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/* -*- Mode: c; tab-width: 8; c-basic-offset: 4; indent-tabs-mode: t; -*- */
/* cairo - a vector graphics library with display and print output
*
* Copyright © 2002 University of Southern California
* Copyright © 2005 Red Hat, Inc.
* Copyright © 2009 Chris Wilson
*
* 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
*
* 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>
* Kristian Høgsberg <krh@redhat.com>
* Chris Wilson <chris@chris-wilson.co.uk>
*/
#include "cairoint.h"
#include "cairo-box-inline.h"
#include "cairo-clip-inline.h"
#include "cairo-clip-private.h"
#include "cairo-error-private.h"
#include "cairo-freed-pool-private.h"
#include "cairo-gstate-private.h"
#include "cairo-path-fixed-private.h"
#include "cairo-pattern-private.h"
#include "cairo-composite-rectangles-private.h"
#include "cairo-region-private.h"
static inline int
pot (int v)
{
v--;
v |= v >> 1;
v |= v >> 2;
v |= v >> 4;
v |= v >> 8;
v |= v >> 16;
v++;
return v;
}
static cairo_bool_t
_cairo_clip_contains_rectangle_box (const cairo_clip_t *clip,
const cairo_rectangle_int_t *rect,
const cairo_box_t *box)
{
int i;
/* clip == NULL means no clip, so the clip contains everything */
if (clip == NULL)
return TRUE;
if (_cairo_clip_is_all_clipped (clip))
return FALSE;
/* If we have a non-trivial path, just say no */
if (clip->path)
return FALSE;
if (! _cairo_rectangle_contains_rectangle (&clip->extents, rect))
return FALSE;
if (clip->num_boxes == 0)
return TRUE;
/* Check for a clip-box that wholly contains the rectangle */
for (i = 0; i < clip->num_boxes; i++) {
if (box->p1.x >= clip->boxes[i].p1.x &&
box->p1.y >= clip->boxes[i].p1.y &&
box->p2.x <= clip->boxes[i].p2.x &&
box->p2.y <= clip->boxes[i].p2.y)
{
return TRUE;
}
}
return FALSE;
}
cairo_bool_t
_cairo_clip_contains_box (const cairo_clip_t *clip,
const cairo_box_t *box)
{
cairo_rectangle_int_t rect;
_cairo_box_round_to_rectangle (box, &rect);
return _cairo_clip_contains_rectangle_box(clip, &rect, box);
}
cairo_bool_t
_cairo_clip_contains_rectangle (const cairo_clip_t *clip,
const cairo_rectangle_int_t *rect)
{
cairo_box_t box;
_cairo_box_from_rectangle_int (&box, rect);
return _cairo_clip_contains_rectangle_box (clip, rect, &box);
}
cairo_clip_t *
_cairo_clip_intersect_rectilinear_path (cairo_clip_t *clip,
const cairo_path_fixed_t *path,
cairo_fill_rule_t fill_rule,
cairo_antialias_t antialias)
{
cairo_status_t status;
cairo_boxes_t boxes;
_cairo_boxes_init (&boxes);
status = _cairo_path_fixed_fill_rectilinear_to_boxes (path,
fill_rule,
antialias,
&boxes);
if (likely (status == CAIRO_STATUS_SUCCESS && boxes.num_boxes))
clip = _cairo_clip_intersect_boxes (clip, &boxes);
else
clip = _cairo_clip_set_all_clipped (clip);
_cairo_boxes_fini (&boxes);
return clip;
}
static cairo_clip_t *
_cairo_clip_intersect_rectangle_box (cairo_clip_t *clip,
const cairo_rectangle_int_t *r,
const cairo_box_t *box)
{
cairo_box_t extents_box;
cairo_bool_t changed = FALSE;
int i, j;
if (clip == NULL) {
clip = _cairo_clip_create ();
if (clip == NULL)
return _cairo_clip_set_all_clipped (clip);
}
if (clip->num_boxes == 0) {
clip->boxes = &clip->embedded_box;
clip->boxes[0] = *box;
clip->num_boxes = 1;
if (clip->path == NULL) {
clip->extents = *r;
} else {
if (! _cairo_rectangle_intersect (&clip->extents, r))
return _cairo_clip_set_all_clipped (clip);
}
if (clip->path == NULL)
clip->is_region = _cairo_box_is_pixel_aligned (box);
return clip;
}
/* Does the new box wholly subsume the clip? Perform a cheap check
* for the common condition of a single clip rectangle.
