[Pixman] [PATCH 2/8] Add pixman_glyph_cache_t API
Søren Sandmann
sandmann at cs.au.dk
Wed May 30 16:41:39 PDT 2012
From: Søren Sandmann Pedersen <ssp at redhat.com>
This new API allows entire glyph strings to be composited in one go
which reduces overhead compared to multiple calls to
pixman_image_composite32().
The pixman_glyph_cache_t is a hash table that maps two keys (a "font"
and a "glyph" key, but they are just keys; there is no distinction
between them as far as pixman is concerned) to a glyph. Glyphs in the
cache can be composited through two new entry points
pixman_glyph_cache_composite_glyphs() and
pixman_glyph_cache_composite_glyphs_no_mask().
A glyph cache may only be inserted into when it is "frozen", which is
achieved by calling pixman_glyph_cache_freeze(). When
pixman_glyph_cache_thaw() is later called, if the cache has become too
crowded, some glyphs (currently the least-recently-used) will
automatically be evicted. This means that a user must ensure that all
the required glyphs are present in the cache before compositing a
string. The intended way to use the cache is like this:
pixman_glyph_t glyphs[MAX_GLYPHS];
pixman_glyph_cache_freeze (cache);
for (i = 0; i < n_glyphs; ++i)
{
const void *g;
if (!(g = pixman_glyph_cache_lookup (cache, font_key, glyph_key)))
{
img = <rasterize glyph as a pixman_image_t>;
g = pixman_glyph_cache_insert (cache, font_key, glyph_key,
glyph_origin_x, glyph_origin_y,
img);
if (!g)
{
/* Clean up out-of-memory condition */
goto oom;
}
glyphs[i].pos_x = glyph_x_pos;
glyphs[i].pos_y = glyph_y_pos;
glyphs[i].glyph = g;
}
}
pixman_composite_glyphs (op, src, dest, ..., cache, n_glyphs, glyphs);
pixman_glyph_cache_thaw (cache);
---
pixman/Makefile.sources | 1 +
pixman/pixman-glyph.c | 439 +++++++++++++++++++++++++++++++++++++++++++++++
pixman/pixman.h | 56 ++++++
3 files changed, 496 insertions(+)
create mode 100644 pixman/pixman-glyph.c
diff --git a/pixman/Makefile.sources b/pixman/Makefile.sources
index ca3f001..11f959d 100644
--- a/pixman/Makefile.sources
+++ b/pixman/Makefile.sources
@@ -10,6 +10,7 @@ libpixman_sources = \
pixman-edge.c \
pixman-edge-accessors.c \
pixman-fast-path.c \
+ pixman-glyph.c \
pixman-general.c \
pixman-gradient-walker.c \
pixman-image.c \
diff --git a/pixman/pixman-glyph.c b/pixman/pixman-glyph.c
new file mode 100644
index 0000000..05aee86
--- /dev/null
+++ b/pixman/pixman-glyph.c
@@ -0,0 +1,439 @@
+/*
+ * Copyright 2010, 2012, Soren Sandmann <sandmann at cs.au.dk>
+ * Copyright 2010, 2011, Red Hat, Inc
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ * Author: Soren Sandmann <sandmann at cs.au.dk>
+ */
+#include <config.h>
+#include <stdlib.h>
+#include "pixman-private.h"
+
+typedef struct glyph_metrics_t glyph_metrics_t;
+typedef struct glyph_t glyph_t;
+
+#define TOMBSTONE ((glyph_t *)0x1)
+
+/* XXX: These numbers are arbitrary---we've never done any measurements.
+ */
+#define N_GLYPHS_HIGH_WATER (16384)
+#define N_GLYPHS_LOW_WATER (8192)
+#define HASH_SIZE (2 * N_GLYPHS_HIGH_WATER)
+#define HASH_MASK (HASH_SIZE - 1)
+
+struct glyph_t
+{
+ void * font_key;
+ void * glyph_key;
+ int origin_x;
+ int origin_y;
+ pixman_image_t * image;
+ pixman_link_t mru_link;
+};
+
+struct pixman_glyph_cache_t
+{
+ int n_glyphs;
+ int n_tombstones;
+ int freeze_count;
+ pixman_list_t mru;
+ glyph_t * glyphs[HASH_SIZE];
+};
+
+static void
+free_glyph (glyph_t *glyph)
+{
+ pixman_list_unlink (&glyph->mru_link);
+ pixman_image_unref (glyph->image);
+ free (glyph);
+}
+
+static unsigned int
+hash (const void *font_key, const void *glyph_key)
+{
+ size_t key = (size_t)font_key + (size_t)glyph_key;
+
+ /* This hash function is based on one found on Thomas Wang's
+ * web page at
+ *
+ * http://www.concentric.net/~Ttwang/tech/inthash.htm
+ *
+ */
+ key = (key << 15) - key - 1;
+ key = key ^ (key >> 12);
+ key = key + (key << 2);
+ key = key ^ (key >> 4);
+ key = key + (key << 3) + (key << 11);
+ key = key ^ (key >> 16);
+
+ return key;
+}
+
+static glyph_t *
+lookup_glyph (pixman_glyph_cache_t *cache,
+ void *font_key,
+ void *glyph_key)
+{
+ unsigned idx;
+ glyph_t *g;
+
+ idx = hash (font_key, glyph_key);
+ while ((g = cache->glyphs[idx++ & HASH_MASK]))
+ {
+ if (g != TOMBSTONE &&
+ g->font_key == font_key &&
+ g->glyph_key == glyph_key)
+ {
+ return g;
+ }
+ }
+
+ return NULL;
+}
+
+static void
+insert_glyph (pixman_glyph_cache_t *cache,
+ glyph_t *glyph)
+{
+ unsigned idx;
+ glyph_t **loc;
+
+ idx = hash (glyph->font_key, glyph->glyph_key);
+
+ /* Note: we assume that there is room in the table. If there isn't,
+ * this will be an infinite loop.
