[region] Add cairo_region_intersect_rectangle() and _subtract_rectangle()

Intersecting with and subtracting rectangles is quite common, and we
already have cairo_union_rectangle().

5 files changed, 61 insertions, 33 deletions

diff --git a/src/cairo-clip.c b/src/cairo-clip.c
index 8ee6a644..cc43c037 100644
--- a/src/cairo-clip.c
+++ b/src/cairo-clip.c
@@ -198,17 +198,8 @@ _cairo_clip_intersect_to_region (cairo_clip_t   *clip,
     if (!clip)
 	return CAIRO_STATUS_SUCCESS;
 
-    if (clip->all_clipped) {
-	cairo_region_t *clip_rect;
-
-	clip_rect = cairo_region_create_rectangle (&clip->surface_rect);
-
-	status = cairo_region_intersect (region, clip_rect);
-
-	cairo_region_destroy (clip_rect);
-
-	return status;
-    }
+    if (clip->all_clipped)
+	return cairo_region_intersect_rectangle (region, &clip->surface_rect);
 
     if (clip->path) {
 	/* Intersect clip path into region. */
@@ -220,18 +211,8 @@ _cairo_clip_intersect_to_region (cairo_clip_t   *clip,
 	    return status;
     }
 
-    if (clip->surface) {
-	cairo_region_t *clip_rect;
-
-	clip_rect = cairo_region_create_rectangle (&clip->surface_rect);
-
-	status = cairo_region_intersect (region, clip_rect);
-
-	cairo_region_destroy (clip_rect);
-
-        if (unlikely (status))
-            return status;
-    }
+    if (clip->surface)
+	return cairo_region_intersect_rectangle (region, &clip->surface_rect);
 
     return CAIRO_STATUS_SUCCESS;
 }
diff --git a/src/cairo-region.c b/src/cairo-region.c
index a2a7a825..55898d9c 100644
--- a/src/cairo-region.c
+++ b/src/cairo-region.c
@@ -178,6 +178,28 @@ cairo_region_subtract (cairo_region_t *dst, cairo_region_t *other)
 }
 
 cairo_status_t
+cairo_region_subtract_rectangle (cairo_region_t *dst,
+				 cairo_rectangle_int_t *rectangle)
+{
+    cairo_status_t status = CAIRO_STATUS_SUCCESS;
+    pixman_region32_t region;
+
+    if (dst->status)
+	return dst->status;
+    
+    pixman_region32_init_rect (&region,
+			       rectangle->x, rectangle->y,
+			       rectangle->width, rectangle->height);
+
+    if (!pixman_region32_subtract (&dst->rgn, &dst->rgn, &region))
+	status = cairo_region_set_error (dst, CAIRO_STATUS_NO_MEMORY);
+
+    pixman_region32_fini (&region);
+    
+    return status;
+}
+
+cairo_status_t
 cairo_region_intersect (cairo_region_t *dst, cairo_region_t *other)
 {
     if (dst->status)
@@ -193,6 +215,27 @@ cairo_region_intersect (cairo_region_t *dst, cairo_region_t *other)
 }
 
 cairo_status_t
+cairo_region_intersect_rectangle (cairo_region_t *dst,
+				  const cairo_rectangle_int_t *rect)
+{
+    cairo_status_t result = CAIRO_STATUS_SUCCESS;
+    pixman_region32_t region;
+
+    if (dst->status)
+	return dst->status;
+    
+    pixman_region32_init_rect (&region,
+			       rect->x, rect->y, rect->width, rect->height);
+
+    if (!pixman_region32_intersect (&dst->rgn, &dst->rgn, &region))
+	result = _cairo_error (CAIRO_STATUS_NO_MEMORY);
+
+    pixman_region32_fini (&region);
+    
+    return result;
+}
+
+cairo_status_t
 cairo_region_union (cairo_region_t *dst,
 		    cairo_region_t *other)
 {
@@ -210,7 +253,7 @@ cairo_region_union (cairo_region_t *dst,
 