*/
if (clip->num_boxes == 1 &&
clip->boxes[0].p1.x >= box->p1.x &&
clip->boxes[0].p1.y >= box->p1.y &&
clip->boxes[0].p2.x <= box->p2.x &&
clip->boxes[0].p2.y <= box->p2.y)
{
return clip;
}
for (i = j = 0; i < clip->num_boxes; i++) {
cairo_box_t *b = &clip->boxes[j];
if (j != i)
*b = clip->boxes[i];
if (box->p1.x > b->p1.x)
b->p1.x = box->p1.x, changed = TRUE;
if (box->p2.x < b->p2.x)
b->p2.x = box->p2.x, changed = TRUE;
if (box->p1.y > b->p1.y)
b->p1.y = box->p1.y, changed = TRUE;
if (box->p2.y < b->p2.y)
b->p2.y = box->p2.y, changed = TRUE;
j += b->p2.x > b->p1.x && b->p2.y > b->p1.y;
}
clip->num_boxes = j;
if (clip->num_boxes == 0)
return _cairo_clip_set_all_clipped (clip);
if (! changed)
return clip;
extents_box = clip->boxes[0];
for (i = 1; i < clip->num_boxes; i++) {
if (clip->boxes[i].p1.x < extents_box.p1.x)
extents_box.p1.x = clip->boxes[i].p1.x;
if (clip->boxes[i].p1.y < extents_box.p1.y)
extents_box.p1.y = clip->boxes[i].p1.y;
if (clip->boxes[i].p2.x > extents_box.p2.x)
extents_box.p2.x = clip->boxes[i].p2.x;
if (clip->boxes[i].p2.y > extents_box.p2.y)
extents_box.p2.y = clip->boxes[i].p2.y;
}
if (clip->path == NULL) {
_cairo_box_round_to_rectangle (&extents_box, &clip->extents);
} else {
cairo_rectangle_int_t extents_rect;
_cairo_box_round_to_rectangle (&extents_box, &extents_rect);
if (! _cairo_rectangle_intersect (&clip->extents, &extents_rect))
return _cairo_clip_set_all_clipped (clip);
}
if (clip->region) {
cairo_region_destroy (clip->region);
clip->region = NULL;
}
clip->is_region = FALSE;
return clip;
}
cairo_clip_t *
_cairo_clip_intersect_box (cairo_clip_t *clip,
const cairo_box_t *box)
{
cairo_rectangle_int_t r;
if (_cairo_clip_is_all_clipped (clip))
return clip;
_cairo_box_round_to_rectangle (box, &r);
if (r.width == 0 || r.height == 0)
return _cairo_clip_set_all_clipped (clip);
return _cairo_clip_intersect_rectangle_box (clip, &r, box);
}
/* Copy a box set to a clip
*
* @param boxes The box set to copy from.
* @param clip The clip to copy to (return buffer).
* @returns Zero if the allocation failed (the clip will be set to
* all-clipped), otherwise non-zero.
