[polygon] Reduce number of branches.

Minimise the number of conditionals taken whilst constructing the polygon.

1 files changed, 21 insertions, 50 deletions

diff --git a/src/cairo-polygon.c b/src/cairo-polygon.c
index 1653f9581..1392bfa18 100644
--- a/src/cairo-polygon.c
+++ b/src/cairo-polygon.c
@@ -36,11 +36,6 @@
 
 #include "cairoint.h"
 
-/* private functions */
-
-static cairo_status_t
-_cairo_polygon_grow (cairo_polygon_t *polygon);
-
 void
 _cairo_polygon_init (cairo_polygon_t *polygon)
 {
@@ -57,31 +52,17 @@ _cairo_polygon_init (cairo_polygon_t *polygon)
 void
 _cairo_polygon_fini (cairo_polygon_t *polygon)
 {
-    if (polygon->edges && polygon->edges != polygon->edges_embedded)
+    if (polygon->edges != polygon->edges_embedded)
 	free (polygon->edges);
-
-    polygon->edges = NULL;
-    polygon->edges_size = 0;
-    polygon->num_edges = 0;
-
-    polygon->has_current_point = FALSE;
-}
-
-cairo_status_t
-_cairo_polygon_status (cairo_polygon_t *polygon)
-{
-    return polygon->status;
 }
 
 /* make room for at least one more edge */
-static cairo_status_t
+static cairo_bool_t
 _cairo_polygon_grow (cairo_polygon_t *polygon)
 {
     cairo_edge_t *new_edges;
     int old_size = polygon->edges_size;
-    int new_size = 2 * old_size;
-
-    assert (polygon->num_edges <= polygon->edges_size);
+    int new_size = 4 * old_size;
 
     if (polygon->edges == polygon->edges_embedded) {
 	new_edges = _cairo_malloc_ab (new_size, sizeof (cairo_edge_t));
@@ -92,34 +73,34 @@ _cairo_polygon_grow (cairo_polygon_t *polygon)
 		                       new_size, sizeof (cairo_edge_t));
     }
 
-    if (new_edges == NULL)
-	return _cairo_error (CAIRO_STATUS_NO_MEMORY);
+    if (new_edges == NULL) {
+	polygon->status = _cairo_error (CAIRO_STATUS_NO_MEMORY);
+	return FALSE;
+    }
 
     polygon->edges = new_edges;
     polygon->edges_size = new_size;
 
-    return CAIRO_STATUS_SUCCESS;
+    return TRUE;
 }
 
-void
-_cairo_polygon_add_edge (cairo_polygon_t *polygon, cairo_point_t *p1, cairo_point_t *p2)
+static void
+_cairo_polygon_add_edge (cairo_polygon_t *polygon,
+			 const cairo_point_t *p1,
+			 const cairo_point_t *p2)
 {
     cairo_edge_t *edge;
 
-    if (polygon->status)
-	return;
-
     /* drop horizontal edges */
     if (p1->y == p2->y)
 	goto DONE;
 
-    if (polygon->num_edges >= polygon->edges_size) {
-	polygon->status = _cairo_polygon_grow (polygon);
-	if (polygon->status)
+    if (polygon->num_edges == polygon->edges_size) {
+	if (! _cairo_polygon_grow (polygon))
 	    return;
     }
 
-    edge = &polygon->edges[polygon->num_edges];
+    edge = &polygon->edges[polygon->num_edges++];
     if (p1->y < p2->y) {
 	edge->edge.p1 = *p1;
 	edge->edge.p2 = *p2;
@@ -130,18 +111,14 @@ _cairo_polygon_add_edge (cairo_polygon_t *polygon, cairo_point_t *p1, cairo_poin
 	edge->clockWise = 0;
     }
 
-    polygon->num_edges++;
-
   DONE:
     _cairo_polygon_move_to (polygon, p2);
 }
 
 void
-_cairo_polygon_move_to (cairo_polygon_t *polygon, cairo_point_t *point)
+_cairo_polygon_move_to (cairo_polygon_t *polygon,
+			const cairo_point_t *point)
 {
-    if (polygon->status)
-	return;
-
     if (! polygon->has_current_point)
 	polygon->first_point = *point;
 
@@ -150,24 +127,18 @@ _cairo_polygon_move_to (cairo_polygon_t *polygon, cairo_point_t *point)
 }
 
 void
-_cairo_polygon_line_to (cairo_polygon_t *polygon, cairo_point_t *point)
+_cairo_polygon_line_to (cairo_polygon_t *polygon,
+			const cairo_point_t *point)
 {
-    if (polygon->status)
-	return;
-
-    if (polygon->has_current_point) {
+    if (polygon->has_current_point)
 	_cairo_polygon_add_edge (polygon, &polygon->current_point, point);
-    } else {
+    else
 	_cairo_polygon_move_to (polygon, point);
-    }
 }
 
 void
 _cairo_polygon_close (cairo_polygon_t *polygon)
 {
-    if (polygon->status)
-	return;
-
     if (polygon->has_current_point) {
 	_cairo_polygon_add_edge (polygon,
 				 &polygon->current_point,