Introduce a new compositor architecture

Having spent the last dev cycle looking at how we could specialize the
compositors for various backends, we once again look for the
commonalities in order to reduce the duplication. In part this is
motivated by the idea that spans is a good interface for both the
existent GL backend and pixman, and so they deserve a dedicated
compositor. xcb/xlib target an identical rendering system and so they
should be using the same compositor, and it should be possible to run
that same compositor locally against pixman to generate reference tests.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

P.S. This brings massive upheaval (read breakage) I've tried delaying in
order to fix as many things as possible but now this one patch does far,
far, far too much. Apologies in advance for breaking your favourite
backend, but trust me in that the end result will be much better. :)

1 files changed, 85 insertions, 26 deletions

diff --git a/src/cairo-scaled-font.c b/src/cairo-scaled-font.c
index 5b775469..be612a9b 100644
--- a/src/cairo-scaled-font.c
+++ b/src/cairo-scaled-font.c
@@ -43,6 +43,7 @@
 #include "cairo-image-surface-private.h"
 #include "cairo-pattern-private.h"
 #include "cairo-scaled-font-private.h"
+#include "cairo-surface-backend-private.h"
 
 #if _XOPEN_SOURCE >= 600 || defined (_ISOC99_SOURCE)
 #define ISFINITE(x) isfinite (x)
@@ -199,10 +200,13 @@ static void
 _cairo_scaled_glyph_fini (cairo_scaled_font_t *scaled_font,
 			  cairo_scaled_glyph_t *scaled_glyph)
 {
-    const cairo_surface_backend_t *surface_backend = scaled_font->surface_backend;
-
-    if (surface_backend != NULL && surface_backend->scaled_glyph_fini != NULL)
-	surface_backend->scaled_glyph_fini (scaled_glyph, scaled_font);
+    while (! cairo_list_is_empty (&scaled_glyph->dev_privates)) {
+	cairo_scaled_glyph_private_t *private =
+	    cairo_list_first_entry (&scaled_glyph->dev_privates,
+				    cairo_scaled_glyph_private_t,
+				    link);
+	private->destroy (private, scaled_glyph, scaled_font);
+    }
 
     if (scaled_glyph->surface != NULL)
 	cairo_surface_destroy (&scaled_glyph->surface->base);
@@ -243,8 +247,7 @@ static const cairo_scaled_font_t _cairo_scaled_font_nil = {
     { NULL, NULL },		/* pages */
     FALSE,			/* cache_frozen */
     FALSE,			/* global_cache_frozen */
-    NULL,			/* surface_backend */
-    NULL,			/* surface_private */
+    { NULL, NULL },		/* privates */
     NULL			/* backend */
 };
 
@@ -445,6 +448,8 @@ _cairo_scaled_glyph_page_destroy (void *closure)
     cairo_scaled_font_t *scaled_font;
     unsigned int n;
 
+    assert (! cairo_list_is_empty (&page->link));
+
     scaled_font = (cairo_scaled_font_t *) page->cache_entry.hash;
     for (n = 0; n < page->num_glyphs; n++) {
 	_cairo_hash_table_remove (scaled_font->glyphs,
@@ -734,8 +739,7 @@ _cairo_scaled_font_init (cairo_scaled_font_t               *scaled_font,
 
     CAIRO_MUTEX_INIT (scaled_font->mutex);
 
-    scaled_font->surface_backend = NULL;
-    scaled_font->surface_private = NULL;
+    cairo_list_init (&scaled_font->dev_privates);
 
     scaled_font->backend = backend;
     cairo_list_init (&scaled_font->link);
@@ -826,9 +830,13 @@ _cairo_scaled_font_fini_internal (cairo_scaled_font_t *scaled_font)
 
     CAIRO_MUTEX_FINI (scaled_font->mutex);
 
-    if (scaled_font->surface_backend != NULL &&
-	scaled_font->surface_backend->scaled_font_fini != NULL)
-	scaled_font->surface_backend->scaled_font_fini (scaled_font);
+    while (! cairo_list_is_empty (&scaled_font->dev_privates)) {
+	cairo_scaled_font_private_t *private =
+	    cairo_list_first_entry (&scaled_font->dev_privates,
+				    cairo_scaled_font_private_t,
+				    link);
+	private->destroy (private, scaled_font);
+    }
 
     if (scaled_font->backend != NULL && scaled_font->backend->fini != NULL)
 	scaled_font->backend->fini (scaled_font);
@@ -836,30 +844,77 @@ _cairo_scaled_font_fini_internal (cairo_scaled_font_t *scaled_font)
     _cairo_user_data_array_fini (&scaled_font->user_data);
 }
 
