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-rw-r--r--src/cairo-polygon.c329
1 files changed, 182 insertions, 147 deletions
diff --git a/src/cairo-polygon.c b/src/cairo-polygon.c
index a8addff2..fdc5c92d 100644
--- a/src/cairo-polygon.c
+++ b/src/cairo-polygon.c
@@ -50,7 +50,7 @@ _cairo_polygon_init (cairo_polygon_t *polygon)
polygon->has_current_point = FALSE;
polygon->has_current_edge = FALSE;
- polygon->has_limits = FALSE;
+ polygon->num_limits = 0;
polygon->extents.p1.x = polygon->extents.p1.y = INT32_MAX;
polygon->extents.p2.x = polygon->extents.p2.y = INT32_MIN;
@@ -58,10 +58,11 @@ _cairo_polygon_init (cairo_polygon_t *polygon)
void
_cairo_polygon_limit (cairo_polygon_t *polygon,
- const cairo_box_t *limits)
+ const cairo_box_t *limits,
+ int num_limits)
{
- polygon->has_limits = TRUE;
- polygon->limits = *limits;
+ polygon->limits = limits;
+ polygon->num_limits = num_limits;
}
void
@@ -159,156 +160,163 @@ static void
_add_clipped_edge (cairo_polygon_t *polygon,
const cairo_point_t *p1,
const cairo_point_t *p2,
- int dir)
+ const int top, const int bottom,
+ const int dir)
{
cairo_point_t p[2];
int top_y, bot_y;
+ int n;
- if (p1->x <= polygon->limits.p1.x && p2->x <= polygon->limits.p1.x)
- {
- p[0].x = polygon->limits.p1.x;
- p[0].y = polygon->limits.p1.y;
- top_y = p1->y;
- if (top_y < p[0].y)
- top_y = p[0].y;
-
- p[1].x = polygon->limits.p1.x;
- p[1].y = polygon->limits.p2.y;
- bot_y = p2->y;
- if (bot_y > p[1].y)
- bot_y = p[1].y;
-
- _add_edge (polygon, &p[0], &p[1], top_y, bot_y, dir);
- }
- else if (p1->x >= polygon->limits.p2.x && p2->x >= polygon->limits.p2.x)
- {
- p[0].x = polygon->limits.p2.x;
- p[0].y = polygon->limits.p1.y;
- top_y = p1->y;
- if (top_y < p[0].y)
- top_y = p[0].y;
-
- p[1].x = polygon->limits.p2.x;
- p[1].y = polygon->limits.p2.y;
- bot_y = p2->y;
- if (bot_y > p[1].y)
- bot_y = p[1].y;
-
- _add_edge (polygon, &p[0], &p[1], top_y, bot_y, dir);
- }
- else if (p1->x >= polygon->limits.p1.x && p2->x >= polygon->limits.p1.x &&
- p1->x <= polygon->limits.p2.x && p2->x <= polygon->limits.p2.x)
- {
- top_y = p1->y;
- if (top_y < polygon->limits.p1.y)
- top_y = polygon->limits.p1.y;
-
- bot_y = p2->y;
- if (bot_y > polygon->limits.p2.y)
- bot_y = polygon->limits.p2.y;
-
- _add_edge (polygon, p1, p2, top_y, bot_y, dir);
- }
- else
- {
- int left_y, right_y;
- int p1_y, p2_y;
+ for (n = 0; n < polygon->num_limits; n++) {
+ const cairo_box_t *limits = &polygon->limits[n];
- left_y = _cairo_edge_compute_intersection_y_for_x (p1, p2,
- polygon->limits.p1.x);
- right_y = _cairo_edge_compute_intersection_y_for_x (p1, p2,
- polygon->limits.p2.x);
+ if (top >= limits->p2.y)
+ continue;
+ if (bottom <= limits->p1.y)
+ continue;
- if (left_y == right_y) /* horizontal within bounds */
- return;
+ if (p1->x <= limits->p1.x && p2->x <= limits->p1.x)
+ {
+ p[0].x = limits->p1.x;
+ p[0].y = limits->p1.y;
+ top_y = top;
+ if (top_y < p[0].y)
+ top_y = p[0].y;
+
+ p[1].x = limits->p1.x;
+ p[1].y = limits->p2.y;
+ bot_y = bottom;
+ if (bot_y > p[1].y)
+ bot_y = p[1].y;
