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kolibrios-fun/contrib/sdk/sources/cairo/src/cairo-path-fixed.c
Sergey Semyonov (Serge) 754f9336f0 upload sdk 
git-svn-id: svn://kolibrios.org@4349 a494cfbc-eb01-0410-851d-a64ba20cac60
2013-12-15 08:09:20 +00:00

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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.
*
* 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-box-inline.h"
#include "cairo-error-private.h"
#include "cairo-list-inline.h"
#include "cairo-path-fixed-private.h"
#include "cairo-slope-private.h"
static cairo_status_t
_cairo_path_fixed_add (cairo_path_fixed_t *path,
cairo_path_op_t op,
const cairo_point_t *points,
int num_points);
static void
_cairo_path_fixed_add_buf (cairo_path_fixed_t *path,
cairo_path_buf_t *buf);
static cairo_path_buf_t *
_cairo_path_buf_create (int size_ops, int size_points);
static void
_cairo_path_buf_destroy (cairo_path_buf_t *buf);
static void
_cairo_path_buf_add_op (cairo_path_buf_t *buf,
cairo_path_op_t op);
static void
_cairo_path_buf_add_points (cairo_path_buf_t *buf,
const cairo_point_t *points,
int num_points);
void
_cairo_path_fixed_init (cairo_path_fixed_t *path)
{
VG (VALGRIND_MAKE_MEM_UNDEFINED (path, sizeof (cairo_path_fixed_t)));
cairo_list_init (&path->buf.base.link);
path->buf.base.num_ops = 0;
path->buf.base.num_points = 0;
path->buf.base.size_ops = ARRAY_LENGTH (path->buf.op);
path->buf.base.size_points = ARRAY_LENGTH (path->buf.points);
path->buf.base.op = path->buf.op;
path->buf.base.points = path->buf.points;
path->current_point.x = 0;
path->current_point.y = 0;
path->last_move_point = path->current_point;
path->has_current_point = FALSE;
path->needs_move_to = TRUE;
path->has_extents = FALSE;
path->has_curve_to = FALSE;
path->stroke_is_rectilinear = TRUE;
path->fill_is_rectilinear = TRUE;
path->fill_maybe_region = TRUE;
path->fill_is_empty = TRUE;
path->extents.p1.x = path->extents.p1.y = 0;
path->extents.p2.x = path->extents.p2.y = 0;
}
cairo_status_t
_cairo_path_fixed_init_copy (cairo_path_fixed_t *path,
const cairo_path_fixed_t *other)
{
cairo_path_buf_t *buf, *other_buf;
unsigned int num_points, num_ops;
VG (VALGRIND_MAKE_MEM_UNDEFINED (path, sizeof (cairo_path_fixed_t)));
cairo_list_init (&path->buf.base.link);
path->buf.base.op = path->buf.op;
path->buf.base.points = path->buf.points;
path->buf.base.size_ops = ARRAY_LENGTH (path->buf.op);
path->buf.base.size_points = ARRAY_LENGTH (path->buf.points);
path->current_point = other->current_point;
path->last_move_point = other->last_move_point;
path->has_current_point = other->has_current_point;
path->needs_move_to = other->needs_move_to;
path->has_extents = other->has_extents;
path->has_curve_to = other->has_curve_to;
path->stroke_is_rectilinear = other->stroke_is_rectilinear;
path->fill_is_rectilinear = other->fill_is_rectilinear;
path->fill_maybe_region = other->fill_maybe_region;
path->fill_is_empty = other->fill_is_empty;
path->extents = other->extents;
path->buf.base.num_ops = other->buf.base.num_ops;
path->buf.base.num_points = other->buf.base.num_points;
memcpy (path->buf.op, other->buf.base.op,
other->buf.base.num_ops * sizeof (other->buf.op[0]));
memcpy (path->buf.points, other->buf.points,
other->buf.base.num_points * sizeof (other->buf.points[0]));
num_points = num_ops = 0;
for (other_buf = cairo_path_buf_next (cairo_path_head (other));
other_buf != cairo_path_head (other);
other_buf = cairo_path_buf_next (other_buf))
{
num_ops += other_buf->num_ops;
num_points += other_buf->num_points;
}
if (num_ops) {
buf = _cairo_path_buf_create (num_ops, num_points);
if (unlikely (buf == NULL)) {
_cairo_path_fixed_fini (path);
return _cairo_error (CAIRO_STATUS_NO_MEMORY);
}
for (other_buf = cairo_path_buf_next (cairo_path_head (other));
other_buf != cairo_path_head (other);
other_buf = cairo_path_buf_next (other_buf))
{
memcpy (buf->op + buf->num_ops, other_buf->op,
other_buf->num_ops * sizeof (buf->op[0]));
buf->num_ops += other_buf->num_ops;
memcpy (buf->points + buf->num_points, other_buf->points,
other_buf->num_points * sizeof (buf->points[0]));
buf->num_points += other_buf->num_points;
}
_cairo_path_fixed_add_buf (path, buf);
}
return CAIRO_STATUS_SUCCESS;
}
unsigned long
_cairo_path_fixed_hash (const cairo_path_fixed_t *path)
{
unsigned long hash = _CAIRO_HASH_INIT_VALUE;
const cairo_path_buf_t *buf;
unsigned int count;
count = 0;
cairo_path_foreach_buf_start (buf, path) {
hash = _cairo_hash_bytes (hash, buf->op,
buf->num_ops * sizeof (buf->op[0]));
count += buf->num_ops;
} cairo_path_foreach_buf_end (buf, path);
hash = _cairo_hash_bytes (hash, &count, sizeof (count));
count = 0;
cairo_path_foreach_buf_start (buf, path) {
hash = _cairo_hash_bytes (hash, buf->points,
buf->num_points * sizeof (buf->points[0]));
count += buf->num_points;
} cairo_path_foreach_buf_end (buf, path);