*/
static cairo_bool_t
_cairo_boxes_copy_to_clip (const cairo_boxes_t *boxes, cairo_clip_t *clip)
{
/* XXX cow-boxes? */
if (boxes->num_boxes == 1) {
clip->boxes = &clip->embedded_box;
clip->boxes[0] = boxes->chunks.base[0];
clip->num_boxes = 1;
return TRUE;
}
clip->boxes = _cairo_boxes_to_array (boxes, &clip->num_boxes);
if (unlikely (clip->boxes == NULL))
{
_cairo_clip_set_all_clipped (clip);
return FALSE;
}
return TRUE;
}
cairo_clip_t *
_cairo_clip_intersect_boxes (cairo_clip_t *clip,
const cairo_boxes_t *boxes)
{
cairo_boxes_t clip_boxes;
cairo_box_t limits;
cairo_rectangle_int_t extents;
if (_cairo_clip_is_all_clipped (clip))
return clip;
if (boxes->num_boxes == 0)
return _cairo_clip_set_all_clipped (clip);
if (boxes->num_boxes == 1)
return _cairo_clip_intersect_box (clip, boxes->chunks.base);
if (clip == NULL)
clip = _cairo_clip_create ();
if (clip->num_boxes) {
_cairo_boxes_init_for_array (&clip_boxes, clip->boxes, clip->num_boxes);
if (unlikely (_cairo_boxes_intersect (&clip_boxes, boxes, &clip_boxes))) {
clip = _cairo_clip_set_all_clipped (clip);
goto out;
}
if (clip->boxes != &clip->embedded_box)
free (clip->boxes);
clip->boxes = NULL;
boxes = &clip_boxes;
}
if (boxes->num_boxes == 0) {
clip = _cairo_clip_set_all_clipped (clip);
goto out;
}
_cairo_boxes_copy_to_clip (boxes, clip);
_cairo_boxes_extents (boxes, &limits);
_cairo_box_round_to_rectangle (&limits, &extents);
if (clip->path == NULL) {
clip->extents = extents;
} else if (! _cairo_rectangle_intersect (&clip->extents, &extents)) {
clip = _cairo_clip_set_all_clipped (clip);
goto out;
}
if (clip->region) {
cairo_region_destroy (clip->region);
clip->region = NULL;
}
clip->is_region = FALSE;
out:
if (boxes == &clip_boxes)
_cairo_boxes_fini (&clip_boxes);
return clip;
}
cairo_clip_t *
_cairo_clip_intersect_rectangle (cairo_clip_t *clip,
const cairo_rectangle_int_t *r)
{
cairo_box_t box;
if (_cairo_clip_is_all_clipped (clip))
return clip;
if (r->width == 0 || r->height == 0)
return _cairo_clip_set_all_clipped (clip);
_cairo_box_from_rectangle_int (&box, r);
return _cairo_clip_intersect_rectangle_box (clip, r, &box);
}
struct reduce {
cairo_clip_t *clip;
cairo_box_t limit;
cairo_box_t extents;
cairo_bool_t inside;
cairo_point_t current_point;
cairo_point_t last_move_to;
};
static void
_add_clipped_edge (struct reduce *r,
const cairo_point_t *p1,
const cairo_point_t *p2,
int y1, int y2)
{
cairo_fixed_t x;
x = _cairo_edge_compute_intersection_x_for_y (p1, p2, y1);
if (x < r->extents.p1.x)
r->extents.p1.x = x;
x = _cairo_edge_compute_intersection_x_for_y (p1, p2, y2);
if (x > r->extents.p2.x)
r->extents.p2.x = x;
if (y1 < r->extents.p1.y)
r->extents.p1.y = y1;
if (y2 > r->extents.p2.y)
r->extents.p2.y = y2;
r->inside = TRUE;
}
static void
_add_edge (struct reduce *r,
const cairo_point_t *p1,
const cairo_point_t *p2)
{
int top, bottom;
int top_y, bot_y;
int n;
if (p1->y < p2->y) {
top = p1->y;
bottom = p2->y;
} else {
top = p2->y;
bottom = p1->y;
}
if (bottom < r->limit.p1.y || top > r->limit.p2.y)
return;
if (p1->x > p2->x) {
const cairo_point_t *t = p1;
p1 = p2;
p2 = t;
}
if (p2->x <= r->limit.p1.x || p1->x >= r->limit.p2.x)
return;
for (n = 0; n < r->clip->num_boxes; n++) {
const cairo_box_t *limits = &r->clip->boxes[n];
if (bottom < limits->p1.y || top > limits->p2.y)
continue;
if (p2->x <= limits->p1.x || p1->x >= limits->p2.x)
continue;
