* object is a nil object, 0 will be returned.
*
* Since: 1.4
**/
unsigned int
cairo_get_reference_count (cairo_t *cr)
{
if (cr == NULL || CAIRO_REFERENCE_COUNT_IS_INVALID (&cr->ref_count))
return 0;
return CAIRO_REFERENCE_COUNT_GET_VALUE (&cr->ref_count);
}
/**
* cairo_save:
* @cr: a #cairo_t
*
* Makes a copy of the current state of @cr and saves it
* on an internal stack of saved states for @cr. When
* cairo_restore() is called, @cr will be restored to
* the saved state. Multiple calls to cairo_save() and
* cairo_restore() can be nested; each call to cairo_restore()
* restores the state from the matching paired cairo_save().
*
* It isn't necessary to clear all saved states before
* a #cairo_t is freed. If the reference count of a #cairo_t
* drops to zero in response to a call to cairo_destroy(),
* any saved states will be freed along with the #cairo_t.
**/
void
cairo_save (cairo_t *cr)
{
cairo_status_t status;
if (unlikely (cr->status))
return;
status = _cairo_gstate_save (&cr->gstate, &cr->gstate_freelist);
if (unlikely (status))
_cairo_set_error (cr, status);
}
slim_hidden_def(cairo_save);
/**
* cairo_restore:
* @cr: a #cairo_t
*
* Restores @cr to the state saved by a preceding call to
* cairo_save() and removes that state from the stack of
* saved states.
**/
void
cairo_restore (cairo_t *cr)
{
cairo_status_t status;
if (unlikely (cr->status))
return;
status = _cairo_gstate_restore (&cr->gstate, &cr->gstate_freelist);
if (unlikely (status))
_cairo_set_error (cr, status);
}
slim_hidden_def(cairo_restore);
/**
* cairo_push_group:
* @cr: a cairo context
*
* Temporarily redirects drawing to an intermediate surface known as a
* group. The redirection lasts until the group is completed by a call
* to cairo_pop_group() or cairo_pop_group_to_source(). These calls
* provide the result of any drawing to the group as a pattern,
* (either as an explicit object, or set as the source pattern).
*
* This group functionality can be convenient for performing
* intermediate compositing. One common use of a group is to render
* objects as opaque within the group, (so that they occlude each
* other), and then blend the result with translucence onto the
* destination.
*
* Groups can be nested arbitrarily deep by making balanced calls to
* cairo_push_group()/cairo_pop_group(). Each call pushes/pops the new
* target group onto/from a stack.
*
* The cairo_push_group() function calls cairo_save() so that any
* changes to the graphics state will not be visible outside the
* group, (the pop_group functions call cairo_restore()).
*
* By default the intermediate group will have a content type of
* %CAIRO_CONTENT_COLOR_ALPHA. Other content types can be chosen for
* the group by using cairo_push_group_with_content() instead.
*
* As an example, here is how one might fill and stroke a path with
* translucence, but without any portion of the fill being visible
* under the stroke:
*
* <informalexample><programlisting>
* cairo_push_group (cr);
* cairo_set_source (cr, fill_pattern);
* cairo_fill_preserve (cr);
* cairo_set_source (cr, stroke_pattern);
* cairo_stroke (cr);
* cairo_pop_group_to_source (cr);
* cairo_paint_with_alpha (cr, alpha);
* </programlisting></informalexample>
*
* Since: 1.2
*/
void
cairo_push_group (cairo_t *cr)
{
cairo_push_group_with_content (cr, CAIRO_CONTENT_COLOR_ALPHA);
}
/**
* cairo_push_group_with_content:
* @cr: a cairo context
* @content: a #cairo_content_t indicating the type of group that
* will be created
*
* Temporarily redirects drawing to an intermediate surface known as a
* group. The redirection lasts until the group is completed by a call
* to cairo_pop_group() or cairo_pop_group_to_source(). These calls
* provide the result of any drawing to the group as a pattern,
* (either as an explicit object, or set as the source pattern).
*
* The group will have a content type of @content. The ability to
* control this content type is the only distinction between this
* function and cairo_push_group() which you should see for a more
* detailed description of group rendering.
*
* Since: 1.2
*/
void
cairo_push_group_with_content (cairo_t *cr, cairo_content_t content)
{
cairo_surface_t *group_surface;
cairo_clip_t *clip;
cairo_status_t status;
if (unlikely (cr->status))
return;
clip = _cairo_gstate_get_clip (cr->gstate);
if (clip->all_clipped) {
group_surface = cairo_image_surface_create (CAIRO_FORMAT_ARGB32, 0, 0);
status = group_surface->status;
if (unlikely (status))
goto bail;
} else {
cairo_surface_t *parent_surface;
const cairo_rectangle_int_t *clip_extents;
cairo_rectangle_int_t extents;
cairo_matrix_t matrix;
cairo_bool_t is_empty;
parent_surface = _cairo_gstate_get_target (cr->gstate);
/* Get the extents that we'll use in creating our new group surface */
is_empty = _cairo_surface_get_extents (parent_surface, &extents);
clip_extents = _cairo_clip_get_extents (_cairo_gstate_get_clip (cr->gstate));
if (clip_extents != NULL)
is_empty = _cairo_rectangle_intersect (&extents, clip_extents);
group_surface = _cairo_surface_create_similar_solid (parent_surface,
content,
extents.width,
extents.height,
CAIRO_COLOR_TRANSPARENT,
TRUE);
status = group_surface->status;
if (unlikely (status))
goto bail;
/* Set device offsets on the new surface so that logically it appears at
* the same location on the parent surface -- when we pop_group this,
* the source pattern will get fixed up for the appropriate target surface
* device offsets, so we want to set our own surface offsets from /that/,
* and not from the device origin. */
cairo_surface_set_device_offset (group_surface,
parent_surface->device_transform.x0 - extents.x,
parent_surface->device_transform.y0 - extents.y);
/* If we have a current path, we need to adjust it to compensate for
* the device offset just applied. */
cairo_matrix_init_translate (&matrix, -extents.x, -extents.y);
_cairo_path_fixed_transform (cr->path, &matrix);
}
/* create a new gstate for the redirect */
cairo_save (cr);
if (unlikely (cr->status))
goto bail;
status = _cairo_gstate_redirect_target (cr->gstate, group_surface);
bail:
cairo_surface_destroy (group_surface);
if (unlikely (status))
_cairo_set_error (cr, status);
}
slim_hidden_def(cairo_push_group_with_content);
/**
* cairo_pop_group:
* @cr: a cairo context
*
* Terminates the redirection begun by a call to cairo_push_group() or
* cairo_push_group_with_content() and returns a new pattern
* containing the results of all drawing operations performed to the
* group.
*
* The cairo_pop_group() function calls cairo_restore(), (balancing a
* call to cairo_save() by the push_group function), so that any
* changes to the graphics state will not be visible outside the
* group.
*
* Return value: a newly created (surface) pattern containing the
* results of all drawing operations performed to the group. The
* caller owns the returned object and should call
* cairo_pattern_destroy() when finished with it.
*
* Since: 1.2
**/
cairo_pattern_t *
cairo_pop_group (cairo_t *cr)
{
cairo_surface_t *group_surface, *parent_target;
cairo_pattern_t *group_pattern;
cairo_matrix_t group_matrix, device_transform_matrix;
cairo_status_t status;
if (unlikely (cr->status))
return _cairo_pattern_create_in_error (cr->status);
/* Grab the active surfaces */
group_surface = _cairo_gstate_get_target (cr->gstate);
parent_target = _cairo_gstate_get_parent_target (cr->gstate);
/* Verify that we are at the right nesting level */
if (parent_target == NULL) {
_cairo_set_error (cr, CAIRO_STATUS_INVALID_POP_GROUP);
return _cairo_pattern_create_in_error (CAIRO_STATUS_INVALID_POP_GROUP);
}
/* We need to save group_surface before we restore; we don't need
* to reference parent_target and original_target, since the
* gstate will still hold refs to them once we restore. */
group_surface = cairo_surface_reference (group_surface);
cairo_restore (cr);
if (unlikely (cr->status)) {
group_pattern = _cairo_pattern_create_in_error (cr->status);
goto done;
}
group_pattern = cairo_pattern_create_for_surface (group_surface);
status = group_pattern->status;
if (unlikely (status)) {
_cairo_set_error (cr, status);
goto done;
}
_cairo_gstate_get_matrix (cr->gstate, &group_matrix);
/* Transform by group_matrix centered around device_transform so that when
* we call _cairo_gstate_copy_transformed_pattern the result is a pattern
* with a matrix equivalent to the device_transform of group_surface. */
if (_cairo_surface_has_device_transform (group_surface)) {
cairo_pattern_set_matrix (group_pattern, &group_surface->device_transform);
_cairo_pattern_transform (group_pattern, &group_matrix);
_cairo_pattern_transform (group_pattern, &group_surface->device_transform_inverse);
} else {
cairo_pattern_set_matrix (group_pattern, &group_matrix);
}
/* If we have a current path, we need to adjust it to compensate for
* the device offset just removed. */
cairo_matrix_multiply (&device_transform_matrix,
&_cairo_gstate_get_target (cr->gstate)->device_transform,
&group_surface->device_transform_inverse);
_cairo_path_fixed_transform (cr->path, &device_transform_matrix);
done:
cairo_surface_destroy (group_surface);
return group_pattern;
}
slim_hidden_def(cairo_pop_group);
/**
* cairo_pop_group_to_source:
* @cr: a cairo context
*
* Terminates the redirection begun by a call to cairo_push_group() or
* cairo_push_group_with_content() and installs the resulting pattern
* as the source pattern in the given cairo context.
*
* The behavior of this function is equivalent to the sequence of
* operations:
*
* <informalexample><programlisting>
* #cairo_pattern_t *group = cairo_pop_group (cr);
* cairo_set_source (cr, group);
* cairo_pattern_destroy (group);
* </programlisting></informalexample>
*
* but is more convenient as their is no need for a variable to store
* the short-lived pointer to the pattern.
*
* The cairo_pop_group() function calls cairo_restore(), (balancing a
* call to cairo_save() by the push_group function), so that any
* changes to the graphics state will not be visible outside the
* group.
*
* Since: 1.2
**/
void
cairo_pop_group_to_source (cairo_t *cr)
{
cairo_pattern_t *group_pattern;
group_pattern = cairo_pop_group (cr);
cairo_set_source (cr, group_pattern);
cairo_pattern_destroy (group_pattern);
}
/**
* cairo_set_operator:
* @cr: a #cairo_t
* @op: a compositing operator, specified as a #cairo_operator_t
*
* Sets the compositing operator to be used for all drawing
* operations. See #cairo_operator_t for details on the semantics of
* each available compositing operator.
*
* The default operator is %CAIRO_OPERATOR_OVER.
**/
void
cairo_set_operator (cairo_t *cr, cairo_operator_t op)
{
cairo_status_t status;
if (unlikely (cr->status))
return;
status = _cairo_gstate_set_operator (cr->gstate, op);
if (unlikely (status))
_cairo_set_error (cr, status);
}
slim_hidden_def (cairo_set_operator);
static cairo_bool_t
_current_source_matches_solid (cairo_t *cr,
double red,
double green,
double blue,
double alpha)
{
const cairo_pattern_t *current;
cairo_color_t color;
current = cr->gstate->source;
if (current->type != CAIRO_PATTERN_TYPE_SOLID)
return FALSE;
red = _cairo_restrict_value (red, 0.0, 1.0);
green = _cairo_restrict_value (green, 0.0, 1.0);
blue = _cairo_restrict_value (blue, 0.0, 1.0);
alpha = _cairo_restrict_value (alpha, 0.0, 1.0);
_cairo_color_init_rgba (&color, red, green, blue, alpha);
return _cairo_color_equal (&color,
&((cairo_solid_pattern_t *) current)->color);
}
/**
* cairo_set_source_rgb
* @cr: a cairo context
* @red: red component of color
* @green: green component of color
* @blue: blue component of color
*
* Sets the source pattern within @cr to an opaque color. This opaque
* color will then be used for any subsequent drawing operation until
* a new source pattern is set.
*
* The color components are floating point numbers in the range 0 to
* 1. If the values passed in are outside that range, they will be
* clamped.
*
* The default source pattern is opaque black, (that is, it is
* equivalent to cairo_set_source_rgb(cr, 0.0, 0.0, 0.0)).
**/
void
cairo_set_source_rgb (cairo_t *cr, double red, double green, double blue)
{
cairo_pattern_t *pattern;
if (unlikely (cr->status))
return;
if (_current_source_matches_solid (cr, red, green, blue, 1.))
return;
/* push the current pattern to the freed lists */
cairo_set_source (cr, (cairo_pattern_t *) &_cairo_pattern_black);
pattern = cairo_pattern_create_rgb (red, green, blue);
cairo_set_source (cr, pattern);
cairo_pattern_destroy (pattern);
}
slim_hidden_def (cairo_set_source_rgb);
/**
* cairo_set_source_rgba:
* @cr: a cairo context
* @red: red component of color
* @green: green component of color
* @blue: blue component of color
* @alpha: alpha component of color
*
* Sets the source pattern within @cr to a translucent color. This
* color will then be used for any subsequent drawing operation until
* a new source pattern is set.
*
* The color and alpha components are floating point numbers in the
* range 0 to 1. If the values passed in are outside that range, they
* will be clamped.