hash = _cairo_hash_bytes (hash, &count, sizeof (count));
return hash;
}
unsigned long
_cairo_path_fixed_size (const cairo_path_fixed_t *path)
{
const cairo_path_buf_t *buf;
int num_points, num_ops;
num_ops = num_points = 0;
cairo_path_foreach_buf_start (buf, path) {
num_ops += buf->num_ops;
num_points += buf->num_points;
} cairo_path_foreach_buf_end (buf, path);
return num_ops * sizeof (buf->op[0]) +
num_points * sizeof (buf->points[0]);
}
cairo_bool_t
_cairo_path_fixed_equal (const cairo_path_fixed_t *a,
const cairo_path_fixed_t *b)
{
const cairo_path_buf_t *buf_a, *buf_b;
const cairo_path_op_t *ops_a, *ops_b;
const cairo_point_t *points_a, *points_b;
int num_points_a, num_ops_a;
int num_points_b, num_ops_b;
if (a == b)
return TRUE;
/* use the flags to quickly differentiate based on contents */
if (a->has_curve_to != b->has_curve_to)
{
return FALSE;
}
if (a->extents.p1.x != b->extents.p1.x ||
a->extents.p1.y != b->extents.p1.y ||
a->extents.p2.x != b->extents.p2.x ||
a->extents.p2.y != b->extents.p2.y)
{
return FALSE;
}
num_ops_a = num_points_a = 0;
cairo_path_foreach_buf_start (buf_a, a) {
num_ops_a += buf_a->num_ops;
num_points_a += buf_a->num_points;
} cairo_path_foreach_buf_end (buf_a, a);
num_ops_b = num_points_b = 0;
cairo_path_foreach_buf_start (buf_b, b) {
num_ops_b += buf_b->num_ops;
num_points_b += buf_b->num_points;
} cairo_path_foreach_buf_end (buf_b, b);
if (num_ops_a == 0 && num_ops_b == 0)
return TRUE;
if (num_ops_a != num_ops_b || num_points_a != num_points_b)
return FALSE;
buf_a = cairo_path_head (a);
num_points_a = buf_a->num_points;
num_ops_a = buf_a->num_ops;
ops_a = buf_a->op;
points_a = buf_a->points;
buf_b = cairo_path_head (b);
num_points_b = buf_b->num_points;
num_ops_b = buf_b->num_ops;
ops_b = buf_b->op;
points_b = buf_b->points;
while (TRUE) {
int num_ops = MIN (num_ops_a, num_ops_b);
int num_points = MIN (num_points_a, num_points_b);
if (memcmp (ops_a, ops_b, num_ops * sizeof (cairo_path_op_t)))
return FALSE;
if (memcmp (points_a, points_b, num_points * sizeof (cairo_point_t)))
return FALSE;
num_ops_a -= num_ops;
ops_a += num_ops;
num_points_a -= num_points;
points_a += num_points;
if (num_ops_a == 0 || num_points_a == 0) {
if (num_ops_a || num_points_a)
return FALSE;
buf_a = cairo_path_buf_next (buf_a);
if (buf_a == cairo_path_head (a))
break;
num_points_a = buf_a->num_points;
num_ops_a = buf_a->num_ops;
ops_a = buf_a->op;
points_a = buf_a->points;
}
num_ops_b -= num_ops;
ops_b += num_ops;
num_points_b -= num_points;
points_b += num_points;
if (num_ops_b == 0 || num_points_b == 0) {
if (num_ops_b || num_points_b)
return FALSE;
buf_b = cairo_path_buf_next (buf_b);
if (buf_b == cairo_path_head (b))
break;
num_points_b = buf_b->num_points;
num_ops_b = buf_b->num_ops;
ops_b = buf_b->op;
points_b = buf_b->points;
}
}
return TRUE;
}
cairo_path_fixed_t *
_cairo_path_fixed_create (void)
{
cairo_path_fixed_t *path;
path = malloc (sizeof (cairo_path_fixed_t));
if (!path) {
_cairo_error_throw (CAIRO_STATUS_NO_MEMORY);
return NULL;
}
_cairo_path_fixed_init (path);
return path;
}
void
_cairo_path_fixed_fini (cairo_path_fixed_t *path)
{
cairo_path_buf_t *buf;
buf = cairo_path_buf_next (cairo_path_head (path));
while (buf != cairo_path_head (path)) {
cairo_path_buf_t *this = buf;
buf = cairo_path_buf_next (buf);
_cairo_path_buf_destroy (this);
}
VG (VALGRIND_MAKE_MEM_NOACCESS (path, sizeof (cairo_path_fixed_t)));
}
void
_cairo_path_fixed_destroy (cairo_path_fixed_t *path)
{
_cairo_path_fixed_fini (path);
free (path);
}
static cairo_path_op_t
_cairo_path_fixed_last_op (cairo_path_fixed_t *path)
{
cairo_path_buf_t *buf;
buf = cairo_path_tail (path);
assert (buf->num_ops != 0);
return buf->op[buf->num_ops - 1];
}
static inline const cairo_point_t *
_cairo_path_fixed_penultimate_point (cairo_path_fixed_t *path)
{
cairo_path_buf_t *buf;
buf = cairo_path_tail (path);
if (likely (buf->num_points >= 2)) {
return &buf->points[buf->num_points - 2];
} else {
cairo_path_buf_t *prev_buf = cairo_path_buf_prev (buf);
assert (prev_buf->num_points >= 2 - buf->num_points);
return &prev_buf->points[prev_buf->num_points - (2 - buf->num_points)];
}
}
static void
_cairo_path_fixed_drop_line_to (cairo_path_fixed_t *path)
{
cairo_path_buf_t *buf;
assert (_cairo_path_fixed_last_op (path) == CAIRO_PATH_OP_LINE_TO);
buf = cairo_path_tail (path);
buf->num_points--;
buf->num_ops--;
}
cairo_status_t
_cairo_path_fixed_move_to (cairo_path_fixed_t *path,
cairo_fixed_t x,
cairo_fixed_t y)
{
_cairo_path_fixed_new_sub_path (path);
path->has_current_point = TRUE;
path->current_point.x = x;
path->current_point.y = y;
path->last_move_point = path->current_point;
return CAIRO_STATUS_SUCCESS;
}
static cairo_status_t
_cairo_path_fixed_move_to_apply (cairo_path_fixed_t *path)
{
if (likely (! path->needs_move_to))
return CAIRO_STATUS_SUCCESS;