 cairo_status_t
 cairo_region_union_rectangle (cairo_region_t *dst,
-			      cairo_rectangle_int_t *rect)
+			      const cairo_rectangle_int_t *rect)
 {
     if (!pixman_region32_union_rect (&dst->rgn, &dst->rgn,
 				     rect->x, rect->y,
diff --git a/src/cairo-surface.c b/src/cairo-surface.c
index 82cd57ea..1c8445f9 100644
--- a/src/cairo-surface.c
+++ b/src/cairo-surface.c
@@ -2679,8 +2679,6 @@ _cairo_surface_composite_fixup_unbounded_internal (cairo_surface_t         *dst,
 {
     cairo_rectangle_int_t dst_rectangle;
     cairo_rectangle_int_t drawn_rectangle;
-    cairo_bool_t has_drawn_region = FALSE;
-    cairo_region_t *drawn_region = NULL;
     cairo_region_t *clear_region = NULL;
     cairo_status_t status;
 
@@ -2708,10 +2706,7 @@ _cairo_surface_composite_fixup_unbounded_internal (cairo_surface_t         *dst,
 
     /* Now compute the area that is in dst_rectangle but not in drawn_rectangle
      */
-    drawn_region = cairo_region_create_rectangle (&drawn_rectangle);
-    has_drawn_region = TRUE;
-
-    status = cairo_region_subtract (clear_region, drawn_region);
+    status = cairo_region_subtract_rectangle (clear_region, &drawn_rectangle);
     if (unlikely (status))
         goto CLEANUP_REGIONS;
 
@@ -2721,8 +2716,6 @@ _cairo_surface_composite_fixup_unbounded_internal (cairo_surface_t         *dst,
                                          clear_region);
 
   CLEANUP_REGIONS:
-    if (drawn_region)
-        cairo_region_destroy (drawn_region);
     cairo_region_destroy (clear_region);
 
     return _cairo_surface_set_error (dst, status);
diff --git a/src/cairo.h b/src/cairo.h
index 7a5a4d3d..269fe4d9 100644
--- a/src/cairo.h
+++ b/src/cairo.h
@@ -2408,13 +2408,22 @@ cairo_public cairo_status_t
 cairo_region_subtract (cairo_region_t *dst, cairo_region_t *other);
 
 cairo_public cairo_status_t
+cairo_region_subtract_rectangle (cairo_region_t *dst,
+				 cairo_rectangle_int_t *rectangle);
+
+cairo_public cairo_status_t
 cairo_region_intersect (cairo_region_t *dst, cairo_region_t *other);
 
 cairo_public cairo_status_t
+cairo_region_intersect_rectangle (cairo_region_t *dst,
+				  const cairo_rectangle_int_t *rect);
+
+cairo_public cairo_status_t
 cairo_region_union (cairo_region_t *dst, cairo_region_t *other);
 
 cairo_public cairo_status_t
-cairo_region_union_rectangle (cairo_region_t *dst, cairo_rectangle_int_t *rectangle);
+cairo_region_union_rectangle (cairo_region_t *dst,
+			      const cairo_rectangle_int_t *rectangle);
 
 
 /* Functions to be used while debugging (not intended for use in production code) */
diff --git a/src/cairoint.h b/src/cairoint.h
index 1f209a76..6c5fd5a6 100644
--- a/src/cairoint.h
+++ b/src/cairoint.h
@@ -2707,7 +2707,9 @@ slim_hidden_proto (cairo_region_contains_rectangle);
 slim_hidden_proto (cairo_region_contains_point);
 slim_hidden_proto (cairo_region_translate);
 slim_hidden_proto (cairo_region_subtract);
+slim_hidden_proto (cairo_region_subtract_rectangle);
 slim_hidden_proto (cairo_region_intersect);
+slim_hidden_proto (cairo_region_intersect_rectangle);
 slim_hidden_proto (cairo_region_union);
 slim_hidden_proto (cairo_region_union_rectangle);