*
* The default source pattern is opaque black, (that is, it is
* equivalent to cairo_set_source_rgba(cr, 0.0, 0.0, 0.0, 1.0)).
**/
void
cairo_set_source_rgba (cairo_t *cr,
double red, double green, double blue,
double alpha)
{
cairo_pattern_t *pattern;
if (unlikely (cr->status))
return;
if (_current_source_matches_solid (cr, red, green, blue, alpha))
return;
/* push the current pattern to the freed lists */
cairo_set_source (cr, (cairo_pattern_t *) &_cairo_pattern_black);
pattern = cairo_pattern_create_rgba (red, green, blue, alpha);
cairo_set_source (cr, pattern);
cairo_pattern_destroy (pattern);
}
/**
* cairo_set_source_surface:
* @cr: a cairo context
* @surface: a surface to be used to set the source pattern
* @x: User-space X coordinate for surface origin
* @y: User-space Y coordinate for surface origin
*
* This is a convenience function for creating a pattern from @surface
* and setting it as the source in @cr with cairo_set_source().
*
* The @x and @y parameters give the user-space coordinate at which
* the surface origin should appear. (The surface origin is its
* upper-left corner before any transformation has been applied.) The
* @x and @y parameters are negated and then set as translation values
* in the pattern matrix.
*
* Other than the initial translation pattern matrix, as described
* above, all other pattern attributes, (such as its extend mode), are
* set to the default values as in cairo_pattern_create_for_surface().
* The resulting pattern can be queried with cairo_get_source() so
* that these attributes can be modified if desired, (eg. to create a
* repeating pattern with cairo_pattern_set_extend()).
**/
void
cairo_set_source_surface (cairo_t *cr,
cairo_surface_t *surface,
double x,
double y)
{
cairo_pattern_t *pattern;
cairo_matrix_t matrix;
if (unlikely (cr->status))
return;
/* push the current pattern to the freed lists */
cairo_set_source (cr, (cairo_pattern_t *) &_cairo_pattern_black);
pattern = cairo_pattern_create_for_surface (surface);
cairo_matrix_init_translate (&matrix, -x, -y);
cairo_pattern_set_matrix (pattern, &matrix);
cairo_set_source (cr, pattern);
cairo_pattern_destroy (pattern);
}
slim_hidden_def (cairo_set_source_surface);
/**
* cairo_set_source
* @cr: a cairo context
* @source: a #cairo_pattern_t to be used as the source for
* subsequent drawing operations.
*
* Sets the source pattern within @cr to @source. This pattern
* will then be used for any subsequent drawing operation until a new
* source pattern is set.
*
* Note: The pattern's transformation matrix will be locked to the
* user space in effect at the time of cairo_set_source(). This means
* that further modifications of the current transformation matrix
* will not affect the source pattern. See cairo_pattern_set_matrix().
*
* The default source pattern is a solid pattern that is opaque black,
* (that is, it is equivalent to cairo_set_source_rgb(cr, 0.0, 0.0,
* 0.0)).
**/
void
cairo_set_source (cairo_t *cr, cairo_pattern_t *source)
{
cairo_status_t status;
if (unlikely (cr->status))
return;
if (source == NULL) {
_cairo_set_error (cr, CAIRO_STATUS_NULL_POINTER);
return;
}
if (source->status) {
_cairo_set_error (cr, source->status);
return;
}
status = _cairo_gstate_set_source (cr->gstate, source);
if (unlikely (status))
_cairo_set_error (cr, status);
}
slim_hidden_def (cairo_set_source);
/**
* cairo_get_source:
* @cr: a cairo context
*
* Gets the current source pattern for @cr.
*
* Return value: the current source pattern. This object is owned by
* cairo. To keep a reference to it, you must call
* cairo_pattern_reference().
**/
cairo_pattern_t *
cairo_get_source (cairo_t *cr)
{
if (unlikely (cr->status))
return _cairo_pattern_create_in_error (cr->status);
return _cairo_gstate_get_source (cr->gstate);
}
/**
* cairo_set_tolerance:
* @cr: a #cairo_t
* @tolerance: the tolerance, in device units (typically pixels)
*
* Sets the tolerance used when converting paths into trapezoids.
* Curved segments of the path will be subdivided until the maximum
* deviation between the original path and the polygonal approximation
* is less than @tolerance. The default value is 0.1. A larger
* value will give better performance, a smaller value, better
* appearance. (Reducing the value from the default value of 0.1
* is unlikely to improve appearance significantly.) The accuracy of paths
* within Cairo is limited by the precision of its internal arithmetic, and
* the prescribed @tolerance is restricted to the smallest
* representable internal value.
**/
void
cairo_set_tolerance (cairo_t *cr, double tolerance)
{
cairo_status_t status;
if (unlikely (cr->status))
return;
if (tolerance < CAIRO_TOLERANCE_MINIMUM)
tolerance = CAIRO_TOLERANCE_MINIMUM;
status = _cairo_gstate_set_tolerance (cr->gstate, tolerance);
if (unlikely (status))
_cairo_set_error (cr, status);
}
slim_hidden_def (cairo_set_tolerance);
/**
* cairo_set_antialias:
* @cr: a #cairo_t
* @antialias: the new antialiasing mode
*
* Set the antialiasing mode of the rasterizer used for drawing shapes.
* This value is a hint, and a particular backend may or may not support
* a particular value. At the current time, no backend supports
* %CAIRO_ANTIALIAS_SUBPIXEL when drawing shapes.
*
* Note that this option does not affect text rendering, instead see
* cairo_font_options_set_antialias().
**/
void
cairo_set_antialias (cairo_t *cr, cairo_antialias_t antialias)
{
cairo_status_t status;
if (unlikely (cr->status))
return;
status = _cairo_gstate_set_antialias (cr->gstate, antialias);
if (unlikely (status))
_cairo_set_error (cr, status);
}
/**
* cairo_set_fill_rule:
* @cr: a #cairo_t
* @fill_rule: a fill rule, specified as a #cairo_fill_rule_t
*
* Set the current fill rule within the cairo context. The fill rule
* is used to determine which regions are inside or outside a complex
* (potentially self-intersecting) path. The current fill rule affects
* both cairo_fill() and cairo_clip(). See #cairo_fill_rule_t for details
* on the semantics of each available fill rule.
*
* The default fill rule is %CAIRO_FILL_RULE_WINDING.
**/
void
cairo_set_fill_rule (cairo_t *cr, cairo_fill_rule_t fill_rule)
{
cairo_status_t status;
if (unlikely (cr->status))
return;
status = _cairo_gstate_set_fill_rule (cr->gstate, fill_rule);
if (unlikely (status))
_cairo_set_error (cr, status);
}
/**
* cairo_set_line_width:
* @cr: a #cairo_t
* @width: a line width
*
* Sets the current line width within the cairo context. The line
* width value specifies the diameter of a pen that is circular in
* user space, (though device-space pen may be an ellipse in general
* due to scaling/shear/rotation of the CTM).
*
* Note: When the description above refers to user space and CTM it
* refers to the user space and CTM in effect at the time of the
* stroking operation, not the user space and CTM in effect at the
* time of the call to cairo_set_line_width(). The simplest usage
* makes both of these spaces identical. That is, if there is no
* change to the CTM between a call to cairo_set_line_width() and the
* stroking operation, then one can just pass user-space values to
* cairo_set_line_width() and ignore this note.
*
* As with the other stroke parameters, the current line width is
* examined by cairo_stroke(), cairo_stroke_extents(), and
* cairo_stroke_to_path(), but does not have any effect during path
* construction.
*
* The default line width value is 2.0.
**/
void
cairo_set_line_width (cairo_t *cr, double width)
{
cairo_status_t status;
if (unlikely (cr->status))
return;
if (width < 0.)
width = 0.;
status = _cairo_gstate_set_line_width (cr->gstate, width);
if (unlikely (status))
_cairo_set_error (cr, status);
}
slim_hidden_def (cairo_set_line_width);
/**
* cairo_set_line_cap:
* @cr: a cairo context
* @line_cap: a line cap style
*
* Sets the current line cap style within the cairo context. See
* #cairo_line_cap_t for details about how the available line cap
* styles are drawn.
*
* As with the other stroke parameters, the current line cap style is
* examined by cairo_stroke(), cairo_stroke_extents(), and
* cairo_stroke_to_path(), but does not have any effect during path
* construction.
*
* The default line cap style is %CAIRO_LINE_CAP_BUTT.
**/
void
cairo_set_line_cap (cairo_t *cr, cairo_line_cap_t line_cap)
{
cairo_status_t status;
if (unlikely (cr->status))
return;
status = _cairo_gstate_set_line_cap (cr->gstate, line_cap);
if (unlikely (status))
_cairo_set_error (cr, status);
}
slim_hidden_def (cairo_set_line_cap);
/**
* cairo_set_line_join:
* @cr: a cairo context
* @line_join: a line join style
*
* Sets the current line join style within the cairo context. See
* #cairo_line_join_t for details about how the available line join
* styles are drawn.
*
* As with the other stroke parameters, the current line join style is
* examined by cairo_stroke(), cairo_stroke_extents(), and
* cairo_stroke_to_path(), but does not have any effect during path
* construction.
*
* The default line join style is %CAIRO_LINE_JOIN_MITER.
**/
void
cairo_set_line_join (cairo_t *cr, cairo_line_join_t line_join)
{
cairo_status_t status;
if (unlikely (cr->status))
return;
status = _cairo_gstate_set_line_join (cr->gstate, line_join);
if (unlikely (status))
_cairo_set_error (cr, status);
}
slim_hidden_def (cairo_set_line_join);
/**
* cairo_set_dash:
* @cr: a cairo context
* @dashes: an array specifying alternate lengths of on and off stroke portions
* @num_dashes: the length of the dashes array
* @offset: an offset into the dash pattern at which the stroke should start
*
* Sets the dash pattern to be used by cairo_stroke(). A dash pattern
* is specified by @dashes, an array of positive values. Each value
* provides the length of alternate "on" and "off" portions of the
* stroke. The @offset specifies an offset into the pattern at which
* the stroke begins.
*
* Each "on" segment will have caps applied as if the segment were a
* separate sub-path. In particular, it is valid to use an "on" length
* of 0.0 with %CAIRO_LINE_CAP_ROUND or %CAIRO_LINE_CAP_SQUARE in order
* to distributed dots or squares along a path.
*
* Note: The length values are in user-space units as evaluated at the
* time of stroking. This is not necessarily the same as the user
* space at the time of cairo_set_dash().
*
* If @num_dashes is 0 dashing is disabled.
*
* If @num_dashes is 1 a symmetric pattern is assumed with alternating
* on and off portions of the size specified by the single value in
* @dashes.
*
* If any value in @dashes is negative, or if all values are 0, then
* @cr will be put into an error state with a status of
* %CAIRO_STATUS_INVALID_DASH.
**/
void
cairo_set_dash (cairo_t *cr,
const double *dashes,
int num_dashes,
double offset)
{
cairo_status_t status;
if (unlikely (cr->status))
return;
status = _cairo_gstate_set_dash (cr->gstate,
dashes, num_dashes, offset);
if (unlikely (status))
_cairo_set_error (cr, status);
}
/**
* cairo_get_dash_count:
* @cr: a #cairo_t
*
* This function returns the length of the dash array in @cr (0 if dashing
* is not currently in effect).
*
* See also cairo_set_dash() and cairo_get_dash().
*
* Return value: the length of the dash array, or 0 if no dash array set.
*
* Since: 1.4
*/
int
cairo_get_dash_count (cairo_t *cr)
{
int num_dashes;
if (unlikely (cr->status))
return 0;
_cairo_gstate_get_dash (cr->gstate, NULL, &num_dashes, NULL);
return num_dashes;
}
/**
* cairo_get_dash:
* @cr: a #cairo_t
* @dashes: return value for the dash array, or %NULL
* @offset: return value for the current dash offset, or %NULL
*
* Gets the current dash array. If not %NULL, @dashes should be big
* enough to hold at least the number of values returned by
* cairo_get_dash_count().
*
* Since: 1.4
**/
void
cairo_get_dash (cairo_t *cr,
double *dashes,
double *offset)
{
if (unlikely (cr->status))
return;
_cairo_gstate_get_dash (cr->gstate, dashes, NULL, offset);
}
/**
* cairo_set_miter_limit:
* @cr: a cairo context
* @limit: miter limit to set
*
* Sets the current miter limit within the cairo context.
*
* If the current line join style is set to %CAIRO_LINE_JOIN_MITER
* (see cairo_set_line_join()), the miter limit is used to determine
* whether the lines should be joined with a bevel instead of a miter.
* Cairo divides the length of the miter by the line width.
* If the result is greater than the miter limit, the style is
* converted to a bevel.
*
* As with the other stroke parameters, the current line miter limit is
* examined by cairo_stroke(), cairo_stroke_extents(), and
* cairo_stroke_to_path(), but does not have any effect during path
* construction.
*
* The default miter limit value is 10.0, which will convert joins
* with interior angles less than 11 degrees to bevels instead of
* miters. For reference, a miter limit of 2.0 makes the miter cutoff
* at 60 degrees, and a miter limit of 1.414 makes the cutoff at 90
* degrees.