path->needs_move_to = FALSE;
if (path->has_extents) {
_cairo_box_add_point (&path->extents, &path->current_point);
} else {
_cairo_box_set (&path->extents, &path->current_point, &path->current_point);
path->has_extents = TRUE;
}
if (path->fill_maybe_region) {
path->fill_maybe_region = _cairo_fixed_is_integer (path->current_point.x) &&
_cairo_fixed_is_integer (path->current_point.y);
}
path->last_move_point = path->current_point;
return _cairo_path_fixed_add (path, CAIRO_PATH_OP_MOVE_TO, &path->current_point, 1);
}
void
_cairo_path_fixed_new_sub_path (cairo_path_fixed_t *path)
{
if (! path->needs_move_to) {
/* If the current subpath doesn't need_move_to, it contains at least one command */
if (path->fill_is_rectilinear) {
/* Implicitly close for fill */
path->fill_is_rectilinear = path->current_point.x == path->last_move_point.x ||
path->current_point.y == path->last_move_point.y;
path->fill_maybe_region &= path->fill_is_rectilinear;
}
path->needs_move_to = TRUE;
}
path->has_current_point = FALSE;
}
cairo_status_t
_cairo_path_fixed_rel_move_to (cairo_path_fixed_t *path,
cairo_fixed_t dx,
cairo_fixed_t dy)
{
if (unlikely (! path->has_current_point))
return _cairo_error (CAIRO_STATUS_NO_CURRENT_POINT);
return _cairo_path_fixed_move_to (path,
path->current_point.x + dx,
path->current_point.y + dy);
}
cairo_status_t
_cairo_path_fixed_line_to (cairo_path_fixed_t *path,
cairo_fixed_t x,
cairo_fixed_t y)
{
cairo_status_t status;
cairo_point_t point;
point.x = x;
point.y = y;
/* When there is not yet a current point, the line_to operation
* becomes a move_to instead. Note: We have to do this by
* explicitly calling into _cairo_path_fixed_move_to to ensure
* that the last_move_point state is updated properly.
*/
if (! path->has_current_point)
return _cairo_path_fixed_move_to (path, point.x, point.y);
status = _cairo_path_fixed_move_to_apply (path);
if (unlikely (status))
return status;
/* If the previous op was but the initial MOVE_TO and this segment
* is degenerate, then we can simply skip this point. Note that
* a move-to followed by a degenerate line-to is a valid path for
* stroking, but at all other times is simply a degenerate segment.
*/
if (_cairo_path_fixed_last_op (path) != CAIRO_PATH_OP_MOVE_TO) {
if (x == path->current_point.x && y == path->current_point.y)
return CAIRO_STATUS_SUCCESS;
}
/* If the previous op was also a LINE_TO with the same gradient,
* then just change its end-point rather than adding a new op.
*/
if (_cairo_path_fixed_last_op (path) == CAIRO_PATH_OP_LINE_TO) {
const cairo_point_t *p;
p = _cairo_path_fixed_penultimate_point (path);
if (p->x == path->current_point.x && p->y == path->current_point.y) {
/* previous line element was degenerate, replace */
_cairo_path_fixed_drop_line_to (path);
} else {
cairo_slope_t prev, self;
_cairo_slope_init (&prev, p, &path->current_point);
_cairo_slope_init (&self, &path->current_point, &point);
if (_cairo_slope_equal (&prev, &self) &&
/* cannot trim anti-parallel segments whilst stroking */
! _cairo_slope_backwards (&prev, &self))
{
_cairo_path_fixed_drop_line_to (path);
/* In this case the flags might be more restrictive than
* what we actually need.
* When changing the flags definition we should check if
* changing the line_to point can affect them.
*/
}
}
}
if (path->stroke_is_rectilinear) {
path->stroke_is_rectilinear = path->current_point.x == x ||
path->current_point.y == y;
path->fill_is_rectilinear &= path->stroke_is_rectilinear;
path->fill_maybe_region &= path->fill_is_rectilinear;
if (path->fill_maybe_region) {
path->fill_maybe_region = _cairo_fixed_is_integer (x) &&
_cairo_fixed_is_integer (y);
}
if (path->fill_is_empty) {
path->fill_is_empty = path->current_point.x == x &&
path->current_point.y == y;
}
}
path->current_point = point;
_cairo_box_add_point (&path->extents, &point);
return _cairo_path_fixed_add (path, CAIRO_PATH_OP_LINE_TO, &point, 1);
}
cairo_status_t
_cairo_path_fixed_rel_line_to (cairo_path_fixed_t *path,
cairo_fixed_t dx,
cairo_fixed_t dy)
{
if (unlikely (! path->has_current_point))
return _cairo_error (CAIRO_STATUS_NO_CURRENT_POINT);
return _cairo_path_fixed_line_to (path,
path->current_point.x + dx,
path->current_point.y + dy);
}
cairo_status_t
_cairo_path_fixed_curve_to (cairo_path_fixed_t *path,
cairo_fixed_t x0, cairo_fixed_t y0,
cairo_fixed_t x1, cairo_fixed_t y1,
cairo_fixed_t x2, cairo_fixed_t y2)
{
cairo_status_t status;
cairo_point_t point[3];
/* If this curves does not move, replace it with a line-to.
* This frequently happens with rounded-rectangles and r==0.
*/
if (path->current_point.x == x2 && path->current_point.y == y2) {
if (x1 == x2 && x0 == x2 && y1 == y2 && y0 == y2)
return _cairo_path_fixed_line_to (path, x2, y2);
/* We may want to check for the absence of a cusp, in which case
* we can also replace the curve-to with a line-to.
