Remove clip handling from generic surface layer.

Handling clip as part of the surface state, as opposed to being part of
the operation state, is cumbersome and a hindrance to providing true proxy
surface support. For example, the clip must be copied from the surface
onto the fallback image, but this was forgotten causing undue hassle in
each backend. Another example is the contortion the meta surface
endures to ensure the clip is correctly recorded. By contrast passing the
clip along with the operation is quite simple and enables us to write
generic handlers for providing surface wrappers. (And in the future, we
should be able to write more esoteric wrappers, e.g. automatic 2x FSAA,
trivially.)

In brief, instead of the surface automatically applying the clip before
calling the backend, the backend can call into a generic helper to apply
clipping. For raster surfaces, clip regions are handled automatically as
part of the composite interface. For vector surfaces, a clip helper is
introduced to replay and callback into an intersect_clip_path() function
as necessary.

Whilst this is not primarily a performance related change (the change
should just move the computation of the clip from the moment it is applied
by the user to the moment it is required by the backend), it is important
to track any potential regression:

ppc:
Speedups
========
image-rgba         evolution-20090607-0    1026085.22 0.18% -> 672972.07 0.77%:  1.52x speedup
▌
image-rgba         evolution-20090618-0    680579.98 0.12% -> 573237.66  0.16%:  1.19x speedup
▎
image-rgba      swfdec-fill-rate-4xaa-0    460296.92 0.36% -> 407464.63  0.42%:  1.13x speedup
▏
image-rgba      swfdec-fill-rate-2xaa-0    128431.95 0.47% -> 115051.86  0.42%:  1.12x speedup
▏
Slowdowns
=========
image-rgba     firefox-periodic-table-0    56837.61 0.78% -> 66055.17    3.20%:  1.09x slowdown
▏

1 files changed, 53 insertions, 60 deletions

diff --git a/boilerplate/cairo-boilerplate-test-surfaces.c b/boilerplate/cairo-boilerplate-test-surfaces.c
index 849627fd3..501866bad 100644
--- a/boilerplate/cairo-boilerplate-test-surfaces.c
+++ b/boilerplate/cairo-boilerplate-test-surfaces.c
@@ -33,6 +33,7 @@
 #include <test-paginated-surface.h>
 #if CAIRO_VERSION >= CAIRO_VERSION_ENCODE(1,9,3)
 #include <test-null-surface.h>
+#include <test-wrapping-surface.h>
 #endif
 
 #include <cairo-types-private.h>
@@ -49,7 +50,8 @@ _cairo_boilerplate_test_fallback_create_surface (const char			 *name,
 						 void				**closure)
 {
     *closure = NULL;
-    return _cairo_test_fallback_surface_create (content, width, height);
+    return _cairo_test_fallback_surface_create (content,
+						ceil (width), ceil (height));
 }
 
 static cairo_surface_t *
@@ -64,7 +66,8 @@ _cairo_boilerplate_test_fallback16_create_surface (const char			 *name,
 						   void				**closure)
 {
     *closure = NULL;
-    return _cairo_test_fallback16_surface_create (content, width, height);
+    return _cairo_test_fallback16_surface_create (content,
+						  ceil (width), ceil (height));
 }
 
 static cairo_surface_t *
@@ -89,11 +92,7 @@ _cairo_boilerplate_test_null_create_surface (const char			 *name,
 static const cairo_user_data_key_t test_paginated_closure_key;
 
 typedef struct {
-    unsigned char *data;
-    cairo_content_t content;
-    int width;
-    int height;
-    int stride;
+    cairo_surface_t *target;
 } test_paginated_closure_t;
 
 static cairo_surface_t *
@@ -115,18 +114,10 @@ _cairo_boilerplate_test_paginated_create_surface (const char			 *name,
     *closure = tpc = xmalloc (sizeof (test_paginated_closure_t));
 
     format = cairo_boilerplate_format_from_content (content);
+    tpc->target = cairo_image_surface_create (format,
+					      ceil (width), ceil (height));
 
-    tpc->content = content;
-    tpc->width = width;
-    tpc->height = height;
-    tpc->stride = cairo_format_stride_for_width (format, width);
-    tpc->data = xcalloc (tpc->stride, height);
-
-    surface = _cairo_test_paginated_surface_create_for_data (tpc->data,
-							     tpc->content,
-							     tpc->width,
-							     tpc->height,
-							     tpc->stride);
+    surface = _cairo_test_paginated_surface_create (tpc->target);
     if (cairo_surface_status (surface))
 	goto CLEANUP;
 
@@ -139,8 +130,9 @@ _cairo_boilerplate_test_paginated_create_surface (const char			 *name,
     cairo_surface_destroy (surface);
     surface = cairo_boilerplate_surface_create_in_error (status);
 