*
* A miter limit for a desired angle can be computed as: miter limit =
* 1/sin(angle/2)
**/
void
cairo_set_miter_limit (cairo_t *cr, double limit)
{
cairo_status_t status;
if (unlikely (cr->status))
return;
status = _cairo_gstate_set_miter_limit (cr->gstate, limit);
if (unlikely (status))
_cairo_set_error (cr, status);
}
/**
* cairo_translate:
* @cr: a cairo context
* @tx: amount to translate in the X direction
* @ty: amount to translate in the Y direction
*
* Modifies the current transformation matrix (CTM) by translating the
* user-space origin by (@tx, @ty). This offset is interpreted as a
* user-space coordinate according to the CTM in place before the new
* call to cairo_translate(). In other words, the translation of the
* user-space origin takes place after any existing transformation.
**/
void
cairo_translate (cairo_t *cr, double tx, double ty)
{
cairo_status_t status;
if (unlikely (cr->status))
return;
status = _cairo_gstate_translate (cr->gstate, tx, ty);
if (unlikely (status))
_cairo_set_error (cr, status);
}
slim_hidden_def (cairo_translate);
/**
* cairo_scale:
* @cr: a cairo context
* @sx: scale factor for the X dimension
* @sy: scale factor for the Y dimension
*
* Modifies the current transformation matrix (CTM) by scaling the X
* and Y user-space axes by @sx and @sy respectively. The scaling of
* the axes takes place after any existing transformation of user
* space.
**/
void
cairo_scale (cairo_t *cr, double sx, double sy)
{
cairo_status_t status;
if (unlikely (cr->status))
return;
status = _cairo_gstate_scale (cr->gstate, sx, sy);
if (unlikely (status))
_cairo_set_error (cr, status);
}
slim_hidden_def (cairo_scale);
/**
* cairo_rotate:
* @cr: a cairo context
* @angle: angle (in radians) by which the user-space axes will be
* rotated
*
* Modifies the current transformation matrix (CTM) by rotating the
* user-space axes by @angle radians. The rotation of the axes takes
* places after any existing transformation of user space. The
* rotation direction for positive angles is from the positive X axis
* toward the positive Y axis.
**/
void
cairo_rotate (cairo_t *cr, double angle)
{
cairo_status_t status;
if (unlikely (cr->status))
return;
status = _cairo_gstate_rotate (cr->gstate, angle);
if (unlikely (status))
_cairo_set_error (cr, status);
}
/**
* cairo_transform:
* @cr: a cairo context
* @matrix: a transformation to be applied to the user-space axes
*
* Modifies the current transformation matrix (CTM) by applying
* @matrix as an additional transformation. The new transformation of
* user space takes place after any existing transformation.
**/
void
cairo_transform (cairo_t *cr,
const cairo_matrix_t *matrix)
{
cairo_status_t status;
if (unlikely (cr->status))
return;
status = _cairo_gstate_transform (cr->gstate, matrix);
if (unlikely (status))
_cairo_set_error (cr, status);
}
slim_hidden_def (cairo_transform);
/**
* cairo_set_matrix:
* @cr: a cairo context
* @matrix: a transformation matrix from user space to device space
*
* Modifies the current transformation matrix (CTM) by setting it
* equal to @matrix.
**/
void
cairo_set_matrix (cairo_t *cr,
const cairo_matrix_t *matrix)
{
cairo_status_t status;
if (unlikely (cr->status))
return;
status = _cairo_gstate_set_matrix (cr->gstate, matrix);
if (unlikely (status))
_cairo_set_error (cr, status);
}
slim_hidden_def (cairo_set_matrix);
/**
* cairo_identity_matrix:
* @cr: a cairo context
*
* Resets the current transformation matrix (CTM) by setting it equal
* to the identity matrix. That is, the user-space and device-space
* axes will be aligned and one user-space unit will transform to one
* device-space unit.
**/
void
cairo_identity_matrix (cairo_t *cr)
{
if (unlikely (cr->status))
return;
_cairo_gstate_identity_matrix (cr->gstate);
}
/**
* cairo_user_to_device:
* @cr: a cairo context
* @x: X value of coordinate (in/out parameter)
* @y: Y value of coordinate (in/out parameter)
*
* Transform a coordinate from user space to device space by
* multiplying the given point by the current transformation matrix
* (CTM).
**/
void
cairo_user_to_device (cairo_t *cr, double *x, double *y)
{
if (unlikely (cr->status))
return;
_cairo_gstate_user_to_device (cr->gstate, x, y);
}
slim_hidden_def (cairo_user_to_device);
/**
* cairo_user_to_device_distance:
* @cr: a cairo context
* @dx: X component of a distance vector (in/out parameter)
* @dy: Y component of a distance vector (in/out parameter)
*
* Transform a distance vector from user space to device space. This
* function is similar to cairo_user_to_device() except that the
* translation components of the CTM will be ignored when transforming
* (@dx,@dy).
**/
void
cairo_user_to_device_distance (cairo_t *cr, double *dx, double *dy)
{
if (unlikely (cr->status))
return;
_cairo_gstate_user_to_device_distance (cr->gstate, dx, dy);
}
slim_hidden_def (cairo_user_to_device_distance);
/**
* cairo_device_to_user:
* @cr: a cairo
* @x: X value of coordinate (in/out parameter)
* @y: Y value of coordinate (in/out parameter)
*
* Transform a coordinate from device space to user space by
* multiplying the given point by the inverse of the current
* transformation matrix (CTM).
**/
void
cairo_device_to_user (cairo_t *cr, double *x, double *y)
{
if (unlikely (cr->status))
return;
_cairo_gstate_device_to_user (cr->gstate, x, y);
}
/**
* cairo_device_to_user_distance:
* @cr: a cairo context
* @dx: X component of a distance vector (in/out parameter)
* @dy: Y component of a distance vector (in/out parameter)
*
* Transform a distance vector from device space to user space. This
* function is similar to cairo_device_to_user() except that the
* translation components of the inverse CTM will be ignored when
* transforming (@dx,@dy).
**/
void
cairo_device_to_user_distance (cairo_t *cr, double *dx, double *dy)
{
if (unlikely (cr->status))
return;
_cairo_gstate_device_to_user_distance (cr->gstate, dx, dy);
}
/**
* cairo_new_path:
* @cr: a cairo context
*
* Clears the current path. After this call there will be no path and
* no current point.
**/
void
cairo_new_path (cairo_t *cr)
{
if (unlikely (cr->status))
return;
_cairo_path_fixed_fini (cr->path);
_cairo_path_fixed_init (cr->path);
}
slim_hidden_def(cairo_new_path);
/**
* cairo_move_to:
* @cr: a cairo context
* @x: the X coordinate of the new position
* @y: the Y coordinate of the new position
*
* Begin a new sub-path. After this call the current point will be (@x,
* @y).
**/
void
cairo_move_to (cairo_t *cr, double x, double y)
{
cairo_status_t status;
cairo_fixed_t x_fixed, y_fixed;
if (unlikely (cr->status))
return;
_cairo_gstate_user_to_backend (cr->gstate, &x, &y);
x_fixed = _cairo_fixed_from_double (x);
y_fixed = _cairo_fixed_from_double (y);
status = _cairo_path_fixed_move_to (cr->path, x_fixed, y_fixed);
if (unlikely (status))
_cairo_set_error (cr, status);
}
slim_hidden_def(cairo_move_to);
/**
* cairo_new_sub_path:
* @cr: a cairo context
*
* Begin a new sub-path. Note that the existing path is not
* affected. After this call there will be no current point.
*
* In many cases, this call is not needed since new sub-paths are
* frequently started with cairo_move_to().
*
* A call to cairo_new_sub_path() is particularly useful when
* beginning a new sub-path with one of the cairo_arc() calls. This
* makes things easier as it is no longer necessary to manually
* compute the arc's initial coordinates for a call to
* cairo_move_to().
*
* Since: 1.2
**/
void
cairo_new_sub_path (cairo_t *cr)
{
if (unlikely (cr->status))
return;
_cairo_path_fixed_new_sub_path (cr->path);
}
/**
* cairo_line_to:
* @cr: a cairo context
* @x: the X coordinate of the end of the new line
* @y: the Y coordinate of the end of the new line
*
* Adds a line to the path from the current point to position (@x, @y)
* in user-space coordinates. After this call the current point
* will be (@x, @y).
*
* If there is no current point before the call to cairo_line_to()
* this function will behave as cairo_move_to(@cr, @x, @y).
**/
void
cairo_line_to (cairo_t *cr, double x, double y)
{
cairo_status_t status;
cairo_fixed_t x_fixed, y_fixed;
if (unlikely (cr->status))
return;
_cairo_gstate_user_to_backend (cr->gstate, &x, &y);
x_fixed = _cairo_fixed_from_double (x);
y_fixed = _cairo_fixed_from_double (y);
status = _cairo_path_fixed_line_to (cr->path, x_fixed, y_fixed);
if (unlikely (status))
_cairo_set_error (cr, status);
}
slim_hidden_def (cairo_line_to);
/**
* cairo_curve_to:
* @cr: a cairo context
* @x1: the X coordinate of the first control point
* @y1: the Y coordinate of the first control point
* @x2: the X coordinate of the second control point
* @y2: the Y coordinate of the second control point
* @x3: the X coordinate of the end of the curve
* @y3: the Y coordinate of the end of the curve
*
* Adds a cubic Bézier spline to the path from the current point to
* position (@x3, @y3) in user-space coordinates, using (@x1, @y1) and
* (@x2, @y2) as the control points. After this call the current point
* will be (@x3, @y3).
*
* If there is no current point before the call to cairo_curve_to()
* this function will behave as if preceded by a call to
* cairo_move_to(@cr, @x1, @y1).
**/
void
cairo_curve_to (cairo_t *cr,
double x1, double y1,
double x2, double y2,
double x3, double y3)
{
cairo_status_t status;
cairo_fixed_t x1_fixed, y1_fixed;
cairo_fixed_t x2_fixed, y2_fixed;
cairo_fixed_t x3_fixed, y3_fixed;
if (unlikely (cr->status))
return;
_cairo_gstate_user_to_backend (cr->gstate, &x1, &y1);
_cairo_gstate_user_to_backend (cr->gstate, &x2, &y2);
_cairo_gstate_user_to_backend (cr->gstate, &x3, &y3);
x1_fixed = _cairo_fixed_from_double (x1);
y1_fixed = _cairo_fixed_from_double (y1);
x2_fixed = _cairo_fixed_from_double (x2);
y2_fixed = _cairo_fixed_from_double (y2);
x3_fixed = _cairo_fixed_from_double (x3);
y3_fixed = _cairo_fixed_from_double (y3);
status = _cairo_path_fixed_curve_to (cr->path,
x1_fixed, y1_fixed,
x2_fixed, y2_fixed,
x3_fixed, y3_fixed);
if (unlikely (status))
_cairo_set_error (cr, status);
}
slim_hidden_def (cairo_curve_to);
/**
* cairo_arc:
* @cr: a cairo context
* @xc: X position of the center of the arc
* @yc: Y position of the center of the arc
* @radius: the radius of the arc
* @angle1: the start angle, in radians
* @angle2: the end angle, in radians
*
* Adds a circular arc of the given @radius to the current path. The
* arc is centered at (@xc, @yc), begins at @angle1 and proceeds in
* the direction of increasing angles to end at @angle2. If @angle2 is
* less than @angle1 it will be progressively increased by 2*M_PI
* until it is greater than @angle1.
*
* If there is a current point, an initial line segment will be added
* to the path to connect the current point to the beginning of the
* arc. If this initial line is undesired, it can be avoided by
* calling cairo_new_sub_path() before calling cairo_arc().
*
* Angles are measured in radians. An angle of 0.0 is in the direction
* of the positive X axis (in user space). An angle of %M_PI/2.0 radians
* (90 degrees) is in the direction of the positive Y axis (in
* user space). Angles increase in the direction from the positive X
* axis toward the positive Y axis. So with the default transformation
* matrix, angles increase in a clockwise direction.
*
* (To convert from degrees to radians, use <literal>degrees * (M_PI /
* 180.)</literal>.)
*
* This function gives the arc in the direction of increasing angles;
* see cairo_arc_negative() to get the arc in the direction of
* decreasing angles.
*
* The arc is circular in user space. To achieve an elliptical arc,
* you can scale the current transformation matrix by different
* amounts in the X and Y directions. For example, to draw an ellipse
* in the box given by @x, @y, @width, @height:
*
* <informalexample><programlisting>
* cairo_save (cr);
* cairo_translate (cr, x + width / 2., y + height / 2.);
* cairo_scale (cr, width / 2., height / 2.);
* cairo_arc (cr, 0., 0., 1., 0., 2 * M_PI);
* cairo_restore (cr);
* </programlisting></informalexample>
**/
void
cairo_arc (cairo_t *cr,
double xc, double yc,
double radius,
double angle1, double angle2)
{
if (unlikely (cr->status))
return;
/* Do nothing, successfully, if radius is <= 0 */
if (radius <= 0.0) {
cairo_line_to (cr, xc, yc); /* might become a move_to */
cairo_line_to (cr, xc, yc);
return;
}
while (angle2 < angle1)
angle2 += 2 * M_PI;
cairo_line_to (cr,
xc + radius * cos (angle1),
yc + radius * sin (angle1));
_cairo_arc_path (cr, xc, yc, radius,
angle1, angle2);
}
/**
* cairo_arc_negative:
* @cr: a cairo context
* @xc: X position of the center of the arc
* @yc: Y position of the center of the arc
* @radius: the radius of the arc
* @angle1: the start angle, in radians
* @angle2: the end angle, in radians
*
* Adds a circular arc of the given @radius to the current path. The
* arc is centered at (@xc, @yc), begins at @angle1 and proceeds in
* the direction of decreasing angles to end at @angle2. If @angle2 is
* greater than @angle1 it will be progressively decreased by 2*M_PI
* until it is less than @angle1.