+ */
+ do
+ {
+ loc = &cache->glyphs[idx++ & HASH_MASK];
+ } while (*loc && *loc != TOMBSTONE);
+
+ if (*loc == TOMBSTONE)
+ cache->n_tombstones--;
+ cache->n_glyphs++;
+
+ *loc = glyph;
+}
+
+static void
+remove_glyph (pixman_glyph_cache_t *cache,
+ glyph_t *glyph)
+{
+ unsigned idx;
+
+ idx = hash (glyph->font_key, glyph->glyph_key);
+ while (cache->glyphs[idx & HASH_MASK] != glyph)
+ idx++;
+
+ cache->glyphs[idx & HASH_MASK] = TOMBSTONE;
+ cache->n_tombstones++;
+ cache->n_glyphs--;
+
+ /* Eliminate tombstones if possible */
+ if (cache->glyphs[(idx + 1) & HASH_MASK] == NULL)
+ {
+ while (cache->glyphs[idx & HASH_MASK] == TOMBSTONE)
+ {
+ cache->glyphs[idx & HASH_MASK] = NULL;
+ cache->n_tombstones--;
+ idx--;
+ }
+ }
+}
+
+static void
+clear_table (pixman_glyph_cache_t *cache)
+{
+ int i;
+
+ for (i = 0; i < HASH_SIZE; ++i)
+ {
+ glyph_t *glyph = cache->glyphs[i];
+
+ if (glyph && glyph != TOMBSTONE)
+ free_glyph (glyph);
+
+ cache->glyphs[i] = NULL;
+ }
+
+ cache->n_glyphs = 0;
+ cache->n_tombstones = 0;
+}
+
+PIXMAN_EXPORT pixman_glyph_cache_t *
+pixman_glyph_cache_create (void)
+{
+ pixman_glyph_cache_t *cache;
+
+ if (!(cache = malloc (sizeof *cache)))
+ return NULL;
+
+ memset (cache->glyphs, 0, sizeof (cache->glyphs));
+ cache->n_glyphs = 0;
+ cache->n_tombstones = 0;
+ cache->freeze_count = 0;
+
+ pixman_list_init (&cache->mru);
+
+ return cache;
+}
+
+PIXMAN_EXPORT void
+pixman_glyph_cache_destroy (pixman_glyph_cache_t *cache)
+{
+ return_if_fail (cache->freeze_count == 0);
+
+ clear_table (cache);
+
+ free (cache);
+}
+
+PIXMAN_EXPORT void
+pixman_glyph_cache_freeze (pixman_glyph_cache_t *cache)
+{
+ cache->freeze_count++;
+}
+
+PIXMAN_EXPORT void
+pixman_glyph_cache_thaw (pixman_glyph_cache_t *cache)
+{
+ if (--cache->freeze_count == 0 &&
+ cache->n_glyphs + cache->n_tombstones > N_GLYPHS_HIGH_WATER)
+ {
+ if (cache->n_tombstones > N_GLYPHS_HIGH_WATER)
+ {
+ /* More than half the entries are
+ * tombstones. Just dump the whole table.
