/*
* Copyright 1987, 1988, 1989, 1998 The Open Group
*
* 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.
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* OPEN GROUP BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
* AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
* Except as contained in this notice, the name of The Open Group shall not be
* used in advertising or otherwise to promote the sale, use or other dealings
* in this Software without prior written authorization from The Open Group.
*
* Copyright 1987, 1988, 1989 by
* Digital Equipment Corporation, Maynard, Massachusetts.
*
* All Rights Reserved
*
* Permission to use, copy, modify, and distribute this software and its
* documentation for any purpose and without fee is hereby granted,
* 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 Digital not be
* used in advertising or publicity pertaining to distribution of the
* software without specific, written prior permission.
*
* DIGITAL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING
* ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL
* DIGITAL 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.
*
* Copyright © 1998 Keith Packard
*
* 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.
*
* KEITH PACKARD DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
* INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
* EVENT SHALL KEITH PACKARD 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.
*/
#include <stdlib.h>
#include <limits.h>
#include <string.h>
#include <stdio.h>
#include "pixman-private.h"
#define PIXREGION_NIL(reg) ((reg)->data && !(reg)->data->numRects)
/* not a region */
#define PIXREGION_NAR(reg) ((reg)->data == pixman_broken_data)
#define PIXREGION_NUMRECTS(reg) ((reg)->data ? (reg)->data->numRects : 1)
#define PIXREGION_SIZE(reg) ((reg)->data ? (reg)->data->size : 0)
#define PIXREGION_RECTS(reg) \
((reg)->data ? (box_type_t *)((reg)->data + 1) \
: &(reg)->extents)
#define PIXREGION_BOXPTR(reg) ((box_type_t *)((reg)->data + 1))
#define PIXREGION_BOX(reg, i) (&PIXREGION_BOXPTR (reg)[i])
#define PIXREGION_TOP(reg) PIXREGION_BOX (reg, (reg)->data->numRects)
#define PIXREGION_END(reg) PIXREGION_BOX (reg, (reg)->data->numRects - 1)
#define GOOD_RECT(rect) ((rect)->x1 < (rect)->x2 && (rect)->y1 < (rect)->y2)
#define BAD_RECT(rect) ((rect)->x1 > (rect)->x2 || (rect)->y1 > (rect)->y2)
#ifdef DEBUG
#define GOOD(reg) \
do \
{ \
if (!PREFIX (_selfcheck (reg))) \
_pixman_log_error (FUNC, "Malformed region " # reg); \
} while (0)
#else
#define GOOD(reg)
#endif
static const box_type_t PREFIX (_empty_box_) = { 0, 0, 0, 0 };
static const region_data_type_t PREFIX (_empty_data_) = { 0, 0 };
#if defined (__llvm__) && !defined (__clang__)
static const volatile region_data_type_t PREFIX (_broken_data_) = { 0, 0 };
#else
static const region_data_type_t PREFIX (_broken_data_) = { 0, 0 };
#endif
static box_type_t *pixman_region_empty_box =
(box_type_t *)&PREFIX (_empty_box_);
static region_data_type_t *pixman_region_empty_data =
(region_data_type_t *)&PREFIX (_empty_data_);
static region_data_type_t *pixman_broken_data =
(region_data_type_t *)&PREFIX (_broken_data_);
static pixman_bool_t
pixman_break (region_type_t *region);
/*
* The functions in this file implement the Region abstraction used extensively
* throughout the X11 sample server. A Region is simply a set of disjoint
* (non-overlapping) rectangles, plus an "extent" rectangle which is the
* smallest single rectangle that contains all the non-overlapping rectangles.
*
* A Region is implemented as a "y-x-banded" array of rectangles. This array
* imposes two degrees of order. First, all rectangles are sorted by top side
* y coordinate first (y1), and then by left side x coordinate (x1).
*
* Furthermore, the rectangles are grouped into "bands". Each rectangle in a
* band has the same top y coordinate (y1), and each has the same bottom y
* coordinate (y2). Thus all rectangles in a band differ only in their left
* and right side (x1 and x2). Bands are implicit in the array of rectangles:
* there is no separate list of band start pointers.
*
* The y-x band representation does not minimize rectangles. In particular,
* if a rectangle vertically crosses a band (the rectangle has scanlines in
* the y1 to y2 area spanned by the band), then the rectangle may be broken
* down into two or more smaller rectangles stacked one atop the other.
*
* ----------- -----------
* | | | | band 0
* | | -------- ----------- --------
* | | | | in y-x banded | | | | band 1
* | | | | form is | | | |
* ----------- | | ----------- --------
* | | | | band 2
* -------- --------
*
* An added constraint on the rectangles is that they must cover as much
* horizontal area as possible: no two rectangles within a band are allowed
* to touch.
*
* Whenever possible, bands will be merged together to cover a greater vertical
* distance (and thus reduce the number of rectangles). Two bands can be merged
* only if the bottom of one touches the top of the other and they have
* rectangles in the same places (of the same width, of course).
*
* Adam de Boor wrote most of the original region code. Joel McCormack
* substantially modified or rewrote most of the core arithmetic routines, and
* added pixman_region_validate in order to support several speed improvements
* to pixman_region_validate_tree. Bob Scheifler changed the representation
* to be more compact when empty or a single rectangle, and did a bunch of
* gratuitous reformatting. Carl Worth did further gratuitous reformatting
* while re-merging the server and client region code into libpixregion.
* Soren Sandmann did even more gratuitous reformatting.
*/
/* true iff two Boxes overlap */
#define EXTENTCHECK(r1, r2) \
(!( ((r1)->x2 <= (r2)->x1) || \
((r1)->x1 >= (r2)->x2) || \
((r1)->y2 <= (r2)->y1) || \
((r1)->y1 >= (r2)->y2) ) )
/* true iff (x,y) is in Box */
#define INBOX(r, x, y) \
( ((r)->x2 > x) && \
((r)->x1 <= x) && \
((r)->y2 > y) && \
((r)->y1 <= y) )
/* true iff Box r1 contains Box r2 */
#define SUBSUMES(r1, r2) \
( ((r1)->x1 <= (r2)->x1) && \
((r1)->x2 >= (r2)->x2) && \
((r1)->y1 <= (r2)->y1) && \
((r1)->y2 >= (r2)->y2) )
static size_t
PIXREGION_SZOF (size_t n)
{
size_t size = n * sizeof(box_type_t);
if (n > UINT32_MAX / sizeof(box_type_t))
return 0;
if (sizeof(region_data_type_t) > UINT32_MAX - size)
return 0;
return size + sizeof(region_data_type_t);
}
static region_data_type_t *
alloc_data (size_t n)
{
size_t sz = PIXREGION_SZOF (n);
if (!sz)
return NULL;
}
#define FREE_DATA(reg) if ((reg)->data && (reg)->data->size) free ((reg)->data)
#define RECTALLOC_BAIL(region, n, bail) \
do \
{ \
if (!(region)->data || \
(((region)->data->numRects + (n)) > (region)->data->size)) \
{ \
if (!pixman_rect_alloc (region, n)) \
goto bail; \
} \
} while (0)
#define RECTALLOC(region, n) \
do \
{ \
if (!(region)->data || \
(((region)->data->numRects + (n)) > (region)->data->size)) \
{ \
if (!pixman_rect_alloc (region, n)) { \
return FALSE; \
} \
} \
} while (0)
#define ADDRECT(next_rect, nx1, ny1, nx2, ny2) \
do \
{ \
next_rect->x1 = nx1; \
next_rect->y1 = ny1; \
next_rect->x2 = nx2; \
next_rect->y2 = ny2; \
next_rect++; \
} \
while (0)
#define NEWRECT(region, next_rect, nx1, ny1, nx2, ny2) \
do \
{ \
if (!(region)->data || \
((region)->data->numRects == (region)->data->size)) \
{ \
if (!pixman_rect_alloc (region, 1)) \
return FALSE; \
next_rect = PIXREGION_TOP (region); \
} \
ADDRECT (next_rect, nx1, ny1, nx2, ny2); \
region->data->numRects++; \
critical_if_fail (region->data->numRects <= region->data->size); \
} while (0)
#define DOWNSIZE(reg, numRects) \
do \
{ \
if (((numRects) < ((reg)->data->size >> 1)) && \
((reg)->data->size > 50)) \
{ \
region_data_type_t * new_data; \
size_t data_size = PIXREGION_SZOF (numRects); \
\
if (!data_size) \
{ \
new_data = NULL; \
} \
else \
{ \
new_data = (region_data_type_t *) \
realloc ((reg)->data, data_size); \
} \
\
if (new_data) \
{ \
new_data->size = (numRects); \
(reg)->data = new_data; \
} \
} \
} while (0)
PIXMAN_EXPORT pixman_bool_t
PREFIX (_equal) (region_type_t *reg1, region_type_t *reg2)
{
int i;
box_type_t *rects1;
box_type_t *rects2;
if (reg1->extents.x1 != reg2->extents.x1)
return FALSE;
if (reg1->extents.x2 != reg2->extents.x2)
return FALSE;
