Coalesce some horizontal boxes when walking active listvspans

1 files changed, 16 insertions, 4 deletions

diff --git a/pixman/pixman-region32.c b/pixman/pixman-region32.c
index 3b20e33a..73b0f638 100644
--- a/pixman/pixman-region32.c
+++ b/pixman/pixman-region32.c
@@ -401,18 +401,30 @@ pixman_region32_init_vspans (pixman_region32_t *region,
 
 	if (new_y > y)
 	{
+	    const pixman_vspan32_t *begin;
 	    int winding = 0;
 
-	    for (span = first_active; span != first_top - 1; ++span)
+	    begin = NULL;
+	    for (span = first_active; span != first_top; ++span)
 	    {
 		winding += (*span)->direction;
 
 		if (winding & winding_mask)
 		{
-		    if (!region_builder_add_box (
-			    &builder, (*span)->x, y, (*(span + 1))->x, new_y))
+		    if (!begin)
+			begin = *span;
+		}
+		else
+		{
+		    if (begin)
 		    {
-			goto out;
+			if (!region_builder_add_box (
+				&builder, begin->x, y, (*span)->x, new_y))
+			{
+			    goto out;
+			}
+
+			begin = NULL;
 		    }
 		}
 	    }