+    cairo_surface_destroy (tpc->target);
+
   CLEANUP:
-    free (tpc->data);
     free (tpc);
     return surface;
 }
@@ -160,8 +152,6 @@ static cairo_status_t
 _cairo_boilerplate_test_paginated_surface_write_to_png (cairo_surface_t	*surface,
 						        const char	*filename)
 {
-    cairo_surface_t *image;
-    cairo_format_t format;
     test_paginated_closure_t *tpc;
     cairo_status_t status;
 
@@ -172,19 +162,7 @@ _cairo_boilerplate_test_paginated_surface_write_to_png (cairo_surface_t	*surface
 	return status;
 
     tpc = cairo_surface_get_user_data (surface, &test_paginated_closure_key);
-
-    format = cairo_boilerplate_format_from_content (tpc->content);
-
-    image = cairo_image_surface_create_for_data (tpc->data,
-						 format,
-						 tpc->width,
-						 tpc->height,
-						 tpc->stride);
-
-    status = cairo_surface_write_to_png (image, filename);
-    cairo_surface_destroy (image);
-
-    return status;
+    return cairo_surface_write_to_png (tpc->target, filename);
 }
 
 static cairo_surface_t *
@@ -193,7 +171,6 @@ _cairo_boilerplate_test_paginated_get_image_surface (cairo_surface_t *surface,
 						     int width,
 						     int height)
 {
-    cairo_format_t format;
     test_paginated_closure_t *tpc;
     cairo_status_t status;
 
@@ -208,30 +185,7 @@ _cairo_boilerplate_test_paginated_get_image_surface (cairo_surface_t *surface,
 	return cairo_boilerplate_surface_create_in_error (status);
 
     tpc = cairo_surface_get_user_data (surface, &test_paginated_closure_key);
-
-    format = cairo_boilerplate_format_from_content (tpc->content);
-
-    if (0) {
-	return cairo_image_surface_create_for_data (tpc->data + tpc->stride * (tpc->height - height) + 4 * (tpc->width - width), /* hide the device offset */
-						    format,
-						    width,
-						    height,
-						    tpc->stride);
-    } else {
-	cairo_surface_t *image, *surface;
-
-	image = cairo_image_surface_create_for_data (tpc->data,
-						     format,
-						     tpc->width,
-						     tpc->height,
-						     tpc->stride);
-	cairo_surface_set_device_offset (image,
-					 tpc->width - width,
-					 tpc->height - height);
-	surface = _cairo_boilerplate_get_image_surface (image, 0, width, height);
-	cairo_surface_destroy (image);
-	return surface;
-    }
+    return _cairo_boilerplate_get_image_surface (tpc->target, 0, width, height);
 }
 
 static void
@@ -239,10 +193,40 @@ _cairo_boilerplate_test_paginated_cleanup (void *closure)
 {
     test_paginated_closure_t *tpc = closure;
 
-    free (tpc->data);
+    cairo_surface_destroy (tpc->target);
     free (tpc);
 }
 
+static cairo_surface_t *
+_cairo_boilerplate_test_wrapping_create_surface (const char			 *name,
+						 cairo_content_t		  content,
+						 double				  width,
+						 double				  height,
+						 double				  max_width,
+						 double				  max_height,
+						 cairo_boilerplate_mode_t	  mode,
+						 int                              id,
+						 void				**closure)
+{
+#if CAIRO_VERSION >= CAIRO_VERSION_ENCODE(1,9,3)
+    cairo_surface_t *target;
+    cairo_surface_t *surface;
+    cairo_format_t format;
+
+    *closure = NULL;
+
+    format = cairo_boilerplate_format_from_content (content);
+    target = cairo_image_surface_create (format, ceil (width), ceil (height));
+    surface = _cairo_test_wrapping_surface_create (target);
+    cairo_surface_destroy (target);
+
+    return surface;
+#else
+    *closure = NULL;
+    return NULL;
+#endif
+}
+
 static const cairo_boilerplate_target_t targets[] = {
     {
 	"test-fallback", "image", NULL, NULL,
@@ -305,6 +289,15 @@ static const cairo_boilerplate_target_t targets[] = {
 	FALSE, TRUE
     },
     {
+	"test-wrapping", "image", NULL, NULL,
+	CAIRO_INTERNAL_SURFACE_TYPE_TEST_WRAPPING,
+	CAIRO_CONTENT_COLOR_ALPHA, 0,
+	_cairo_boilerplate_test_wrapping_create_surface,
+	NULL, NULL,
+	_cairo_boilerplate_get_image_surface,
+	cairo_surface_write_to_png,
+    },
+    {
 	"null", "image", NULL, NULL,
 	CAIRO_INTERNAL_SURFACE_TYPE_NULL,
 	CAIRO_CONTENT_COLOR_ALPHA, 0,