if (reg1->extents.y1 != reg2->extents.y1)
return FALSE;
if (reg1->extents.y2 != reg2->extents.y2)
return FALSE;
if (PIXREGION_NUMRECTS (reg1) != PIXREGION_NUMRECTS (reg2))
return FALSE;
rects1 = PIXREGION_RECTS (reg1);
rects2 = PIXREGION_RECTS (reg2);
for (i = 0; i != PIXREGION_NUMRECTS (reg1); i++)
{
if (rects1[i].x1 != rects2[i].x1)
return FALSE;
if (rects1[i].x2 != rects2[i].x2)
return FALSE;
if (rects1[i].y1 != rects2[i].y1)
return FALSE;
if (rects1[i].y2 != rects2[i].y2)
return FALSE;
}
return TRUE;
}
int
PREFIX (_print) (region_type_t *rgn)
{
int num, size;
int i;
box_type_t * rects;
num = PIXREGION_NUMRECTS (rgn);
size = PIXREGION_SIZE (rgn);
rects = PIXREGION_RECTS (rgn);
fprintf (stderr
, "num: %d size: %d\n", num
, size
); fprintf (stderr
, "extents: %d %d %d %d\n", rgn->extents.x1,
rgn->extents.y1,
rgn->extents.x2,
rgn->extents.y2);
for (i = 0; i < num; i++)
{
rects[i].x1, rects[i].y1, rects[i].x2, rects[i].y2);
}
return(num);
}
PIXMAN_EXPORT void
PREFIX (_init) (region_type_t *region)
{
region->extents = *pixman_region_empty_box;
region->data = pixman_region_empty_data;
}
PIXMAN_EXPORT void
PREFIX (_init_rect) (region_type_t * region,
int x,
int y,
unsigned int width,
unsigned int height)
{
region->extents.x1 = x;
region->extents.y1 = y;
region->extents.x2 = x + width;
region->extents.y2 = y + height;
if (!GOOD_RECT (®ion->extents))
{
if (BAD_RECT (®ion->extents))
_pixman_log_error (FUNC, "Invalid rectangle passed");
PREFIX (_init) (region);
return;
}
region->data = NULL;
}
PIXMAN_EXPORT void
PREFIX (_init_with_extents) (region_type_t *region, box_type_t *extents)
{
if (!GOOD_RECT (extents))
{
if (BAD_RECT (extents))
_pixman_log_error (FUNC, "Invalid rectangle passed");
PREFIX (_init) (region);
return;
}
region->extents = *extents;
region->data = NULL;
}
PIXMAN_EXPORT void
PREFIX (_fini) (region_type_t *region)
{
GOOD (region);
FREE_DATA (region);
}
PIXMAN_EXPORT int
PREFIX (_n_rects) (region_type_t *region)
{
return PIXREGION_NUMRECTS (region);
}
PIXMAN_EXPORT box_type_t *
PREFIX (_rectangles) (region_type_t *region,
int *n_rects)
{
if (n_rects)
*n_rects = PIXREGION_NUMRECTS (region);
return PIXREGION_RECTS (region);
}
static pixman_bool_t
pixman_break (region_type_t *region)
{
FREE_DATA (region);
region->extents = *pixman_region_empty_box;
region->data = pixman_broken_data;
return FALSE;
}
static pixman_bool_t
pixman_rect_alloc (region_type_t * region,
int n)
{
region_data_type_t *data;
if (!region->data)
{
n++;
region->data = alloc_data (n);
if (!region->data)
return pixman_break (region);
region->data->numRects = 1;
*PIXREGION_BOXPTR (region) = region->extents;
}
else if (!region->data->size)
{
region->data = alloc_data (n);
if (!region->data)
return pixman_break (region);
region->data->numRects = 0;
}
else
{
size_t data_size;
if (n == 1)
{
n = region->data->numRects;
if (n > 500) /* XXX pick numbers out of a hat */
n = 250;
}
n += region->data->numRects;
data_size = PIXREGION_SZOF (n);
if (!data_size)
{
data = NULL;
}
else
{
data = (region_data_type_t *)
realloc (region
->data
, PIXREGION_SZOF
(n
)); }
if (!data)
return pixman_break (region);
region->data = data;
}
region->data->size = n;
return TRUE;
}
PIXMAN_EXPORT pixman_bool_t
PREFIX (_copy) (region_type_t *dst, region_type_t *src)
{
GOOD (dst);
GOOD (src);
if (dst == src)
return TRUE;
dst->extents = src->extents;
if (!src->data || !src->data->size)
{
FREE_DATA (dst);
dst->data = src->data;
return TRUE;
}
if (!dst->data || (dst->data->size < src->data->numRects))
{
FREE_DATA (dst);
dst->data = alloc_data (src->data->numRects);
if (!dst->data)
return pixman_break (dst);
dst->data->size = src->data->numRects;
}
dst->data->numRects = src->data->numRects;
memmove ((char *)PIXREGION_BOXPTR
(dst
), (char *)PIXREGION_BOXPTR
(src
), dst->data->numRects * sizeof(box_type_t));
return TRUE;
}
/*======================================================================
* Generic Region Operator
*====================================================================*/
/*-
*-----------------------------------------------------------------------
* pixman_coalesce --
* Attempt to merge the boxes in the current band with those in the
* previous one. We are guaranteed that the current band extends to
* the end of the rects array. Used only by pixman_op.
*
* Results:
* The new index for the previous band.
*
* Side Effects:
* If coalescing takes place:
* - rectangles in the previous band will have their y2 fields
* altered.
* - region->data->numRects will be decreased.
*
*-----------------------------------------------------------------------
*/
static inline int
pixman_coalesce (region_type_t * region, /* Region to coalesce */
int prev_start, /* Index of start of previous band */
int cur_start) /* Index of start of current band */
{
box_type_t *prev_box; /* Current box in previous band */
box_type_t *cur_box; /* Current box in current band */
int numRects; /* Number rectangles in both bands */
int y2; /* Bottom of current band */
/*
* Figure out how many rectangles are in the band.
*/
numRects = cur_start - prev_start;
critical_if_fail (numRects == region->data->numRects - cur_start);
if (!numRects) return cur_start;
/*
* The bands may only be coalesced if the bottom of the previous
* matches the top scanline of the current.
*/
prev_box = PIXREGION_BOX (region, prev_start);
cur_box = PIXREGION_BOX (region, cur_start);
if (prev_box->y2 != cur_box->y1) return cur_start;
/*
* Make sure the bands have boxes in the same places. This
* assumes that boxes have been added in such a way that they
* cover the most area possible. I.e. two boxes in a band must
* have some horizontal space between them.
*/
y2 = cur_box->y2;
do
{
if ((prev_box->x1 != cur_box->x1) || (prev_box->x2 != cur_box->x2))
return (cur_start);
prev_box++;
cur_box++;
numRects--;
}
while (numRects);
/*
* The bands may be merged, so set the bottom y of each box
* in the previous band to the bottom y of the current band.
*/
numRects = cur_start - prev_start;
region->data->numRects -= numRects;
do
{
prev_box--;
prev_box->y2 = y2;
numRects--;
}
while (numRects);
return prev_start;
}
/* Quicky macro to avoid trivial reject procedure calls to pixman_coalesce */
#define COALESCE(new_reg, prev_band, cur_band) \
do \
{ \
if (cur_band - prev_band == new_reg->data->numRects - cur_band) \
prev_band = pixman_coalesce (new_reg, prev_band, cur_band); \
else \
prev_band = cur_band; \
} while (0)
/*-
*-----------------------------------------------------------------------
* pixman_region_append_non_o --
* Handle a non-overlapping band for the union and subtract operations.
* Just adds the (top/bottom-clipped) rectangles into the region.
* Doesn't have to check for subsumption or anything.
*
* Results:
* None.
*
* Side Effects:
* region->data->numRects is incremented and the rectangles overwritten
* with the rectangles we're passed.
*
*-----------------------------------------------------------------------
*/
static inline pixman_bool_t
pixman_region_append_non_o (region_type_t * region,
box_type_t * r,
box_type_t * r_end,
int y1,
int y2)
{
box_type_t *next_rect;
int new_rects;
new_rects = r_end - r;
critical_if_fail (y1 < y2);
critical_if_fail (new_rects != 0);
/* Make sure we have enough space for all rectangles to be added */
RECTALLOC (region, new_rects);
next_rect = PIXREGION_TOP (region);
region->data->numRects += new_rects;
do
{
critical_if_fail (r->x1 < r->x2);
ADDRECT (next_rect, r->x1, y1, r->x2, y2);
r++;
}
while (r != r_end);
return TRUE;
}
#define FIND_BAND(r, r_band_end, r_end, ry1) \
do \
{ \
ry1 = r->y1; \
r_band_end = r + 1; \
while ((r_band_end != r_end) && (r_band_end->y1 == ry1)) { \
r_band_end++; \
} \
} while (0)
#define APPEND_REGIONS(new_reg, r, r_end) \
do \
{ \
int new_rects; \
if ((new_rects = r_end - r)) { \
RECTALLOC_BAIL (new_reg, new_rects, bail); \
memmove ((char *)PIXREGION_TOP (new_reg), (char *)r, \
new_rects * sizeof(box_type_t)); \
new_reg->data->numRects += new_rects; \
} \
} while (0)
/*-
*-----------------------------------------------------------------------
* pixman_op --
* Apply an operation to two regions. Called by pixman_region_union, pixman_region_inverse,
* pixman_region_subtract, pixman_region_intersect.... Both regions MUST have at least one
* rectangle, and cannot be the same object.