+ */
+ clear_table (cache);
+ }
+
+ while (cache->n_glyphs > N_GLYPHS_LOW_WATER)
+ {
+ glyph_t *glyph = CONTAINER_OF (glyph_t, mru_link, cache->mru.tail);
+
+ remove_glyph (cache, glyph);
+ free_glyph (glyph);
+ }
+ }
+}
+
+PIXMAN_EXPORT const void *
+pixman_glyph_cache_lookup (pixman_glyph_cache_t *cache,
+ void *font_key,
+ void *glyph_key)
+{
+ return lookup_glyph (cache, font_key, glyph_key);
+}
+
+PIXMAN_EXPORT const void *
+pixman_glyph_cache_insert (pixman_glyph_cache_t *cache,
+ void *font_key,
+ void *glyph_key,
+ int origin_x,
+ int origin_y,
+ pixman_image_t *image)
+{
+ glyph_t *glyph;
+ int32_t width, height;
+
+ return_val_if_fail (cache->freeze_count > 0, NULL);
+ return_val_if_fail (image->type == BITS, NULL);
+
+ width = image->bits.width;
+ height = image->bits.height;
+
+ if (cache->n_glyphs >= HASH_SIZE)
+ return NULL;
+
+ if (!(glyph = malloc (sizeof *glyph)))
+ return NULL;
+
+ glyph->font_key = font_key;
+ glyph->glyph_key = glyph_key;
+ glyph->origin_x = origin_x;
+ glyph->origin_y = origin_y;
+
+ if (!(glyph->image = pixman_image_create_bits (
+ image->bits.format, width, height, NULL, -1)))
+ {
+ free (glyph);
+ return NULL;
+ }
+
+ pixman_image_composite32 (PIXMAN_OP_SRC,
+ image, NULL, glyph->image, 0, 0, 0, 0, 0, 0,
+ width, height);
+
+ if (PIXMAN_FORMAT_A (glyph->image->bits.format) != 0 &&
+ PIXMAN_FORMAT_RGB (glyph->image->bits.format) != 0)
+ {
+ pixman_image_set_component_alpha (glyph->image, TRUE);
+ }
+
+ pixman_list_prepend (&cache->mru, &glyph->mru_link);
+
+ _pixman_image_validate (glyph->image);
+ insert_glyph (cache, glyph);
+
+ return glyph;
+}
+
+PIXMAN_EXPORT void
+pixman_glyph_cache_remove (pixman_glyph_cache_t *cache,
+ void *font_key,
+ void *glyph_key)
+{
+ glyph_t *glyph;
+
+ if ((glyph = lookup_glyph (cache, font_key, glyph_key)))
+ {
+ remove_glyph (cache, glyph);
+
+ free_glyph (glyph);
+ }
+}
+
+PIXMAN_EXPORT void
+pixman_glyph_get_extents (pixman_glyph_cache_t *cache,
+ int n_glyphs,
+ pixman_glyph_t *glyphs,
+ pixman_box32_t *extents)
+{
+ int i;
+
+ extents->x1 = extents->y1 = INT32_MAX;
+ extents->x2 = extents->y2 = INT32_MIN;
+
+ for (i = 0; i < n_glyphs; ++i)
+ {
+ glyph_t *glyph = (glyph_t *)glyphs[i].glyph;
+ int x1, y1, x2, y2;
+
+ x1 = glyphs[i].x - glyph->origin_x;
+ y1 = glyphs[i].y - glyph->origin_y;
+ x2 = glyphs[i].x - glyph->origin_x + glyph->image->bits.width;
+ y2 = glyphs[i].y - glyph->origin_y + glyph->image->bits.height;
+
+ if (x1 < extents->x1)
+ extents->x1 = x1;
+ if (y1 < extents->y1)
+ extents->y1 = y1;
+ if (x2 > extents->x2)
+ extents->x2 = x2;
+ if (y2 > extents->y2)
+ extents->y2 = y2;
+ }
+}
+
+PIXMAN_EXPORT void
+pixman_composite_glyphs_no_mask (pixman_op_t op,
+ pixman_image_t *src,
+ pixman_image_t *dest,
+ int32_t src_x,
+ int32_t src_y,
+ int32_t dest_x,
+ int32_t dest_y,
+ pixman_glyph_cache_t *cache,
+ int n_glyphs,
+ pixman_glyph_t *glyphs)
+{
+ int i;
+
+ for (i = 0; i < n_glyphs; ++i)
+ {
+ glyph_t *glyph = (glyph_t *)glyphs[i].glyph;
+ pixman_image_t *glyph_img = glyph->image;
+
+ pixman_image_composite32 (op, src, glyph_img, dest,
+ src_x + glyphs[i].x - glyph->origin_x,
+ src_y + glyphs[i].y - glyph->origin_y,
+ 0, 0,
+ dest_x + glyphs[i].x - glyph->origin_x,
+ dest_y + glyphs[i].y - glyph->origin_y,
+ glyph_img->bits.width,
+ glyph_img->bits.height);
+ }
+}
+
+/* Conceptually, the glyphs are PIXMAN_OP_ADDed to an infinitely big mask image at
+ * the position such that the glyph origin point is positioned at the
+ * (glyphs[i].x, glyphs[i].y) point. Then the (mask_x, mask_y) point of this image
+ * and the (src_x, src_y) position of the source image are both aligned with (dest_x, dest_y)
+ * in the destination image.
