mutter/pango/cogl-pango-glyph-cache.c
Neil Roberts 14ed963b05 cogl-debug: Add an option to disable atlasing sharing
If COGL_DEBUG contains disable-shared-atlas Cogl will not try to share
the atlas between glyphs and images.
2011-05-05 17:32:31 +01:00

415 lines
13 KiB
C

/*
* Clutter.
*
* An OpenGL based 'interactive canvas' library.
*
* Authored By Matthew Allum <mallum@openedhand.com>
*
* Copyright (C) 2008 OpenedHand
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see <http://www.gnu.org/licenses>.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <glib.h>
#include "cogl-pango-glyph-cache.h"
#include "cogl-pango-private.h"
#include "cogl/cogl-atlas.h"
#include "cogl/cogl-atlas-texture-private.h"
typedef struct _CoglPangoGlyphCacheKey CoglPangoGlyphCacheKey;
struct _CoglPangoGlyphCache
{
/* Hash table to quickly check whether a particular glyph in a
particular font is already cached */
GHashTable *hash_table;
/* List of CoglAtlases */
GSList *atlases;
/* List of callbacks to invoke when an atlas is reorganized */
GHookList reorganize_callbacks;
/* TRUE if we've ever stored a texture in the global atlas. This is
used to make sure we only register one callback to listen for
global atlas reorganizations */
gboolean using_global_atlas;
/* True if some of the glyphs are dirty. This is used as an
optimization in _cogl_pango_glyph_cache_set_dirty_glyphs to avoid
iterating the hash table if we know none of them are dirty */
gboolean has_dirty_glyphs;
/* Whether mipmapping is being used for this cache. This only
affects whether we decide to put the glyph in the global atlas */
gboolean use_mipmapping;
};
struct _CoglPangoGlyphCacheKey
{
PangoFont *font;
PangoGlyph glyph;
};
static void
cogl_pango_glyph_cache_value_free (CoglPangoGlyphCacheValue *value)
{
if (value->texture)
cogl_handle_unref (value->texture);
g_slice_free (CoglPangoGlyphCacheValue, value);
}
static void
cogl_pango_glyph_cache_key_free (CoglPangoGlyphCacheKey *key)
{
g_object_unref (key->font);
g_slice_free (CoglPangoGlyphCacheKey, key);
}
static guint
cogl_pango_glyph_cache_hash_func (gconstpointer key)
{
const CoglPangoGlyphCacheKey *cache_key
= (const CoglPangoGlyphCacheKey *) key;
/* Generate a number affected by both the font and the glyph
number. We can safely directly compare the pointers because the
key holds a reference to the font so it is not possible that a
different font will have the same memory address */
return GPOINTER_TO_UINT (cache_key->font) ^ cache_key->glyph;
}
static gboolean
cogl_pango_glyph_cache_equal_func (gconstpointer a,
gconstpointer b)
{
const CoglPangoGlyphCacheKey *key_a
= (const CoglPangoGlyphCacheKey *) a;
const CoglPangoGlyphCacheKey *key_b
= (const CoglPangoGlyphCacheKey *) b;
/* We can safely directly compare the pointers for the fonts because
the key holds a reference to the font so it is not possible that
a different font will have the same memory address */
return key_a->font == key_b->font
&& key_a->glyph == key_b->glyph;
}
CoglPangoGlyphCache *
cogl_pango_glyph_cache_new (gboolean use_mipmapping)
{
CoglPangoGlyphCache *cache;
cache = g_malloc (sizeof (CoglPangoGlyphCache));
cache->hash_table = g_hash_table_new_full
(cogl_pango_glyph_cache_hash_func,
cogl_pango_glyph_cache_equal_func,
(GDestroyNotify) cogl_pango_glyph_cache_key_free,