-/* XXX: allow multiple backends to share the font */
 void
-_cairo_scaled_font_revoke_ownership (cairo_scaled_font_t *scaled_font)
+_cairo_scaled_font_fini (cairo_scaled_font_t *scaled_font)
 {
-    if (scaled_font->surface_backend == NULL)
-	return;
+    /* Release the lock to avoid the possibility of a recursive
+     * deadlock when the scaled font destroy closure gets called. */
+    CAIRO_MUTEX_UNLOCK (_cairo_scaled_font_map_mutex);
+    _cairo_scaled_font_fini_internal (scaled_font);
+    CAIRO_MUTEX_LOCK (_cairo_scaled_font_map_mutex);
+}
 
-    _cairo_scaled_font_reset_cache (scaled_font);
+void
+_cairo_scaled_font_attach_private (cairo_scaled_font_t *scaled_font,
+				   cairo_scaled_font_private_t *private,
+				   const void *key,
+				   void (*destroy) (cairo_scaled_font_private_t *,
+						    cairo_scaled_font_t *))
+{
+    private->key = key;
+    private->destroy = destroy;
+    cairo_list_add (&private->link, &scaled_font->dev_privates);
+}
+
+cairo_scaled_font_private_t *
+_cairo_scaled_font_find_private (cairo_scaled_font_t *scaled_font,
+				 const void *key)
+{
+    cairo_scaled_font_private_t *priv;
 
-    if (scaled_font->surface_backend->scaled_font_fini != NULL)
-	scaled_font->surface_backend->scaled_font_fini (scaled_font);
+    cairo_list_foreach_entry (priv, cairo_scaled_font_private_t,
+			      &scaled_font->dev_privates, link)
+    {
+	if (priv->key == key) {
+	    if (priv->link.prev != &scaled_font->dev_privates)
+		cairo_list_move (&priv->link, &scaled_font->dev_privates);
+	    return priv;
+	}
+    }
 
-    scaled_font->surface_backend = NULL;
-    scaled_font->surface_private = NULL;
+    return NULL;
 }
 
 void
-_cairo_scaled_font_fini (cairo_scaled_font_t *scaled_font)
+_cairo_scaled_glyph_attach_private (cairo_scaled_glyph_t *scaled_glyph,
+				   cairo_scaled_glyph_private_t *private,
+				   const void *key,
+				   void (*destroy) (cairo_scaled_glyph_private_t *,
+						    cairo_scaled_glyph_t *,
+						    cairo_scaled_font_t *))
 {
-    /* Release the lock to avoid the possibility of a recursive
-     * deadlock when the scaled font destroy closure gets called. */
-    CAIRO_MUTEX_UNLOCK (_cairo_scaled_font_map_mutex);
-    _cairo_scaled_font_fini_internal (scaled_font);
-    CAIRO_MUTEX_LOCK (_cairo_scaled_font_map_mutex);
+    private->key = key;
+    private->destroy = destroy;
+    cairo_list_add (&private->link, &scaled_glyph->dev_privates);
+}
+
+cairo_scaled_glyph_private_t *
+_cairo_scaled_glyph_find_private (cairo_scaled_glyph_t *scaled_glyph,
+				 const void *key)
+{
+    cairo_scaled_glyph_private_t *priv;
+
+    cairo_list_foreach_entry (priv, cairo_scaled_glyph_private_t,
+			      &scaled_glyph->dev_privates, link)
+    {
+	if (priv->key == key) {
+	    if (priv->link.prev != &scaled_glyph->dev_privates)
+		cairo_list_move (&priv->link, &scaled_glyph->dev_privates);
+	    return priv;
+	}
+    }
+
+    return NULL;
 }
 
 /**
@@ -2209,6 +2264,8 @@ _cairo_scaled_font_glyph_approximate_extents (cairo_scaled_font_t	 *scaled_font,
     extents->height = ceil (y1 + pad) - extents->y;
 }
 
+#if 0
+/* XXX win32 */
 cairo_status_t
 _cairo_scaled_font_show_glyphs (cairo_scaled_font_t	*scaled_font,
 				cairo_operator_t	 op,
@@ -2399,6 +2456,7 @@ CLEANUP_MASK:
 	cairo_surface_destroy (mask);
     return _cairo_scaled_font_set_error (scaled_font, status);
 }
+#endif
 
 /* Add a single-device-unit rectangle to a path. */
 static cairo_status_t
@@ -2844,6 +2902,7 @@ _cairo_scaled_glyph_lookup (cairo_scaled_font_t *scaled_font,
 
 	memset (scaled_glyph, 0, sizeof (cairo_scaled_glyph_t));
 	_cairo_scaled_glyph_set_index (scaled_glyph, index);
+	cairo_list_init (&scaled_glyph->dev_privates);
 
 	/* ask backend to initialize metrics and shape fields */
 	status =