*
* See cairo_arc() for more details. This function differs only in the
* direction of the arc between the two angles.
**/
void
cairo_arc_negative (cairo_t *cr,
double xc, double yc,
double radius,
double angle1, double angle2)
{
if (unlikely (cr->status))
return;
/* Do nothing, successfully, if radius is <= 0 */
if (radius <= 0.0)
return;
while (angle2 > angle1)
angle2 -= 2 * M_PI;
cairo_line_to (cr,
xc + radius * cos (angle1),
yc + radius * sin (angle1));
_cairo_arc_path_negative (cr, xc, yc, radius,
angle1, angle2);
}
/* XXX: NYI
void
cairo_arc_to (cairo_t *cr,
double x1, double y1,
double x2, double y2,
double radius)
{
cairo_status_t status;
if (unlikely (cr->status))
return;
status = _cairo_gstate_arc_to (cr->gstate,
x1, y1,
x2, y2,
radius);
if (unlikely (status))
_cairo_set_error (cr, status);
}
*/
/**
* cairo_rel_move_to:
* @cr: a cairo context
* @dx: the X offset
* @dy: the Y offset
*
* Begin a new sub-path. After this call the current point will offset
* by (@x, @y).
*
* Given a current point of (x, y), cairo_rel_move_to(@cr, @dx, @dy)
* is logically equivalent to cairo_move_to(@cr, x + @dx, y + @dy).
*
* It is an error to call this function with no current point. Doing
* so will cause @cr to shutdown with a status of
* %CAIRO_STATUS_NO_CURRENT_POINT.
**/
void
cairo_rel_move_to (cairo_t *cr, double dx, double dy)
{
cairo_fixed_t dx_fixed, dy_fixed;
cairo_status_t status;
if (unlikely (cr->status))
return;
_cairo_gstate_user_to_device_distance (cr->gstate, &dx, &dy);
dx_fixed = _cairo_fixed_from_double (dx);
dy_fixed = _cairo_fixed_from_double (dy);
status = _cairo_path_fixed_rel_move_to (cr->path, dx_fixed, dy_fixed);
if (unlikely (status))
_cairo_set_error (cr, status);
}
/**
* cairo_rel_line_to:
* @cr: a cairo context
* @dx: the X offset to the end of the new line
* @dy: the Y offset to the end of the new line
*
* Relative-coordinate version of cairo_line_to(). Adds a line to the
* path from the current point to a point that is offset from the
* current point by (@dx, @dy) in user space. After this call the
* current point will be offset by (@dx, @dy).
*
* Given a current point of (x, y), cairo_rel_line_to(@cr, @dx, @dy)
* is logically equivalent to cairo_line_to(@cr, x + @dx, y + @dy).
*
* It is an error to call this function with no current point. Doing
* so will cause @cr to shutdown with a status of
* %CAIRO_STATUS_NO_CURRENT_POINT.
**/
void
cairo_rel_line_to (cairo_t *cr, double dx, double dy)
{
cairo_fixed_t dx_fixed, dy_fixed;
cairo_status_t status;
if (unlikely (cr->status))
return;
_cairo_gstate_user_to_device_distance (cr->gstate, &dx, &dy);
dx_fixed = _cairo_fixed_from_double (dx);
dy_fixed = _cairo_fixed_from_double (dy);
status = _cairo_path_fixed_rel_line_to (cr->path, dx_fixed, dy_fixed);
if (unlikely (status))
_cairo_set_error (cr, status);
}
slim_hidden_def(cairo_rel_line_to);
/**
* cairo_rel_curve_to:
* @cr: a cairo context
* @dx1: the X offset to the first control point
* @dy1: the Y offset to the first control point
* @dx2: the X offset to the second control point
* @dy2: the Y offset to the second control point
* @dx3: the X offset to the end of the curve
* @dy3: the Y offset to the end of the curve
*
* Relative-coordinate version of cairo_curve_to(). All offsets are
* relative to the current point. Adds a cubic Bézier spline to the
* path from the current point to a point offset from the current
* point by (@dx3, @dy3), using points offset by (@dx1, @dy1) and
* (@dx2, @dy2) as the control points. After this call the current
* point will be offset by (@dx3, @dy3).
*
* Given a current point of (x, y), cairo_rel_curve_to(@cr, @dx1,
* @dy1, @dx2, @dy2, @dx3, @dy3) is logically equivalent to
* cairo_curve_to(@cr, x+@dx1, y+@dy1, x+@dx2, y+@dy2, x+@dx3, y+@dy3).
*
* It is an error to call this function with no current point. Doing
* so will cause @cr to shutdown with a status of
* %CAIRO_STATUS_NO_CURRENT_POINT.
**/
void
cairo_rel_curve_to (cairo_t *cr,
double dx1, double dy1,
double dx2, double dy2,
double dx3, double dy3)
{
cairo_fixed_t dx1_fixed, dy1_fixed;
cairo_fixed_t dx2_fixed, dy2_fixed;
cairo_fixed_t dx3_fixed, dy3_fixed;
cairo_status_t status;
if (unlikely (cr->status))
return;
_cairo_gstate_user_to_device_distance (cr->gstate, &dx1, &dy1);
_cairo_gstate_user_to_device_distance (cr->gstate, &dx2, &dy2);
_cairo_gstate_user_to_device_distance (cr->gstate, &dx3, &dy3);
dx1_fixed = _cairo_fixed_from_double (dx1);
dy1_fixed = _cairo_fixed_from_double (dy1);
dx2_fixed = _cairo_fixed_from_double (dx2);
dy2_fixed = _cairo_fixed_from_double (dy2);
dx3_fixed = _cairo_fixed_from_double (dx3);
dy3_fixed = _cairo_fixed_from_double (dy3);
status = _cairo_path_fixed_rel_curve_to (cr->path,
dx1_fixed, dy1_fixed,
dx2_fixed, dy2_fixed,
dx3_fixed, dy3_fixed);
if (unlikely (status))
_cairo_set_error (cr, status);
}
/**
* cairo_rectangle:
* @cr: a cairo context
* @x: the X coordinate of the top left corner of the rectangle
* @y: the Y coordinate to the top left corner of the rectangle
* @width: the width of the rectangle
* @height: the height of the rectangle
*
* Adds a closed sub-path rectangle of the given size to the current
* path at position (@x, @y) in user-space coordinates.
*
* This function is logically equivalent to:
* <informalexample><programlisting>
* cairo_move_to (cr, x, y);
* cairo_rel_line_to (cr, width, 0);
* cairo_rel_line_to (cr, 0, height);
* cairo_rel_line_to (cr, -width, 0);
* cairo_close_path (cr);
* </programlisting></informalexample>
**/
void
cairo_rectangle (cairo_t *cr,
double x, double y,
double width, double height)
{
if (unlikely (cr->status))
return;
cairo_move_to (cr, x, y);
cairo_rel_line_to (cr, width, 0);
cairo_rel_line_to (cr, 0, height);
cairo_rel_line_to (cr, -width, 0);
cairo_close_path (cr);
}
#if 0
/* XXX: NYI */
void
cairo_stroke_to_path (cairo_t *cr)
{
cairo_status_t status;
if (unlikely (cr->status))
return;
/* The code in _cairo_recording_surface_get_path has a poorman's stroke_to_path */
status = _cairo_gstate_stroke_path (cr->gstate);
if (unlikely (status))
_cairo_set_error (cr, status);
}
#endif
/**
* cairo_close_path:
* @cr: a cairo context
*
* Adds a line segment to the path from the current point to the
* beginning of the current sub-path, (the most recent point passed to
* cairo_move_to()), and closes this sub-path. After this call the
* current point will be at the joined endpoint of the sub-path.
*
* The behavior of cairo_close_path() is distinct from simply calling
* cairo_line_to() with the equivalent coordinate in the case of
* stroking. When a closed sub-path is stroked, there are no caps on
* the ends of the sub-path. Instead, there is a line join connecting
* the final and initial segments of the sub-path.
*
* If there is no current point before the call to cairo_close_path(),
* this function will have no effect.
*
* Note: As of cairo version 1.2.4 any call to cairo_close_path() will
* place an explicit MOVE_TO element into the path immediately after
* the CLOSE_PATH element, (which can be seen in cairo_copy_path() for
* example). This can simplify path processing in some cases as it may
* not be necessary to save the "last move_to point" during processing
* as the MOVE_TO immediately after the CLOSE_PATH will provide that
* point.
**/
void
cairo_close_path (cairo_t *cr)
{
cairo_status_t status;
if (unlikely (cr->status))
return;
status = _cairo_path_fixed_close_path (cr->path);
if (unlikely (status))
_cairo_set_error (cr, status);
}
slim_hidden_def(cairo_close_path);
/**
* cairo_path_extents:
* @cr: a cairo context
* @x1: left of the resulting extents
* @y1: top of the resulting extents
* @x2: right of the resulting extents
* @y2: bottom of the resulting extents
*
* Computes a bounding box in user-space coordinates covering the
* points on the current path. If the current path is empty, returns
* an empty rectangle ((0,0), (0,0)). Stroke parameters, fill rule,
* surface dimensions and clipping are not taken into account.
*
* Contrast with cairo_fill_extents() and cairo_stroke_extents() which
* return the extents of only the area that would be "inked" by
* the corresponding drawing operations.
*
* The result of cairo_path_extents() is defined as equivalent to the
* limit of cairo_stroke_extents() with %CAIRO_LINE_CAP_ROUND as the
* line width approaches 0.0, (but never reaching the empty-rectangle
* returned by cairo_stroke_extents() for a line width of 0.0).
*
* Specifically, this means that zero-area sub-paths such as
* cairo_move_to();cairo_line_to() segments, (even degenerate cases
* where the coordinates to both calls are identical), will be
* considered as contributing to the extents. However, a lone
* cairo_move_to() will not contribute to the results of
* cairo_path_extents().
*
* Since: 1.6
**/
void
cairo_path_extents (cairo_t *cr,
double *x1, double *y1, double *x2, double *y2)
{
if (unlikely (cr->status)) {
if (x1)
*x1 = 0.0;
if (y1)
*y1 = 0.0;
if (x2)
*x2 = 0.0;
if (y2)
*y2 = 0.0;
return;
}
_cairo_gstate_path_extents (cr->gstate,
cr->path,
x1, y1, x2, y2);
}
/**
* cairo_paint:
* @cr: a cairo context
*
* A drawing operator that paints the current source everywhere within
* the current clip region.
**/
void
cairo_paint (cairo_t *cr)
{
cairo_status_t status;
if (unlikely (cr->status))
return;
status = _cairo_gstate_paint (cr->gstate);
if (unlikely (status))
_cairo_set_error (cr, status);
}
slim_hidden_def (cairo_paint);
/**
* cairo_paint_with_alpha:
* @cr: a cairo context
* @alpha: alpha value, between 0 (transparent) and 1 (opaque)
*
* A drawing operator that paints the current source everywhere within
* the current clip region using a mask of constant alpha value
* @alpha. The effect is similar to cairo_paint(), but the drawing
* is faded out using the alpha value.
**/
void
cairo_paint_with_alpha (cairo_t *cr,
double alpha)
{
cairo_status_t status;
cairo_color_t color;
cairo_solid_pattern_t pattern;
if (unlikely (cr->status))
return;
if (CAIRO_ALPHA_IS_OPAQUE (alpha)) {
cairo_paint (cr);
return;
}
if (CAIRO_ALPHA_IS_ZERO (alpha) &&
_cairo_operator_bounded_by_mask (cr->gstate->op)) {
return;
}
_cairo_color_init_rgba (&color, 0., 0., 0., alpha);
_cairo_pattern_init_solid (&pattern, &color);
status = _cairo_gstate_mask (cr->gstate, &pattern.base);
if (unlikely (status))
_cairo_set_error (cr, status);
_cairo_pattern_fini (&pattern.base);
}
/**
* cairo_mask:
* @cr: a cairo context
* @pattern: a #cairo_pattern_t
*
* A drawing operator that paints the current source
* using the alpha channel of @pattern as a mask. (Opaque
* areas of @pattern are painted with the source, transparent
* areas are not painted.)
*/
void
cairo_mask (cairo_t *cr,
cairo_pattern_t *pattern)
{
cairo_status_t status;
if (unlikely (cr->status))
return;
if (pattern == NULL) {
_cairo_set_error (cr, CAIRO_STATUS_NULL_POINTER);
return;
}
if (pattern->status) {
_cairo_set_error (cr, pattern->status);
return;
}
status = _cairo_gstate_mask (cr->gstate, pattern);
if (unlikely (status))
_cairo_set_error (cr, status);
}
slim_hidden_def (cairo_mask);
/**
* cairo_mask_surface:
* @cr: a cairo context
* @surface: a #cairo_surface_t
* @surface_x: X coordinate at which to place the origin of @surface
* @surface_y: Y coordinate at which to place the origin of @surface
*
* A drawing operator that paints the current source
* using the alpha channel of @surface as a mask. (Opaque
* areas of @surface are painted with the source, transparent
* areas are not painted.)