*/
}
/* make sure subpaths are started properly */
if (! path->has_current_point) {
status = _cairo_path_fixed_move_to (path, x0, y0);
assert (status == CAIRO_STATUS_SUCCESS);
}
status = _cairo_path_fixed_move_to_apply (path);
if (unlikely (status))
return status;
/* If the previous op was a degenerate LINE_TO, drop it. */
if (_cairo_path_fixed_last_op (path) == CAIRO_PATH_OP_LINE_TO) {
const cairo_point_t *p;
p = _cairo_path_fixed_penultimate_point (path);
if (p->x == path->current_point.x && p->y == path->current_point.y) {
/* previous line element was degenerate, replace */
_cairo_path_fixed_drop_line_to (path);
}
}
point[0].x = x0; point[0].y = y0;
point[1].x = x1; point[1].y = y1;
point[2].x = x2; point[2].y = y2;
_cairo_box_add_curve_to (&path->extents, &path->current_point,
&point[0], &point[1], &point[2]);
path->current_point = point[2];
path->has_curve_to = TRUE;
path->stroke_is_rectilinear = FALSE;
path->fill_is_rectilinear = FALSE;
path->fill_maybe_region = FALSE;
path->fill_is_empty = FALSE;
return _cairo_path_fixed_add (path, CAIRO_PATH_OP_CURVE_TO, point, 3);
}
cairo_status_t
_cairo_path_fixed_rel_curve_to (cairo_path_fixed_t *path,
cairo_fixed_t dx0, cairo_fixed_t dy0,
cairo_fixed_t dx1, cairo_fixed_t dy1,
cairo_fixed_t dx2, cairo_fixed_t dy2)
{
if (unlikely (! path->has_current_point))
return _cairo_error (CAIRO_STATUS_NO_CURRENT_POINT);
return _cairo_path_fixed_curve_to (path,
path->current_point.x + dx0,
path->current_point.y + dy0,
path->current_point.x + dx1,
path->current_point.y + dy1,
path->current_point.x + dx2,
path->current_point.y + dy2);
}
cairo_status_t
_cairo_path_fixed_close_path (cairo_path_fixed_t *path)
{
cairo_status_t status;
if (! path->has_current_point)
return CAIRO_STATUS_SUCCESS;
/*
* Add a line_to, to compute flags and solve any degeneracy.
* It will be removed later (if it was actually added).
*/
status = _cairo_path_fixed_line_to (path,
path->last_move_point.x,
path->last_move_point.y);
if (unlikely (status))
return status;
/*
* If the command used to close the path is a line_to, drop it.
* We must check that last command is actually a line_to,
* because the path could have been closed with a curve_to (and
* the previous line_to not added as it would be degenerate).
*/
if (_cairo_path_fixed_last_op (path) == CAIRO_PATH_OP_LINE_TO)
_cairo_path_fixed_drop_line_to (path);
path->needs_move_to = TRUE; /* After close_path, add an implicit move_to */
return _cairo_path_fixed_add (path, CAIRO_PATH_OP_CLOSE_PATH, NULL, 0);
}
cairo_bool_t
_cairo_path_fixed_get_current_point (cairo_path_fixed_t *path,
cairo_fixed_t *x,
cairo_fixed_t *y)
{
if (! path->has_current_point)
return FALSE;
*x = path->current_point.x;
*y = path->current_point.y;
return TRUE;
}
static cairo_status_t
_cairo_path_fixed_add (cairo_path_fixed_t *path,
cairo_path_op_t op,
const cairo_point_t *points,
int num_points)
{
cairo_path_buf_t *buf = cairo_path_tail (path);
if (buf->num_ops + 1 > buf->size_ops ||
buf->num_points + num_points > buf->size_points)
{
buf = _cairo_path_buf_create (buf->num_ops * 2, buf->num_points * 2);
if (unlikely (buf == NULL))
return _cairo_error (CAIRO_STATUS_NO_MEMORY);
_cairo_path_fixed_add_buf (path, buf);
}
if (WATCH_PATH) {
const char *op_str[] = {
"move-to",
"line-to",
"curve-to",
"close-path",
};
char buf[1024];
int len = 0;
int i;
len += snprintf (buf + len, sizeof (buf), "[");
for (i = 0; i < num_points; i++) {
if (i != 0)
len += snprintf (buf + len, sizeof (buf), " ");
len += snprintf (buf + len, sizeof (buf), "(%f, %f)",
_cairo_fixed_to_double (points[i].x),
_cairo_fixed_to_double (points[i].y));
}
len += snprintf (buf + len, sizeof (buf), "]");
#define STRINGIFYFLAG(x) (path->x ? #x " " : "")
fprintf (stderr,
"_cairo_path_fixed_add (%s, %s) [%s%s%s%s%s%s%s%s]\n",
op_str[(int) op], buf,
STRINGIFYFLAG(has_current_point),
STRINGIFYFLAG(needs_move_to),
STRINGIFYFLAG(has_extents),
STRINGIFYFLAG(has_curve_to),
STRINGIFYFLAG(stroke_is_rectilinear),
STRINGIFYFLAG(fill_is_rectilinear),
STRINGIFYFLAG(fill_is_empty),
STRINGIFYFLAG(fill_maybe_region)
);
#undef STRINGIFYFLAG
}
_cairo_path_buf_add_op (buf, op);
_cairo_path_buf_add_points (buf, points, num_points);
return CAIRO_STATUS_SUCCESS;
}
static void
_cairo_path_fixed_add_buf (cairo_path_fixed_t *path,
cairo_path_buf_t *buf)
{
cairo_list_add_tail (&buf->link, &cairo_path_head (path)->link);
}
COMPILE_TIME_ASSERT (sizeof (cairo_path_op_t) == 1);
static cairo_path_buf_t *
_cairo_path_buf_create (int size_ops, int size_points)
{
cairo_path_buf_t *buf;
/* adjust size_ops to ensure that buf->points is naturally aligned */
size_ops += sizeof (double) - ((sizeof (cairo_path_buf_t) + size_ops) % sizeof (double));
buf = _cairo_malloc_ab_plus_c (size_points, sizeof (cairo_point_t), size_ops + sizeof (cairo_path_buf_t));
if (buf) {
buf->num_ops = 0;
buf->num_points = 0;
buf->size_ops = size_ops;
buf->size_points = size_points;
buf->op = (cairo_path_op_t *) (buf + 1);
buf->points = (cairo_point_t *) (buf->op + size_ops);
}
return buf;
}
static void
_cairo_path_buf_destroy (cairo_path_buf_t *buf)
{
free (buf);
}
static void
_cairo_path_buf_add_op (cairo_path_buf_t *buf,
cairo_path_op_t op)
{
buf->op[buf->num_ops++] = op;
}
static void
_cairo_path_buf_add_points (cairo_path_buf_t *buf,
const cairo_point_t *points,
int num_points)
{
if (num_points == 0)
return;
memcpy (buf->points + buf->num_points,
points,
sizeof (points[0]) * num_points);
buf->num_points += num_points;
}
cairo_status_t
_cairo_path_fixed_interpret (const cairo_path_fixed_t *path,
cairo_path_fixed_move_to_func_t *move_to,
cairo_path_fixed_line_to_func_t *line_to,