if (p1->x >= limits->p1.x && p2->x <= limits->p1.x) {
top_y = top;
bot_y = bottom;
} else {
int p1_y, p2_y;
p1_y = _cairo_edge_compute_intersection_y_for_x (p1, p2,
limits->p1.x);
p2_y = _cairo_edge_compute_intersection_y_for_x (p1, p2,
limits->p2.x);
if (p1_y < p2_y) {
top_y = p1_y;
bot_y = p2_y;
} else {
top_y = p2_y;
bot_y = p1_y;
}
if (top_y < top)
top_y = top;
if (bot_y > bottom)
bot_y = bottom;
}
if (top_y < limits->p1.y)
top_y = limits->p1.y;
if (bot_y > limits->p2.y)
bot_y = limits->p2.y;
if (bot_y > top_y)
_add_clipped_edge (r, p1, p2, top_y, bot_y);
}
}
static cairo_status_t
_reduce_line_to (void *closure,
const cairo_point_t *point)
{
struct reduce *r = closure;
_add_edge (r, &r->current_point, point);
r->current_point = *point;
return CAIRO_STATUS_SUCCESS;
}
static cairo_status_t
_reduce_close (void *closure)
{
struct reduce *r = closure;
return _reduce_line_to (r, &r->last_move_to);
}
static cairo_status_t
_reduce_move_to (void *closure,
const cairo_point_t *point)
{
struct reduce *r = closure;
cairo_status_t status;
/* close current subpath */
status = _reduce_close (closure);
/* make sure that the closure represents a degenerate path */
r->current_point = *point;
r->last_move_to = *point;
return status;
}
static cairo_clip_t *
_cairo_clip_reduce_to_boxes (cairo_clip_t *clip)
{
struct reduce r;
cairo_clip_path_t *clip_path;
cairo_status_t status;
return clip;
if (clip->path == NULL)
return clip;
r.clip = clip;
r.extents.p1.x = r.extents.p1.y = INT_MAX;
r.extents.p2.x = r.extents.p2.y = INT_MIN;
r.inside = FALSE;
r.limit.p1.x = _cairo_fixed_from_int (clip->extents.x);
r.limit.p1.y = _cairo_fixed_from_int (clip->extents.y);
r.limit.p2.x = _cairo_fixed_from_int (clip->extents.x + clip->extents.width);
r.limit.p2.y = _cairo_fixed_from_int (clip->extents.y + clip->extents.height);
clip_path = clip->path;
do {
r.current_point.x = 0;
r.current_point.y = 0;
r.last_move_to = r.current_point;
status = _cairo_path_fixed_interpret_flat (&clip_path->path,
_reduce_move_to,
_reduce_line_to,
_reduce_close,
&r,
clip_path->tolerance);
assert (status == CAIRO_STATUS_SUCCESS);
_reduce_close (&r);
} while ((clip_path = clip_path->prev));
if (! r.inside) {
_cairo_clip_path_destroy (clip->path);
clip->path = NULL;
}
return _cairo_clip_intersect_box (clip, &r.extents);
}
cairo_clip_t *
_cairo_clip_reduce_to_rectangle (const cairo_clip_t *clip,
const cairo_rectangle_int_t *r)
{
cairo_clip_t *copy;
if (_cairo_clip_is_all_clipped (clip))
return (cairo_clip_t *) clip;
if (_cairo_clip_contains_rectangle (clip, r))
return _cairo_clip_intersect_rectangle (NULL, r);
copy = _cairo_clip_copy_intersect_rectangle (clip, r);
if (_cairo_clip_is_all_clipped (copy))
return copy;
return _cairo_clip_reduce_to_boxes (copy);
}
cairo_clip_t *
_cairo_clip_reduce_for_composite (const cairo_clip_t *clip,
cairo_composite_rectangles_t *extents)
{
const cairo_rectangle_int_t *r;
r = extents->is_bounded ? &extents->bounded : &extents->unbounded;
return _cairo_clip_reduce_to_rectangle (clip, r);
}
cairo_clip_t *
_cairo_clip_from_boxes (const cairo_boxes_t *boxes)
{
cairo_box_t extents;
cairo_clip_t *clip = _cairo_clip_create ();
if (clip == NULL)
return _cairo_clip_set_all_clipped (clip);
if (unlikely (! _cairo_boxes_copy_to_clip (boxes, clip)))
return clip;
_cairo_boxes_extents (boxes, &extents);
_cairo_box_round_to_rectangle (&extents, &clip->extents);
return clip;
}