Fix shared use of recording surface with paginated targets

The problem is _cairo_recording_surface_replay_and_create_regions()
stores the cairo_recording_region_type_t in the same structure as the
recording commands. This does not work well when the recording surface
is used as source by multiple surfaces

Fix this by moving the cairo_recording_region_type_t into a separate
struct cairo_recording_regions_array_t. This struct is stored in a
list that allows multiple create regions results to be store in the
surface.

The new function _cairo_recording_surface_region_array_attach() is
used to create a new cairo_recording_regions_array_t, attach it to the
recording surface and return a unique region id.

The _cairo_recording_surface_replay_and_create_regions() and
_cairo_recording_surface_replay_region() functions use this region id
to identify the cairo_recording_regions_array_t.

To handle nested recording surfaces, when replaying a recording, the
region id is passed to the target as an extra parameter in the surface
pattern. The wrapper surface makes a temporary copy of the pattern to
ensure the snapshot pattern in the recording surface is not modified.

cairo_recording_regions_array_t has a reference count so the target
can hold on to the cairo_recording_regions_array_t after the paginated
surface has called _cairo_recording_surface_region_array_remove().

1 files changed, 55 insertions, 8 deletions

diff --git a/src/cairo-recording-surface-private.h b/src/cairo-recording-surface-private.h
index 3d325383b..7d4de1ed9 100644
--- a/src/cairo-recording-surface-private.h
+++ b/src/cairo-recording-surface-private.h
@@ -1,3 +1,4 @@
+/* -*- Mode: c; tab-width: 8; c-basic-offset: 4; indent-tabs-mode: t; -*- */
 /* cairo - a vector graphics library with display and print output
  *
  * Copyright © 2005 Red Hat, Inc
@@ -55,14 +56,19 @@ typedef enum {
 } cairo_command_type_t;
 
 typedef enum {
-    CAIRO_RECORDING_REGION_ALL,
+    CAIRO_RECORDING_REGION_ALL = 0,
     CAIRO_RECORDING_REGION_NATIVE,
     CAIRO_RECORDING_REGION_IMAGE_FALLBACK
 } cairo_recording_region_type_t;
 
+typedef enum {
+    CAIRO_RECORDING_REPLAY,
+    CAIRO_RECORDING_CREATE_REGIONS,
+    CAIRO_RECORDING_REPLAY_REGION
+} cairo_recording_replay_type_t;
+
 typedef struct _cairo_command_header {
     cairo_command_type_t	 type;
-    cairo_recording_region_type_t region;
     cairo_operator_t		 op;
     cairo_rectangle_int_t	 extents;
     cairo_clip_t		*clip;
@@ -155,8 +161,27 @@ typedef struct _cairo_recording_surface {
 	struct bbtree *left, *right;
 	cairo_command_header_t *chain;
     } bbtree;
+
+    /* The mutex protects modification to all subsequent fields. */
+    cairo_mutex_t mutex;
+
+    cairo_list_t region_array_list;
+
 } cairo_recording_surface_t;
 
+typedef struct _cairo_recording_region_element {
+    cairo_recording_region_type_t region;
+    unsigned int source_id;
+    unsigned int mask_id;
+} cairo_recording_region_element_t;
+
+typedef struct _cairo_recording_region_array {
+    unsigned int id;
+    cairo_reference_count_t ref_count;
+    cairo_array_t regions; /* cairo_recording_region_element_t */
+    cairo_list_t link;
+} cairo_recording_regions_array_t;
+
 slim_hidden_proto (cairo_recording_surface_create);
 
 cairo_private cairo_int_status_t
@@ -182,18 +207,21 @@ cairo_private cairo_status_t
 _cairo_recording_surface_replay_with_clip (cairo_surface_t *surface,
 					   const cairo_matrix_t *surface_transform,
 					   cairo_surface_t *target,
-					   const cairo_clip_t *target_clip);
+					   const cairo_clip_t *target_clip,
+                                           cairo_bool_t surface_is_unbounded);
 
 cairo_private cairo_status_t
-_cairo_recording_surface_replay_and_create_regions (cairo_surface_t *surface,
+_cairo_recording_surface_replay_and_create_regions (cairo_surface_t      *surface,
+                                                    unsigned int          regions_id,
 						    const cairo_matrix_t *surface_transform,
-						    cairo_surface_t *target,
-						    cairo_bool_t surface_is_unbounded);
+						    cairo_surface_t      *target,
+						    cairo_bool_t          surface_is_unbounded);
 cairo_private cairo_status_t
 _cairo_recording_surface_replay_region (cairo_surface_t			*surface,
-					const cairo_rectangle_int_t *surface_extents,
+                                        unsigned int                     regions_id,
+					const cairo_rectangle_int_t     *surface_extents,
 					cairo_surface_t			*target,
-					cairo_recording_region_type_t	region);
+					cairo_recording_region_type_t	 region);
 
 cairo_private cairo_status_t
 _cairo_recording_surface_get_bbox (cairo_recording_surface_t *recording,
@@ -211,4 +239,23 @@ _cairo_recording_surface_has_only_bilevel_alpha (cairo_recording_surface_t *surf
 cairo_private cairo_bool_t
 _cairo_recording_surface_has_only_op_over (cairo_recording_surface_t *surface);
 
+cairo_private cairo_status_t
+_cairo_recording_surface_region_array_attach (cairo_surface_t *surface,
+                                              unsigned int    *id);
+
+cairo_private void
+_cairo_recording_surface_region_array_reference (cairo_surface_t *surface,
+                                                 unsigned int     id);
+
+cairo_private void
+_cairo_recording_surface_region_array_remove (cairo_surface_t *surface,
+                                              unsigned int     id);
+
+cairo_private void
+_cairo_debug_print_recording_surface (FILE            *file,
+				      cairo_surface_t *surface,
+                                      unsigned int     regions_id,
+				      int              indent,
+				      cairo_bool_t     recurse);
+
 #endif /* CAIRO_RECORDING_SURFACE_H */