cairo_status_t
_cairo_path_fixed_stroke_to_polygon (const cairo_path_fixed_t *path,
const cairo_stroke_style_t *style,
const cairo_matrix_t *ctm,
const cairo_matrix_t *ctm_inverse,
double tolerance,
cairo_polygon_t *polygon)
{
struct stroker stroker;
cairo_status_t status;
if (style->num_dashes) {
return _cairo_path_fixed_stroke_dashed_to_polygon (path,
style,
ctm,
ctm_inverse,
tolerance,
polygon);
}
stroker.has_bounds = polygon->num_limits;
if (stroker.has_bounds) {
/* Extend the bounds in each direction to account for the maximum area
* we might generate trapezoids, to capture line segments that are
* outside of the bounds but which might generate rendering that's
* within bounds.
*/
double dx, dy;
cairo_fixed_t fdx, fdy;
int i;
stroker.bounds = polygon->limits[0];
for (i = 1; i < polygon->num_limits; i++)
_cairo_box_add_box (&stroker.bounds, &polygon->limits[i]);
_cairo_stroke_style_max_distance_from_path (style, path, ctm, &dx, &dy);
fdx = _cairo_fixed_from_double (dx);
fdy = _cairo_fixed_from_double (dy);
stroker.bounds.p1.x -= fdx;
stroker.bounds.p2.x += fdx;
stroker.bounds.p1.y -= fdy;
stroker.bounds.p2.y += fdy;
}
stroker.style = *style;
stroker.ctm = ctm;
stroker.ctm_inverse = ctm_inverse;
stroker.tolerance = tolerance;
stroker.half_line_width = style->line_width / 2.;
/* To test whether we need to join two segments of a spline using
* a round-join or a bevel-join, we can inspect the angle between the
* two segments. If the difference between the chord distance
* (half-line-width times the cosine of the bisection angle) and the
* half-line-width itself is greater than tolerance then we need to
* inject a point.
*/
stroker.spline_cusp_tolerance = 1 - tolerance / stroker.half_line_width;
stroker.spline_cusp_tolerance *= stroker.spline_cusp_tolerance;
stroker.spline_cusp_tolerance *= 2;
stroker.spline_cusp_tolerance -= 1;
stroker.ctm_det_positive =
_cairo_matrix_compute_determinant (ctm) >= 0.0;
stroker.pen.num_vertices = 0;
if (path->has_curve_to ||
style->line_join == CAIRO_LINE_JOIN_ROUND ||
style->line_cap == CAIRO_LINE_CAP_ROUND) {
status = _cairo_pen_init (&stroker.pen,
stroker.half_line_width,
tolerance, ctm);
if (unlikely (status))
return status;
/* If the line width is so small that the pen is reduced to a
single point, then we have nothing to do. */
if (stroker.pen.num_vertices <= 1)
return CAIRO_STATUS_SUCCESS;
}
stroker.has_current_face = FALSE;
stroker.has_first_face = FALSE;
stroker.has_initial_sub_path = FALSE;
#if DEBUG
remove ("contours.txt");
remove ("polygons.txt");
_cairo_contour_init (&stroker.path, 0);
#endif
_cairo_contour_init (&stroker.cw.contour, 1);
_cairo_contour_init (&stroker.ccw.contour, -1);
tolerance *= CAIRO_FIXED_ONE;
tolerance *= tolerance;
stroker.contour_tolerance = tolerance;
stroker.polygon = polygon;
status = _cairo_path_fixed_interpret (path,
move_to,
line_to,
curve_to,
close_path,
&stroker);
/* Cap the start and end of the final sub path as needed */
if (likely (status == CAIRO_STATUS_SUCCESS))
add_caps (&stroker);
_cairo_contour_fini (&stroker.cw.contour);
_cairo_contour_fini (&stroker.ccw.contour);
if (stroker.pen.num_vertices)
_cairo_pen_fini (&stroker.pen);
#if DEBUG
{
FILE *file = fopen ("polygons.txt", "a");
_cairo_debug_print_polygon (file, polygon);
fclose (file);
}
#endif
return status;
}
cairo_status_t
_cairo_path_fixed_stroke_to_polygon (const cairo_path_fixed_t *path,
const cairo_stroke_style_t *style,
const cairo_matrix_t *ctm,
const cairo_matrix_t *ctm_inverse,
double tolerance,
cairo_polygon_t *polygon)
{
struct stroker stroker;
cairo_status_t status;
if (style->num_dashes) {
return _cairo_path_fixed_stroke_dashed_to_polygon (path,
style,
ctm,
ctm_inverse,
