mutter/clutter/pango/cogl-pango-glyph-cache.c
Neil Roberts 54d8aadf1d [cogl] Move the texture filters to be a property of the material layer
The texture filters are now a property of the material layer rather
than the texture object. Whenever a texture is painted with a material
it sets the filters on all of the GL textures in the Cogl texture. The
filter is cached so that it won't be changed unnecessarily.

The automatic mipmap generation has changed so that the mipmaps are
only generated when the texture is painted instead of every time the
data changes. Changing the texture sets a flag to mark that the
mipmaps are dirty. This works better if the FBO extension is available
because we can use glGenerateMipmap. If the extension is not available
it will temporarily enable automatic mipmap generation and reupload
the first pixel of each slice. This requires tracking the data for the
first pixel.

The COGL_TEXTURE_AUTO_MIPMAP flag has been replaced with
COGL_TEXTURE_NO_AUTO_MIPMAP so that it will default to
auto-mipmapping. The mipmap generation is now effectively free if you
are not using a mipmap filter mode so you would only want to disable
it if you had some special reason to generate your own mipmaps.

ClutterTexture no longer has to store its own copy of the filter
mode. Instead it stores it in the material and the property is
directly set and read from that. This fixes problems with the filters
getting out of sync when a cogl handle is set on the texture
directly. It also avoids the mess of having to rerealize the texture
if the filter quality changes to HIGH because Cogl will take of
generating the mipmaps if needed.
2009-06-04 19:03:40 +01:00