*/
void
cairo_mask_surface (cairo_t *cr,
cairo_surface_t *surface,
double surface_x,
double surface_y)
{
cairo_pattern_t *pattern;
cairo_matrix_t matrix;
if (unlikely (cr->status))
return;
pattern = cairo_pattern_create_for_surface (surface);
cairo_matrix_init_translate (&matrix, - surface_x, - surface_y);
cairo_pattern_set_matrix (pattern, &matrix);
cairo_mask (cr, pattern);
cairo_pattern_destroy (pattern);
}
/**
* cairo_stroke:
* @cr: a cairo context
*
* A drawing operator that strokes the current path according to the
* current line width, line join, line cap, and dash settings. After
* cairo_stroke(), the current path will be cleared from the cairo
* context. See cairo_set_line_width(), cairo_set_line_join(),
* cairo_set_line_cap(), cairo_set_dash(), and
* cairo_stroke_preserve().
*
* Note: Degenerate segments and sub-paths are treated specially and
* provide a useful result. These can result in two different
* situations:
*
* 1. Zero-length "on" segments set in cairo_set_dash(). If the cap
* style is %CAIRO_LINE_CAP_ROUND or %CAIRO_LINE_CAP_SQUARE then these
* segments will be drawn as circular dots or squares respectively. In
* the case of %CAIRO_LINE_CAP_SQUARE, the orientation of the squares
* is determined by the direction of the underlying path.
*
* 2. A sub-path created by cairo_move_to() followed by either a
* cairo_close_path() or one or more calls to cairo_line_to() to the
* same coordinate as the cairo_move_to(). If the cap style is
* %CAIRO_LINE_CAP_ROUND then these sub-paths will be drawn as circular
* dots. Note that in the case of %CAIRO_LINE_CAP_SQUARE a degenerate
* sub-path will not be drawn at all, (since the correct orientation
* is indeterminate).
*
* In no case will a cap style of %CAIRO_LINE_CAP_BUTT cause anything
* to be drawn in the case of either degenerate segments or sub-paths.
**/
void
cairo_stroke (cairo_t *cr)
{
cairo_stroke_preserve (cr);
cairo_new_path (cr);
}
slim_hidden_def(cairo_stroke);
/**
* cairo_stroke_preserve:
* @cr: a cairo context
*
* A drawing operator that strokes the current path according to the
* current line width, line join, line cap, and dash settings. Unlike
* cairo_stroke(), cairo_stroke_preserve() preserves the path within the
* cairo context.
*
* See cairo_set_line_width(), cairo_set_line_join(),
* cairo_set_line_cap(), cairo_set_dash(), and
* cairo_stroke_preserve().
**/
void
cairo_stroke_preserve (cairo_t *cr)
{
cairo_status_t status;
if (unlikely (cr->status))
return;
status = _cairo_gstate_stroke (cr->gstate, cr->path);
if (unlikely (status))
_cairo_set_error (cr, status);
}
slim_hidden_def(cairo_stroke_preserve);
/**
* cairo_fill:
* @cr: a cairo context
*
* A drawing operator that fills the current path according to the
* current fill rule, (each sub-path is implicitly closed before being
* filled). After cairo_fill(), the current path will be cleared from
* the cairo context. See cairo_set_fill_rule() and
* cairo_fill_preserve().
**/
void
cairo_fill (cairo_t *cr)
{
cairo_fill_preserve (cr);
cairo_new_path (cr);
}
/**
* cairo_fill_preserve:
* @cr: a cairo context
*
* A drawing operator that fills the current path according to the
* current fill rule, (each sub-path is implicitly closed before being
* filled). Unlike cairo_fill(), cairo_fill_preserve() preserves the
* path within the cairo context.
*
* See cairo_set_fill_rule() and cairo_fill().
**/
void
cairo_fill_preserve (cairo_t *cr)
{
cairo_status_t status;
if (unlikely (cr->status))
return;
status = _cairo_gstate_fill (cr->gstate, cr->path);
if (unlikely (status))
_cairo_set_error (cr, status);
}
slim_hidden_def(cairo_fill_preserve);
/**
* cairo_copy_page:
* @cr: a cairo context
*
* Emits the current page for backends that support multiple pages, but
* doesn't clear it, so, the contents of the current page will be retained
* for the next page too. Use cairo_show_page() if you want to get an
* empty page after the emission.
*
* This is a convenience function that simply calls
* cairo_surface_copy_page() on @cr's target.
**/
void
cairo_copy_page (cairo_t *cr)
{
cairo_status_t status;
if (unlikely (cr->status))
return;
status = _cairo_gstate_copy_page (cr->gstate);
if (unlikely (status))
_cairo_set_error (cr, status);
}
/**
* cairo_show_page:
* @cr: a cairo context
*
* Emits and clears the current page for backends that support multiple
* pages. Use cairo_copy_page() if you don't want to clear the page.
*
* This is a convenience function that simply calls
* cairo_surface_show_page() on @cr's target.
**/
void
cairo_show_page (cairo_t *cr)
{
cairo_status_t status;
if (unlikely (cr->status))
return;
status = _cairo_gstate_show_page (cr->gstate);
if (unlikely (status))
_cairo_set_error (cr, status);
}
/**
* cairo_in_stroke:
* @cr: a cairo context
* @x: X coordinate of the point to test
* @y: Y coordinate of the point to test
*
* Tests whether the given point is inside the area that would be
* affected by a cairo_stroke() operation given the current path and
* stroking parameters. Surface dimensions and clipping are not taken
* into account.
*
* See cairo_stroke(), cairo_set_line_width(), cairo_set_line_join(),
* cairo_set_line_cap(), cairo_set_dash(), and
* cairo_stroke_preserve().
*
* Return value: A non-zero value if the point is inside, or zero if
* outside.
**/
cairo_bool_t
cairo_in_stroke (cairo_t *cr, double x, double y)
{
cairo_status_t status;
cairo_bool_t inside = FALSE;
if (unlikely (cr->status))
return FALSE;
status = _cairo_gstate_in_stroke (cr->gstate,
cr->path,
x, y, &inside);
if (unlikely (status))
_cairo_set_error (cr, status);
return inside;
}
/**
* cairo_in_fill:
* @cr: a cairo context
* @x: X coordinate of the point to test
* @y: Y coordinate of the point to test
*
* Tests whether the given point is inside the area that would be
* affected by a cairo_fill() operation given the current path and
* filling parameters. Surface dimensions and clipping are not taken
* into account.
*
* See cairo_fill(), cairo_set_fill_rule() and cairo_fill_preserve().
*
* Return value: A non-zero value if the point is inside, or zero if
* outside.
**/
cairo_bool_t
cairo_in_fill (cairo_t *cr, double x, double y)
{
if (unlikely (cr->status))
return FALSE;
return _cairo_gstate_in_fill (cr->gstate, cr->path, x, y);
}
/**
* cairo_stroke_extents:
* @cr: a cairo context
* @x1: left of the resulting extents
* @y1: top of the resulting extents
* @x2: right of the resulting extents
* @y2: bottom of the resulting extents
*
* Computes a bounding box in user coordinates covering the area that
* would be affected, (the "inked" area), by a cairo_stroke()
* operation given the current path and stroke parameters.
* If the current path is empty, returns an empty rectangle ((0,0), (0,0)).
* Surface dimensions and clipping are not taken into account.
*
* Note that if the line width is set to exactly zero, then
* cairo_stroke_extents() will return an empty rectangle. Contrast with
* cairo_path_extents() which can be used to compute the non-empty
* bounds as the line width approaches zero.
*
* Note that cairo_stroke_extents() must necessarily do more work to
* compute the precise inked areas in light of the stroke parameters,
* so cairo_path_extents() may be more desirable for sake of
* performance if non-inked path extents are desired.
*
* See cairo_stroke(), cairo_set_line_width(), cairo_set_line_join(),
* cairo_set_line_cap(), cairo_set_dash(), and
* cairo_stroke_preserve().
**/
void
cairo_stroke_extents (cairo_t *cr,
double *x1, double *y1, double *x2, double *y2)
{
cairo_status_t status;
if (unlikely (cr->status)) {
if (x1)
*x1 = 0.0;
if (y1)
*y1 = 0.0;
if (x2)
*x2 = 0.0;
if (y2)
*y2 = 0.0;
return;
}
status = _cairo_gstate_stroke_extents (cr->gstate,
cr->path,
x1, y1, x2, y2);
if (unlikely (status))
_cairo_set_error (cr, status);
}
/**
* cairo_fill_extents:
* @cr: a cairo context
* @x1: left of the resulting extents
* @y1: top of the resulting extents
* @x2: right of the resulting extents
* @y2: bottom of the resulting extents
*
* Computes a bounding box in user coordinates covering the area that
* would be affected, (the "inked" area), by a cairo_fill() operation
* given the current path and fill parameters. If the current path is
* empty, returns an empty rectangle ((0,0), (0,0)). Surface
* dimensions and clipping are not taken into account.
*
* Contrast with cairo_path_extents(), which is similar, but returns
* non-zero extents for some paths with no inked area, (such as a
* simple line segment).
*
* Note that cairo_fill_extents() must necessarily do more work to
* compute the precise inked areas in light of the fill rule, so
* cairo_path_extents() may be more desirable for sake of performance
* if the non-inked path extents are desired.
*
* See cairo_fill(), cairo_set_fill_rule() and cairo_fill_preserve().
**/
void
cairo_fill_extents (cairo_t *cr,
double *x1, double *y1, double *x2, double *y2)
{
cairo_status_t status;
if (unlikely (cr->status)) {
if (x1)
*x1 = 0.0;
if (y1)
*y1 = 0.0;
if (x2)
*x2 = 0.0;
if (y2)
*y2 = 0.0;
return;
}
status = _cairo_gstate_fill_extents (cr->gstate,
cr->path,
x1, y1, x2, y2);
if (unlikely (status))
_cairo_set_error (cr, status);
}
/**
* cairo_clip:
* @cr: a cairo context
*
* Establishes a new clip region by intersecting the current clip
* region with the current path as it would be filled by cairo_fill()
* and according to the current fill rule (see cairo_set_fill_rule()).
*
* After cairo_clip(), the current path will be cleared from the cairo
* context.
*
* The current clip region affects all drawing operations by
* effectively masking out any changes to the surface that are outside
* the current clip region.
*
* Calling cairo_clip() can only make the clip region smaller, never
* larger. But the current clip is part of the graphics state, so a
* temporary restriction of the clip region can be achieved by
* calling cairo_clip() within a cairo_save()/cairo_restore()
* pair. The only other means of increasing the size of the clip
* region is cairo_reset_clip().
**/
void
cairo_clip (cairo_t *cr)
{
cairo_clip_preserve (cr);
cairo_new_path (cr);
}
/**
* cairo_clip_preserve:
* @cr: a cairo context
*
* Establishes a new clip region by intersecting the current clip
* region with the current path as it would be filled by cairo_fill()
* and according to the current fill rule (see cairo_set_fill_rule()).
*
* Unlike cairo_clip(), cairo_clip_preserve() preserves the path within
* the cairo context.
*
* The current clip region affects all drawing operations by
* effectively masking out any changes to the surface that are outside
* the current clip region.
*
* Calling cairo_clip_preserve() can only make the clip region smaller, never
* larger. But the current clip is part of the graphics state, so a
* temporary restriction of the clip region can be achieved by
* calling cairo_clip_preserve() within a cairo_save()/cairo_restore()
* pair. The only other means of increasing the size of the clip
* region is cairo_reset_clip().
**/
void
cairo_clip_preserve (cairo_t *cr)
{
cairo_status_t status;
if (unlikely (cr->status))
return;
status = _cairo_gstate_clip (cr->gstate, cr->path);
if (unlikely (status))
_cairo_set_error (cr, status);
}
slim_hidden_def(cairo_clip_preserve);
/**
* cairo_reset_clip:
* @cr: a cairo context
*
* Reset the current clip region to its original, unrestricted
* state. That is, set the clip region to an infinitely large shape
* containing the target surface. Equivalently, if infinity is too
* hard to grasp, one can imagine the clip region being reset to the
* exact bounds of the target surface.
*
* Note that code meant to be reusable should not call
* cairo_reset_clip() as it will cause results unexpected by
* higher-level code which calls cairo_clip(). Consider using
* cairo_save() and cairo_restore() around cairo_clip() as a more
* robust means of temporarily restricting the clip region.
**/
void
cairo_reset_clip (cairo_t *cr)
{
cairo_status_t status;
if (unlikely (cr->status))
return;
status = _cairo_gstate_reset_clip (cr->gstate);
if (unlikely (status))
_cairo_set_error (cr, status);
}
/**
* cairo_clip_extents:
* @cr: a cairo context
* @x1: left of the resulting extents
* @y1: top of the resulting extents
* @x2: right of the resulting extents
* @y2: bottom of the resulting extents
*
* Computes a bounding box in user coordinates covering the area inside the
* current clip.
