[Pixman] [PATCH 1/7] Refactor calculation of cover flags

[Ben Avison]

This patch has no effect upon the way the flags are calculated, but splitting
it out into a separate patch like this means we can consider the bilinear and
nearest calculations independently.
---
 pixman/pixman.c |   25 ++++++++-----------------
 1 files changed, 8 insertions(+), 17 deletions(-)

diff --git a/pixman/pixman.c b/pixman/pixman.c
index a07c577..982c820 100644
--- a/pixman/pixman.c
+++ b/pixman/pixman.c
@@ -497,29 +497,20 @@ analyze_extent (pixman_image_t       *image,
     if (!compute_transformed_extents (transform, extents, &transformed))
 	return FALSE;
 
-    /* Expand the source area by a tiny bit so account of different rounding that
-     * may happen during sampling. Note that (8 * pixman_fixed_e) is very far from
-     * 0.5 so this won't cause the area computed to be overly pessimistic.
-     */
-    transformed.x1 -= 8 * pixman_fixed_e;
-    transformed.y1 -= 8 * pixman_fixed_e;
-    transformed.x2 += 8 * pixman_fixed_e;
-    transformed.y2 += 8 * pixman_fixed_e;
-
     if (image->common.type == BITS)
     {
-	if (pixman_fixed_to_int (transformed.x1) >= 0			&&
-	    pixman_fixed_to_int (transformed.y1) >= 0			&&
-	    pixman_fixed_to_int (transformed.x2) < image->bits.width	&&
-	    pixman_fixed_to_int (transformed.y2) < image->bits.height)
+	if (pixman_fixed_to_int (transformed.x1 - 8 * pixman_fixed_e) >= 0                &&
+	    pixman_fixed_to_int (transformed.y1 - 8 * pixman_fixed_e) >= 0                &&
+	    pixman_fixed_to_int (transformed.x2 + 8 * pixman_fixed_e) < image->bits.width &&
+	    pixman_fixed_to_int (transformed.y2 + 8 * pixman_fixed_e) < image->bits.height)
 	{
 	    *flags |= FAST_PATH_SAMPLES_COVER_CLIP_NEAREST;
 	}
 
-	if (pixman_fixed_to_int (transformed.x1 - pixman_fixed_1 / 2) >= 0		  &&
-	    pixman_fixed_to_int (transformed.y1 - pixman_fixed_1 / 2) >= 0		  &&
-	    pixman_fixed_to_int (transformed.x2 + pixman_fixed_1 / 2) < image->bits.width &&
-	    pixman_fixed_to_int (transformed.y2 + pixman_fixed_1 / 2) < image->bits.height)
+	if (pixman_fixed_to_int (transformed.x1 - pixman_fixed_1 / 2 - 8 * pixman_fixed_e) >= 0                &&
+	    pixman_fixed_to_int (transformed.y1 - pixman_fixed_1 / 2 - 8 * pixman_fixed_e) >= 0                &&
+	    pixman_fixed_to_int (transformed.x2 + pixman_fixed_1 / 2 + 8 * pixman_fixed_e) < image->bits.width &&
+	    pixman_fixed_to_int (transformed.y2 + pixman_fixed_1 / 2 + 8 * pixman_fixed_e) < image->bits.height)
 	{
 	    *flags |= FAST_PATH_SAMPLES_COVER_CLIP_BILINEAR;
 	}
-- 
1.7.5.4