*
* Results:
* TRUE if successful.
*
* Side Effects:
* The new region is overwritten.
* overlap set to TRUE if overlap_func ever returns TRUE.
*
* Notes:
* The idea behind this function is to view the two regions as sets.
* Together they cover a rectangle of area that this function divides
* into horizontal bands where points are covered only by one region
* or by both. For the first case, the non_overlap_func is called with
* each the band and the band's upper and lower extents. For the
* second, the overlap_func is called to process the entire band. It
* is responsible for clipping the rectangles in the band, though
* this function provides the boundaries.
* At the end of each band, the new region is coalesced, if possible,
* to reduce the number of rectangles in the region.
*
*-----------------------------------------------------------------------
*/
typedef pixman_bool_t (*overlap_proc_ptr) (region_type_t *region,
box_type_t * r1,
box_type_t * r1_end,
box_type_t * r2,
box_type_t * r2_end,
int y1,
int y2);
static pixman_bool_t
pixman_op (region_type_t * new_reg, /* Place to store result */
region_type_t * reg1, /* First region in operation */
region_type_t * reg2, /* 2d region in operation */
overlap_proc_ptr overlap_func, /* Function to call for over-
* lapping bands */
int append_non1, /* Append non-overlapping bands
* in region 1 ?
*/
int append_non2 /* Append non-overlapping bands
* in region 2 ?
*/
)
{
box_type_t *r1; /* Pointer into first region */
box_type_t *r2; /* Pointer into 2d region */
box_type_t *r1_end; /* End of 1st region */
box_type_t *r2_end; /* End of 2d region */
int ybot; /* Bottom of intersection */
int ytop; /* Top of intersection */
region_data_type_t *old_data; /* Old data for new_reg */
int prev_band; /* Index of start of
* previous band in new_reg */
int cur_band; /* Index of start of current
* band in new_reg */
box_type_t * r1_band_end; /* End of current band in r1 */
box_type_t * r2_band_end; /* End of current band in r2 */
int top; /* Top of non-overlapping band */
int bot; /* Bottom of non-overlapping band*/
int r1y1; /* Temps for r1->y1 and r2->y1 */
int r2y1;
int new_size;
int numRects;
/*
* Break any region computed from a broken region
*/
if (PIXREGION_NAR (reg1) || PIXREGION_NAR (reg2))
return pixman_break (new_reg);
/*
* Initialization:
* set r1, r2, r1_end and r2_end appropriately, save the rectangles
* of the destination region until the end in case it's one of
* the two source regions, then mark the "new" region empty, allocating
* another array of rectangles for it to use.
*/
r1 = PIXREGION_RECTS (reg1);
new_size = PIXREGION_NUMRECTS (reg1);
r1_end = r1 + new_size;
numRects = PIXREGION_NUMRECTS (reg2);
r2 = PIXREGION_RECTS (reg2);
r2_end = r2 + numRects;
critical_if_fail (r1 != r1_end);
critical_if_fail (r2 != r2_end);
old_data = (region_data_type_t *)NULL;
if (((new_reg == reg1) && (new_size > 1)) ||
((new_reg == reg2) && (numRects > 1)))
{
old_data = new_reg->data;
new_reg->data = pixman_region_empty_data;
}
/* guess at new size */
if (numRects > new_size)
new_size = numRects;
new_size <<= 1;
if (!new_reg->data)
new_reg->data = pixman_region_empty_data;
else if (new_reg->data->size)
new_reg->data->numRects = 0;
if (new_size > new_reg->data->size)
{
if (!pixman_rect_alloc (new_reg, new_size))
{
return FALSE;
}
}
/*
* Initialize ybot.
* In the upcoming loop, ybot and ytop serve different functions depending
* on whether the band being handled is an overlapping or non-overlapping
* band.
* In the case of a non-overlapping band (only one of the regions
* has points in the band), ybot is the bottom of the most recent
* intersection and thus clips the top of the rectangles in that band.
* ytop is the top of the next intersection between the two regions and
* serves to clip the bottom of the rectangles in the current band.
* For an overlapping band (where the two regions intersect), ytop clips
* the top of the rectangles of both regions and ybot clips the bottoms.
*/
ybot = MIN (r1->y1, r2->y1);
/*
* prev_band serves to mark the start of the previous band so rectangles
* can be coalesced into larger rectangles. qv. pixman_coalesce, above.
* In the beginning, there is no previous band, so prev_band == cur_band
* (cur_band is set later on, of course, but the first band will always
* start at index 0). prev_band and cur_band must be indices because of
* the possible expansion, and resultant moving, of the new region's
* array of rectangles.
*/
prev_band = 0;
do
{
/*
* This algorithm proceeds one source-band (as opposed to a
* destination band, which is determined by where the two regions
* intersect) at a time. r1_band_end and r2_band_end serve to mark the
* rectangle after the last one in the current band for their
* respective regions.
*/
critical_if_fail (r1 != r1_end);
critical_if_fail (r2 != r2_end);
FIND_BAND (r1, r1_band_end, r1_end, r1y1);
FIND_BAND (r2, r2_band_end, r2_end, r2y1);
/*
* First handle the band that doesn't intersect, if any.
*
* Note that attention is restricted to one band in the
* non-intersecting region at once, so if a region has n
* bands between the current position and the next place it overlaps
* the other, this entire loop will be passed through n times.
*/
if (r1y1 < r2y1)
{
if (append_non1)
{
top = MAX (r1y1, ybot);
bot = MIN (r1->y2, r2y1);
if (top != bot)
{
cur_band = new_reg->data->numRects;
if (!pixman_region_append_non_o (new_reg, r1, r1_band_end, top, bot))
goto bail;
COALESCE (new_reg, prev_band, cur_band);
}
}
ytop = r2y1;
}
else if (r2y1 < r1y1)
{
if (append_non2)
{
top = MAX (r2y1, ybot);
bot = MIN (r2->y2, r1y1);
if (top != bot)
{
cur_band = new_reg->data->numRects;
if (!pixman_region_append_non_o (new_reg, r2, r2_band_end, top, bot))
goto bail;
COALESCE (new_reg, prev_band, cur_band);
}
}
ytop = r1y1;
}
else
{
ytop = r1y1;
}
/*
* Now see if we've hit an intersecting band. The two bands only
* intersect if ybot > ytop
*/
ybot = MIN (r1->y2, r2->y2);
if (ybot > ytop)
{
cur_band = new_reg->data->numRects;
if (!(*overlap_func)(new_reg,
r1, r1_band_end,
r2, r2_band_end,
ytop, ybot))
{
goto bail;
}
COALESCE (new_reg, prev_band, cur_band);
}
/*
* If we've finished with a band (y2 == ybot) we skip forward
* in the region to the next band.
*/
if (r1->y2 == ybot)
r1 = r1_band_end;
if (r2->y2 == ybot)
r2 = r2_band_end;
}
while (r1 != r1_end && r2 != r2_end);
/*
* Deal with whichever region (if any) still has rectangles left.
*
* We only need to worry about banding and coalescing for the very first
* band left. After that, we can just group all remaining boxes,
* regardless of how many bands, into one final append to the list.
*/
if ((r1 != r1_end) && append_non1)
{
/* Do first non_overlap1Func call, which may be able to coalesce */
FIND_BAND (r1, r1_band_end, r1_end, r1y1);
cur_band = new_reg->data->numRects;
if (!pixman_region_append_non_o (new_reg,
r1, r1_band_end,
MAX (r1y1, ybot), r1->y2))
{
goto bail;
}
COALESCE (new_reg, prev_band, cur_band);
/* Just append the rest of the boxes */
APPEND_REGIONS (new_reg, r1_band_end, r1_end);
}
else if ((r2 != r2_end) && append_non2)
{
/* Do first non_overlap2Func call, which may be able to coalesce */
FIND_BAND (r2, r2_band_end, r2_end, r2y1);
cur_band = new_reg->data->numRects;
if (!pixman_region_append_non_o (new_reg,
r2, r2_band_end,
MAX (r2y1, ybot), r2->y2))
{
goto bail;
}
COALESCE (new_reg, prev_band, cur_band);
/* Append rest of boxes */
APPEND_REGIONS (new_reg, r2_band_end, r2_end);
}
if (!(numRects = new_reg->data->numRects))
{
FREE_DATA (new_reg);
new_reg->data = pixman_region_empty_data;
}
else if (numRects == 1)
{
new_reg->extents = *PIXREGION_BOXPTR (new_reg);
FREE_DATA (new_reg);
new_reg->data = (region_data_type_t *)NULL;
}
else
{
DOWNSIZE (new_reg, numRects);
}
return TRUE;
bail:
return pixman_break (new_reg);
}
/*-
*-----------------------------------------------------------------------
* pixman_set_extents --
* Reset the extents of a region to what they should be. Called by
* pixman_region_subtract and pixman_region_intersect as they can't
* figure it out along the way or do so easily, as pixman_region_union can.