(GDestroyNotify) cogl_pango_glyph_cache_value_free);
cache->atlases = NULL;
g_hook_list_init (&cache->reorganize_callbacks, sizeof (GHook));
cache->has_dirty_glyphs = FALSE;
cache->use_mipmapping = use_mipmapping;
return cache;
}
static void
cogl_pango_glyph_cache_reorganize_cb (void *user_data)
{
CoglPangoGlyphCache *cache = user_data;
g_hook_list_invoke (&cache->reorganize_callbacks, FALSE);
}
void
cogl_pango_glyph_cache_clear (CoglPangoGlyphCache *cache)
{
g_slist_foreach (cache->atlases, (GFunc) cogl_object_unref, NULL);
g_slist_free (cache->atlases);
cache->atlases = NULL;
cache->has_dirty_glyphs = FALSE;
g_hash_table_remove_all (cache->hash_table);
}
void
cogl_pango_glyph_cache_free (CoglPangoGlyphCache *cache)
{
if (cache->using_global_atlas)
_cogl_atlas_texture_remove_reorganize_callback
(cogl_pango_glyph_cache_reorganize_cb, cache);
cogl_pango_glyph_cache_clear (cache);
g_hash_table_unref (cache->hash_table);
g_hook_list_clear (&cache->reorganize_callbacks);
g_free (cache);
}
static void
cogl_pango_glyph_cache_update_position_cb (void *user_data,
CoglHandle new_texture,
const CoglRectangleMapEntry *rect)
{
CoglPangoGlyphCacheValue *value = user_data;
float tex_width, tex_height;
if (value->texture)
cogl_handle_unref (value->texture);
value->texture = cogl_handle_ref (new_texture);
tex_width = cogl_texture_get_width (new_texture);
tex_height = cogl_texture_get_height (new_texture);
value->tx1 = rect->x / tex_width;
value->ty1 = rect->y / tex_height;
value->tx2 = (rect->x + value->draw_width) / tex_width;
value->ty2 = (rect->y + value->draw_height) / tex_height;
value->tx_pixel = rect->x;
value->ty_pixel = rect->y;
/* The glyph has changed position so it will need to be redrawn */
value->dirty = TRUE;
}
static gboolean
cogl_pango_glyph_cache_add_to_global_atlas (CoglPangoGlyphCache *cache,
PangoFont *font,
PangoGlyph glyph,
CoglPangoGlyphCacheValue *value)
{
CoglHandle texture;
if (COGL_DEBUG_ENABLED (COGL_DEBUG_DISABLE_SHARED_ATLAS))
return FALSE;
/* If the cache is using mipmapping then we can't use the global
atlas because it would just get migrated back out */
if (cache->use_mipmapping)
return FALSE;
texture = _cogl_atlas_texture_new_with_size (value->draw_width,
value->draw_height,
COGL_TEXTURE_NONE,
COGL_PIXEL_FORMAT_RGBA_8888_PRE);
if (texture == COGL_INVALID_HANDLE)
return FALSE;
value->texture = texture;
value->tx1 = 0;
value->ty1 = 0;
value->tx2 = 1;
value->ty2 = 1;
value->tx_pixel = 0;
value->ty_pixel = 0;
/* The first time we store a texture in the global atlas we'll
register for notifications when the global atlas is reorganized
so we can forward the notification on as a glyph
reorganization */
if (!cache->using_global_atlas)
{
_cogl_atlas_texture_add_reorganize_callback
(cogl_pango_glyph_cache_reorganize_cb, cache);
cache->using_global_atlas = TRUE;
}
return TRUE;
}
static gboolean
cogl_pango_glyph_cache_add_to_local_atlas (CoglPangoGlyphCache *cache,
PangoFont *font,
PangoGlyph glyph,
CoglPangoGlyphCacheValue *value)
{
CoglAtlas *atlas = NULL;
GSList *l;
/* Look for an atlas that can reserve the space */
for (l = cache->atlases; l; l = l->next)
if (_cogl_atlas_reserve_space (l->data,
value->draw_width + 1,
value->draw_height + 1,
value))
{
atlas = l->data;
break;
}
/* If we couldn't find one then start a new atlas */
if (atlas == NULL)