+
+ _add_edge (polygon, &p[0], &p[1], top_y, bot_y, dir);
+ }
+ else if (p1->x >= limits->p2.x && p2->x >= limits->p2.x)
+ {
+ p[0].x = limits->p2.x;
+ p[0].y = limits->p1.y;
+ top_y = top;
+ if (top_y < p[0].y)
+ top_y = p[0].y;
+
+ p[1].x = limits->p2.x;
+ p[1].y = limits->p2.y;
+ bot_y = bottom;
+ if (bot_y > p[1].y)
+ bot_y = p[1].y;
+
+ _add_edge (polygon, &p[0], &p[1], top_y, bot_y, dir);
+ }
+ else if (p1->x >= limits->p1.x && p2->x >= limits->p1.x &&
+ p1->x <= limits->p2.x && p2->x <= limits->p2.x)
+ {
+ top_y = top;
+ if (top_y < limits->p1.y)
+ top_y = limits->p1.y;
- p1_y = p1->y;
- p2_y = p2->y;
-
- if (left_y < right_y) {
- if (p1->x < polygon->limits.p1.x && left_y > polygon->limits.p1.y)
- {
- p[0].x = polygon->limits.p1.x;
- p[0].y = polygon->limits.p1.y;
- top_y = p1_y;
- if (top_y < p[0].y)
- top_y = p[0].y;
-
- p[1].x = polygon->limits.p1.x;
- p[1].y = polygon->limits.p2.y;
- bot_y = left_y;
- if (bot_y > p[1].y)
- bot_y = p[1].y;
-
- if (bot_y > top_y)
- _add_edge (polygon, &p[0], &p[1], top_y, bot_y, dir);
- p1_y = bot_y;
- }
+ bot_y = bottom;
+ if (bot_y > limits->p2.y)
+ bot_y = limits->p2.y;
- if (p2->x > polygon->limits.p2.x && right_y < polygon->limits.p2.y)
- {
- p[0].x = polygon->limits.p2.x;
- p[0].y = polygon->limits.p1.y;
- top_y = right_y;
- if (top_y < p[0].y)
- top_y = p[0].y;
-
- p[1].x = polygon->limits.p2.x;
- p[1].y = polygon->limits.p2.y;
- bot_y = p2_y;
- if (bot_y > p[1].y)
- bot_y = p[1].y;
-
- if (bot_y > top_y)
- _add_edge (polygon, &p[0], &p[1], top_y, bot_y, dir);
- p2_y = top_y;
- }
- } else {
- if (p1->x > polygon->limits.p2.x && right_y > polygon->limits.p1.y)
- {
- p[0].x = polygon->limits.p2.x;
- p[0].y = polygon->limits.p1.y;
- top_y = p1_y;
- if (top_y < p[0].y)
- top_y = p[0].y;
-
- p[1].x = polygon->limits.p2.x;
- p[1].y = polygon->limits.p2.y;
- bot_y = right_y;
- if (bot_y > p[1].y)
- bot_y = p[1].y;
-
- if (bot_y > top_y)
- _add_edge (polygon, &p[0], &p[1], top_y, bot_y, dir);
- p1_y = bot_y;
- }
+ _add_edge (polygon, p1, p2, top_y, bot_y, dir);
+ }
+ else
+ {
+ int left_y, right_y;
+ int p1_y, p2_y;
- if (p2->x < polygon->limits.p1.x && left_y < polygon->limits.p2.y)
- {
- p[0].x = polygon->limits.p1.x;
- p[0].y = polygon->limits.p1.y;
- top_y = left_y;
- if (top_y < p[0].y)
- top_y = p[0].y;
-
- p[1].x = polygon->limits.p1.x;
- p[1].y = polygon->limits.p2.y;
- bot_y = p2_y;
- if (bot_y > p[1].y)
- bot_y = p[1].y;
-
- if (bot_y > top_y)
- _add_edge (polygon, &p[0], &p[1], top_y, bot_y, dir);
- p2_y = top_y;
+ left_y = _cairo_edge_compute_intersection_y_for_x (p1, p2,
+ limits->p1.x);
+ right_y = _cairo_edge_compute_intersection_y_for_x (p1, p2,
+ limits->p2.x);
+
+ if (left_y == right_y) /* horizontal within bounds */
+ return;
+
+ p1_y = top;
+ p2_y = bottom;
+
+ if (left_y < right_y) {
+ if (p1->x < limits->p1.x && left_y > limits->p1.y) {
+ p[0].x = limits->p1.x;
+ p[0].y = limits->p1.y;
+ top_y = p1_y;
+ if (top_y < p[0].y)
+ top_y = p[0].y;
+
+ p[1].x = limits->p1.x;
+ p[1].y = limits->p2.y;
+ bot_y = left_y;
