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, 59 insertions, 35 deletions

diff --git a/src/cairo-type3-glyph-surface.c b/src/cairo-type3-glyph-surface.c
index 6e7259609..f55b12ac8 100644
--- a/src/cairo-type3-glyph-surface.c
+++ b/src/cairo-type3-glyph-surface.c
@@ -42,9 +42,31 @@
 #include "cairo-output-stream-private.h"
 #include "cairo-meta-surface-private.h"
 #include "cairo-analysis-surface-private.h"
+#include "cairo-surface-clipper-private.h"
 
 static const cairo_surface_backend_t cairo_type3_glyph_surface_backend;
 
+static cairo_status_t
+_cairo_type3_glyph_surface_clipper_intersect_clip_path (cairo_surface_clipper_t *clipper,
+							cairo_path_fixed_t *path,
+							cairo_fill_rule_t   fill_rule,
+							double		    tolerance,
+							cairo_antialias_t   antialias)
+{
+    cairo_type3_glyph_surface_t *surface = cairo_container_of (clipper,
+							       cairo_type3_glyph_surface_t,
+							       clipper);
+
+    if (path == NULL) {
+	_cairo_output_stream_printf (surface->stream, "Q q\n");
+	return CAIRO_STATUS_SUCCESS;
+    }
+
+    return _cairo_pdf_operators_clip (&surface->pdf_operators,
+				      path,
+				      fill_rule);
+}
+
 cairo_surface_t *
 _cairo_type3_glyph_surface_create (cairo_scaled_font_t			 *scaled_font,
 				   cairo_output_stream_t		 *stream,
@@ -81,6 +103,9 @@ _cairo_type3_glyph_surface_create (cairo_scaled_font_t			 *scaled_font,
 			       &surface->cairo_to_pdf,
 			       font_subsets);
 
+    _cairo_surface_clipper_init (&surface->clipper,
+				 _cairo_type3_glyph_surface_clipper_intersect_clip_path);
+
     return &surface->base;
 }
 
@@ -156,29 +181,10 @@ _cairo_type3_glyph_surface_finish (void *abstract_surface)
 }
 
 static cairo_int_status_t
-_cairo_type3_glyph_surface_intersect_clip_path (void		   *abstract_surface,
-						cairo_path_fixed_t *path,
-						cairo_fill_rule_t   fill_rule,
-						double		    tolerance,
-						cairo_antialias_t   antialias)
-{
-    cairo_type3_glyph_surface_t *surface = abstract_surface;
-
-    if (path == NULL) {
-	_cairo_output_stream_printf (surface->stream, "Q q\n");
-	return CAIRO_STATUS_SUCCESS;
-    }
-
-    return _cairo_pdf_operators_clip (&surface->pdf_operators,
-				      path,
-				      fill_rule);
-}
-
-static cairo_int_status_t
 _cairo_type3_glyph_surface_paint (void			*abstract_surface,
 				  cairo_operator_t	 op,
 				  const cairo_pattern_t	*source,
-				  cairo_rectangle_int_t	*extents)
+				  cairo_clip_t		*clip)
 {
     cairo_type3_glyph_surface_t *surface = abstract_surface;
     const cairo_surface_pattern_t *pattern;
@@ -189,8 +195,13 @@ _cairo_type3_glyph_surface_paint (void			*abstract_surface,
     if (source->type != CAIRO_PATTERN_TYPE_SURFACE)
 	return CAIRO_INT_STATUS_IMAGE_FALLBACK;
 
+    status = _cairo_surface_clipper_set_clip (&surface->clipper, clip);
+    if (unlikely (status))
+	return status;
+
     pattern = (const cairo_surface_pattern_t *) source;
-    status = _cairo_surface_acquire_source_image (pattern->surface, &image, &image_extra);
+    status = _cairo_surface_acquire_source_image (pattern->surface,
+						  &image, &image_extra);
     if (unlikely (status))
 	goto fail;
 