{
atlas = _cogl_atlas_new (COGL_PIXEL_FORMAT_A_8,
COGL_ATLAS_CLEAR_TEXTURE |
COGL_ATLAS_DISABLE_MIGRATION,
cogl_pango_glyph_cache_update_position_cb);
COGL_NOTE (ATLAS, "Created new atlas for glyphs: %p", atlas);
/* If we still can't reserve space then something has gone
seriously wrong so we'll just give up */
if (!_cogl_atlas_reserve_space (atlas,
value->draw_width + 1,
value->draw_height + 1,
value))
{
cogl_object_unref (atlas);
return FALSE;
}
_cogl_atlas_add_reorganize_callback
(atlas, cogl_pango_glyph_cache_reorganize_cb, NULL, cache);
cache->atlases = g_slist_prepend (cache->atlases, atlas);
}
return TRUE;
}
CoglPangoGlyphCacheValue *
cogl_pango_glyph_cache_lookup (CoglPangoGlyphCache *cache,
gboolean create,
PangoFont *font,
PangoGlyph glyph)
{
CoglPangoGlyphCacheKey lookup_key;
CoglPangoGlyphCacheValue *value;
lookup_key.font = font;
lookup_key.glyph = glyph;
value = g_hash_table_lookup (cache->hash_table, &lookup_key);
if (create && value == NULL)
{
CoglPangoGlyphCacheKey *key;
PangoRectangle ink_rect;
value = g_slice_new (CoglPangoGlyphCacheValue);
value->texture = COGL_INVALID_HANDLE;
pango_font_get_glyph_extents (font, glyph, &ink_rect, NULL);
pango_extents_to_pixels (&ink_rect, NULL);
value->draw_x = ink_rect.x;
value->draw_y = ink_rect.y;
value->draw_width = ink_rect.width;
value->draw_height = ink_rect.height;
/* If the glyph is zero-sized then we don't need to reserve any
space for it and we can just avoid painting anything */
if (ink_rect.width < 1 || ink_rect.height < 1)
value->dirty = FALSE;
else
{
/* Try adding the glyph to the global atlas... */
if (!cogl_pango_glyph_cache_add_to_global_atlas (cache,
font,
glyph,
value) &&
/* If it fails try the local atlas */
!cogl_pango_glyph_cache_add_to_local_atlas (cache,
font,
glyph,
value))
{
cogl_pango_glyph_cache_value_free (value);
return NULL;
}
value->dirty = TRUE;
cache->has_dirty_glyphs = TRUE;
}
key = g_slice_new (CoglPangoGlyphCacheKey);
key->font = g_object_ref (font);
key->glyph = glyph;
g_hash_table_insert (cache->hash_table, key, value);
}
return value;
}
static void
_cogl_pango_glyph_cache_set_dirty_glyphs_cb (gpointer key_ptr,
gpointer value_ptr,
gpointer user_data)
{
CoglPangoGlyphCacheKey *key = key_ptr;
CoglPangoGlyphCacheValue *value = value_ptr;
CoglPangoGlyphCacheDirtyFunc func = user_data;
if (value->dirty)
{
func (key->font, key->glyph, value);
value->dirty = FALSE;
}
}
void
_cogl_pango_glyph_cache_set_dirty_glyphs (CoglPangoGlyphCache *cache,
CoglPangoGlyphCacheDirtyFunc func)
{
/* If we know that there are no dirty glyphs then we can shortcut
out early */
if (!cache->has_dirty_glyphs)
return;
g_hash_table_foreach (cache->hash_table,
_cogl_pango_glyph_cache_set_dirty_glyphs_cb,
func);
cache->has_dirty_glyphs = FALSE;
}
void
_cogl_pango_glyph_cache_add_reorganize_callback (CoglPangoGlyphCache *cache,
GHookFunc func,
void *user_data)
{
GHook *hook = g_hook_alloc (&cache->reorganize_callbacks);
hook->func = func;
hook->data = user_data;
g_hook_prepend (&cache->reorganize_callbacks, hook);
}
void
_cogl_pango_glyph_cache_remove_reorganize_callback (CoglPangoGlyphCache *cache,
GHookFunc func,
void *user_data)
{
GHook *hook = g_hook_find_func_data (&cache->reorganize_callbacks,
FALSE,
func,
user_data);
if (hook)
g_hook_destroy_link (&cache->reorganize_callbacks, hook);
}