*
* Results:
* None.
*
* Side Effects:
* The region's 'extents' structure is overwritten.
*
*-----------------------------------------------------------------------
*/
static void
pixman_set_extents (region_type_t *region)
{
box_type_t *box, *box_end;
if (!region->data)
return;
if (!region->data->size)
{
region->extents.x2 = region->extents.x1;
region->extents.y2 = region->extents.y1;
return;
}
box = PIXREGION_BOXPTR (region);
box_end = PIXREGION_END (region);
/*
* Since box is the first rectangle in the region, it must have the
* smallest y1 and since box_end is the last rectangle in the region,
* it must have the largest y2, because of banding. Initialize x1 and
* x2 from box and box_end, resp., as good things to initialize them
* to...
*/
region->extents.x1 = box->x1;
region->extents.y1 = box->y1;
region->extents.x2 = box_end->x2;
region->extents.y2 = box_end->y2;
critical_if_fail (region->extents.y1 < region->extents.y2);
while (box <= box_end)
{
if (box->x1 < region->extents.x1)
region->extents.x1 = box->x1;
if (box->x2 > region->extents.x2)
region->extents.x2 = box->x2;
box++;
}
critical_if_fail (region->extents.x1 < region->extents.x2);
}
/*======================================================================
* Region Intersection
*====================================================================*/
/*-
*-----------------------------------------------------------------------
* pixman_region_intersect_o --
* Handle an overlapping band for pixman_region_intersect.
*
* Results:
* TRUE if successful.
*
* Side Effects:
* Rectangles may be added to the region.
*
*-----------------------------------------------------------------------
*/
/*ARGSUSED*/
static pixman_bool_t
pixman_region_intersect_o (region_type_t *region,
box_type_t * r1,
box_type_t * r1_end,
box_type_t * r2,
box_type_t * r2_end,
int y1,
int y2)
{
int x1;
int x2;
box_type_t * next_rect;
next_rect = PIXREGION_TOP (region);
critical_if_fail (y1 < y2);
critical_if_fail (r1 != r1_end && r2 != r2_end);
do
{
x1 = MAX (r1->x1, r2->x1);
x2 = MIN (r1->x2, r2->x2);
/*
* If there's any overlap between the two rectangles, add that
* overlap to the new region.
*/
if (x1 < x2)
NEWRECT (region, next_rect, x1, y1, x2, y2);
/*
* Advance the pointer(s) with the leftmost right side, since the next
* rectangle on that list may still overlap the other region's
* current rectangle.
*/
if (r1->x2 == x2)
{
r1++;
}
if (r2->x2 == x2)
{
r2++;
}
}
while ((r1 != r1_end) && (r2 != r2_end));
return TRUE;
}
PIXMAN_EXPORT pixman_bool_t
PREFIX (_intersect) (region_type_t * new_reg,
region_type_t * reg1,
region_type_t * reg2)
{
GOOD (reg1);
GOOD (reg2);
GOOD (new_reg);
/* check for trivial reject */
if (PIXREGION_NIL (reg1) || PIXREGION_NIL (reg2) ||
!EXTENTCHECK (®1->extents, ®2->extents))
{
/* Covers about 20% of all cases */
FREE_DATA (new_reg);
new_reg->extents.x2 = new_reg->extents.x1;
new_reg->extents.y2 = new_reg->extents.y1;
if (PIXREGION_NAR (reg1) || PIXREGION_NAR (reg2))
{
new_reg->data = pixman_broken_data;
return FALSE;
}
else
{
new_reg->data = pixman_region_empty_data;
}
}
else if (!reg1->data && !reg2->data)
{
/* Covers about 80% of cases that aren't trivially rejected */
new_reg->extents.x1 = MAX (reg1->extents.x1, reg2->extents.x1);
new_reg->extents.y1 = MAX (reg1->extents.y1, reg2->extents.y1);
new_reg->extents.x2 = MIN (reg1->extents.x2, reg2->extents.x2);
new_reg->extents.y2 = MIN (reg1->extents.y2, reg2->extents.y2);
FREE_DATA (new_reg);
new_reg->data = (region_data_type_t *)NULL;
}
else if (!reg2->data && SUBSUMES (®2->extents, ®1->extents))
{
return PREFIX (_copy) (new_reg, reg1);
}
else if (!reg1->data && SUBSUMES (®1->extents, ®2->extents))
{
return PREFIX (_copy) (new_reg, reg2);
}
else if (reg1 == reg2)
{
return PREFIX (_copy) (new_reg, reg1);
}
else
{
/* General purpose intersection */
if (!pixman_op (new_reg, reg1, reg2, pixman_region_intersect_o, FALSE, FALSE))
return FALSE;
pixman_set_extents (new_reg);
}
GOOD (new_reg);
return(TRUE);
}
#define MERGERECT(r) \
do \
{ \
if (r->x1 <= x2) \
{ \
/* Merge with current rectangle */ \
if (x2 < r->x2) \
x2 = r->x2; \
} \
else \
{ \
/* Add current rectangle, start new one */ \
NEWRECT (region, next_rect, x1, y1, x2, y2); \
x1 = r->x1; \
x2 = r->x2; \
} \
r++; \
} while (0)
/*======================================================================
* Region Union
*====================================================================*/
/*-
*-----------------------------------------------------------------------
* pixman_region_union_o --
* Handle an overlapping band for the union operation. Picks the
* left-most rectangle each time and merges it into the region.
*
* Results:
* TRUE if successful.
*
* Side Effects:
* region is overwritten.
* overlap is set to TRUE if any boxes overlap.
*
*-----------------------------------------------------------------------
*/
static pixman_bool_t
pixman_region_union_o (region_type_t *region,
box_type_t * r1,
box_type_t * r1_end,
box_type_t * r2,
box_type_t * r2_end,
int y1,
int y2)
{
box_type_t *next_rect;
int x1; /* left and right side of current union */
int x2;
critical_if_fail (y1 < y2);
critical_if_fail (r1 != r1_end && r2 != r2_end);
next_rect = PIXREGION_TOP (region);
/* Start off current rectangle */
if (r1->x1 < r2->x1)
{
x1 = r1->x1;
x2 = r1->x2;
r1++;
}
else
{
x1 = r2->x1;
x2 = r2->x2;
r2++;
}
while (r1 != r1_end && r2 != r2_end)
{
if (r1->x1 < r2->x1)
MERGERECT (r1);
else
MERGERECT (r2);
}
/* Finish off whoever (if any) is left */
if (r1 != r1_end)
{
do
{
MERGERECT (r1);
}
while (r1 != r1_end);
}
else if (r2 != r2_end)
{
do
{
MERGERECT (r2);
}
while (r2 != r2_end);
}
/* Add current rectangle */
NEWRECT (region, next_rect, x1, y1, x2, y2);
return TRUE;
}
PIXMAN_EXPORT pixman_bool_t
PREFIX(_intersect_rect) (region_type_t *dest,
region_type_t *source,
int x, int y,
unsigned int width,
unsigned int height)
{
region_type_t region;
region.data = NULL;
region.extents.x1 = x;
region.extents.y1 = y;
region.extents.x2 = x + width;
region.extents.y2 = y + height;
return PREFIX(_intersect) (dest, source, ®ion);
}
/* Convenience function for performing union of region with a
* single rectangle
*/
PIXMAN_EXPORT pixman_bool_t
PREFIX (_union_rect) (region_type_t *dest,
region_type_t *source,
int x,
int y,
unsigned int width,
unsigned int height)
{
region_type_t region;
region.extents.x1 = x;
region.extents.y1 = y;
region.extents.x2 = x + width;
region.extents.y2 = y + height;
if (!GOOD_RECT (®ion.extents))
{
if (BAD_RECT (®ion.extents))
_pixman_log_error (FUNC, "Invalid rectangle passed");
return PREFIX (_copy) (dest, source);
}
region.data = NULL;
return PREFIX (_union) (dest, source, ®ion);
}
PIXMAN_EXPORT pixman_bool_t
PREFIX (_union) (region_type_t *new_reg,
region_type_t *reg1,
region_type_t *reg2)
{
/* Return TRUE if some overlap
* between reg1, reg2
*/
GOOD (reg1);
GOOD (reg2);
GOOD (new_reg);
/* checks all the simple cases */
/*
* Region 1 and 2 are the same
*/
if (reg1 == reg2)
return PREFIX (_copy) (new_reg, reg1);
/*
* Region 1 is empty
*/
if (PIXREGION_NIL (reg1))
{
if (PIXREGION_NAR (reg1))
return pixman_break (new_reg);
if (new_reg != reg2)
return PREFIX (_copy) (new_reg, reg2);
return TRUE;
}
/*
* Region 2 is empty
*/
if (PIXREGION_NIL (reg2))
{
if (PIXREGION_NAR (reg2))
return pixman_break (new_reg);
if (new_reg != reg1)
return PREFIX (_copy) (new_reg, reg1);
return TRUE;
}
/*
* Region 1 completely subsumes region 2
*/
if (!reg1->data && SUBSUMES (®1->extents, ®2->extents))
{
if (new_reg != reg1)
return PREFIX (_copy) (new_reg, reg1);
return TRUE;
}
/*
* Region 2 completely subsumes region 1
*/
if (!reg2->data && SUBSUMES (®2->extents, ®1->extents))
{
if (new_reg != reg2)
return PREFIX (_copy) (new_reg, reg2);
return TRUE;
}
if (!pixman_op (new_reg, reg1, reg2, pixman_region_union_o, TRUE, TRUE))
return FALSE;
new_reg->extents.x1 = MIN (reg1->extents.x1, reg2->extents.x1);