*
* Since: 1.4
**/
void
cairo_clip_extents (cairo_t *cr,
double *x1, double *y1,
double *x2, double *y2)
{
if (unlikely (cr->status)) {
if (x1)
*x1 = 0.0;
if (y1)
*y1 = 0.0;
if (x2)
*x2 = 0.0;
if (y2)
*y2 = 0.0;
return;
}
if (! _cairo_gstate_clip_extents (cr->gstate, x1, y1, x2, y2)) {
*x1 = -INFINITY;
*y1 = -INFINITY;
*x2 = +INFINITY;
*y2 = +INFINITY;
}
}
/**
* cairo_in_clip:
* @cr: a cairo context
* @x: X coordinate of the point to test
* @y: Y coordinate of the point to test
*
* Tests whether the given point is inside the area that would be
* visible through the current clip, i.e. the area that would be filled by
* a cairo_paint() operation.
*
* See cairo_clip(), and cairo_clip_preserve().
*
* Return value: A non-zero value if the point is inside, or zero if
* outside.
*
* Since: 1.10
**/
cairo_bool_t
cairo_in_clip (cairo_t *cr, double x, double y)
{
if (unlikely (cr->status))
return FALSE;
return _cairo_gstate_in_clip (cr->gstate, x, y);
}
static cairo_rectangle_list_t *
_cairo_rectangle_list_create_in_error (cairo_status_t status)
{
cairo_rectangle_list_t *list;
if (status == CAIRO_STATUS_NO_MEMORY)
return (cairo_rectangle_list_t*) &_cairo_rectangles_nil;
list = malloc (sizeof (cairo_rectangle_list_t));
if (unlikely (list == NULL)) {
status = _cairo_error (CAIRO_STATUS_NO_MEMORY);
return (cairo_rectangle_list_t*) &_cairo_rectangles_nil;
}
list->status = status;
list->rectangles = NULL;
list->num_rectangles = 0;
return list;
}
/**
* cairo_copy_clip_rectangle_list:
* @cr: a cairo context
*
* Gets the current clip region as a list of rectangles in user coordinates.
* Never returns %NULL.
*
* The status in the list may be %CAIRO_STATUS_CLIP_NOT_REPRESENTABLE to
* indicate that the clip region cannot be represented as a list of
* user-space rectangles. The status may have other values to indicate
* other errors.
*
* Returns: the current clip region as a list of rectangles in user coordinates,
* which should be destroyed using cairo_rectangle_list_destroy().
*
* Since: 1.4
**/
cairo_rectangle_list_t *
cairo_copy_clip_rectangle_list (cairo_t *cr)
{
if (unlikely (cr->status))
return _cairo_rectangle_list_create_in_error (cr->status);
return _cairo_gstate_copy_clip_rectangle_list (cr->gstate);
}
/**
* cairo_select_font_face:
* @cr: a #cairo_t
* @family: a font family name, encoded in UTF-8
* @slant: the slant for the font
* @weight: the weight for the font
*
* Note: The cairo_select_font_face() function call is part of what
* the cairo designers call the "toy" text API. It is convenient for
* short demos and simple programs, but it is not expected to be
* adequate for serious text-using applications.
*
* Selects a family and style of font from a simplified description as
* a family name, slant and weight. Cairo provides no operation to
* list available family names on the system (this is a "toy",
* remember), but the standard CSS2 generic family names, ("serif",
* "sans-serif", "cursive", "fantasy", "monospace"), are likely to
* work as expected.
*
* If @family starts with the string "@cairo:", or if no native font
* backends are compiled in, cairo will use an internal font family.
* The internal font family recognizes many modifiers in the @family
* string, most notably, it recognizes the string "monospace". That is,
* the family name "@cairo:monospace" will use the monospace version of
* the internal font family.
*
* For "real" font selection, see the font-backend-specific
* font_face_create functions for the font backend you are using. (For
* example, if you are using the freetype-based cairo-ft font backend,
* see cairo_ft_font_face_create_for_ft_face() or
* cairo_ft_font_face_create_for_pattern().) The resulting font face
* could then be used with cairo_scaled_font_create() and
* cairo_set_scaled_font().
*
* Similarly, when using the "real" font support, you can call
* directly into the underlying font system, (such as fontconfig or
* freetype), for operations such as listing available fonts, etc.
*
* It is expected that most applications will need to use a more
* comprehensive font handling and text layout library, (for example,
* pango), in conjunction with cairo.
*
* If text is drawn without a call to cairo_select_font_face(), (nor
* cairo_set_font_face() nor cairo_set_scaled_font()), the default
* family is platform-specific, but is essentially "sans-serif".
* Default slant is %CAIRO_FONT_SLANT_NORMAL, and default weight is
* %CAIRO_FONT_WEIGHT_NORMAL.
*
* This function is equivalent to a call to cairo_toy_font_face_create()
* followed by cairo_set_font_face().
**/
void
cairo_select_font_face (cairo_t *cr,
const char *family,
cairo_font_slant_t slant,
cairo_font_weight_t weight)
{
cairo_status_t status;
if (unlikely (cr->status))
return;
status = _cairo_gstate_select_font_face (cr->gstate, family, slant, weight);
if (unlikely (status))
_cairo_set_error (cr, status);
}
/**
* cairo_font_extents:
* @cr: a #cairo_t
* @extents: a #cairo_font_extents_t object into which the results
* will be stored.
*
* Gets the font extents for the currently selected font.
**/
void
cairo_font_extents (cairo_t *cr,
cairo_font_extents_t *extents)
{
cairo_status_t status;
extents->ascent = 0.0;
extents->descent = 0.0;
extents->height = 0.0;
extents->max_x_advance = 0.0;
extents->max_y_advance = 0.0;
if (unlikely (cr->status))
return;
status = _cairo_gstate_get_font_extents (cr->gstate, extents);
if (unlikely (status))
_cairo_set_error (cr, status);
}
/**
* cairo_set_font_face:
* @cr: a #cairo_t
* @font_face: a #cairo_font_face_t, or %NULL to restore to the default font
*
* Replaces the current #cairo_font_face_t object in the #cairo_t with
* @font_face. The replaced font face in the #cairo_t will be
* destroyed if there are no other references to it.
**/
void
cairo_set_font_face (cairo_t *cr,
cairo_font_face_t *font_face)
{
cairo_status_t status;
if (unlikely (cr->status))
return;
status = _cairo_gstate_set_font_face (cr->gstate, font_face);
if (unlikely (status))
_cairo_set_error (cr, status);
}
/**
* cairo_get_font_face:
* @cr: a #cairo_t
*
* Gets the current font face for a #cairo_t.
*
* Return value: the current font face. This object is owned by
* cairo. To keep a reference to it, you must call
* cairo_font_face_reference().
*
* This function never returns %NULL. If memory cannot be allocated, a
* special "nil" #cairo_font_face_t object will be returned on which
* cairo_font_face_status() returns %CAIRO_STATUS_NO_MEMORY. Using
* this nil object will cause its error state to propagate to other
* objects it is passed to, (for example, calling
* cairo_set_font_face() with a nil font will trigger an error that
* will shutdown the #cairo_t object).
**/
cairo_font_face_t *
cairo_get_font_face (cairo_t *cr)
{
cairo_status_t status;
cairo_font_face_t *font_face;
if (unlikely (cr->status))
return (cairo_font_face_t*) &_cairo_font_face_nil;
status = _cairo_gstate_get_font_face (cr->gstate, &font_face);
if (unlikely (status)) {
_cairo_set_error (cr, status);
return (cairo_font_face_t*) &_cairo_font_face_nil;
}
return font_face;
}
/**
* cairo_set_font_size:
* @cr: a #cairo_t
* @size: the new font size, in user space units
*
* Sets the current font matrix to a scale by a factor of @size, replacing
* any font matrix previously set with cairo_set_font_size() or
* cairo_set_font_matrix(). This results in a font size of @size user space
* units. (More precisely, this matrix will result in the font's
* em-square being a @size by @size square in user space.)
*
* If text is drawn without a call to cairo_set_font_size(), (nor
* cairo_set_font_matrix() nor cairo_set_scaled_font()), the default
* font size is 10.0.
**/
void
cairo_set_font_size (cairo_t *cr, double size)
{
cairo_status_t status;
if (unlikely (cr->status))
return;
status = _cairo_gstate_set_font_size (cr->gstate, size);
if (unlikely (status))
_cairo_set_error (cr, status);
}
slim_hidden_def (cairo_set_font_size);
/**
* cairo_set_font_matrix
* @cr: a #cairo_t
* @matrix: a #cairo_matrix_t describing a transform to be applied to
* the current font.
*
* Sets the current font matrix to @matrix. The font matrix gives a
* transformation from the design space of the font (in this space,
* the em-square is 1 unit by 1 unit) to user space. Normally, a
* simple scale is used (see cairo_set_font_size()), but a more
* complex font matrix can be used to shear the font
* or stretch it unequally along the two axes
**/
void
cairo_set_font_matrix (cairo_t *cr,
const cairo_matrix_t *matrix)
{
cairo_status_t status;
if (unlikely (cr->status))
return;
status = _cairo_gstate_set_font_matrix (cr->gstate, matrix);
if (unlikely (status))
_cairo_set_error (cr, status);
}
/**
* cairo_get_font_matrix
* @cr: a #cairo_t
* @matrix: return value for the matrix
*
* Stores the current font matrix into @matrix. See
* cairo_set_font_matrix().
**/
void
cairo_get_font_matrix (cairo_t *cr, cairo_matrix_t *matrix)
{
if (unlikely (cr->status)) {
cairo_matrix_init_identity (matrix);
return;
}
_cairo_gstate_get_font_matrix (cr->gstate, matrix);
}
/**
* cairo_set_font_options:
* @cr: a #cairo_t
* @options: font options to use
*
* Sets a set of custom font rendering options for the #cairo_t.
* Rendering options are derived by merging these options with the
* options derived from underlying surface; if the value in @options
* has a default value (like %CAIRO_ANTIALIAS_DEFAULT), then the value
* from the surface is used.
**/
void
cairo_set_font_options (cairo_t *cr,
const cairo_font_options_t *options)
{
cairo_status_t status;
if (unlikely (cr->status))
return;
status = cairo_font_options_status ((cairo_font_options_t *) options);
if (unlikely (status)) {
_cairo_set_error (cr, status);
return;
}
_cairo_gstate_set_font_options (cr->gstate, options);
}
slim_hidden_def (cairo_set_font_options);
/**
* cairo_get_font_options:
* @cr: a #cairo_t
* @options: a #cairo_font_options_t object into which to store
* the retrieved options. All existing values are overwritten
*
* Retrieves font rendering options set via #cairo_set_font_options.
* Note that the returned options do not include any options derived
* from the underlying surface; they are literally the options
* passed to cairo_set_font_options().
**/
void
cairo_get_font_options (cairo_t *cr,
cairo_font_options_t *options)
{
/* check that we aren't trying to overwrite the nil object */
if (cairo_font_options_status (options))
return;
if (unlikely (cr->status)) {
_cairo_font_options_init_default (options);
return;
}
_cairo_gstate_get_font_options (cr->gstate, options);
}
/**
* cairo_set_scaled_font:
* @cr: a #cairo_t
* @scaled_font: a #cairo_scaled_font_t
*
* Replaces the current font face, font matrix, and font options in
* the #cairo_t with those of the #cairo_scaled_font_t. Except for
* some translation, the current CTM of the #cairo_t should be the
* same as that of the #cairo_scaled_font_t, which can be accessed
* using cairo_scaled_font_get_ctm().
*
* Since: 1.2
**/
void
cairo_set_scaled_font (cairo_t *cr,
const cairo_scaled_font_t *scaled_font)
{
cairo_status_t status;
cairo_bool_t was_previous;
if (unlikely (cr->status))
return;
if (scaled_font == NULL) {
status = _cairo_error (CAIRO_STATUS_NULL_POINTER);
goto BAIL;
}
status = scaled_font->status;
if (unlikely (status))
goto BAIL;
if (scaled_font == cr->gstate->scaled_font)
return;
was_previous = scaled_font == cr->gstate->previous_scaled_font;
status = _cairo_gstate_set_font_face (cr->gstate, scaled_font->font_face);
if (unlikely (status))
goto BAIL;
status = _cairo_gstate_set_font_matrix (cr->gstate, &scaled_font->font_matrix);
if (unlikely (status))
goto BAIL;
_cairo_gstate_set_font_options (cr->gstate, &scaled_font->options);
if (was_previous)
cr->gstate->scaled_font = cairo_scaled_font_reference ((cairo_scaled_font_t *) scaled_font);
return;
BAIL:
_cairo_set_error (cr, status);
}
/**
* cairo_get_scaled_font:
* @cr: a #cairo_t
*
* Gets the current scaled font for a #cairo_t.
*
* Return value: the current scaled font. This object is owned by
* cairo. To keep a reference to it, you must call
* cairo_scaled_font_reference().
*
* This function never returns %NULL. If memory cannot be allocated, a
* special "nil" #cairo_scaled_font_t object will be returned on which
* cairo_scaled_font_status() returns %CAIRO_STATUS_NO_MEMORY. Using
* this nil object will cause its error state to propagate to other
* objects it is passed to, (for example, calling
* cairo_set_scaled_font() with a nil font will trigger an error that
* will shutdown the #cairo_t object).
