Only reduce the clip if it is not in active use for the operation

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

5 files changed, 44 insertions, 36 deletions

diff --git a/src/cairo-composite-rectangles-private.h b/src/cairo-composite-rectangles-private.h
index c6dac3092..dd5bd4156 100644
--- a/src/cairo-composite-rectangles-private.h
+++ b/src/cairo-composite-rectangles-private.h
@@ -53,11 +53,13 @@ CAIRO_BEGIN_DECLS
 struct _cairo_composite_rectangles {
     cairo_rectangle_int_t source;
     cairo_rectangle_int_t mask;
-    cairo_rectangle_int_t bounded; /* dst */
-    cairo_rectangle_int_t unbounded; /* clip */
+    cairo_rectangle_int_t destination;
+
+    cairo_rectangle_int_t bounded; /* source? IN mask? IN unbounded */
+    cairo_rectangle_int_t unbounded; /* destination IN clip */
     uint32_t is_bounded;
 
-    cairo_clip_t *clip;
+    cairo_clip_t *clip; /* clip will be reduced to the minimal container */
 };
 
 cairo_private cairo_int_status_t
@@ -108,6 +110,10 @@ cairo_private cairo_int_status_t
 _cairo_composite_rectangles_intersect_mask_extents (cairo_composite_rectangles_t *extents,
 						    const cairo_box_t *box);
 
+cairo_private cairo_bool_t
+_cairo_composite_rectangles_can_reduce_clip (cairo_composite_rectangles_t *composite,
+					     cairo_clip_t *clip);
+
 cairo_private void
 _cairo_composite_rectangles_fini (cairo_composite_rectangles_t *extents);
 
diff --git a/src/cairo-composite-rectangles.c b/src/cairo-composite-rectangles.c
index 439f453bd..6083973f6 100644
--- a/src/cairo-composite-rectangles.c
+++ b/src/cairo-composite-rectangles.c
@@ -54,11 +54,12 @@ _cairo_composite_rectangles_init (cairo_composite_rectangles_t *extents,
 				  const cairo_clip_t *clip)
 {
     extents->clip = NULL;
+    extents->destination = *unbounded;
 
     if (_cairo_clip_is_all_clipped (clip))
 	return FALSE;
 
-    extents->unbounded = *unbounded;
+    extents->unbounded = extents->destination;
     if (clip != NULL) {
 	if (! _cairo_rectangle_intersect (&extents->unbounded,
 					  _cairo_clip_get_extents (clip)))
@@ -247,3 +248,26 @@ _cairo_composite_rectangles_init_for_glyphs (cairo_composite_rectangles_t *exten
 
     return _cairo_composite_rectangles_intersect (extents, clip);
 }
+
+cairo_bool_t
+_cairo_composite_rectangles_can_reduce_clip (cairo_composite_rectangles_t *composite,
+					     cairo_clip_t *clip)
+{
+    cairo_rectangle_int_t extents;
+
+    if (clip == NULL)
+	return TRUE;
+
+    /* XXX In the not a region case, we could still search through the boxes */
+    if (! _cairo_clip_is_region (clip))
+	return FALSE;
+
+    extents = composite->destination;
+    if (composite->is_bounded & CAIRO_OPERATOR_BOUND_BY_SOURCE)
+	_cairo_rectangle_intersect (&extents, &composite->source);
+    if (composite->is_bounded & CAIRO_OPERATOR_BOUND_BY_MASK)
+	_cairo_rectangle_intersect (&extents, &composite->mask);
+
+    return cairo_region_contains_rectangle (_cairo_clip_get_region (clip),
+					    &extents) == CAIRO_REGION_OVERLAP_IN;
+}
diff --git a/src/cairo-pdf-surface.c b/src/cairo-pdf-surface.c
index ca3a4d237..dd5f68c19 100644
--- a/src/cairo-pdf-surface.c
+++ b/src/cairo-pdf-surface.c
@@ -5793,22 +5793,13 @@ _cairo_pdf_surface_set_clip (cairo_pdf_surface_t *surface,
 {
     cairo_clip_t *clip = composite->clip;
 
-    if (_cairo_clip_is_region (clip) &&
-	cairo_region_contains_rectangle (_cairo_clip_get_region (clip),
-					 &composite->unbounded) == CAIRO_REGION_OVERLAP_IN)
-    {
-	    clip = NULL;
-    }
+    if (_cairo_composite_rectangles_can_reduce_clip (composite, clip))
+	clip = NULL;
 
     if (clip == NULL) {
-	cairo_clip_t *current = surface->clipper.clip;
-
-	if (current && _cairo_clip_is_region (current) &&
-	    cairo_region_contains_rectangle (_cairo_clip_get_region (current),
-					     &composite->unbounded) == CAIRO_REGION_OVERLAP_IN)
-	{
+	if (_cairo_composite_rectangles_can_reduce_clip (composite,
+							 surface->clipper.clip))
 	    return CAIRO_STATUS_SUCCESS;
-	}
     }
 
     return _cairo_surface_clipper_set_clip (&surface->clipper, clip);
diff --git a/src/cairo-ps-surface.c b/src/cairo-ps-surface.c
index 267fd59d3..a9961fe34 100644
--- a/src/cairo-ps-surface.c
+++ b/src/cairo-ps-surface.c
@@ -3617,28 +3617,18 @@ _cairo_ps_surface_set_clip (cairo_ps_surface_t *surface,
 {
     cairo_clip_t *clip = composite->clip;
 
-    if (_cairo_clip_is_region (clip) &&
-	cairo_region_contains_rectangle (_cairo_clip_get_region (clip),
-					 &composite->unbounded) == CAIRO_REGION_OVERLAP_IN)
-    {
-	    clip = NULL;
-    }
+    if (_cairo_composite_rectangles_can_reduce_clip (composite, clip))
+	clip = NULL;
 
     if (clip == NULL) {
-	cairo_clip_t *current = surface->clipper.clip;
-
-	if (current && _cairo_clip_is_region (current) &&
-	    cairo_region_contains_rectangle (_cairo_clip_get_region (current),
-					     &composite->unbounded) == CAIRO_REGION_OVERLAP_IN)
-	{
+	if (_cairo_composite_rectangles_can_reduce_clip (composite,
+							 surface->clipper.clip))
 	    return CAIRO_STATUS_SUCCESS;
-	}
     }
 
     return _cairo_surface_clipper_set_clip (&surface->clipper, clip);
 }
 
-
 static cairo_int_status_t
 _cairo_ps_surface_paint (void			*abstract_surface,
 			 cairo_operator_t	 op,
diff --git a/src/cairo-recording-surface.c b/src/cairo-recording-surface.c
index 87b911900..0daf67576 100644
--- a/src/cairo-recording-surface.c
+++ b/src/cairo-recording-surface.c
@@ -587,11 +587,8 @@ _command_init (cairo_recording_surface_t *surface,
 
     /* steal the clip */
     command->clip = NULL;
-    if (! _cairo_clip_is_region (composite->clip) ||
-	composite->mask.width > composite->unbounded.width ||
-	composite->mask.height > composite->unbounded.height ||
-	cairo_region_contains_rectangle (_cairo_clip_get_region (composite->clip),
-					 &composite->unbounded) != CAIRO_REGION_OVERLAP_IN)
+    if (! _cairo_composite_rectangles_can_reduce_clip (composite,
+						       composite->clip))
     {
 	command->clip = composite->clip;
 	composite->clip = NULL;