new_reg->extents.y1 = MIN (reg1->extents.y1, reg2->extents.y1);
new_reg->extents.x2 = MAX (reg1->extents.x2, reg2->extents.x2);
new_reg->extents.y2 = MAX (reg1->extents.y2, reg2->extents.y2);
GOOD (new_reg);
return TRUE;
}
/*======================================================================
* Batch Rectangle Union
*====================================================================*/
#define EXCHANGE_RECTS(a, b) \
{ \
box_type_t t; \
t = rects[a]; \
rects[a] = rects[b]; \
rects[b] = t; \
}
static void
quick_sort_rects (
box_type_t rects[],
int numRects)
{
int y1;
int x1;
int i, j;
box_type_t *r;
/* Always called with numRects > 1 */
do
{
if (numRects == 2)
{
if (rects[0].y1 > rects[1].y1 ||
(rects[0].y1 == rects[1].y1 && rects[0].x1 > rects[1].x1))
{
EXCHANGE_RECTS (0, 1);
}
return;
}
/* Choose partition element, stick in location 0 */
EXCHANGE_RECTS (0, numRects >> 1);
y1 = rects[0].y1;
x1 = rects[0].x1;
/* Partition array */
i = 0;
j = numRects;
do
{
r = &(rects[i]);
do
{
r++;
i++;
}
while (i != numRects && (r->y1 < y1 || (r->y1 == y1 && r->x1 < x1)));
r = &(rects[j]);
do
{
r--;
j--;
}
while (y1 < r->y1 || (y1 == r->y1 && x1 < r->x1));
if (i < j)
EXCHANGE_RECTS (i, j);
}
while (i < j);
/* Move partition element back to middle */
EXCHANGE_RECTS (0, j);
/* Recurse */
if (numRects - j - 1 > 1)
quick_sort_rects (&rects[j + 1], numRects - j - 1);
numRects = j;
}
while (numRects > 1);
}
/*-
*-----------------------------------------------------------------------
* pixman_region_validate --
*
* Take a ``region'' which is a non-y-x-banded random collection of
* rectangles, and compute a nice region which is the union of all the
* rectangles.
*
* Results:
* TRUE if successful.
*
* Side Effects:
* The passed-in ``region'' may be modified.
* overlap set to TRUE if any retangles overlapped,
* else FALSE;
*
* Strategy:
* Step 1. Sort the rectangles into ascending order with primary key y1
* and secondary key x1.
*
* Step 2. Split the rectangles into the minimum number of proper y-x
* banded regions. This may require horizontally merging
* rectangles, and vertically coalescing bands. With any luck,
* this step in an identity transformation (ala the Box widget),
* or a coalescing into 1 box (ala Menus).
*
* Step 3. Merge the separate regions down to a single region by calling
* pixman_region_union. Maximize the work each pixman_region_union call does by using
* a binary merge.
*
*-----------------------------------------------------------------------
*/
static pixman_bool_t
validate (region_type_t * badreg)
{
/* Descriptor for regions under construction in Step 2. */
typedef struct
{
region_type_t reg;
int prev_band;
int cur_band;
} region_info_t;
region_info_t stack_regions[64];
int numRects; /* Original numRects for badreg */
region_info_t *ri; /* Array of current regions */
int num_ri; /* Number of entries used in ri */
int size_ri; /* Number of entries available in ri */
int i; /* Index into rects */
int j; /* Index into ri */
region_info_t *rit; /* &ri[j] */
region_type_t *reg; /* ri[j].reg */
box_type_t *box; /* Current box in rects */
box_type_t *ri_box; /* Last box in ri[j].reg */
region_type_t *hreg; /* ri[j_half].reg */
pixman_bool_t ret = TRUE;
if (!badreg->data)
{
GOOD (badreg);
return TRUE;
}
numRects = badreg->data->numRects;
if (!numRects)
{
if (PIXREGION_NAR (badreg))
return FALSE;
GOOD (badreg);
return TRUE;
}
if (badreg->extents.x1 < badreg->extents.x2)
{
if ((numRects) == 1)
{
FREE_DATA (badreg);
badreg->data = (region_data_type_t *) NULL;
}
else
{
DOWNSIZE (badreg, numRects);
}
GOOD (badreg);
return TRUE;
}
/* Step 1: Sort the rects array into ascending (y1, x1) order */
quick_sort_rects (PIXREGION_BOXPTR (badreg), numRects);
/* Step 2: Scatter the sorted array into the minimum number of regions */
/* Set up the first region to be the first rectangle in badreg */
/* Note that step 2 code will never overflow the ri[0].reg rects array */
ri = stack_regions;
size_ri = sizeof (stack_regions) / sizeof (stack_regions[0]);
num_ri = 1;
ri[0].prev_band = 0;
ri[0].cur_band = 0;
ri[0].reg = *badreg;
box = PIXREGION_BOXPTR (&ri[0].reg);
ri[0].reg.extents = *box;
ri[0].reg.data->numRects = 1;
badreg->extents = *pixman_region_empty_box;
badreg->data = pixman_region_empty_data;
/* Now scatter rectangles into the minimum set of valid regions. If the
* next rectangle to be added to a region would force an existing rectangle
* in the region to be split up in order to maintain y-x banding, just
* forget it. Try the next region. If it doesn't fit cleanly into any
* region, make a new one.
*/
for (i = numRects; --i > 0;)
{
box++;
/* Look for a region to append box to */
for (j = num_ri, rit = ri; --j >= 0; rit++)
{
reg = &rit->reg;
ri_box = PIXREGION_END (reg);
if (box->y1 == ri_box->y1 && box->y2 == ri_box->y2)
{
/* box is in same band as ri_box. Merge or append it */
if (box->x1 <= ri_box->x2)
{
/* Merge it with ri_box */
if (box->x2 > ri_box->x2)
ri_box->x2 = box->x2;
}
else
{
RECTALLOC_BAIL (reg, 1, bail);
*PIXREGION_TOP (reg) = *box;
reg->data->numRects++;
}
goto next_rect; /* So sue me */
}
else if (box->y1 >= ri_box->y2)
{
/* Put box into new band */
if (reg->extents.x2 < ri_box->x2)
reg->extents.x2 = ri_box->x2;
if (reg->extents.x1 > box->x1)
reg->extents.x1 = box->x1;
COALESCE (reg, rit->prev_band, rit->cur_band);
rit->cur_band = reg->data->numRects;
RECTALLOC_BAIL (reg, 1, bail);
*PIXREGION_TOP (reg) = *box;
reg->data->numRects++;
goto next_rect;
}
/* Well, this region was inappropriate. Try the next one. */
} /* for j */
/* Uh-oh. No regions were appropriate. Create a new one. */
if (size_ri == num_ri)
{
size_t data_size;
/* Oops, allocate space for new region information */
size_ri <<= 1;
data_size = size_ri * sizeof(region_info_t);
if (data_size / size_ri != sizeof(region_info_t))
goto bail;
if (ri == stack_regions)
{
if (!rit)
goto bail;
memcpy (rit
, ri
, num_ri
* sizeof (region_info_t
)); }
else
{
rit
= (region_info_t
*) realloc (ri
, data_size
); if (!rit)
goto bail;
}
ri = rit;
rit = &ri[num_ri];
}
num_ri++;
rit->prev_band = 0;
rit->cur_band = 0;
rit->reg.extents = *box;
rit->reg.data = (region_data_type_t *)NULL;
/* MUST force allocation */
if (!pixman_rect_alloc (&rit->reg, (i + num_ri) / num_ri))
goto bail;
next_rect: ;
} /* for i */
/* Make a final pass over each region in order to COALESCE and set
* extents.x2 and extents.y2
*/
for (j = num_ri, rit = ri; --j >= 0; rit++)
{
reg = &rit->reg;
ri_box = PIXREGION_END (reg);
reg->extents.y2 = ri_box->y2;
if (reg->extents.x2 < ri_box->x2)
reg->extents.x2 = ri_box->x2;
COALESCE (reg, rit->prev_band, rit->cur_band);
if (reg->data->numRects == 1) /* keep unions happy below */
{
FREE_DATA (reg);
reg->data = (region_data_type_t *)NULL;
}
}
/* Step 3: Union all regions into a single region */
while (num_ri > 1)
{
int half = num_ri / 2;
for (j = num_ri & 1; j < (half + (num_ri & 1)); j++)
{
reg = &ri[j].reg;
hreg = &ri[j + half].reg;
if (!pixman_op (reg, reg, hreg, pixman_region_union_o, TRUE, TRUE))
ret = FALSE;
if (hreg->extents.x1 < reg->extents.x1)
reg->extents.x1 = hreg->extents.x1;
if (hreg->extents.y1 < reg->extents.y1)
reg->extents.y1 = hreg->extents.y1;
if (hreg->extents.x2 > reg->extents.x2)
reg->extents.x2 = hreg->extents.x2;
if (hreg->extents.y2 > reg->extents.y2)
reg->extents.y2 = hreg->extents.y2;
FREE_DATA (hreg);
}
num_ri -= half;
if (!ret)
goto bail;
}
*badreg = ri[0].reg;
if (ri != stack_regions)
GOOD (badreg);
return ret;
bail:
for (i = 0; i < num_ri; i++)
FREE_DATA (&ri[i].reg);
if (ri != stack_regions)
return pixman_break (badreg);
}
/*======================================================================
* Region Subtraction
*====================================================================*/
/*-
*-----------------------------------------------------------------------
* pixman_region_subtract_o --
* Overlapping band subtraction. x1 is the left-most point not yet
* checked.
