image: Implement high level interface.

Write a dedicated compositor for pixman so that we avoid the
middle-layer syndrome of surface-fallback. The major upshot of this
rewrite is that the image surface is now several times quicker for glyph
compositing, which dramatically improves performance for text rendering
by firefox and friends. It also uses a couple of the new scan
convertors, such as the rectangular scan converter for rectilinear
paths.

Speedups
========
image-rgba          firefox-talos-gfx-0    342050.17 (342155.88 0.02%) -> 69412.44 (69702.90 0.21%):  4.93x speedup
███▉
image-rgba                        vim-0    97518.13 (97696.23 1.21%) -> 30712.63 (31238.65 0.85%):  3.18x speedup
██▏
image-rgba                  evolution-0    69927.77 (110261.08 19.84%) -> 24430.05 (25368.85 1.89%):  2.86x speedup
█▉
image-rgba                    poppler-0    41452.61 (41547.03 2.51%) -> 21195.52 (21656.85 1.08%):  1.96x speedup
█
image-rgba       firefox-planet-gnome-0    217512.61 (217636.80 0.06%) -> 123341.02 (123641.94 0.12%):  1.76x speedup
▊
image-rgba             swfdec-youtube-0    41302.71 (41373.60 0.11%) -> 31343.93 (31488.87 0.23%):  1.32x speedup
▍
image-rgba         swfdec-giant-steps-0    20699.54 (20739.52 0.10%) -> 17360.19 (17375.51 0.04%):  1.19x speedup
▎
image-rgba                       gvim-0    167837.47 (168027.68 0.51%) -> 151105.94 (151635.85 0.18%):  1.11x speedup
▏
image-rgba          firefox-talos-svg-0    375273.43 (388250.94 1.60%) -> 356846.09 (370370.08 1.86%):  1.05x speedup

src/cairo-mutex-list-private.h

@@ -38,6 +38,8 @@
 
 CAIRO_MUTEX_DECLARE (_cairo_pattern_solid_surface_cache_lock)
 
+CAIRO_MUTEX_DECLARE (_cairo_image_solid_cache_mutex)
+
 CAIRO_MUTEX_DECLARE (_cairo_toy_font_face_mutex)
 CAIRO_MUTEX_DECLARE (_cairo_intern_string_mutex)
 CAIRO_MUTEX_DECLARE (_cairo_scaled_font_map_mutex)

src/cairo-xcb-surface.c

@@ -600,14 +600,8 @@ _get_image_surface (cairo_xcb_surface_t     *surface,
 	 * which takes data in an arbitrary format and converts it
 	 * to something supported by that library.
 	 */
-	image = (cairo_image_surface_t *)
-	    _cairo_image_surface_create_with_masks (data,
-						    &masks,
-						    extents.width,
-						    extents.height,
-						    bytes_per_line);
-	if (image->base.status)
-	    goto FAIL;
+	ASSERT_NOT_REACHED;
+	goto FAIL;
     }
 
     /* Let the surface take ownership of the data */

src/cairoint.h

@@ -833,7 +833,6 @@ struct _cairo_image_surface {
     int depth;
 
     pixman_image_t *pixman_image;
-    cairo_region_t *clip_region;
 
     unsigned owns_data : 1;
     unsigned transparency : 2;
@@ -2162,9 +2161,15 @@ _cairo_format_bits_per_pixel (cairo_format_t format) cairo_const;
 cairo_private cairo_format_t
 _cairo_format_from_content (cairo_content_t content) cairo_const;
 
+cairo_private cairo_format_t
+_cairo_format_from_pixman_format (pixman_format_code_t pixman_format);
+
 cairo_private cairo_content_t
 _cairo_content_from_format (cairo_format_t format) cairo_const;
 
+cairo_private cairo_content_t
+_cairo_content_from_pixman_format (pixman_format_code_t pixman_format);
+
 cairo_private cairo_surface_t *
 _cairo_image_surface_create_for_pixman_image (pixman_image_t		*pixman_image,
 					      pixman_format_code_t	 pixman_format);
@@ -2184,25 +2189,11 @@ _cairo_image_surface_create_with_pixman_format (unsigned char		*data,
 						int			 height,
 						int			 stride);
 
-cairo_private cairo_surface_t *
-_cairo_image_surface_create_with_masks (unsigned char	       *data,
-					cairo_format_masks_t   *format,
-					int			width,
-					int			height,
-					int			stride);
-
 cairo_private cairo_surface_t *
 _cairo_image_surface_create_with_content (cairo_content_t	content,
 					  int			width,
 					  int			height);
 
-cairo_private cairo_surface_t *
-_cairo_image_surface_create_for_data_with_content (unsigned char	*data,
-						   cairo_content_t	 content,
-						   int			 width,
-						   int			 height,
-						   int			 stride);
-
 cairo_private void
 _cairo_image_surface_assume_ownership_of_data (cairo_image_surface_t *surface);