+ *
+ * Finally, compositing takes place in the (dest_x, dest_y, dst_x + width, dst_y + height)
+ * rectangle.
+ *
+ * TODO:
+ * - Trim the mask to the destination clip/image?
+ * - Trim composite region based on sources, when the op ignores 0s.
+ */
+PIXMAN_EXPORT void
+pixman_composite_glyphs (pixman_op_t op,
+ pixman_image_t *src,
+ pixman_image_t *dest,
+ pixman_format_code_t mask_format,
+ int32_t src_x,
+ int32_t src_y,
+ int32_t mask_x,
+ int32_t mask_y,
+ int32_t dest_x,
+ int32_t dest_y,
+ int32_t width,
+ int32_t height,
+ pixman_glyph_cache_t *cache,
+ int n_glyphs,
+ pixman_glyph_t *glyphs)
+{
+ pixman_image_t *mask;
+ int i;
+
+ if (!(mask = pixman_image_create_bits (mask_format, width, height, NULL, -1)))
+ return;
+
+ if (PIXMAN_FORMAT_A (mask_format) != 0 &&
+ PIXMAN_FORMAT_RGB (mask_format) != 0)
+ {
+ pixman_image_set_component_alpha (mask, TRUE);
+ }
+
+ for (i = 0; i < n_glyphs; ++i)
+ {
+ glyph_t *glyph = (glyph_t *)glyphs[i].glyph;
+ pixman_image_t *glyph_img = glyph->image;
+
+ pixman_image_composite32 (PIXMAN_OP_ADD, glyph_img, NULL, mask,
+ 0, 0, 0, 0,
+ glyphs[i].x - glyph->origin_x - mask_x,
+ glyphs[i].y - glyph->origin_y - mask_y,
+ glyph->image->bits.width,
+ glyph->image->bits.height);
+ }
+
+ pixman_image_composite32 (op, src, mask, dest,
+ src_x, src_y,
+ 0, 0,
+ dest_x, dest_y,
+ width, height);
+
+ pixman_image_unref (mask);
+}
diff --git a/pixman/pixman.h b/pixman/pixman.h
index 18d9513..17be98b 100644
--- a/pixman/pixman.h
+++ b/pixman/pixman.h
@@ -868,6 +868,62 @@ void pixman_image_composite32 (pixman_op_t op,
void pixman_disable_out_of_bounds_workaround (void);
/*
+ * Glyphs
+ */
+typedef struct pixman_glyph_cache_t pixman_glyph_cache_t;
+typedef struct
+{
+ int x, y;
+ const void *glyph;
+} pixman_glyph_t;
+
+pixman_glyph_cache_t *pixman_glyph_cache_create (void);
+void pixman_glyph_cache_destroy (pixman_glyph_cache_t *cache);
+void pixman_glyph_cache_freeze (pixman_glyph_cache_t *cache);
+void pixman_glyph_cache_thaw (pixman_glyph_cache_t *cache);
+const void * pixman_glyph_cache_lookup (pixman_glyph_cache_t *cache,
+ void *font_key,
+ void *glyph_key);
+const void * pixman_glyph_cache_insert (pixman_glyph_cache_t *cache,
+ void *font_key,
+ void *glyph_key,
+ int origin_x,
+ int origin_y,
+ pixman_image_t *glyph_image);
+void pixman_glyph_cache_remove (pixman_glyph_cache_t *cache,
+ void *font_key,
+ void *glyph_key);
+void pixman_glyph_get_extents (pixman_glyph_cache_t *cache,
+ int n_glyphs,
+ pixman_glyph_t *glyphs,
+ pixman_box32_t *extents);
+void pixman_composite_glyphs (pixman_op_t op,
+ pixman_image_t *src,
+ pixman_image_t *dest,
+ pixman_format_code_t mask_format,
+ int32_t src_x,
+ int32_t src_y,
+ int32_t mask_x,
+ int32_t mask_y,
+ int32_t dest_x,
+ int32_t dest_y,
+ int32_t width,
+ int32_t height,
+ pixman_glyph_cache_t *cache,
+ int n_glyphs,
+ pixman_glyph_t *glyphs);
+void pixman_composite_glyphs_no_mask (pixman_op_t op,
+ pixman_image_t *src,
+ pixman_image_t *dest,
+ int32_t src_x,
+ int32_t src_y,
+ int32_t dest_x,
+ int32_t dest_y,
+ pixman_glyph_cache_t *cache,
+ int n_glyphs,
+ pixman_glyph_t *glyphs);
+
+/*
* Trapezoids
*/
typedef struct pixman_edge pixman_edge_t;
--
1.7.10.2
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