*
* Results:
* TRUE if successful.
*
* Side Effects:
* region may have rectangles added to it.
*
*-----------------------------------------------------------------------
*/
/*ARGSUSED*/
static pixman_bool_t
pixman_region_subtract_o (region_type_t * region,
box_type_t * r1,
box_type_t * r1_end,
box_type_t * r2,
box_type_t * r2_end,
int y1,
int y2)
{
box_type_t * next_rect;
int x1;
x1 = r1->x1;
critical_if_fail (y1 < y2);
critical_if_fail (r1 != r1_end && r2 != r2_end);
next_rect = PIXREGION_TOP (region);
do
{
if (r2->x2 <= x1)
{
/*
* Subtrahend entirely to left of minuend: go to next subtrahend.
*/
r2++;
}
else if (r2->x1 <= x1)
{
/*
* Subtrahend precedes minuend: nuke left edge of minuend.
*/
x1 = r2->x2;
if (x1 >= r1->x2)
{
/*
* Minuend completely covered: advance to next minuend and
* reset left fence to edge of new minuend.
*/
r1++;
if (r1 != r1_end)
x1 = r1->x1;
}
else
{
/*
* Subtrahend now used up since it doesn't extend beyond
* minuend
*/
r2++;
}
}
else if (r2->x1 < r1->x2)
{
/*
* Left part of subtrahend covers part of minuend: add uncovered
* part of minuend to region and skip to next subtrahend.
*/
critical_if_fail (x1 < r2->x1);
NEWRECT (region, next_rect, x1, y1, r2->x1, y2);
x1 = r2->x2;
if (x1 >= r1->x2)
{
/*
* Minuend used up: advance to new...
*/
r1++;
if (r1 != r1_end)
x1 = r1->x1;
}
else
{
/*
* Subtrahend used up
*/
r2++;
}
}
else
{
/*
* Minuend used up: add any remaining piece before advancing.
*/
if (r1->x2 > x1)
NEWRECT (region, next_rect, x1, y1, r1->x2, y2);
r1++;
if (r1 != r1_end)
x1 = r1->x1;
}
}
while ((r1 != r1_end) && (r2 != r2_end));
/*
* Add remaining minuend rectangles to region.
*/
while (r1 != r1_end)
{
critical_if_fail (x1 < r1->x2);
NEWRECT (region, next_rect, x1, y1, r1->x2, y2);
r1++;
if (r1 != r1_end)
x1 = r1->x1;
}
return TRUE;
}
/*-
*-----------------------------------------------------------------------
* pixman_region_subtract --
* Subtract reg_s from reg_m and leave the result in reg_d.
* S stands for subtrahend, M for minuend and D for difference.
*
* Results:
* TRUE if successful.
*
* Side Effects:
* reg_d is overwritten.
*
*-----------------------------------------------------------------------
*/
PIXMAN_EXPORT pixman_bool_t
PREFIX (_subtract) (region_type_t *reg_d,
region_type_t *reg_m,
region_type_t *reg_s)
{
GOOD (reg_m);
GOOD (reg_s);
GOOD (reg_d);
/* check for trivial rejects */
if (PIXREGION_NIL (reg_m) || PIXREGION_NIL (reg_s) ||
!EXTENTCHECK (®_m->extents, ®_s->extents))
{
if (PIXREGION_NAR (reg_s))
return pixman_break (reg_d);
return PREFIX (_copy) (reg_d, reg_m);
}
else if (reg_m == reg_s)
{
FREE_DATA (reg_d);
reg_d->extents.x2 = reg_d->extents.x1;
reg_d->extents.y2 = reg_d->extents.y1;
reg_d->data = pixman_region_empty_data;
return TRUE;
}
/* Add those rectangles in region 1 that aren't in region 2,
do yucky subtraction for overlaps, and
just throw away rectangles in region 2 that aren't in region 1 */
if (!pixman_op (reg_d, reg_m, reg_s, pixman_region_subtract_o, TRUE, FALSE))
return FALSE;
/*
* Can't alter reg_d's extents before we call pixman_op because
* it might be one of the source regions and pixman_op depends
* on the extents of those regions being unaltered. Besides, this
* way there's no checking against rectangles that will be nuked
* due to coalescing, so we have to examine fewer rectangles.
*/
pixman_set_extents (reg_d);
GOOD (reg_d);
return TRUE;
}
/*======================================================================
* Region Inversion
*====================================================================*/
/*-
*-----------------------------------------------------------------------
* pixman_region_inverse --
* Take a region and a box and return a region that is everything
* in the box but not in the region. The careful reader will note
* that this is the same as subtracting the region from the box...
*
* Results:
* TRUE.
*
* Side Effects:
* new_reg is overwritten.
*
*-----------------------------------------------------------------------
*/
PIXMAN_EXPORT pixman_bool_t
PREFIX (_inverse) (region_type_t *new_reg, /* Destination region */
region_type_t *reg1, /* Region to invert */
box_type_t * inv_rect) /* Bounding box for inversion */
{
region_type_t inv_reg; /* Quick and dirty region made from the
* bounding box */
GOOD (reg1);
GOOD (new_reg);
/* check for trivial rejects */
if (PIXREGION_NIL (reg1) || !EXTENTCHECK (inv_rect, ®1->extents))
{
if (PIXREGION_NAR (reg1))
return pixman_break (new_reg);
new_reg->extents = *inv_rect;
FREE_DATA (new_reg);
new_reg->data = (region_data_type_t *)NULL;
return TRUE;
}
/* Add those rectangles in region 1 that aren't in region 2,
* do yucky subtraction for overlaps, and
* just throw away rectangles in region 2 that aren't in region 1
*/
inv_reg.extents = *inv_rect;
inv_reg.data = (region_data_type_t *)NULL;
if (!pixman_op (new_reg, &inv_reg, reg1, pixman_region_subtract_o, TRUE, FALSE))
return FALSE;
/*
* Can't alter new_reg's extents before we call pixman_op because
* it might be one of the source regions and pixman_op depends
* on the extents of those regions being unaltered. Besides, this
* way there's no checking against rectangles that will be nuked
* due to coalescing, so we have to examine fewer rectangles.
*/
pixman_set_extents (new_reg);
GOOD (new_reg);
return TRUE;
}
/* In time O(log n), locate the first box whose y2 is greater than y.
* Return @end if no such box exists.
*/
static box_type_t *
find_box_for_y (box_type_t *begin, box_type_t *end, int y)
{
box_type_t *mid;
if (end == begin)
return end;
if (end - begin == 1)
{
if (begin->y2 > y)
return begin;
else
return end;
}
mid = begin + (end - begin) / 2;
if (mid->y2 > y)
{
/* If no box is found in [begin, mid], the function
* will return @mid, which is then known to be the
* correct answer.
*/
return find_box_for_y (begin, mid, y);
}
else
{
return find_box_for_y (mid, end, y);
}
}
/*
* rect_in(region, rect)
* This routine takes a pointer to a region and a pointer to a box
* and determines if the box is outside/inside/partly inside the region.