@@ -209,9 +220,11 @@ _cairo_type3_glyph_surface_mask (void			*abstract_surface,
 				 cairo_operator_t	 op,
 				 const cairo_pattern_t	*source,
 				 const cairo_pattern_t	*mask,
-				 cairo_rectangle_int_t	*extents)
+				 cairo_clip_t		*clip)
 {
-    return _cairo_type3_glyph_surface_paint (abstract_surface, op, mask, extents);
+    return _cairo_type3_glyph_surface_paint (abstract_surface,
+					     op, mask,
+					     clip);
 }
 
 static cairo_int_status_t
@@ -224,9 +237,14 @@ _cairo_type3_glyph_surface_stroke (void			*abstract_surface,
 				   cairo_matrix_t	*ctm_inverse,
 				   double		 tolerance,
 				   cairo_antialias_t	 antialias,
-				   cairo_rectangle_int_t *extents)
+				   cairo_clip_t		*clip)
 {
     cairo_type3_glyph_surface_t *surface = abstract_surface;
+    cairo_int_status_t status;
+
+    status = _cairo_surface_clipper_set_clip (&surface->clipper, clip);
+    if (unlikely (status))
+	return status;
 
     return _cairo_pdf_operators_stroke (&surface->pdf_operators,
 					path,
@@ -243,16 +261,18 @@ _cairo_type3_glyph_surface_fill (void			*abstract_surface,
 				 cairo_fill_rule_t	 fill_rule,
 				 double			 tolerance,
 				 cairo_antialias_t	 antialias,
-				 cairo_rectangle_int_t  *extents)
+				 cairo_clip_t		*clip)
 {
     cairo_type3_glyph_surface_t *surface = abstract_surface;
     cairo_int_status_t status;
 
-    status = _cairo_pdf_operators_fill (&surface->pdf_operators,
-					path,
-					fill_rule);
+    status = _cairo_surface_clipper_set_clip (&surface->clipper, clip);
+    if (unlikely (status))
+	return status;
 
-    return status;
+    return _cairo_pdf_operators_fill (&surface->pdf_operators,
+				      path,
+				      fill_rule);
 }
 
 static cairo_int_status_t
@@ -262,8 +282,8 @@ _cairo_type3_glyph_surface_show_glyphs (void		     *abstract_surface,
 					cairo_glyph_t        *glyphs,
 					int		      num_glyphs,
 					cairo_scaled_font_t  *scaled_font,
-					int		     *remaining_glyphs,
-					cairo_rectangle_int_t *extents)
+					cairo_clip_t	     *clip,
+					int		     *remaining_glyphs)
 {
     cairo_type3_glyph_surface_t *surface = abstract_surface;
     cairo_int_status_t status;
@@ -271,8 +291,14 @@ _cairo_type3_glyph_surface_show_glyphs (void		     *abstract_surface,
     cairo_matrix_t new_ctm, ctm_inverse;
     int i;
 
-    for (i = 0; i < num_glyphs; i++)
-	cairo_matrix_transform_point (&surface->cairo_to_pdf, &glyphs[i].x, &glyphs[i].y);
+    status = _cairo_surface_clipper_set_clip (&surface->clipper, clip);
+    if (unlikely (status))
+	return status;
+
+    for (i = 0; i < num_glyphs; i++) {
+	cairo_matrix_transform_point (&surface->cairo_to_pdf,
+				      &glyphs[i].x, &glyphs[i].y);
+    }
 
     /* We require the matrix to be invertable. */
     ctm_inverse = scaled_font->ctm;
@@ -316,8 +342,6 @@ static const cairo_surface_backend_t cairo_type3_glyph_surface_backend = {
     NULL, /* check_span_renderer */
     NULL, /* cairo_type3_glyph_surface_copy_page */
     NULL, /* _cairo_type3_glyph_surface_show_page */
-    NULL, /* set_clip_region */
-    _cairo_type3_glyph_surface_intersect_clip_path,
     NULL, /* _cairo_type3_glyph_surface_get_extents */
     NULL, /* old_show_glyphs */
     NULL, /* _cairo_type3_glyph_surface_get_font_options */