cairo_path_fixed_curve_to_func_t *curve_to,
cairo_path_fixed_close_path_func_t *close_path,
void *closure)
{
const cairo_path_buf_t *buf;
cairo_status_t status;
cairo_path_foreach_buf_start (buf, path) {
const cairo_point_t *points = buf->points;
unsigned int i;
for (i = 0; i < buf->num_ops; i++) {
switch (buf->op[i]) {
case CAIRO_PATH_OP_MOVE_TO:
status = (*move_to) (closure, &points[0]);
points += 1;
break;
case CAIRO_PATH_OP_LINE_TO:
status = (*line_to) (closure, &points[0]);
points += 1;
break;
case CAIRO_PATH_OP_CURVE_TO:
status = (*curve_to) (closure, &points[0], &points[1], &points[2]);
points += 3;
break;
default:
ASSERT_NOT_REACHED;
case CAIRO_PATH_OP_CLOSE_PATH:
status = (*close_path) (closure);
break;
}
if (unlikely (status))
return status;
}
} cairo_path_foreach_buf_end (buf, path);
return CAIRO_STATUS_SUCCESS;
}
typedef struct _cairo_path_fixed_append_closure {
cairo_point_t offset;
cairo_path_fixed_t *path;
} cairo_path_fixed_append_closure_t;
static cairo_status_t
_append_move_to (void *abstract_closure,
const cairo_point_t *point)
{
cairo_path_fixed_append_closure_t *closure = abstract_closure;
return _cairo_path_fixed_move_to (closure->path,
point->x + closure->offset.x,
point->y + closure->offset.y);
}
static cairo_status_t
_append_line_to (void *abstract_closure,
const cairo_point_t *point)
{
cairo_path_fixed_append_closure_t *closure = abstract_closure;
return _cairo_path_fixed_line_to (closure->path,
point->x + closure->offset.x,
point->y + closure->offset.y);
}
static cairo_status_t
_append_curve_to (void *abstract_closure,
const cairo_point_t *p0,
const cairo_point_t *p1,
const cairo_point_t *p2)
{
cairo_path_fixed_append_closure_t *closure = abstract_closure;
return _cairo_path_fixed_curve_to (closure->path,
p0->x + closure->offset.x,
p0->y + closure->offset.y,
p1->x + closure->offset.x,
p1->y + closure->offset.y,
p2->x + closure->offset.x,
p2->y + closure->offset.y);
}
static cairo_status_t
_append_close_path (void *abstract_closure)
{
cairo_path_fixed_append_closure_t *closure = abstract_closure;
return _cairo_path_fixed_close_path (closure->path);
}
cairo_status_t
_cairo_path_fixed_append (cairo_path_fixed_t *path,
const cairo_path_fixed_t *other,
cairo_fixed_t tx,
cairo_fixed_t ty)
{
cairo_path_fixed_append_closure_t closure;
closure.path = path;
closure.offset.x = tx;
closure.offset.y = ty;
return _cairo_path_fixed_interpret (other,
_append_move_to,
_append_line_to,
_append_curve_to,
_append_close_path,
&closure);
}
static void
_cairo_path_fixed_offset_and_scale (cairo_path_fixed_t *path,
cairo_fixed_t offx,
cairo_fixed_t offy,
cairo_fixed_t scalex,
cairo_fixed_t scaley)
{
cairo_path_buf_t *buf;
unsigned int i;
if (scalex == CAIRO_FIXED_ONE && scaley == CAIRO_FIXED_ONE) {
_cairo_path_fixed_translate (path, offx, offy);
return;
}
path->last_move_point.x = _cairo_fixed_mul (scalex, path->last_move_point.x) + offx;
path->last_move_point.y = _cairo_fixed_mul (scaley, path->last_move_point.y) + offy;
path->current_point.x = _cairo_fixed_mul (scalex, path->current_point.x) + offx;
path->current_point.y = _cairo_fixed_mul (scaley, path->current_point.y) + offy;
path->fill_maybe_region = TRUE;
cairo_path_foreach_buf_start (buf, path) {
for (i = 0; i < buf->num_points; i++) {
if (scalex != CAIRO_FIXED_ONE)
buf->points[i].x = _cairo_fixed_mul (buf->points[i].x, scalex);
buf->points[i].x += offx;
if (scaley != CAIRO_FIXED_ONE)
buf->points[i].y = _cairo_fixed_mul (buf->points[i].y, scaley);
buf->points[i].y += offy;
if (path->fill_maybe_region) {
path->fill_maybe_region = _cairo_fixed_is_integer (buf->points[i].x) &&
_cairo_fixed_is_integer (buf->points[i].y);
}
}
} cairo_path_foreach_buf_end (buf, path);
path->fill_maybe_region &= path->fill_is_rectilinear;
path->extents.p1.x = _cairo_fixed_mul (scalex, path->extents.p1.x) + offx;
path->extents.p2.x = _cairo_fixed_mul (scalex, path->extents.p2.x) + offx;
if (scalex < 0) {
cairo_fixed_t t = path->extents.p1.x;
path->extents.p1.x = path->extents.p2.x;
path->extents.p2.x = t;
}
path->extents.p1.y = _cairo_fixed_mul (scaley, path->extents.p1.y) + offy;
path->extents.p2.y = _cairo_fixed_mul (scaley, path->extents.p2.y) + offy;
if (scaley < 0) {
cairo_fixed_t t = path->extents.p1.y;
path->extents.p1.y = path->extents.p2.y;
path->extents.p2.y = t;
}
}
void
_cairo_path_fixed_translate (cairo_path_fixed_t *path,
cairo_fixed_t offx,
cairo_fixed_t offy)
{
cairo_path_buf_t *buf;
unsigned int i;
if (offx == 0 && offy == 0)
return;
path->last_move_point.x += offx;
path->last_move_point.y += offy;
path->current_point.x += offx;
path->current_point.y += offy;
path->fill_maybe_region = TRUE;
cairo_path_foreach_buf_start (buf, path) {
for (i = 0; i < buf->num_points; i++) {
buf->points[i].x += offx;
buf->points[i].y += offy;
if (path->fill_maybe_region) {
path->fill_maybe_region = _cairo_fixed_is_integer (buf->points[i].x) &&
_cairo_fixed_is_integer (buf->points[i].y);
}
}
} cairo_path_foreach_buf_end (buf, path);
path->fill_maybe_region &= path->fill_is_rectilinear;
path->extents.p1.x += offx;
path->extents.p1.y += offy;
path->extents.p2.x += offx;
path->extents.p2.y += offy;
}
static inline void
_cairo_path_fixed_transform_point (cairo_point_t *p,
const cairo_matrix_t *matrix)
{
double dx, dy;
dx = _cairo_fixed_to_double (p->x);
dy = _cairo_fixed_to_double (p->y);
cairo_matrix_transform_point (matrix, &dx, &dy);
p->x = _cairo_fixed_from_double (dx);
p->y = _cairo_fixed_from_double (dy);
}
/**
* _cairo_path_fixed_transform:
* @path: a #cairo_path_fixed_t to be transformed
* @matrix: a #cairo_matrix_t
*
* Transform the fixed-point path according to the given matrix.