*
* The idea is to travel through the list of rectangles trying to cover the
* passed box with them. Anytime a piece of the rectangle isn't covered
* by a band of rectangles, part_out is set TRUE. Any time a rectangle in
* the region covers part of the box, part_in is set TRUE. The process ends
* when either the box has been completely covered (we reached a band that
* doesn't overlap the box, part_in is TRUE and part_out is false), the
* box has been partially covered (part_in == part_out == TRUE -- because of
* the banding, the first time this is true we know the box is only
* partially in the region) or is outside the region (we reached a band
* that doesn't overlap the box at all and part_in is false)
*/
PIXMAN_EXPORT pixman_region_overlap_t
PREFIX (_contains_rectangle) (region_type_t * region,
box_type_t * prect)
{
box_type_t * pbox;
box_type_t * pbox_end;
int part_in, part_out;
int numRects;
int x, y;
GOOD (region);
numRects = PIXREGION_NUMRECTS (region);
/* useful optimization */
if (!numRects || !EXTENTCHECK (®ion->extents, prect))
return(PIXMAN_REGION_OUT);
if (numRects == 1)
{
/* We know that it must be PIXMAN_REGION_IN or PIXMAN_REGION_PART */
if (SUBSUMES (®ion->extents, prect))
return(PIXMAN_REGION_IN);
else
return(PIXMAN_REGION_PART);
}
part_out = FALSE;
part_in = FALSE;
/* (x,y) starts at upper left of rect, moving to the right and down */
x = prect->x1;
y = prect->y1;
/* can stop when both part_out and part_in are TRUE, or we reach prect->y2 */
for (pbox = PIXREGION_BOXPTR (region), pbox_end = pbox + numRects;
pbox != pbox_end;
pbox++)
{
/* getting up to speed or skipping remainder of band */
if (pbox->y2 <= y)
{
if ((pbox = find_box_for_y (pbox, pbox_end, y)) == pbox_end)
break;
}
if (pbox->y1 > y)
{
part_out = TRUE; /* missed part of rectangle above */
if (part_in || (pbox->y1 >= prect->y2))
break;
y = pbox->y1; /* x guaranteed to be == prect->x1 */
}
if (pbox->x2 <= x)
continue; /* not far enough over yet */
if (pbox->x1 > x)
{
part_out = TRUE; /* missed part of rectangle to left */
if (part_in)
break;
}
if (pbox->x1 < prect->x2)
{
part_in = TRUE; /* definitely overlap */
if (part_out)
break;
}
if (pbox->x2 >= prect->x2)
{
y = pbox->y2; /* finished with this band */
if (y >= prect->y2)
break;
x = prect->x1; /* reset x out to left again */
}
else
{
/*
* Because boxes in a band are maximal width, if the first box
* to overlap the rectangle doesn't completely cover it in that
* band, the rectangle must be partially out, since some of it
* will be uncovered in that band. part_in will have been set true
* by now...
*/
part_out = TRUE;
break;
}
}
if (part_in)
{
if (y < prect->y2)
return PIXMAN_REGION_PART;
else
return PIXMAN_REGION_IN;
}
else
{
return PIXMAN_REGION_OUT;
}
}
/* PREFIX(_translate) (region, x, y)
* translates in place
*/
PIXMAN_EXPORT void
PREFIX (_translate) (region_type_t *region, int x, int y)
{
overflow_int_t x1, x2, y1, y2;
int nbox;
box_type_t * pbox;
GOOD (region);
region->extents.x1 = x1 = region->extents.x1 + x;
region->extents.y1 = y1 = region->extents.y1 + y;
region->extents.x2 = x2 = region->extents.x2 + x;
region->extents.y2 = y2 = region->extents.y2 + y;
if (((x1 - PIXMAN_REGION_MIN) | (y1 - PIXMAN_REGION_MIN) | (PIXMAN_REGION_MAX - x2) | (PIXMAN_REGION_MAX - y2)) >= 0)
{
if (region->data && (nbox = region->data->numRects))
{
for (pbox = PIXREGION_BOXPTR (region); nbox--; pbox++)
{
pbox->x1 += x;
pbox->y1 += y;
pbox->x2 += x;
pbox->y2 += y;
}
}
return;
}
if (((x2 - PIXMAN_REGION_MIN) | (y2 - PIXMAN_REGION_MIN) | (PIXMAN_REGION_MAX - x1) | (PIXMAN_REGION_MAX - y1)) <= 0)
{
region->extents.x2 = region->extents.x1;
region->extents.y2 = region->extents.y1;
FREE_DATA (region);
region->data = pixman_region_empty_data;
return;
}
if (x1 < PIXMAN_REGION_MIN)
region->extents.x1 = PIXMAN_REGION_MIN;
else if (x2 > PIXMAN_REGION_MAX)
region->extents.x2 = PIXMAN_REGION_MAX;
if (y1 < PIXMAN_REGION_MIN)
region->extents.y1 = PIXMAN_REGION_MIN;
else if (y2 > PIXMAN_REGION_MAX)
region->extents.y2 = PIXMAN_REGION_MAX;
if (region->data && (nbox = region->data->numRects))
{
box_type_t * pbox_out;
for (pbox_out = pbox = PIXREGION_BOXPTR (region); nbox--; pbox++)
{
pbox_out->x1 = x1 = pbox->x1 + x;
pbox_out->y1 = y1 = pbox->y1 + y;
pbox_out->x2 = x2 = pbox->x2 + x;
pbox_out->y2 = y2 = pbox->y2 + y;
if (((x2 - PIXMAN_REGION_MIN) | (y2 - PIXMAN_REGION_MIN) |
(PIXMAN_REGION_MAX - x1) | (PIXMAN_REGION_MAX - y1)) <= 0)
{
region->data->numRects--;
continue;
}
if (x1 < PIXMAN_REGION_MIN)
pbox_out->x1 = PIXMAN_REGION_MIN;
else if (x2 > PIXMAN_REGION_MAX)
pbox_out->x2 = PIXMAN_REGION_MAX;
if (y1 < PIXMAN_REGION_MIN)
pbox_out->y1 = PIXMAN_REGION_MIN;
else if (y2 > PIXMAN_REGION_MAX)
pbox_out->y2 = PIXMAN_REGION_MAX;
pbox_out++;
}
if (pbox_out != pbox)
{
if (region->data->numRects == 1)
{
region->extents = *PIXREGION_BOXPTR (region);
FREE_DATA (region);
region->data = (region_data_type_t *)NULL;
}
else
{
pixman_set_extents (region);
}
}
}
GOOD (region);
}
PIXMAN_EXPORT void
PREFIX (_reset) (region_type_t *region, box_type_t *box)
{
GOOD (region);
critical_if_fail (GOOD_RECT (box));
region->extents = *box;
FREE_DATA (region);
region->data = NULL;
}
PIXMAN_EXPORT void
PREFIX (_clear) (region_type_t *region)
{
GOOD (region);
FREE_DATA (region);
region->extents = *pixman_region_empty_box;
region->data = pixman_region_empty_data;
}
/* box is "return" value */
PIXMAN_EXPORT int
PREFIX (_contains_point) (region_type_t * region,
int x, int y,
box_type_t * box)
{
box_type_t *pbox, *pbox_end;
int numRects;
GOOD (region);
numRects = PIXREGION_NUMRECTS (region);
if (!numRects || !INBOX (®ion->extents, x, y))
return(FALSE);
if (numRects == 1)
{
if (box)
*box = region->extents;
return(TRUE);
}
pbox = PIXREGION_BOXPTR (region);
pbox_end = pbox + numRects;
pbox = find_box_for_y (pbox, pbox_end, y);
for (;pbox != pbox_end; pbox++)
{
if ((y < pbox->y1) || (x < pbox->x1))
break; /* missed it */
if (x >= pbox->x2)
continue; /* not there yet */
if (box)
*box = *pbox;
return(TRUE);
}
return(FALSE);
}
PIXMAN_EXPORT int
PREFIX (_not_empty) (region_type_t * region)
{
GOOD (region);
return(!PIXREGION_NIL (region));
}
PIXMAN_EXPORT box_type_t *
PREFIX (_extents) (region_type_t * region)
{
GOOD (region);
return(®ion->extents);
}
/*
* Clip a list of scanlines to a region. The caller has allocated the
* space. FSorted is non-zero if the scanline origins are in ascending order.
*
* returns the number of new, clipped scanlines.
