sna/trapezoids: Use the corrected trapezoid origin for aligned boxes

The rule for the origin of the CompositeTrapezoids routine is the
upper-left corner of the first trapezoid. Care must be taken in case the
trapezoid edge is upside down to consider the upper vertex.

Reported-by: "Jasper St. Pierre" <jstpierre@mecheye.net>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

1 files changed, 29 insertions, 13 deletions

diff --git a/src/sna/sna_trapezoids_boxes.c b/src/sna/sna_trapezoids_boxes.c
index 2f7028fc..a2045dcb 100644
--- a/src/sna/sna_trapezoids_boxes.c
+++ b/src/sna/sna_trapezoids_boxes.c
@@ -120,13 +120,16 @@ composite_aligned_boxes(struct sna *sna,
 	BoxRec stack_boxes[64], *boxes;
 	pixman_region16_t region, clip;
 	struct sna_composite_op tmp;
+	int16_t dst_x, dst_y;
 	bool ret = true;
 	int dx, dy, n, num_boxes;
 
 	if (NO_ALIGNED_BOXES)
 		return false;
 
-	DBG(("%s\n", __FUNCTION__));
+	DBG(("%s: pixmap=%ld, nboxes=%d, dx=(%d, %d)\n", __FUNCTION__,
+	    get_drawable_pixmap(dst->pDrawable)->drawable.serialNumber,
+	    ntrap, dst->pDrawable->x, dst->pDrawable->y));
 
 	boxes = stack_boxes;
 	if (ntrap > (int)ARRAY_SIZE(stack_boxes)) {
@@ -168,19 +171,20 @@ composite_aligned_boxes(struct sna *sna,
 	if (num_boxes == 0)
 		goto free_boxes;
 
-	DBG(("%s: extents (%d, %d), (%d, %d) offset of (%d, %d)\n",
+	trapezoid_origin(&traps[0].left, &dst_x, &dst_y);
+
+	DBG(("%s: extents (%d, %d), (%d, %d) offset of (%d, %d), origin (%d, %d)\n",
 	     __FUNCTION__,
 	     region.extents.x1, region.extents.y1,
 	     region.extents.x2, region.extents.y2,
 	     region.extents.x1 - boxes[0].x1,
-	     region.extents.y1 - boxes[0].y1));
-
-	src_x += region.extents.x1 - boxes[0].x1;
-	src_y += region.extents.y1 - boxes[0].y1;
+	     region.extents.y1 - boxes[0].y1,
+	     dst_x, dst_y));
 
 	if (!sna_compute_composite_region(&clip,
 					  src, NULL, dst,
-					  src_x,  src_y,
+					  src_x + region.extents.x1 - dst_x - dx,
+					  src_y + region.extents.y1 - dst_y - dy,
 					  0, 0,
 					  region.extents.x1 - dx, region.extents.y1 - dy,
 					  region.extents.x2 - region.extents.x1,
@@ -193,14 +197,24 @@ composite_aligned_boxes(struct sna *sna,
 	if (op == PictOpClear && sna->clear)
 		src = sna->clear;
 
+	DBG(("%s: clipped extents (%d, %d), (%d, %d);  now offset by (%d, %d), orgin (%d, %d)\n",
+	     __FUNCTION__,
+	     clip.extents.x1, clip.extents.y1,
+	     clip.extents.x2, clip.extents.y2,
+	     clip.extents.x1 - boxes[0].x1,
+	     clip.extents.y1 - boxes[0].y1,
+	     dst_x, dst_y));
+
 	if (force_fallback ||
 	    !sna->render.composite(sna, op, src, NULL, dst,
-				   src_x,  src_y,
+				   src_x + clip.extents.x1 - dst_x,
+				   src_y + clip.extents.y1 - dst_y,
 				   0, 0,
 				   clip.extents.x1,  clip.extents.y1,
 				   clip.extents.x2 - clip.extents.x1,
 				   clip.extents.y2 - clip.extents.y1,
-				   COMPOSITE_PARTIAL, memset(&tmp, 0, sizeof(tmp)))) {
+				   (clip.data || num_boxes > 1) ?  COMPOSITE_PARTIAL : 0,
+				   memset(&tmp, 0, sizeof(tmp)))) {
 		unsigned int flags;
 		const pixman_box16_t *b;
 		int i, count;
@@ -232,6 +246,8 @@ composite_aligned_boxes(struct sna *sna,
 		}
 
 		DBG(("%s: fbComposite()\n", __FUNCTION__));
+		src_x -= dst_x - dx;
+		src_y -= dst_y - dy;
 		if (maskFormat) {
 			pixman_region_init_rects(&region, boxes, num_boxes);
 			RegionIntersect(&region, &region, &clip);
@@ -241,8 +257,8 @@ composite_aligned_boxes(struct sna *sna,
 				count = region_num_rects(&region);
 				for (i = 0; i < count; i++) {
 					fbComposite(op, src, NULL, dst,
-						    src_x + b[i].x1 - boxes[0].x1,
-						    src_y + b[i].y1 - boxes[0].y1,
+						    src_x + b[i].x1,
+						    src_y + b[i].y1,
 						    0, 0,
 						    b[i].x1, b[i].y1,
 						    b[i].x2 - b[i].x1, b[i].y2 - b[i].y1);
@@ -259,8 +275,8 @@ composite_aligned_boxes(struct sna *sna,
 				if (sigtrap_get() == 0) {
 					for (i = 0; i < count; i++) {
 						fbComposite(op, src, NULL, dst,
-							    src_x + b[i].x1 - boxes[0].x1,
-							    src_y + b[i].y1 - boxes[0].y1,
+							    src_x + b[i].x1,
+							    src_y + b[i].y1,
 							    0, 0,
 							    b[i].x1, b[i].y1,
 							    b[i].x2 - b[i].x1, b[i].y2 - b[i].y1);