* There is a fast path for the case where @matrix has no rotation
* or shear.
**/
void
_cairo_path_fixed_transform (cairo_path_fixed_t *path,
const cairo_matrix_t *matrix)
{
cairo_box_t extents;
cairo_point_t point;
cairo_path_buf_t *buf;
unsigned int i;
if (matrix->yx == 0.0 && matrix->xy == 0.0) {
/* Fast path for the common case of scale+transform */
_cairo_path_fixed_offset_and_scale (path,
_cairo_fixed_from_double (matrix->x0),
_cairo_fixed_from_double (matrix->y0),
_cairo_fixed_from_double (matrix->xx),
_cairo_fixed_from_double (matrix->yy));
return;
}
_cairo_path_fixed_transform_point (&path->last_move_point, matrix);
_cairo_path_fixed_transform_point (&path->current_point, matrix);
buf = cairo_path_head (path);
if (buf->num_points == 0)
return;
extents = path->extents;
point = buf->points[0];
_cairo_path_fixed_transform_point (&point, matrix);
_cairo_box_set (&path->extents, &point, &point);
cairo_path_foreach_buf_start (buf, path) {
for (i = 0; i < buf->num_points; i++) {
_cairo_path_fixed_transform_point (&buf->points[i], matrix);
_cairo_box_add_point (&path->extents, &buf->points[i]);
}
} cairo_path_foreach_buf_end (buf, path);
if (path->has_curve_to) {
cairo_bool_t is_tight;
_cairo_matrix_transform_bounding_box_fixed (matrix, &extents, &is_tight);
if (!is_tight) {
cairo_bool_t has_extents;
has_extents = _cairo_path_bounder_extents (path, &extents);
assert (has_extents);
}
path->extents = extents;
}
/* flags might become more strict than needed */
path->stroke_is_rectilinear = FALSE;
path->fill_is_rectilinear = FALSE;
path->fill_is_empty = FALSE;
path->fill_maybe_region = FALSE;
}
/* Closure for path flattening */
typedef struct cairo_path_flattener {
double tolerance;
cairo_point_t current_point;
cairo_path_fixed_move_to_func_t *move_to;
cairo_path_fixed_line_to_func_t *line_to;
cairo_path_fixed_close_path_func_t *close_path;
void *closure;
} cpf_t;
static cairo_status_t
_cpf_move_to (void *closure,
const cairo_point_t *point)
{
cpf_t *cpf = closure;
cpf->current_point = *point;
return cpf->move_to (cpf->closure, point);
}
static cairo_status_t
_cpf_line_to (void *closure,
const cairo_point_t *point)
{
cpf_t *cpf = closure;
cpf->current_point = *point;
return cpf->line_to (cpf->closure, point);
}
static cairo_status_t
_cpf_curve_to (void *closure,
const cairo_point_t *p1,
const cairo_point_t *p2,
const cairo_point_t *p3)
{
cpf_t *cpf = closure;
cairo_spline_t spline;
cairo_point_t *p0 = &cpf->current_point;
if (! _cairo_spline_init (&spline,
(cairo_spline_add_point_func_t)cpf->line_to,
cpf->closure,
p0, p1, p2, p3))
{
return _cpf_line_to (closure, p3);
}
cpf->current_point = *p3;
return _cairo_spline_decompose (&spline, cpf->tolerance);
}
static cairo_status_t
_cpf_close_path (void *closure)
{
cpf_t *cpf = closure;
return cpf->close_path (cpf->closure);
}
cairo_status_t
_cairo_path_fixed_interpret_flat (const cairo_path_fixed_t *path,
cairo_path_fixed_move_to_func_t *move_to,
cairo_path_fixed_line_to_func_t *line_to,
cairo_path_fixed_close_path_func_t *close_path,
void *closure,
double tolerance)
{
cpf_t flattener;
if (! path->has_curve_to) {
return _cairo_path_fixed_interpret (path,
move_to,
line_to,
NULL,
close_path,
closure);
}
flattener.tolerance = tolerance;
flattener.move_to = move_to;
flattener.line_to = line_to;
flattener.close_path = close_path;
flattener.closure = closure;
return _cairo_path_fixed_interpret (path,
_cpf_move_to,
_cpf_line_to,
_cpf_curve_to,
_cpf_close_path,
&flattener);
}
static inline void
_canonical_box (cairo_box_t *box,
const cairo_point_t *p1,
const cairo_point_t *p2)
{
if (p1->x <= p2->x) {
box->p1.x = p1->x;
box->p2.x = p2->x;
} else {
box->p1.x = p2->x;
box->p2.x = p1->x;
}
if (p1->y <= p2->y) {
box->p1.y = p1->y;
box->p2.y = p2->y;
} else {
box->p1.y = p2->y;
box->p2.y = p1->y;
}
}
static inline cairo_bool_t
_path_is_quad (const cairo_path_fixed_t *path)
{
const cairo_path_buf_t *buf = cairo_path_head (path);
/* Do we have the right number of ops? */
if (buf->num_ops < 4 || buf->num_ops > 6)
return FALSE;
/* Check whether the ops are those that would be used for a rectangle */
if (buf->op[0] != CAIRO_PATH_OP_MOVE_TO ||
buf->op[1] != CAIRO_PATH_OP_LINE_TO ||
buf->op[2] != CAIRO_PATH_OP_LINE_TO ||
buf->op[3] != CAIRO_PATH_OP_LINE_TO)
{
return FALSE;
}
/* we accept an implicit close for filled paths */
if (buf->num_ops > 4) {