*/
PIXMAN_EXPORT pixman_bool_t
PREFIX (_selfcheck) (region_type_t *reg)
{
int i, numRects;
if ((reg->extents.x1 > reg->extents.x2) ||
(reg->extents.y1 > reg->extents.y2))
{
return FALSE;
}
numRects = PIXREGION_NUMRECTS (reg);
if (!numRects)
{
return ((reg->extents.x1 == reg->extents.x2) &&
(reg->extents.y1 == reg->extents.y2) &&
(reg->data->size || (reg->data == pixman_region_empty_data)));
}
else if (numRects == 1)
{
return (!reg->data);
}
else
{
box_type_t * pbox_p, * pbox_n;
box_type_t box;
pbox_p = PIXREGION_RECTS (reg);
box = *pbox_p;
box.y2 = pbox_p[numRects - 1].y2;
pbox_n = pbox_p + 1;
for (i = numRects; --i > 0; pbox_p++, pbox_n++)
{
if ((pbox_n->x1 >= pbox_n->x2) ||
(pbox_n->y1 >= pbox_n->y2))
{
return FALSE;
}
if (pbox_n->x1 < box.x1)
box.x1 = pbox_n->x1;
if (pbox_n->x2 > box.x2)
box.x2 = pbox_n->x2;
if ((pbox_n->y1 < pbox_p->y1) ||
((pbox_n->y1 == pbox_p->y1) &&
((pbox_n->x1 < pbox_p->x2) || (pbox_n->y2 != pbox_p->y2))))
{
return FALSE;
}
}
return ((box.x1 == reg->extents.x1) &&
(box.x2 == reg->extents.x2) &&
(box.y1 == reg->extents.y1) &&
(box.y2 == reg->extents.y2));
}
}
PIXMAN_EXPORT pixman_bool_t
PREFIX (_init_rects) (region_type_t *region,
const box_type_t *boxes, int count)
{
box_type_t *rects;
int displacement;
int i;
/* if it's 1, then we just want to set the extents, so call
* the existing method. */
if (count == 1)
{
PREFIX (_init_rect) (region,
boxes[0].x1,
boxes[0].y1,
boxes[0].x2 - boxes[0].x1,
boxes[0].y2 - boxes[0].y1);
return TRUE;
}
PREFIX (_init) (region);
/* if it's 0, don't call pixman_rect_alloc -- 0 rectangles is
* a special case, and causing pixman_rect_alloc would cause
* us to leak memory (because the 0-rect case should be the
* static pixman_region_empty_data data).
*/
if (count == 0)
return TRUE;
if (!pixman_rect_alloc (region, count))
return FALSE;
rects = PIXREGION_RECTS (region);
/* Copy in the rects */
memcpy (rects
, boxes
, sizeof(box_type_t
) * count
); region->data->numRects = count;
/* Eliminate empty and malformed rectangles */
displacement = 0;
for (i = 0; i < count; ++i)
{
box_type_t *box = &rects[i];
if (box->x1 >= box->x2 || box->y1 >= box->y2)
displacement++;
else if (displacement)
rects[i - displacement] = rects[i];
}
region->data->numRects -= displacement;
/* If eliminating empty rectangles caused there
* to be only 0 or 1 rectangles, deal with that.
*/
if (region->data->numRects == 0)
{
FREE_DATA (region);
PREFIX (_init) (region);
return TRUE;
}
if (region->data->numRects == 1)
{
region->extents = rects[0];
FREE_DATA (region);
region->data = NULL;
GOOD (region);
return TRUE;
}
/* Validate */
region->extents.x1 = region->extents.x2 = 0;
return validate (region);
}
#define READ(_ptr) (*(_ptr))
static inline box_type_t *
bitmap_addrect (region_type_t *reg,
box_type_t *r,
box_type_t **first_rect,
int rx1, int ry1,
int rx2, int ry2)
{
if ((rx1 < rx2) && (ry1 < ry2) &&
(!(reg->data->numRects &&
((r-1)->y1 == ry1) && ((r-1)->y2 == ry2) &&
((r-1)->x1 <= rx1) && ((r-1)->x2 >= rx2))))
{
if (reg->data->numRects == reg->data->size)
{
if (!pixman_rect_alloc (reg, 1))
return NULL;
*first_rect = PIXREGION_BOXPTR(reg);
r = *first_rect + reg->data->numRects;
}
r->x1 = rx1;
r->y1 = ry1;
r->x2 = rx2;
r->y2 = ry2;
reg->data->numRects++;
if (r->x1 < reg->extents.x1)
reg->extents.x1 = r->x1;
if (r->x2 > reg->extents.x2)
reg->extents.x2 = r->x2;
r++;
}
return r;
}
/* Convert bitmap clip mask into clipping region.
* First, goes through each line and makes boxes by noting the transitions
* from 0 to 1 and 1 to 0.
* Then it coalesces the current line with the previous if they have boxes
* at the same X coordinates.
* Stride is in number of uint32_t per line.
*/
PIXMAN_EXPORT void
PREFIX (_init_from_image) (region_type_t *region,
pixman_image_t *image)
{
uint32_t mask0 = 0xffffffff & ~SCREEN_SHIFT_RIGHT(0xffffffff, 1);
box_type_t *first_rect, *rects, *prect_line_start;
box_type_t *old_rect, *new_rect;
uint32_t *pw, w, *pw_line, *pw_line_end;
int irect_prev_start, irect_line_start;
int h, base, rx1 = 0, crects;
int ib;
pixman_bool_t in_box, same;
int width, height, stride;
PREFIX(_init) (region);
critical_if_fail (region->data);
return_if_fail (image->type == BITS);
return_if_fail (image->bits.format == PIXMAN_a1);
pw_line = pixman_image_get_data (image);
width = pixman_image_get_width (image);
height = pixman_image_get_height (image);
stride = pixman_image_get_stride (image) / 4;
first_rect = PIXREGION_BOXPTR(region);
rects = first_rect;
region->extents.x1 = width - 1;
region->extents.x2 = 0;
irect_prev_start = -1;
for (h = 0; h < height; h++)
{
pw = pw_line;
pw_line += stride;
irect_line_start = rects - first_rect;
/* If the Screen left most bit of the word is set, we're starting in
* a box */
if (READ(pw) & mask0)
{
in_box = TRUE;
rx1 = 0;
}
else
{
in_box = FALSE;
}
/* Process all words which are fully in the pixmap */
pw_line_end = pw + (width >> 5);
for (base = 0; pw < pw_line_end; base += 32)
{
w = READ(pw++);
if (in_box)
{
if (!~w)
continue;
}
else
{
if (!w)
continue;
}
for (ib = 0; ib < 32; ib++)
{
/* If the Screen left most bit of the word is set, we're
* starting a box */
if (w & mask0)
{
if (!in_box)
{
rx1 = base + ib;
/* start new box */
in_box = TRUE;
}
}
else
{
if (in_box)
{
/* end box */
rects = bitmap_addrect (region, rects, &first_rect,
rx1, h, base + ib, h + 1);
if (rects == NULL)
goto error;
in_box = FALSE;
}
}
/* Shift the word VISUALLY left one. */
w = SCREEN_SHIFT_LEFT(w, 1);
}
}
if (width & 31)
{
/* Process final partial word on line */
w = READ(pw++);
for (ib = 0; ib < (width & 31); ib++)
{
/* If the Screen left most bit of the word is set, we're
* starting a box */
if (w & mask0)
{
if (!in_box)
{
rx1 = base + ib;
/* start new box */
in_box = TRUE;
}
}
else
{
if (in_box)
{
/* end box */
rects = bitmap_addrect(region, rects, &first_rect,
rx1, h, base + ib, h + 1);
if (rects == NULL)
goto error;
in_box = FALSE;
}
}
/* Shift the word VISUALLY left one. */
w = SCREEN_SHIFT_LEFT(w, 1);
}
}
/* If scanline ended with last bit set, end the box */
if (in_box)
{
rects = bitmap_addrect(region, rects, &first_rect,
rx1, h, base + (width & 31), h + 1);
if (rects == NULL)
goto error;
}
/* if all rectangles on this line have the same x-coords as
* those on the previous line, then add 1 to all the previous y2s and
* throw away all the rectangles from this line
*/
same = FALSE;
if (irect_prev_start != -1)
{
crects = irect_line_start - irect_prev_start;
if (crects != 0 &&
crects == ((rects - first_rect) - irect_line_start))
{
old_rect = first_rect + irect_prev_start;
new_rect = prect_line_start = first_rect + irect_line_start;
same = TRUE;
while (old_rect < prect_line_start)
{
if ((old_rect->x1 != new_rect->x1) ||
(old_rect->x2 != new_rect->x2))
{
same = FALSE;
break;
}
old_rect++;
new_rect++;
}
if (same)
{
old_rect = first_rect + irect_prev_start;
while (old_rect < prect_line_start)
{
old_rect->y2 += 1;
old_rect++;
}
rects -= crects;
region->data->numRects -= crects;
}
}
}
if(!same)
irect_prev_start = irect_line_start;
}
if (!region->data->numRects)
{
region->extents.x1 = region->extents.x2 = 0;
}
else
{
region->extents.y1 = PIXREGION_BOXPTR(region)->y1;
region->extents.y2 = PIXREGION_END(region)->y2;
if (region->data->numRects == 1)
{
region->data = NULL;
}
}
error:
return;
}