*
* Since: 1.4
**/
cairo_scaled_font_t *
cairo_get_scaled_font (cairo_t *cr)
{
cairo_status_t status;
cairo_scaled_font_t *scaled_font;
if (unlikely (cr->status))
return _cairo_scaled_font_create_in_error (cr->status);
status = _cairo_gstate_get_scaled_font (cr->gstate, &scaled_font);
if (unlikely (status)) {
_cairo_set_error (cr, status);
return _cairo_scaled_font_create_in_error (status);
}
return scaled_font;
}
/**
* cairo_text_extents:
* @cr: a #cairo_t
* @utf8: a NUL-terminated string of text encoded in UTF-8, or %NULL
* @extents: a #cairo_text_extents_t object into which the results
* will be stored
*
* Gets the extents for a string of text. The extents describe a
* user-space rectangle that encloses the "inked" portion of the text,
* (as it would be drawn by cairo_show_text()). Additionally, the
* x_advance and y_advance values indicate the amount by which the
* current point would be advanced by cairo_show_text().
*
* Note that whitespace characters do not directly contribute to the
* size of the rectangle (extents.width and extents.height). They do
* contribute indirectly by changing the position of non-whitespace
* characters. In particular, trailing whitespace characters are
* likely to not affect the size of the rectangle, though they will
* affect the x_advance and y_advance values.
**/
void
cairo_text_extents (cairo_t *cr,
const char *utf8,
cairo_text_extents_t *extents)
{
cairo_status_t status;
cairo_glyph_t *glyphs = NULL;
int num_glyphs;
double x, y;
extents->x_bearing = 0.0;
extents->y_bearing = 0.0;
extents->width = 0.0;
extents->height = 0.0;
extents->x_advance = 0.0;
extents->y_advance = 0.0;
if (unlikely (cr->status))
return;
if (utf8 == NULL)
return;
cairo_get_current_point (cr, &x, &y);
status = _cairo_gstate_text_to_glyphs (cr->gstate,
x, y,
utf8, strlen (utf8),
&glyphs, &num_glyphs,
NULL, NULL,
NULL);
if (status == CAIRO_STATUS_SUCCESS)
status = _cairo_gstate_glyph_extents (cr->gstate,
glyphs, num_glyphs,
extents);
cairo_glyph_free (glyphs);
if (unlikely (status))
_cairo_set_error (cr, status);
}
/**
* cairo_glyph_extents:
* @cr: a #cairo_t
* @glyphs: an array of #cairo_glyph_t objects
* @num_glyphs: the number of elements in @glyphs
* @extents: a #cairo_text_extents_t object into which the results
* will be stored
*
* Gets the extents for an array of glyphs. The extents describe a
* user-space rectangle that encloses the "inked" portion of the
* glyphs, (as they would be drawn by cairo_show_glyphs()).
* Additionally, the x_advance and y_advance values indicate the
* amount by which the current point would be advanced by
* cairo_show_glyphs().
*
* Note that whitespace glyphs do not contribute to the size of the
* rectangle (extents.width and extents.height).
**/
void
cairo_glyph_extents (cairo_t *cr,
const cairo_glyph_t *glyphs,
int num_glyphs,
cairo_text_extents_t *extents)
{
cairo_status_t status;
extents->x_bearing = 0.0;
extents->y_bearing = 0.0;
extents->width = 0.0;
extents->height = 0.0;
extents->x_advance = 0.0;
extents->y_advance = 0.0;
if (unlikely (cr->status))
return;
if (num_glyphs == 0)
return;
if (num_glyphs < 0) {
_cairo_set_error (cr, CAIRO_STATUS_NEGATIVE_COUNT);
return;
}
if (glyphs == NULL) {
_cairo_set_error (cr, CAIRO_STATUS_NULL_POINTER);
return;
}
status = _cairo_gstate_glyph_extents (cr->gstate, glyphs, num_glyphs,
extents);
if (unlikely (status))
_cairo_set_error (cr, status);
}
/**
* cairo_show_text:
* @cr: a cairo context
* @utf8: a NUL-terminated string of text encoded in UTF-8, or %NULL
*
* A drawing operator that generates the shape from a string of UTF-8
* characters, rendered according to the current font_face, font_size
* (font_matrix), and font_options.
*
* This function first computes a set of glyphs for the string of
* text. The first glyph is placed so that its origin is at the
* current point. The origin of each subsequent glyph is offset from
* that of the previous glyph by the advance values of the previous
* glyph.
*
* After this call the current point is moved to the origin of where
* the next glyph would be placed in this same progression. That is,
* the current point will be at the origin of the final glyph offset
* by its advance values. This allows for easy display of a single
* logical string with multiple calls to cairo_show_text().
*
* Note: The cairo_show_text() function call is part of what the cairo
* designers call the "toy" text API. It is convenient for short demos
* and simple programs, but it is not expected to be adequate for
* serious text-using applications. See cairo_show_glyphs() for the
* "real" text display API in cairo.
**/
void
cairo_show_text (cairo_t *cr, const char *utf8)
{
cairo_text_extents_t extents;
cairo_status_t status;
cairo_glyph_t *glyphs, *last_glyph;
cairo_text_cluster_t *clusters;
int utf8_len, num_glyphs, num_clusters;
cairo_text_cluster_flags_t cluster_flags;
double x, y;
cairo_bool_t has_show_text_glyphs;
cairo_glyph_t stack_glyphs[CAIRO_STACK_ARRAY_LENGTH (cairo_glyph_t)];
cairo_text_cluster_t stack_clusters[CAIRO_STACK_ARRAY_LENGTH (cairo_text_cluster_t)];
if (unlikely (cr->status))
return;
if (utf8 == NULL)
return;
cairo_get_current_point (cr, &x, &y);
utf8_len = strlen (utf8);
has_show_text_glyphs =
cairo_surface_has_show_text_glyphs (cairo_get_target (cr));
glyphs = stack_glyphs;
num_glyphs = ARRAY_LENGTH (stack_glyphs);
if (has_show_text_glyphs) {
clusters = stack_clusters;
num_clusters = ARRAY_LENGTH (stack_clusters);
} else {
clusters = NULL;
num_clusters = 0;
}
status = _cairo_gstate_text_to_glyphs (cr->gstate,
x, y,
utf8, utf8_len,
&glyphs, &num_glyphs,
has_show_text_glyphs ? &clusters : NULL, &num_clusters,
&cluster_flags);
if (unlikely (status))
goto BAIL;
if (num_glyphs == 0)
return;
status = _cairo_gstate_show_text_glyphs (cr->gstate,
utf8, utf8_len,
glyphs, num_glyphs,
clusters, num_clusters,
cluster_flags);
if (unlikely (status))
goto BAIL;
last_glyph = &glyphs[num_glyphs - 1];
status = _cairo_gstate_glyph_extents (cr->gstate,
last_glyph, 1,
&extents);
if (unlikely (status))
goto BAIL;
x = last_glyph->x + extents.x_advance;
y = last_glyph->y + extents.y_advance;
cairo_move_to (cr, x, y);
BAIL:
if (glyphs != stack_glyphs)
cairo_glyph_free (glyphs);
if (clusters != stack_clusters)
cairo_text_cluster_free (clusters);
if (unlikely (status))
_cairo_set_error (cr, status);
}
/**
* cairo_show_glyphs:
* @cr: a cairo context
* @glyphs: array of glyphs to show
* @num_glyphs: number of glyphs to show
*
* A drawing operator that generates the shape from an array of glyphs,
* rendered according to the current font face, font size
* (font matrix), and font options.
**/
void
cairo_show_glyphs (cairo_t *cr, const cairo_glyph_t *glyphs, int num_glyphs)
{
cairo_status_t status;
if (unlikely (cr->status))
return;
if (num_glyphs == 0)
return;
if (num_glyphs < 0) {
_cairo_set_error (cr, CAIRO_STATUS_NEGATIVE_COUNT);
return;
}
if (glyphs == NULL) {
_cairo_set_error (cr, CAIRO_STATUS_NULL_POINTER);
return;
}
status = _cairo_gstate_show_text_glyphs (cr->gstate,
NULL, 0,
glyphs, num_glyphs,
NULL, 0,
FALSE);
if (unlikely (status))
_cairo_set_error (cr, status);
}
/**
* cairo_show_text_glyphs:
* @cr: a cairo context
* @utf8: a string of text encoded in UTF-8
* @utf8_len: length of @utf8 in bytes, or -1 if it is NUL-terminated
* @glyphs: array of glyphs to show
* @num_glyphs: number of glyphs to show
* @clusters: array of cluster mapping information
* @num_clusters: number of clusters in the mapping
* @cluster_flags: cluster mapping flags
*
* This operation has rendering effects similar to cairo_show_glyphs()
* but, if the target surface supports it, uses the provided text and
* cluster mapping to embed the text for the glyphs shown in the output.
* If the target does not support the extended attributes, this function
* acts like the basic cairo_show_glyphs() as if it had been passed
* @glyphs and @num_glyphs.
*
* The mapping between @utf8 and @glyphs is provided by an array of
* <firstterm>clusters</firstterm>. Each cluster covers a number of
* text bytes and glyphs, and neighboring clusters cover neighboring
* areas of @utf8 and @glyphs. The clusters should collectively cover @utf8
* and @glyphs in entirety.
*
* The first cluster always covers bytes from the beginning of @utf8.
* If @cluster_flags do not have the %CAIRO_TEXT_CLUSTER_FLAG_BACKWARD
* set, the first cluster also covers the beginning
* of @glyphs, otherwise it covers the end of the @glyphs array and
* following clusters move backward.
*
* See #cairo_text_cluster_t for constraints on valid clusters.
*
* Since: 1.8
**/
void
cairo_show_text_glyphs (cairo_t *cr,
const char *utf8,
int utf8_len,
const cairo_glyph_t *glyphs,
int num_glyphs,
const cairo_text_cluster_t *clusters,
int num_clusters,
cairo_text_cluster_flags_t cluster_flags)
{
cairo_status_t status;
if (unlikely (cr->status))
return;
/* A slew of sanity checks */
/* Special case for NULL and -1 */
if (utf8 == NULL && utf8_len == -1)
utf8_len = 0;
/* No NULLs for non-zeros */
if ((num_glyphs && glyphs == NULL) ||
(utf8_len && utf8 == NULL) ||
(num_clusters && clusters == NULL)) {
_cairo_set_error (cr, CAIRO_STATUS_NULL_POINTER);
return;
}
/* A -1 for utf8_len means NUL-terminated */
if (utf8_len == -1)
utf8_len = strlen (utf8);
/* Apart from that, no negatives */
if (num_glyphs < 0 || utf8_len < 0 || num_clusters < 0) {
_cairo_set_error (cr, CAIRO_STATUS_NEGATIVE_COUNT);
return;
}
/* Make sure clusters cover the entire glyphs and utf8 arrays,
* and that cluster boundaries are UTF-8 boundaries. */
status = _cairo_validate_text_clusters (utf8, utf8_len,
glyphs, num_glyphs,
clusters, num_clusters, cluster_flags);
if (status == CAIRO_STATUS_INVALID_CLUSTERS) {
/* Either got invalid UTF-8 text, or cluster mapping is bad.
* Differentiate those. */
cairo_status_t status2;
status2 = _cairo_utf8_to_ucs4 (utf8, utf8_len, NULL, NULL);
if (status2)
status = status2;
_cairo_set_error (cr, status);
return;
}
if (num_glyphs == 0 && utf8_len == 0)
return;
status = _cairo_gstate_show_text_glyphs (cr->gstate,
utf8, utf8_len,
glyphs, num_glyphs,
clusters, num_clusters, cluster_flags);
if (unlikely (status))
_cairo_set_error (cr, status);
}
/**
* cairo_text_path:
* @cr: a cairo context
* @utf8: a NUL-terminated string of text encoded in UTF-8, or %NULL
*
* Adds closed paths for text to the current path. The generated
* path if filled, achieves an effect similar to that of
* cairo_show_text().
*
* Text conversion and positioning is done similar to cairo_show_text().
*
* Like cairo_show_text(), After this call the current point is
* moved to the origin of where the next glyph would be placed in
* this same progression. That is, the current point will be at
* the origin of the final glyph offset by its advance values.
* This allows for chaining multiple calls to to cairo_text_path()
* without having to set current point in between.
*
* Note: The cairo_text_path() function call is part of what the cairo
* designers call the "toy" text API. It is convenient for short demos
* and simple programs, but it is not expected to be adequate for
* serious text-using applications. See cairo_glyph_path() for the
* "real" text path API in cairo.
**/
void
cairo_text_path (cairo_t *cr, const char *utf8)
{
cairo_status_t status;
cairo_text_extents_t extents;
cairo_glyph_t stack_glyphs[CAIRO_STACK_ARRAY_LENGTH (cairo_glyph_t)];
cairo_glyph_t *glyphs, *last_glyph;
int num_glyphs;
double x, y;
if (unlikely (cr->status))
return;
if (utf8 == NULL)
return;
cairo_get_current_point (cr, &x, &y);
glyphs = stack_glyphs;
num_glyphs = ARRAY_LENGTH (stack_glyphs);
status = _cairo_gstate_text_to_glyphs (cr->gstate,
x, y,
utf8, strlen (utf8),
&glyphs, &num_glyphs,
NULL, NULL,
NULL);
if (unlikely (status))
goto BAIL;
if (num_glyphs == 0)
return;
status = _cairo_gstate_glyph_path (cr->gstate,
glyphs, num_glyphs,
cr->path);
if (unlikely (status))
goto BAIL;
last_glyph = &glyphs[num_glyphs - 1];
status = _cairo_gstate_glyph_extents (cr->gstate,
last_glyph, 1,
&extents);
if (unlikely (status))
goto BAIL;
x = last_glyph->x + extents.x_advance;
y = last_glyph->y + extents.y_advance;
cairo_move_to (cr, x, y);
BAIL:
if (glyphs != stack_glyphs)
cairo_glyph_free (glyphs);
if (unlikely (status))
_cairo_set_error (cr, status);
}
/**
* cairo_glyph_path:
* @cr: a cairo context
* @glyphs: array of glyphs to show
* @num_glyphs: number of glyphs to show
*
* Adds closed paths for the glyphs to the current path. The generated
* path if filled, achieves an effect similar to that of
* cairo_show_glyphs().