/* Now, there are choices. The rectangle might end with a LINE_TO
* (to the original point), but this isn't required. If it
* doesn't, then it must end with a CLOSE_PATH. */
if (buf->op[4] == CAIRO_PATH_OP_LINE_TO) {
if (buf->points[4].x != buf->points[0].x ||
buf->points[4].y != buf->points[0].y)
return FALSE;
} else if (buf->op[4] != CAIRO_PATH_OP_CLOSE_PATH) {
return FALSE;
}
if (buf->num_ops == 6) {
/* A trailing CLOSE_PATH or MOVE_TO is ok */
if (buf->op[5] != CAIRO_PATH_OP_MOVE_TO &&
buf->op[5] != CAIRO_PATH_OP_CLOSE_PATH)
return FALSE;
}
}
return TRUE;
}
static inline cairo_bool_t
_points_form_rect (const cairo_point_t *points)
{
if (points[0].y == points[1].y &&
points[1].x == points[2].x &&
points[2].y == points[3].y &&
points[3].x == points[0].x)
return TRUE;
if (points[0].x == points[1].x &&
points[1].y == points[2].y &&
points[2].x == points[3].x &&
points[3].y == points[0].y)
return TRUE;
return FALSE;
}
/*
* Check whether the given path contains a single rectangle.
*/
cairo_bool_t
_cairo_path_fixed_is_box (const cairo_path_fixed_t *path,
cairo_box_t *box)
{
const cairo_path_buf_t *buf;
if (! path->fill_is_rectilinear)
return FALSE;
if (! _path_is_quad (path))
return FALSE;
buf = cairo_path_head (path);
if (_points_form_rect (buf->points)) {
_canonical_box (box, &buf->points[0], &buf->points[2]);
return TRUE;
}
return FALSE;
}
/* Determine whether two lines A->B and C->D intersect based on the
* algorithm described here: http://paulbourke.net/geometry/pointlineplane/ */
static inline cairo_bool_t
_lines_intersect_or_are_coincident (cairo_point_t a,
cairo_point_t b,
cairo_point_t c,
cairo_point_t d)
{
cairo_int64_t numerator_a, numerator_b, denominator;
cairo_bool_t denominator_negative;
denominator = _cairo_int64_sub (_cairo_int32x32_64_mul (d.y - c.y, b.x - a.x),
_cairo_int32x32_64_mul (d.x - c.x, b.y - a.y));
numerator_a = _cairo_int64_sub (_cairo_int32x32_64_mul (d.x - c.x, a.y - c.y),
_cairo_int32x32_64_mul (d.y - c.y, a.x - c.x));
numerator_b = _cairo_int64_sub (_cairo_int32x32_64_mul (b.x - a.x, a.y - c.y),
_cairo_int32x32_64_mul (b.y - a.y, a.x - c.x));
if (_cairo_int64_is_zero (denominator)) {
/* If the denominator and numerators are both zero,
* the lines are coincident. */
if (_cairo_int64_is_zero (numerator_a) && _cairo_int64_is_zero (numerator_b))
return TRUE;
/* Otherwise, a zero denominator indicates the lines are
* parallel and never intersect. */
return FALSE;
}
/* The lines intersect if both quotients are between 0 and 1 (exclusive). */
/* We first test whether either quotient is a negative number. */
denominator_negative = _cairo_int64_negative (denominator);
if (_cairo_int64_negative (numerator_a) ^ denominator_negative)
return FALSE;
if (_cairo_int64_negative (numerator_b) ^ denominator_negative)
return FALSE;
/* A zero quotient indicates an "intersection" at an endpoint, which
* we aren't considering a true intersection. */
if (_cairo_int64_is_zero (numerator_a) || _cairo_int64_is_zero (numerator_b))
return FALSE;
/* If the absolute value of the numerator is larger than or equal to the
* denominator the result of the division would be greater than or equal
* to one. */
if (! denominator_negative) {
if (! _cairo_int64_lt (numerator_a, denominator) ||
! _cairo_int64_lt (numerator_b, denominator))
return FALSE;
} else {
if (! _cairo_int64_lt (denominator, numerator_a) ||
! _cairo_int64_lt (denominator, numerator_b))
return FALSE;
}
return TRUE;
}
cairo_bool_t
_cairo_path_fixed_is_simple_quad (const cairo_path_fixed_t *path)
{
const cairo_point_t *points;
if (! _path_is_quad (path))
return FALSE;
points = cairo_path_head (path)->points;
if (_points_form_rect (points))
return TRUE;
if (_lines_intersect_or_are_coincident (points[0], points[1],
points[3], points[2]))
return FALSE;
if (_lines_intersect_or_are_coincident (points[0], points[3],
points[1], points[2]))
return FALSE;
return TRUE;
}
cairo_bool_t
_cairo_path_fixed_is_stroke_box (const cairo_path_fixed_t *path,
cairo_box_t *box)
{
const cairo_path_buf_t *buf = cairo_path_head (path);
if (! path->fill_is_rectilinear)
return FALSE;
/* Do we have the right number of ops? */
if (buf->num_ops != 5)
return FALSE;
/* Check whether the ops are those that would be used for a rectangle */
if (buf->op[0] != CAIRO_PATH_OP_MOVE_TO ||
buf->op[1] != CAIRO_PATH_OP_LINE_TO ||
buf->op[2] != CAIRO_PATH_OP_LINE_TO ||
