mutter/cogl-pango/cogl-pango-glyph-cache.c
Robert Bragg 73e8a6d7ce Allow lazy texture storage allocation
Consistent with how we lazily allocate framebuffers this patch allows us
to instantiate textures but still specify constraints and requirements
before allocating storage so that we can be sure to allocate the most
appropriate/efficient storage.

This adds a cogl_texture_allocate() function that is analogous to
cogl_framebuffer_allocate() which can optionally be called to explicitly
allocate storage and catch any errors. If this function isn't used
explicitly then Cogl will implicitly ensure textures are allocated
before the storage is needed.

It is generally recommended to rely on lazy storage allocation or at
least perform explicit allocation as late as possible so Cogl can be
fully informed about the best way to allocate storage.

Reviewed-by: Neil Roberts <neil@linux.intel.com>

(cherry picked from commit 1fa7c0f10a8a03043e3c75cb079a49625df098b7)

Note: This reverts the cogl_texture_rectangle_new_with_size API change
that dropped the CoglError argument and keeps the semantics of
allocating the texture immediately. This is because Mutter currently
uses this API so we will probably look at updating this later once
we have a corresponding Mutter patch prepared. The other API changes
were kept since they only affected experimental api.
2013-01-22 17:48:17 +00:00

433 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
{
CoglContext *ctx;
/* 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 */
CoglBool 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 */
CoglBool 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 */
CoglBool use_mipmapping;
};
struct _CoglPangoGlyphCacheKey
{
PangoFont *font;
PangoGlyph glyph;
};
static void
cogl_pango_glyph_cache_value_free (CoglPangoGlyphCacheValue *value)
{
if (value->texture)
cogl_object_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 unsigned int
cogl_pango_glyph_cache_hash_func (const void *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 CoglBool
cogl_pango_glyph_cache_equal_func (const void *a, const void *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 (CoglContext *ctx,
CoglBool use_mipmapping)
{
CoglPangoGlyphCache *cache;
cache = g_malloc (sizeof (CoglPangoGlyphCache));
/* Note: as a rule we don't take references to a CoglContext
* internally since */
cache->ctx = ctx;
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->using_global_atlas = 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 (
cache->ctx,
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,
CoglTexture *new_texture,
const CoglRectangleMapEntry *rect)
{
CoglPangoGlyphCacheValue *value = user_data;
float tex_width, tex_height;
if (value->texture)
cogl_object_unref (value->texture);
value->texture = cogl_object_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 CoglBool
cogl_pango_glyph_cache_add_to_global_atlas (CoglPangoGlyphCache *cache,
PangoFont *font,
PangoGlyph glyph,
CoglPangoGlyphCacheValue *value)
{
CoglAtlasTexture *texture;
CoglError *ignore_error = NULL;
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 (cache->ctx,
value->draw_width,
value->draw_height,
COGL_TEXTURE_NONE,
COGL_PIXEL_FORMAT_RGBA_8888_PRE,
&ignore_error);
if (texture == NULL)
{
cogl_error_free (ignore_error);
return FALSE;
}
value->texture = COGL_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
(cache->ctx,
cogl_pango_glyph_cache_reorganize_cb, cache);
cache->using_global_atlas = TRUE;
}
return TRUE;
}
static CoglBool
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,
CoglBool 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 = NULL;
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 (void *key_ptr,
void *value_ptr,
void *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);
}