[Pixman] [PATCH] Remove x and y coordinates from analyze_extents() and compute_sample_extents()

[Søren Sandmann]

From: Søren Sandmann Pedersen <ssp at redhat.com>

These coordinates were only ever used for subtracting from the extents
box to put it into the coordinate space of the image, so we might as
well do this coordinate translation only once before entering the
functions.
---
 pixman/pixman.c |   63 ++++++++++++++++++++++++++++++++----------------------
 1 files changed, 37 insertions(+), 26 deletions(-)

diff --git a/pixman/pixman.c b/pixman/pixman.c
index 75b80c0..9af6e2f 100644
--- a/pixman/pixman.c
+++ b/pixman/pixman.c
@@ -448,7 +448,7 @@ update_cache:
 
 static pixman_bool_t
 compute_sample_extents (pixman_transform_t *transform,
-			pixman_box32_t *extents, int x, int y, 
+			pixman_box32_t *extents,
 			pixman_fixed_t x_off, pixman_fixed_t y_off,
 			pixman_fixed_t width, pixman_fixed_t height)
 {
@@ -456,10 +456,10 @@ compute_sample_extents (pixman_transform_t *transform,
     pixman_fixed_48_16_t tx1, ty1, tx2, ty2;
 
     /* We have checked earlier that (extents->x1 - x) etc. fit in a pixman_fixed_t */
-    x1 = (pixman_fixed_48_16_t)pixman_int_to_fixed (extents->x1 - x) + pixman_fixed_1 / 2;
-    y1 = (pixman_fixed_48_16_t)pixman_int_to_fixed (extents->y1 - y) + pixman_fixed_1 / 2;
-    x2 = (pixman_fixed_48_16_t)pixman_int_to_fixed (extents->x2 - x) - pixman_fixed_1 / 2;
-    y2 = (pixman_fixed_48_16_t)pixman_int_to_fixed (extents->y2 - y) - pixman_fixed_1 / 2;
+    x1 = (pixman_fixed_48_16_t)pixman_int_to_fixed (extents->x1) + pixman_fixed_1 / 2;
+    y1 = (pixman_fixed_48_16_t)pixman_int_to_fixed (extents->y1) + pixman_fixed_1 / 2;
+    x2 = (pixman_fixed_48_16_t)pixman_int_to_fixed (extents->x2) - pixman_fixed_1 / 2;
+    y2 = (pixman_fixed_48_16_t)pixman_int_to_fixed (extents->y2) - pixman_fixed_1 / 2;
 
     if (!transform)
     {
@@ -474,7 +474,7 @@ compute_sample_extents (pixman_transform_t *transform,
 
 	/* Silence GCC */
 	tx1 = ty1 = tx2 = ty2 = 0;
-    
+
 	for (i = 0; i < 4; ++i)
 	{
 	    pixman_fixed_48_16_t tx, ty;
@@ -541,8 +541,9 @@ compute_sample_extents (pixman_transform_t *transform,
 #define IS_16BIT(x) (((x) >= INT16_MIN) && ((x) <= INT16_MAX))
 
 static pixman_bool_t
-analyze_extent (pixman_image_t *image, int x, int y,
-		const pixman_box32_t *extents, uint32_t *flags)
+analyze_extent (pixman_image_t       *image,
+		const pixman_box32_t *extents,
+		uint32_t             *flags)
 {
     pixman_transform_t *transform;
     pixman_fixed_t *params;
@@ -558,10 +559,10 @@ analyze_extent (pixman_image_t *image, int x, int y,
      * check here that the expanded-by-one source
      * extents in destination space fits in 16 bits
      */
-    if (!IS_16BIT (extents->x1 - x - 1)		||
-	!IS_16BIT (extents->y1 - y - 1)		||
-	!IS_16BIT (extents->x2 - x + 1)		||
-	!IS_16BIT (extents->y2 - y + 1))
+    if (!IS_16BIT (extents->x1 - 1)		||
+	!IS_16BIT (extents->y1 - 1)		||
+	!IS_16BIT (extents->x2 + 1)		||
+	!IS_16BIT (extents->y2 + 1))
     {
 	return FALSE;
     }
@@ -577,17 +578,17 @@ analyze_extent (pixman_image_t *image, int x, int y,
 	    return FALSE;
 