tolerance,
polygon);
}
stroker.style = *style;
stroker.ctm = ctm;
stroker.ctm_inverse = ctm_inverse;
stroker.tolerance = tolerance;
stroker.ctm_det_positive =
_cairo_matrix_compute_determinant (ctm) >= 0.0;
stroker.pen.num_vertices = 0;
if (path->has_curve_to ||
style->line_join == CAIRO_LINE_JOIN_ROUND ||
style->line_cap == CAIRO_LINE_CAP_ROUND) {
status = _cairo_pen_init (&stroker.pen,
style->line_width / 2.0,
tolerance, ctm);
if (unlikely (status))
return status;
/* If the line width is so small that the pen is reduced to a
single point, then we have nothing to do. */
if (stroker.pen.num_vertices <= 1)
return CAIRO_STATUS_SUCCESS;
}
stroker.has_current_face = FALSE;
stroker.has_first_face = FALSE;
stroker.has_initial_sub_path = FALSE;
#if DEBUG
remove ("contours.txt");
remove ("polygons.txt");
_cairo_contour_init (&stroker.path, 0);
#endif
_cairo_contour_init (&stroker.cw.contour, 1);
_cairo_contour_init (&stroker.ccw.contour, -1);
tolerance *= CAIRO_FIXED_ONE;
tolerance *= tolerance;
stroker.contour_tolerance = tolerance;
stroker.polygon = polygon;
status = _cairo_path_fixed_interpret (path,
move_to,
line_to,
curve_to,
close_path,
&stroker);
/* Cap the start and end of the final sub path as needed */
if (likely (status == CAIRO_STATUS_SUCCESS))
add_caps (&stroker);
_cairo_contour_fini (&stroker.cw.contour);
_cairo_contour_fini (&stroker.ccw.contour);
if (stroker.pen.num_vertices)
_cairo_pen_fini (&stroker.pen);
#if DEBUG
{
FILE *file = fopen ("polygons.txt", "a");
_cairo_debug_print_polygon (file, polygon);
fclose (file);
}
#endif
return status;
}
cairo_status_t
_cairo_polygon_intersect (cairo_polygon_t *a, int winding_a,
cairo_polygon_t *b, int winding_b)
{
cairo_status_t status;
cairo_bo_start_event_t stack_events[CAIRO_STACK_ARRAY_LENGTH (cairo_bo_start_event_t)];
cairo_bo_start_event_t *events;
cairo_bo_event_t *stack_event_ptrs[ARRAY_LENGTH (stack_events) + 1];
cairo_bo_event_t **event_ptrs;
int num_events;
int i, j;
/* XXX lazy */
if (winding_a != CAIRO_FILL_RULE_WINDING) {
status = _cairo_polygon_reduce (a, winding_a);
if (unlikely (status))
return status;
}
if (winding_b != CAIRO_FILL_RULE_WINDING) {
status = _cairo_polygon_reduce (b, winding_b);
if (unlikely (status))
return status;
}
if (unlikely (0 == a->num_edges))
return CAIRO_STATUS_SUCCESS;
if (unlikely (0 == b->num_edges)) {
a->num_edges = 0;
return CAIRO_STATUS_SUCCESS;
}
events = stack_events;
event_ptrs = stack_event_ptrs;
num_events = a->num_edges + b->num_edges;
if (num_events > ARRAY_LENGTH (stack_events)) {
events = _cairo_malloc_ab_plus_c (num_events,
sizeof (cairo_bo_start_event_t) +
sizeof (cairo_bo_event_t *),
sizeof (cairo_bo_event_t *));
if (unlikely (events == NULL))
return _cairo_error (CAIRO_STATUS_NO_MEMORY);
event_ptrs = (cairo_bo_event_t **) (events + num_events);
}
j = 0;
for (i = 0; i < a->num_edges; i++) {
event_ptrs[j] = (cairo_bo_event_t *) &events[j];
events[j].type = CAIRO_BO_EVENT_TYPE_START;
events[j].point.y.ordinate = a->edges[i].top;
events[j].point.y.approx = EXACT;
events[j].point.x.ordinate =
_line_compute_intersection_x_for_y (&a->edges[i].line,
events[j].point.y.ordinate);
events[j].point.x.approx = EXACT;
events[j].edge.a_or_b = 0;
events[j].edge.edge = a->edges[i];
events[j].edge.deferred.other = NULL;
events[j].edge.prev = NULL;
events[j].edge.next = NULL;
j++;
}
for (i = 0; i < b->num_edges; i++) {
event_ptrs[j] = (cairo_bo_event_t *) &events[j];
events[j].type = CAIRO_BO_EVENT_TYPE_START;
events[j].point.y.ordinate = b->edges[i].top;
events[j].point.y.approx = EXACT;
events[j].point.x.ordinate =
_line_compute_intersection_x_for_y (&b->edges[i].line,
events[j].point.y.ordinate);
events[j].point.x.approx = EXACT;
