/* -*- Mode: c; c-basic-offset: 4; tab-width: 8; indent-tabs-mode: t; -*- */
/*
* Copyright © 2000 SuSE, Inc.
* Copyright © 2007 Red Hat, Inc.
* Copyright © 2000 Keith Packard, member of The XFree86 Project, Inc.
* 2005 Lars Knoll & Zack Rusin, Trolltech
*
* Permission to use, copy, modify, distribute, and sell this software and its
* documentation for any purpose is hereby granted without fee, provided that
* the above copyright notice appear in all copies and that both that
* copyright notice and this permission notice appear in supporting
* documentation, and that the name of Keith Packard not be used in
* advertising or publicity pertaining to distribution of the software without
* specific, written prior permission. Keith Packard makes no
* representations about the suitability of this software for any purpose. It
* is provided "as is" without express or implied warranty.
*
* THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS
* SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS, IN NO EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY
* SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
* AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
* OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
* SOFTWARE.
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <stdlib.h>
#include "pixman-private.h"
static source_image_class_t
linear_gradient_classify (pixman_image_t *image,
int x,
int y,
int width,
int height)
{
source_image_t *source = (source_image_t *)image;
linear_gradient_t *linear = (linear_gradient_t *)image;
pixman_vector_t v;
pixman_fixed_32_32_t l;
pixman_fixed_48_16_t dx, dy;
double inc;
source_image_class_t class;
class = SOURCE_IMAGE_CLASS_UNKNOWN;
if (source->common.transform)
{
/* projective transformation */
if (source->common.transform->matrix[2][0] != 0 ||
source->common.transform->matrix[2][1] != 0 ||
source->common.transform->matrix[2][2] == 0)
{
return class;
}
v.vector[0] = source->common.transform->matrix[0][1];
v.vector[1] = source->common.transform->matrix[1][1];
v.vector[2] = source->common.transform->matrix[2][2];
}
else
{
v.vector[0] = 0;
v.vector[1] = pixman_fixed_1;
v.vector[2] = pixman_fixed_1;
}
dx = linear->p2.x - linear->p1.x;
dy = linear->p2.y - linear->p1.y;
l = dx * dx + dy * dy;
if (l == 0)
return class;
/*
* compute how much the input of the gradient walked changes
* when moving vertically through the whole image
*/
inc = height * (double) pixman_fixed_1 * pixman_fixed_1 *
(dx * v.vector[0] + dy * v.vector[1]) /
(v.vector[2] * (double) l);
/* check that casting to integer would result in 0 */
if (-1 < inc && inc < 1)
class = SOURCE_IMAGE_CLASS_HORIZONTAL;
return class;
}
static void
linear_gradient_get_scanline_32 (pixman_image_t *image,
int x,
int y,
int width,
uint32_t * buffer,
const uint32_t *mask)
{
pixman_vector_t v, unit;
pixman_fixed_32_32_t l;
pixman_fixed_48_16_t dx, dy;
gradient_t *gradient = (gradient_t *)image;
source_image_t *source = (source_image_t *)image;
linear_gradient_t *linear = (linear_gradient_t *)image;
uint32_t *end = buffer + width;
pixman_gradient_walker_t walker;
_pixman_gradient_walker_init (&walker, gradient, source->common.repeat);
/* reference point is the center of the pixel */
v.vector[0] = pixman_int_to_fixed (x) + pixman_fixed_1 / 2;
v.vector[1] = pixman_int_to_fixed (y) + pixman_fixed_1 / 2;
v.vector[2] = pixman_fixed_1;
if (source->common.transform)
{
if (!pixman_transform_point_3d (source->common.transform, &v))
return;
unit.vector[0] = source->common.transform->matrix[0][0];
unit.vector[1] = source->common.transform->matrix[1][0];
unit.vector[2] = source->common.transform->matrix[2][0];
}
else
{
unit.vector[0] = pixman_fixed_1;
unit.vector[1] = 0;
unit.vector[2] = 0;
}
dx = linear->p2.x - linear->p1.x;
dy = linear->p2.y - linear->p1.y;
l = dx * dx + dy * dy;
if (l == 0 || unit.vector[2] == 0)
{
/* affine transformation only */
pixman_fixed_32_32_t t, next_inc;
double inc;
if (l == 0 || v.vector[2] == 0)
{
t = 0;
inc = 0;
}
else
{
double invden, v2;
invden = pixman_fixed_1 * (double) pixman_fixed_1 /
(l * (double) v.vector[2]);
v2 = v.vector[2] * (1. / pixman_fixed_1);
t = ((dx * v.vector[0] + dy * v.vector[1]) -
(dx * linear->p1.x + dy * linear->p1.y) * v2) * invden;
inc = (dx * unit.vector[0] + dy * unit.vector[1]) * invden;
}
next_inc = 0;
if (((pixman_fixed_32_32_t )(inc * width)) == 0)
{
register uint32_t color;
color = _pixman_gradient_walker_pixel (&walker, t);
while (buffer < end)
*buffer++ = color;
}
else
{
int i;
i = 0;
while (buffer < end)
{
if (!mask || *mask++)
{
*buffer = _pixman_gradient_walker_pixel (&walker,
t + next_inc);
}
i++;
next_inc = inc * i;
buffer++;
}
}
}
else
{
/* projective transformation */
double t;
t = 0;
while (buffer < end)
{
if (!mask || *mask++)
{
if (v.vector[2] != 0)
{
double invden, v2;
invden = pixman_fixed_1 * (double) pixman_fixed_1 /
(l * (double) v.vector[2]);
v2 = v.vector[2] * (1. / pixman_fixed_1);
t = ((dx * v.vector[0] + dy * v.vector[1]) -
(dx * linear->p1.x + dy * linear->p1.y) * v2) * invden;
}
*buffer = _pixman_gradient_walker_pixel (&walker, t);
}
++buffer;
v.vector[0] += unit.vector[0];
v.vector[1] += unit.vector[1];
v.vector[2] += unit.vector[2];
}
}
}
static void
linear_gradient_property_changed (pixman_image_t *image)
{
image->common.get_scanline_32 = linear_gradient_get_scanline_32;
image->common.get_scanline_64 = _pixman_image_get_scanline_generic_64;
}
PIXMAN_EXPORT pixman_image_t *
pixman_image_create_linear_gradient (pixman_point_fixed_t * p1,
pixman_point_fixed_t * p2,
const pixman_gradient_stop_t *stops,
int n_stops)
{
pixman_image_t *image;
linear_gradient_t *linear;
image = _pixman_image_allocate ();
if (!image)
return NULL;
linear = &image->linear;
if (!_pixman_init_gradient (&linear->common, stops, n_stops))
{
return NULL;
}
linear->p1 = *p1;
linear->p2 = *p2;
image->type = LINEAR;
image->common.classify = linear_gradient_classify;
image->common.property_changed = linear_gradient_property_changed;
return image;
}