**/
void
cairo_glyph_path (cairo_t *cr, const cairo_glyph_t *glyphs, int num_glyphs)
{
cairo_status_t status;
if (unlikely (cr->status))
return;
if (num_glyphs == 0)
return;
if (num_glyphs < 0) {
_cairo_set_error (cr, CAIRO_STATUS_NEGATIVE_COUNT);
return;
}
if (glyphs == NULL) {
_cairo_set_error (cr, CAIRO_STATUS_NULL_POINTER);
return;
}
status = _cairo_gstate_glyph_path (cr->gstate,
glyphs, num_glyphs,
cr->path);
if (unlikely (status))
_cairo_set_error (cr, status);
}
/**
* cairo_get_operator:
* @cr: a cairo context
*
* Gets the current compositing operator for a cairo context.
*
* Return value: the current compositing operator.
**/
cairo_operator_t
cairo_get_operator (cairo_t *cr)
{
if (unlikely (cr->status))
return CAIRO_GSTATE_OPERATOR_DEFAULT;
return _cairo_gstate_get_operator (cr->gstate);
}
/**
* cairo_get_tolerance:
* @cr: a cairo context
*
* Gets the current tolerance value, as set by cairo_set_tolerance().
*
* Return value: the current tolerance value.
**/
double
cairo_get_tolerance (cairo_t *cr)
{
if (unlikely (cr->status))
return CAIRO_GSTATE_TOLERANCE_DEFAULT;
return _cairo_gstate_get_tolerance (cr->gstate);
}
slim_hidden_def (cairo_get_tolerance);
/**
* cairo_get_antialias:
* @cr: a cairo context
*
* Gets the current shape antialiasing mode, as set by cairo_set_shape_antialias().
*
* Return value: the current shape antialiasing mode.
**/
cairo_antialias_t
cairo_get_antialias (cairo_t *cr)
{
if (unlikely (cr->status))
return CAIRO_ANTIALIAS_DEFAULT;
return _cairo_gstate_get_antialias (cr->gstate);
}
/**
* cairo_has_current_point:
* @cr: a cairo context
*
* Returns whether a current point is defined on the current path.
* See cairo_get_current_point() for details on the current point.
*
* Return value: whether a current point is defined.
*
* Since: 1.6
**/
cairo_bool_t
cairo_has_current_point (cairo_t *cr)
{
if (unlikely (cr->status))
return FALSE;
return cr->path->has_current_point;
}
/**
* cairo_get_current_point:
* @cr: a cairo context
* @x: return value for X coordinate of the current point
* @y: return value for Y coordinate of the current point
*
* Gets the current point of the current path, which is
* conceptually the final point reached by the path so far.
*
* The current point is returned in the user-space coordinate
* system. If there is no defined current point or if @cr is in an
* error status, @x and @y will both be set to 0.0. It is possible to
* check this in advance with cairo_has_current_point().
*
* Most path construction functions alter the current point. See the
* following for details on how they affect the current point:
* cairo_new_path(), cairo_new_sub_path(),
* cairo_append_path(), cairo_close_path(),
* cairo_move_to(), cairo_line_to(), cairo_curve_to(),
* cairo_rel_move_to(), cairo_rel_line_to(), cairo_rel_curve_to(),
* cairo_arc(), cairo_arc_negative(), cairo_rectangle(),
* cairo_text_path(), cairo_glyph_path(), cairo_stroke_to_path().
*
* Some functions use and alter the current point but do not
* otherwise change current path:
* cairo_show_text().
*
* Some functions unset the current path and as a result, current point:
* cairo_fill(), cairo_stroke().
**/
void
cairo_get_current_point (cairo_t *cr, double *x_ret, double *y_ret)
{
cairo_fixed_t x_fixed, y_fixed;
double x, y;
if (cr->status == CAIRO_STATUS_SUCCESS &&
_cairo_path_fixed_get_current_point (cr->path, &x_fixed, &y_fixed))
{
x = _cairo_fixed_to_double (x_fixed);
y = _cairo_fixed_to_double (y_fixed);
_cairo_gstate_backend_to_user (cr->gstate, &x, &y);
}
else
{
x = 0.0;
y = 0.0;
}
if (x_ret)
*x_ret = x;
if (y_ret)
*y_ret = y;
}
slim_hidden_def(cairo_get_current_point);
/**
* cairo_get_fill_rule:
* @cr: a cairo context
*
* Gets the current fill rule, as set by cairo_set_fill_rule().
*
* Return value: the current fill rule.
**/
cairo_fill_rule_t
cairo_get_fill_rule (cairo_t *cr)
{
if (unlikely (cr->status))
return CAIRO_GSTATE_FILL_RULE_DEFAULT;
return _cairo_gstate_get_fill_rule (cr->gstate);
}
/**
* cairo_get_line_width:
* @cr: a cairo context
*
* This function returns the current line width value exactly as set by
* cairo_set_line_width(). Note that the value is unchanged even if
* the CTM has changed between the calls to cairo_set_line_width() and
* cairo_get_line_width().
*
* Return value: the current line width.
**/
double
cairo_get_line_width (cairo_t *cr)
{
if (unlikely (cr->status))
return CAIRO_GSTATE_LINE_WIDTH_DEFAULT;
return _cairo_gstate_get_line_width (cr->gstate);
}
slim_hidden_def (cairo_get_line_width);
/**
* cairo_get_line_cap:
* @cr: a cairo context
*
* Gets the current line cap style, as set by cairo_set_line_cap().
*
* Return value: the current line cap style.
**/
cairo_line_cap_t
cairo_get_line_cap (cairo_t *cr)
{
if (unlikely (cr->status))
return CAIRO_GSTATE_LINE_CAP_DEFAULT;
return _cairo_gstate_get_line_cap (cr->gstate);
}
/**
* cairo_get_line_join:
* @cr: a cairo context
*
* Gets the current line join style, as set by cairo_set_line_join().
*
* Return value: the current line join style.
**/
cairo_line_join_t
cairo_get_line_join (cairo_t *cr)
{
if (unlikely (cr->status))
return CAIRO_GSTATE_LINE_JOIN_DEFAULT;
return _cairo_gstate_get_line_join (cr->gstate);
}
/**
* cairo_get_miter_limit:
* @cr: a cairo context
*
* Gets the current miter limit, as set by cairo_set_miter_limit().
*
* Return value: the current miter limit.
**/
double
cairo_get_miter_limit (cairo_t *cr)
{
if (unlikely (cr->status))
return CAIRO_GSTATE_MITER_LIMIT_DEFAULT;
return _cairo_gstate_get_miter_limit (cr->gstate);
}
/**
* cairo_get_matrix:
* @cr: a cairo context
* @matrix: return value for the matrix
*
* Stores the current transformation matrix (CTM) into @matrix.
**/
void
cairo_get_matrix (cairo_t *cr, cairo_matrix_t *matrix)
{
if (unlikely (cr->status)) {
cairo_matrix_init_identity (matrix);
return;
}
_cairo_gstate_get_matrix (cr->gstate, matrix);
}
slim_hidden_def (cairo_get_matrix);
/**
* cairo_get_target:
* @cr: a cairo context
*
* Gets the target surface for the cairo context as passed to
* cairo_create().
*
* This function will always return a valid pointer, but the result
* can be a "nil" surface if @cr is already in an error state,
* (ie. cairo_status() <literal>!=</literal> %CAIRO_STATUS_SUCCESS).
* A nil surface is indicated by cairo_surface_status()
* <literal>!=</literal> %CAIRO_STATUS_SUCCESS.
*
* Return value: the target surface. This object is owned by cairo. To
* keep a reference to it, you must call cairo_surface_reference().
**/
cairo_surface_t *
cairo_get_target (cairo_t *cr)
{
if (unlikely (cr->status))
return _cairo_surface_create_in_error (cr->status);
return _cairo_gstate_get_original_target (cr->gstate);
}
slim_hidden_def (cairo_get_target);
/**
* cairo_get_group_target:
* @cr: a cairo context
*
* Gets the current destination surface for the context. This is either
* the original target surface as passed to cairo_create() or the target
* surface for the current group as started by the most recent call to
* cairo_push_group() or cairo_push_group_with_content().
*
* This function will always return a valid pointer, but the result
* can be a "nil" surface if @cr is already in an error state,
* (ie. cairo_status() <literal>!=</literal> %CAIRO_STATUS_SUCCESS).
* A nil surface is indicated by cairo_surface_status()
* <literal>!=</literal> %CAIRO_STATUS_SUCCESS.
*
* Return value: the target surface. This object is owned by cairo. To
* keep a reference to it, you must call cairo_surface_reference().
*
* Since: 1.2
**/
cairo_surface_t *
cairo_get_group_target (cairo_t *cr)
{
if (unlikely (cr->status))
return _cairo_surface_create_in_error (cr->status);
return _cairo_gstate_get_target (cr->gstate);
}
/**
* cairo_copy_path:
* @cr: a cairo context
*
* Creates a copy of the current path and returns it to the user as a
* #cairo_path_t. See #cairo_path_data_t for hints on how to iterate
* over the returned data structure.
*
* This function will always return a valid pointer, but the result
* will have no data (<literal>data==%NULL</literal> and
* <literal>num_data==0</literal>), if either of the following
* conditions hold:
*
* <orderedlist>
* <listitem>If there is insufficient memory to copy the path. In this
* case <literal>path->status</literal> will be set to
* %CAIRO_STATUS_NO_MEMORY.</listitem>
* <listitem>If @cr is already in an error state. In this case
* <literal>path->status</literal> will contain the same status that
* would be returned by cairo_status().</listitem>
* </orderedlist>
*
* Return value: the copy of the current path. The caller owns the
* returned object and should call cairo_path_destroy() when finished
* with it.
**/
cairo_path_t *
cairo_copy_path (cairo_t *cr)
{
if (unlikely (cr->status))
return _cairo_path_create_in_error (cr->status);
return _cairo_path_create (cr->path, cr->gstate);
}
/**
* cairo_copy_path_flat:
* @cr: a cairo context
*
* Gets a flattened copy of the current path and returns it to the
* user as a #cairo_path_t. See #cairo_path_data_t for hints on
* how to iterate over the returned data structure.
*
* This function is like cairo_copy_path() except that any curves
* in the path will be approximated with piecewise-linear
* approximations, (accurate to within the current tolerance
* value). That is, the result is guaranteed to not have any elements
* of type %CAIRO_PATH_CURVE_TO which will instead be replaced by a
* series of %CAIRO_PATH_LINE_TO elements.
*
* This function will always return a valid pointer, but the result
* will have no data (<literal>data==%NULL</literal> and
* <literal>num_data==0</literal>), if either of the following
* conditions hold:
*
* <orderedlist>
* <listitem>If there is insufficient memory to copy the path. In this
* case <literal>path->status</literal> will be set to
* %CAIRO_STATUS_NO_MEMORY.</listitem>
* <listitem>If @cr is already in an error state. In this case
* <literal>path->status</literal> will contain the same status that
* would be returned by cairo_status().</listitem>
* </orderedlist>
*
* Return value: the copy of the current path. The caller owns the
* returned object and should call cairo_path_destroy() when finished
* with it.
**/
cairo_path_t *
cairo_copy_path_flat (cairo_t *cr)
{
if (unlikely (cr->status))
return _cairo_path_create_in_error (cr->status);
return _cairo_path_create_flat (cr->path, cr->gstate);
}
/**
* cairo_append_path:
* @cr: a cairo context
* @path: path to be appended
*
* Append the @path onto the current path. The @path may be either the
* return value from one of cairo_copy_path() or
* cairo_copy_path_flat() or it may be constructed manually. See
* #cairo_path_t for details on how the path data structure should be
* initialized, and note that <literal>path->status</literal> must be
* initialized to %CAIRO_STATUS_SUCCESS.
**/
void
cairo_append_path (cairo_t *cr,
const cairo_path_t *path)
{
cairo_status_t status;
if (unlikely (cr->status))
return;
if (path == NULL) {
_cairo_set_error (cr, CAIRO_STATUS_NULL_POINTER);
return;
}
if (path->status) {
if (path->status > CAIRO_STATUS_SUCCESS &&
path->status <= CAIRO_STATUS_LAST_STATUS)
_cairo_set_error (cr, path->status);
else
_cairo_set_error (cr, CAIRO_STATUS_INVALID_STATUS);
return;
}
if (path->num_data == 0)
return;
if (path->data == NULL) {
_cairo_set_error (cr, CAIRO_STATUS_NULL_POINTER);
return;
}
status = _cairo_path_append_to_context (path, cr);
if (unlikely (status))
_cairo_set_error (cr, status);
}
/**
* cairo_status:
* @cr: a cairo context
*
* Checks whether an error has previously occurred for this context.
*
* Returns: the current status of this context, see #cairo_status_t
**/
cairo_status_t
cairo_status (cairo_t *cr)
{
return cr->status;
}
slim_hidden_def (cairo_status);