events[j].edge.a_or_b = 1;
events[j].edge.edge = b->edges[i];
events[j].edge.deferred.other = NULL;
events[j].edge.prev = NULL;
events[j].edge.next = NULL;
j++;
}
assert (j == num_events);
#if 0
{
FILE *file = fopen ("clip_a.txt", "w");
_cairo_debug_print_polygon (file, a);
fclose (file);
}
{
FILE *file = fopen ("clip_b.txt", "w");
_cairo_debug_print_polygon (file, b);
fclose (file);
}
#endif
a->num_edges = 0;
status = intersection_sweep (event_ptrs, num_events, a);
if (events != stack_events)
free (events);
#if 0
{
FILE *file = fopen ("clip_result.txt", "w");
_cairo_debug_print_polygon (file, a);
fclose (file);
}
#endif
return status;
}
cairo_status_t
_cairo_polygon_reduce (cairo_polygon_t *polygon,
cairo_fill_rule_t fill_rule)
{
cairo_status_t status;
cairo_bo_start_event_t stack_events[CAIRO_STACK_ARRAY_LENGTH (cairo_bo_start_event_t)];
cairo_bo_start_event_t *events;
cairo_bo_event_t *stack_event_ptrs[ARRAY_LENGTH (stack_events) + 1];
cairo_bo_event_t **event_ptrs;
int num_limits;
int num_events;
int i;
num_events = polygon->num_edges;
if (unlikely (0 == num_events))
return CAIRO_STATUS_SUCCESS;
if (DEBUG_POLYGON) {
FILE *file = fopen ("reduce_in.txt", "w");
_cairo_debug_print_polygon (file, polygon);
fclose (file);
}
events = stack_events;
event_ptrs = stack_event_ptrs;
if (num_events > ARRAY_LENGTH (stack_events)) {
events = _cairo_malloc_ab_plus_c (num_events,
sizeof (cairo_bo_start_event_t) +
sizeof (cairo_bo_event_t *),
sizeof (cairo_bo_event_t *));
if (unlikely (events == NULL))
return _cairo_error (CAIRO_STATUS_NO_MEMORY);
event_ptrs = (cairo_bo_event_t **) (events + num_events);
}
for (i = 0; i < num_events; i++) {
event_ptrs[i] = (cairo_bo_event_t *) &events[i];
events[i].type = CAIRO_BO_EVENT_TYPE_START;
events[i].point.y = polygon->edges[i].top;
events[i].point.x =
_line_compute_intersection_x_for_y (&polygon->edges[i].line,
events[i].point.y);
events[i].edge.edge = polygon->edges[i];
events[i].edge.deferred.right = NULL;
events[i].edge.prev = NULL;
events[i].edge.next = NULL;
}
num_limits = polygon->num_limits; polygon->num_limits = 0;
polygon->num_edges = 0;
status = _cairo_bentley_ottmann_tessellate_bo_edges (event_ptrs,
num_events,
fill_rule,
polygon);
polygon->num_limits = num_limits;
if (events != stack_events)
free (events);
if (DEBUG_POLYGON) {
FILE *file = fopen ("reduce_out.txt", "w");
_cairo_debug_print_polygon (file, polygon);
fclose (file);
}
return status;
}
static cairo_int_status_t
_cairo_spans_compositor_stroke (const cairo_compositor_t *_compositor,
cairo_composite_rectangles_t *extents,
const cairo_path_fixed_t *path,
const cairo_stroke_style_t *style,
const cairo_matrix_t *ctm,
const cairo_matrix_t *ctm_inverse,
double tolerance,
cairo_antialias_t antialias)
{
const cairo_spans_compositor_t *compositor = (cairo_spans_compositor_t*)_compositor;
cairo_int_status_t status;
TRACE_ (_cairo_debug_print_path (stderr, path));
status = CAIRO_INT_STATUS_UNSUPPORTED;
if (_cairo_path_fixed_stroke_is_rectilinear (path)) {
cairo_boxes_t boxes;
_cairo_boxes_init (&boxes);
if (! _cairo_clip_contains_rectangle (extents->clip, &extents->mask))
_cairo_boxes_limit (&boxes,
extents->clip->boxes,
extents->clip->num_boxes);
status = _cairo_path_fixed_stroke_rectilinear_to_boxes (path,
style,
ctm,
antialias,
&boxes);
if (likely (status == CAIRO_INT_STATUS_SUCCESS))
status = clip_and_composite_boxes (compositor, extents, &boxes);
_cairo_boxes_fini (&boxes);
}
if (status == CAIRO_INT_STATUS_UNSUPPORTED) {
cairo_polygon_t polygon;
cairo_fill_rule_t fill_rule = CAIRO_FILL_RULE_WINDING;
if (extents->mask.width > extents->unbounded.width ||
extents->mask.height > extents->unbounded.height)
{
cairo_box_t limits;