353 lines
9.8 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"
/* Minimum width/height for each texture */
#define MIN_TEXTURE_SIZE 256
/* All glyph with heights within this margin from each other can be
put in the same band */
#define BAND_HEIGHT_ROUND 4
typedef struct _CoglPangoGlyphCacheKey CoglPangoGlyphCacheKey;
typedef struct _CoglPangoGlyphCacheTexture CoglPangoGlyphCacheTexture;
typedef struct _CoglPangoGlyphCacheBand CoglPangoGlyphCacheBand;
struct _CoglPangoGlyphCache
{
/* Hash table to quickly check whether a particular glyph in a
particular font is already cached */
GHashTable *hash_table;
/* List of textures */
CoglPangoGlyphCacheTexture *textures;
/* List of horizontal bands of glyphs */
CoglPangoGlyphCacheBand *bands;
};
struct _CoglPangoGlyphCacheKey
{
PangoFont *font;
PangoGlyph glyph;
};
/* Represents one texture that will be used to store glyphs. The
texture is divided into horizontal bands which all contain glyphs
of approximatly the same height */
struct _CoglPangoGlyphCacheTexture
{
/* The width and height of the texture which should always be a
power of two. This can vary so that glyphs larger than
MIN_TEXTURE_SIZE can use a bigger texture */
int texture_size;
/* The remaining vertical space not taken up by any bands */
int space_remaining;
/* The actual texture */
CoglHandle texture;
CoglPangoGlyphCacheTexture *next;
};
/* Represents one horizontal band of a texture. Each band contains
glyphs of a similar height */
struct _CoglPangoGlyphCacheBand
{
/* The y position of the top of the band */
int top;
/* The height of the band */
int height;
/* The remaining horizontal space not taken up by any glyphs */
int space_remaining;
/* The size of the texture. Needed to calculate texture
coordinates */
int texture_size;
/* The texture containing this band */
CoglHandle texture;
CoglPangoGlyphCacheBand *next;
};
static void
cogl_pango_glyph_cache_value_free (CoglPangoGlyphCacheValue *value)
{
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;
}
static void
cogl_pango_glyph_cache_free_textures (CoglPangoGlyphCacheTexture *node)
{
CoglPangoGlyphCacheTexture *next;
while (node)
{
next = node->next;
cogl_handle_unref (node->texture);
g_slice_free (CoglPangoGlyphCacheTexture, node);
node = next;
}
}
static void
cogl_pango_glyph_cache_free_bands (CoglPangoGlyphCacheBand *node)
{
CoglPangoGlyphCacheBand *next;
while (node)
{
next = node->next;
cogl_handle_unref (node->texture);
g_slice_free (CoglPangoGlyphCacheBand, node);
node = next;
}
}
CoglPangoGlyphCache *
cogl_pango_glyph_cache_new (void)
{
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->textures = NULL;
cache->bands = NULL;
return cache;
}
void
cogl_pango_glyph_cache_clear (CoglPangoGlyphCache *cache)
{
cogl_pango_glyph_cache_free_textures (cache->textures);
cache->textures = NULL;
cogl_pango_glyph_cache_free_bands (cache->bands);
cache->bands = NULL;
g_hash_table_remove_all (cache->hash_table);
}
void
cogl_pango_glyph_cache_free (CoglPangoGlyphCache *cache)
{
cogl_pango_glyph_cache_clear (cache);
g_hash_table_unref (cache->hash_table);
g_free (cache);
}
CoglPangoGlyphCacheValue *
cogl_pango_glyph_cache_lookup (CoglPangoGlyphCache *cache,
PangoFont *font,
PangoGlyph glyph)
{
CoglPangoGlyphCacheKey key;
key.font = font;
key.glyph = glyph;
return (CoglPangoGlyphCacheValue *)
g_hash_table_lookup (cache->hash_table, &key);
}
CoglPangoGlyphCacheValue *
cogl_pango_glyph_cache_set (CoglPangoGlyphCache *cache,
PangoFont *font,
PangoGlyph glyph,
gconstpointer pixels,
int width,
int height,
int stride,
int draw_x,
int draw_y)
{
int band_height;
CoglPangoGlyphCacheBand *band;
CoglPangoGlyphCacheKey *key;
CoglPangoGlyphCacheValue *value;
/* Reserve an extra pixel gap around the glyph so that it can pull
in blank pixels when linear filtering is enabled */
width++;
height++;
/* Round the height up to the nearest multiple of
BAND_HEIGHT_ROUND */
band_height = (height + BAND_HEIGHT_ROUND - 1) & ~(BAND_HEIGHT_ROUND - 1);
/* Look for a band with the same height and enough width available */
for (band = cache->bands;
band && (band->height != band_height || band->space_remaining < width);
band = band->next);
if (band == NULL)
{
CoglPangoGlyphCacheTexture *texture;
/* Look for a texture with enough vertical space left for a band
with this height */
for (texture = cache->textures;
texture && (texture->space_remaining < band_height
|| texture->texture_size < width);
texture = texture->next);
if (texture == NULL)
{
guchar *clear_data;
/* Allocate a new texture that is the nearest power of two
greater than the band height or the minimum size,
whichever is lower */
texture = g_slice_new (CoglPangoGlyphCacheTexture);
texture->texture_size = MIN_TEXTURE_SIZE;
while (texture->texture_size < band_height ||
texture->texture_size < width)
{
texture->texture_size *= 2;
}
/* Allocate an empty buffer to clear the texture */
clear_data =
g_malloc0 (texture->texture_size * texture->texture_size);
texture->texture =
cogl_texture_new_from_data (texture->texture_size,
texture->texture_size,
COGL_TEXTURE_NONE,
COGL_PIXEL_FORMAT_A_8,
COGL_PIXEL_FORMAT_A_8,
texture->texture_size,
clear_data);
g_free (clear_data);
texture->space_remaining = texture->texture_size;
texture->next = cache->textures;
cache->textures = texture;
}
band = g_slice_new (CoglPangoGlyphCacheBand);
band->top = texture->texture_size - texture->space_remaining;
band->height = band_height;
band->space_remaining = texture->texture_size;
band->texture = cogl_handle_ref (texture->texture);
band->texture_size = texture->texture_size;
band->next = cache->bands;
cache->bands = band;
texture->space_remaining -= band_height;
}
band->space_remaining -= width;
width--;
height--;
cogl_texture_set_region (band->texture,
0, 0,
band->space_remaining,
band->top,
width, height,
width, height,
COGL_PIXEL_FORMAT_A_8,
stride,
pixels);
key = g_slice_new (CoglPangoGlyphCacheKey);
key->font = g_object_ref (font);
key->glyph = glyph;
value = g_slice_new (CoglPangoGlyphCacheValue);
value->texture = cogl_handle_ref (band->texture);
value->tx1 = (float)(band->space_remaining)
/ band->texture_size;
value->tx2 = (float)(band->space_remaining + width)
/ band->texture_size;
value->ty1 = (float)(band->top)
/ band->texture_size;
value->ty2 = (float)(band->top + height)
/ band->texture_size;
value->draw_x = draw_x;
value->draw_y = draw_y;
value->draw_width = width;
value->draw_height = height;
g_hash_table_insert (cache->hash_table, key, value);
return value;
}