 #define ID_AND_NEAREST (FAST_PATH_ID_TRANSFORM | FAST_PATH_NEAREST_FILTER)
-	
+
 	if ((image->common.flags & ID_AND_NEAREST) == ID_AND_NEAREST &&
-	    extents->x1 - x >= 0 &&
-	    extents->y1 - y >= 0 &&
-	    extents->x2 - x <= image->bits.width &&
-	    extents->y2 - y <= image->bits.height)
+	    extents->x1 >= 0 &&
+	    extents->y1 >= 0 &&
+	    extents->x2 <= image->bits.width &&
+	    extents->y2 <= image->bits.height)
 	{
 	    *flags |= FAST_PATH_SAMPLES_COVER_CLIP;
 	    return TRUE;
 	}
-    
+
 	switch (image->common.filter)
 	{
 	case PIXMAN_FILTER_CONVOLUTION:
@@ -623,7 +624,7 @@ analyze_extent (pixman_image_t *image, int x, int y,
 	 * the source image, and set the FAST_PATH_SAMPLES_COVER_CLIP if it is.
 	 */
 	ex = *extents;
-	if (compute_sample_extents (transform, &ex, x, y, x_off, y_off, width, height) &&
+	if (compute_sample_extents (transform, &ex, x_off, y_off, width, height) &&
 	    ex.x1 >= 0 && ex.y1 >= 0 &&
 	    ex.x2 <= image->bits.width && ex.y2 <= image->bits.height)
 	{
@@ -647,7 +648,7 @@ analyze_extent (pixman_image_t *image, int x, int y,
     ex.x2 = extents->x2 + 1;
     ex.y2 = extents->y2 + 1;
 
-    if (!compute_sample_extents (transform, &ex, x, y, x_off, y_off, width, height))
+    if (!compute_sample_extents (transform, &ex, x_off, y_off, width, height))
 	return FALSE;
 
     return TRUE;
@@ -689,7 +690,7 @@ pixman_image_composite32 (pixman_op_t      op,
     pixman_format_code_t src_format, mask_format, dest_format;
     uint32_t src_flags, mask_flags, dest_flags;
     pixman_region32_t region;
-    pixman_box32_t *extents;
+    pixman_box32_t extents;
     pixman_implementation_t *imp;
     pixman_composite_func_t func;
 
@@ -736,12 +737,22 @@ pixman_image_composite32 (pixman_op_t      op,
 	goto out;
     }
 
-    extents = pixman_region32_extents (&region);
+    extents = *pixman_region32_extents (&region);
+
+    extents.x1 -= dest_x - src_x;
+    extents.y1 -= dest_y - src_y;
+    extents.x2 -= dest_x - src_x;
+    extents.y2 -= dest_y - src_y;
 
-    if (!analyze_extent (src, dest_x - src_x, dest_y - src_y, extents, &src_flags))
+    if (!analyze_extent (src, &extents, &src_flags))
 	goto out;
 
-    if (!analyze_extent (mask, dest_x - mask_x, dest_y - mask_y, extents, &mask_flags))
+    extents.x1 -= src_x - mask_x;
+    extents.y1 -= src_y - mask_y;
+    extents.x2 -= src_x - mask_x;
+    extents.y2 -= src_y - mask_y;
+
+    if (!analyze_extent (mask, &extents, &mask_flags))
 	goto out;
 
     /* If the clip is within the source samples, and the samples are opaque,
@@ -751,10 +762,10 @@ pixman_image_composite32 (pixman_op_t      op,
 
     if ((src_flags & BOTH) == BOTH)
 	src_flags |= FAST_PATH_IS_OPAQUE;
-    
+
     if ((mask_flags & BOTH) == BOTH)
 	mask_flags |= FAST_PATH_IS_OPAQUE;
-    
+
     /*
      * Check if we can replace our operator by a simpler one
      * if the src or dest are opaque. The output operator should be
-- 
1.6.0.6