_cairo_box_from_rectangle (&limits, &extents->unbounded);
_cairo_polygon_init (&polygon, &limits, 1);
}
else
{
_cairo_polygon_init (&polygon, NULL, 0);
}
status = _cairo_path_fixed_stroke_to_polygon (path,
style,
ctm, ctm_inverse,
tolerance,
&polygon);
TRACE_ (_cairo_debug_print_polygon (stderr, &polygon));
if (status == CAIRO_INT_STATUS_SUCCESS && extents->clip->num_boxes > 1) {
status = _cairo_polygon_intersect_with_boxes (&polygon, &fill_rule,
extents->clip->boxes,
extents->clip->num_boxes);
}
if (likely (status == CAIRO_INT_STATUS_SUCCESS)) {
cairo_clip_t *saved_clip = extents->clip;
if (extents->is_bounded) {
extents->clip = _cairo_clip_copy_path (extents->clip);
extents->clip = _cairo_clip_intersect_box(extents->clip,
&polygon.extents);
}
status = clip_and_composite_polygon (compositor, extents, &polygon,
fill_rule, antialias);
if (extents->is_bounded) {
_cairo_clip_destroy (extents->clip);
extents->clip = saved_clip;
}
}
_cairo_polygon_fini (&polygon);
}
return status;
}
static cairo_int_status_t
_cairo_spans_compositor_fill (const cairo_compositor_t *_compositor,
cairo_composite_rectangles_t *extents,
const cairo_path_fixed_t *path,
cairo_fill_rule_t fill_rule,
double tolerance,
cairo_antialias_t antialias)
{
const cairo_spans_compositor_t *compositor = (cairo_spans_compositor_t*)_compositor;
cairo_int_status_t status;
TRACE((stderr, "%s op=%d, antialias=%d\n", __FUNCTION__, extents->op, antialias));
status = CAIRO_INT_STATUS_UNSUPPORTED;
if (_cairo_path_fixed_fill_is_rectilinear (path)) {
cairo_boxes_t boxes;
TRACE((stderr, "%s - rectilinear\n", __FUNCTION__));
_cairo_boxes_init (&boxes);
if (! _cairo_clip_contains_rectangle (extents->clip, &extents->mask))
_cairo_boxes_limit (&boxes,
extents->clip->boxes,
extents->clip->num_boxes);
status = _cairo_path_fixed_fill_rectilinear_to_boxes (path,
fill_rule,
antialias,
&boxes);
if (likely (status == CAIRO_INT_STATUS_SUCCESS))
status = clip_and_composite_boxes (compositor, extents, &boxes);
_cairo_boxes_fini (&boxes);
}
if (status == CAIRO_INT_STATUS_UNSUPPORTED) {
cairo_polygon_t polygon;
TRACE((stderr, "%s - polygon\n", __FUNCTION__));
if (! _cairo_rectangle_contains_rectangle (&extents->unbounded,
&extents->mask))
{
TRACE((stderr, "%s - clipping to bounds\n", __FUNCTION__));
if (extents->clip->num_boxes == 1) {
_cairo_polygon_init (&polygon, extents->clip->boxes, 1);
} else {
cairo_box_t limits;
_cairo_box_from_rectangle (&limits, &extents->unbounded);
_cairo_polygon_init (&polygon, &limits, 1);
}
}
else
{
_cairo_polygon_init (&polygon, NULL, 0);
}
status = _cairo_path_fixed_fill_to_polygon (path, tolerance, &polygon);
TRACE_ (_cairo_debug_print_polygon (stderr, &polygon));
polygon.num_limits = 0;
if (status == CAIRO_INT_STATUS_SUCCESS && extents->clip->num_boxes > 1) {
TRACE((stderr, "%s - polygon intersect with %d clip boxes\n",
__FUNCTION__, extents->clip->num_boxes));
status = _cairo_polygon_intersect_with_boxes (&polygon, &fill_rule,
extents->clip->boxes,
extents->clip->num_boxes);
}
TRACE_ (_cairo_debug_print_polygon (stderr, &polygon));
if (likely (status == CAIRO_INT_STATUS_SUCCESS)) {
cairo_clip_t *saved_clip = extents->clip;
if (extents->is_bounded) {
TRACE((stderr, "%s - polygon discard clip boxes\n",
__FUNCTION__));
extents->clip = _cairo_clip_copy_path (extents->clip);
extents->clip = _cairo_clip_intersect_box(extents->clip,
&polygon.extents);
}
status = clip_and_composite_polygon (compositor, extents, &polygon,
fill_rule, antialias);
if (extents->is_bounded) {
_cairo_clip_destroy (extents->clip);
extents->clip = saved_clip;
}
}
_cairo_polygon_fini (&polygon);
TRACE((stderr, "%s - polygon status=%d\n", __FUNCTION__, status));
}
return status;
}