+ if (bot_y > p[1].y)
+ bot_y = p[1].y;
+
+ if (bot_y > top_y)
+ _add_edge (polygon, &p[0], &p[1], top_y, bot_y, dir);
+ p1_y = bot_y;
+ }
+
+ if (p2->x > limits->p2.x && right_y < limits->p2.y) {
+ p[0].x = limits->p2.x;
+ p[0].y = limits->p1.y;
+ top_y = right_y;
+ if (top_y < p[0].y)
+ top_y = p[0].y;
+
+ p[1].x = limits->p2.x;
+ p[1].y = limits->p2.y;
+ bot_y = p2_y;
+ if (bot_y > p[1].y)
+ bot_y = p[1].y;
+
+ if (bot_y > top_y)
+ _add_edge (polygon, &p[0], &p[1], top_y, bot_y, dir);
+ p2_y = top_y;
+ }
+ } else {
+ if (p1->x > limits->p2.x && right_y > limits->p1.y) {
+ p[0].x = limits->p2.x;
+ p[0].y = limits->p1.y;
+ top_y = p1_y;
+ if (top_y < p[0].y)
+ top_y = p[0].y;
+
+ p[1].x = limits->p2.x;
+ p[1].y = limits->p2.y;
+ bot_y = right_y;
+ if (bot_y > p[1].y)
+ bot_y = p[1].y;
+
+ if (bot_y > top_y)
+ _add_edge (polygon, &p[0], &p[1], top_y, bot_y, dir);
+ p1_y = bot_y;
+ }
+
+ if (p2->x < limits->p1.x && left_y < limits->p2.y) {
+ p[0].x = limits->p1.x;
+ p[0].y = limits->p1.y;
+ top_y = left_y;
+ if (top_y < p[0].y)
+ top_y = p[0].y;
+
+ p[1].x = limits->p1.x;
+ p[1].y = limits->p2.y;
+ bot_y = p2_y;
+ if (bot_y > p[1].y)
+ bot_y = p[1].y;
+
+ if (bot_y > top_y)
+ _add_edge (polygon, &p[0], &p[1], top_y, bot_y, dir);
+ p2_y = top_y;
+ }
}
- }
- if (p1_y < polygon->limits.p1.y)
- p1_y = polygon->limits.p1.y;
- if (p2_y > polygon->limits.p2.y)
- p2_y = polygon->limits.p2.y;
- if (p2_y > p1_y)
- _add_edge (polygon, p1, p2, p1_y, p2_y, dir);
+ if (p1_y < limits->p1.y)
+ p1_y = limits->p1.y;
+ if (p2_y > limits->p2.y)
+ p2_y = limits->p2.y;
+ if (p2_y > p1_y)
+ _add_edge (polygon, p1, p2, p1_y, p2_y, dir);
+ }
}
}
@@ -331,14 +339,14 @@ _cairo_polygon_add_edge (cairo_polygon_t *polygon,
dir = -1;
}
- if (polygon->has_limits) {
- if (p2->y <= polygon->limits.p1.y)
+ if (polygon->num_limits) {
+ if (p2->y <= polygon->limits[0].p1.y)
return;
- if (p1->y >= polygon->limits.p2.y)
+ if (p1->y >= polygon->limits[polygon->num_limits-1].p2.y)
return;
- _add_clipped_edge (polygon, p1, p2, dir);
+ _add_clipped_edge (polygon, p1, p2, p1->y, p2->y, dir);
} else
_add_edge (polygon, p1, p2, p1->y, p2->y, dir);
}
@@ -352,6 +360,33 @@ _cairo_polygon_add_external_edge (void *polygon,
return _cairo_polygon_status (polygon);
}
+cairo_status_t
+_cairo_polygon_add_line (cairo_polygon_t *polygon,
+ const cairo_line_t *line,
+ int top, int bottom,
+ int dir)
+{
+ /* drop horizontal edges */
+ if (line->p1.y == line->p2.y)
+ return CAIRO_STATUS_SUCCESS;
+
+ if (bottom <= top)
+ return CAIRO_STATUS_SUCCESS;
+
+ if (polygon->num_limits) {
+ if (line->p2.y <= polygon->limits[0].p1.y)
+ return CAIRO_STATUS_SUCCESS;
+
+ if (line->p1.y >= polygon->limits[polygon->num_limits-1].p2.y)
+ return CAIRO_STATUS_SUCCESS;
+
+ _add_clipped_edge (polygon, &line->p1, &line->p2, top, bottom, dir);
+ } else
+ _add_edge (polygon, &line->p1, &line->p2, top, bottom, dir);
+
+ return _cairo_polygon_status (polygon);
+}
+
/* flattened path operations */
void
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-18 15:44:37 +0000