buf->op[3] != CAIRO_PATH_OP_LINE_TO ||
buf->op[4] != CAIRO_PATH_OP_CLOSE_PATH)
{
return FALSE;
}
/* Ok, we may have a box, if the points line up */
if (buf->points[0].y == buf->points[1].y &&
buf->points[1].x == buf->points[2].x &&
buf->points[2].y == buf->points[3].y &&
buf->points[3].x == buf->points[0].x)
{
_canonical_box (box, &buf->points[0], &buf->points[2]);
return TRUE;
}
if (buf->points[0].x == buf->points[1].x &&
buf->points[1].y == buf->points[2].y &&
buf->points[2].x == buf->points[3].x &&
buf->points[3].y == buf->points[0].y)
{
_canonical_box (box, &buf->points[0], &buf->points[2]);
return TRUE;
}
return FALSE;
}
/*
* Check whether the given path contains a single rectangle
* that 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>
*/
cairo_bool_t
_cairo_path_fixed_is_rectangle (const cairo_path_fixed_t *path,
cairo_box_t *box)
{
const cairo_path_buf_t *buf;
if (! _cairo_path_fixed_is_box (path, box))
return FALSE;
/* This check is valid because the current implementation of
* _cairo_path_fixed_is_box () only accepts rectangles like:
* move,line,line,line[,line|close[,close|move]]. */
buf = cairo_path_head (path);
if (buf->num_ops > 4)
return TRUE;
return FALSE;
}
void
_cairo_path_fixed_iter_init (cairo_path_fixed_iter_t *iter,
const cairo_path_fixed_t *path)
{
iter->first = iter->buf = cairo_path_head (path);
iter->n_op = 0;
iter->n_point = 0;
}
static cairo_bool_t
_cairo_path_fixed_iter_next_op (cairo_path_fixed_iter_t *iter)
{
if (++iter->n_op >= iter->buf->num_ops) {
iter->buf = cairo_path_buf_next (iter->buf);
if (iter->buf == iter->first) {
iter->buf = NULL;
return FALSE;
}
iter->n_op = 0;
iter->n_point = 0;
}
return TRUE;
}
cairo_bool_t
_cairo_path_fixed_iter_is_fill_box (cairo_path_fixed_iter_t *_iter,
cairo_box_t *box)
{
cairo_point_t points[5];
cairo_path_fixed_iter_t iter;
if (_iter->buf == NULL)
return FALSE;
iter = *_iter;
if (iter.n_op == iter.buf->num_ops && ! _cairo_path_fixed_iter_next_op (&iter))
return FALSE;
/* Check whether the ops are those that would be used for a rectangle */
if (iter.buf->op[iter.n_op] != CAIRO_PATH_OP_MOVE_TO)
return FALSE;
points[0] = iter.buf->points[iter.n_point++];
if (! _cairo_path_fixed_iter_next_op (&iter))
return FALSE;
if (iter.buf->op[iter.n_op] != CAIRO_PATH_OP_LINE_TO)
return FALSE;
points[1] = iter.buf->points[iter.n_point++];
if (! _cairo_path_fixed_iter_next_op (&iter))
return FALSE;
/* a horizontal/vertical closed line is also a degenerate rectangle */
switch (iter.buf->op[iter.n_op]) {
case CAIRO_PATH_OP_CLOSE_PATH:
_cairo_path_fixed_iter_next_op (&iter);
case CAIRO_PATH_OP_MOVE_TO: /* implicit close */
box->p1 = box->p2 = points[0];
*_iter = iter;
return TRUE;
default:
return FALSE;
case CAIRO_PATH_OP_LINE_TO:
break;
}
points[2] = iter.buf->points[iter.n_point++];
if (! _cairo_path_fixed_iter_next_op (&iter))
return FALSE;
if (iter.buf->op[iter.n_op] != CAIRO_PATH_OP_LINE_TO)
return FALSE;
points[3] = iter.buf->points[iter.n_point++];
/* Now, there are choices. The rectangle might end with a LINE_TO
* (to the original point), but this isn't required. If it
* doesn't, then it must end with a CLOSE_PATH (which may be implicit). */
if (! _cairo_path_fixed_iter_next_op (&iter)) {
/* implicit close due to fill */
} else if (iter.buf->op[iter.n_op] == CAIRO_PATH_OP_LINE_TO) {
points[4] = iter.buf->points[iter.n_point++];
if (points[4].x != points[0].x || points[4].y != points[0].y)
return FALSE;
_cairo_path_fixed_iter_next_op (&iter);
} else if (iter.buf->op[iter.n_op] == CAIRO_PATH_OP_CLOSE_PATH) {
_cairo_path_fixed_iter_next_op (&iter);
} else if (iter.buf->op[iter.n_op] == CAIRO_PATH_OP_MOVE_TO) {
/* implicit close-path due to new-sub-path */
} else {
return FALSE;
}
/* Ok, we may have a box, if the points line up */
if (points[0].y == points[1].y &&
points[1].x == points[2].x &&
points[2].y == points[3].y &&
points[3].x == points[0].x)
{
box->p1 = points[0];
box->p2 = points[2];
*_iter = iter;
return TRUE;
}
if (points[0].x == points[1].x &&
points[1].y == points[2].y &&
points[2].x == points[3].x &&
points[3].y == points[0].y)
{
box->p1 = points[1];
box->p2 = points[3];
*_iter = iter;
return TRUE;
}
return FALSE;
}
cairo_bool_t
_cairo_path_fixed_iter_at_end (const cairo_path_fixed_iter_t *iter)
{
if (iter->buf == NULL)
return TRUE;
return iter->n_op == iter->buf->num_ops;
}
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