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 /*

  * Copyright 2010, 2012, Soren Sandmann <sandmann@cs.au.dk>

  * Copyright 2010, 2011, 2012, 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@cs.au.dk>

  */

 #ifdef HAVE_CONFIG_H

 #include <config.h>

 #endif

 #include "pixman-private.h"

 #include <stdlib.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;

     }

 }

 /* This function returns a format that is suitable for use as a mask for the

  * set of glyphs in question.

  */

 PIXMAN_EXPORT pixman_format_code_t

 pixman_glyph_get_mask_format (pixman_glyph_cache_t *cache,

 			      int		    n_glyphs,

 			      const pixman_glyph_t *glyphs)

 {

     pixman_format_code_t format = PIXMAN_a1;

     int i;

     for (i = 0; i < n_glyphs; ++i)

     {

 	const glyph_t *glyph = glyphs[i].glyph;

 	pixman_format_code_t glyph_format = glyph->image->bits.format;

 	if (PIXMAN_FORMAT_TYPE (glyph_format) == PIXMAN_TYPE_A)

 	{

 	    if (PIXMAN_FORMAT_A (glyph_format) > PIXMAN_FORMAT_A (format))

 		format = glyph_format;

 	}

 	else

 	{

 	    return PIXMAN_a8r8g8b8;

 	}

     }

     return format;

 }

 static pixman_bool_t

 box32_intersect (pixman_box32_t *dest,

 		 const pixman_box32_t *box1,

 		 const pixman_box32_t *box2)

 {

     dest->x1 = MAX (box1->x1, box2->x1);

     dest->y1 = MAX (box1->y1, box2->y1);

     dest->x2 = MIN (box1->x2, box2->x2);

     dest->y2 = MIN (box1->y2, box2->y2);

     return dest->x2 > dest->x1 && dest->y2 > dest->y1;

 }

 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,

 				 const pixman_glyph_t  *glyphs)

 {

     pixman_region32_t region;

     pixman_format_code_t glyph_format = PIXMAN_null;

     uint32_t glyph_flags = 0;

     pixman_format_code_t dest_format;

     uint32_t dest_flags;

     pixman_composite_func_t func = NULL;

     pixman_implementation_t *implementation = NULL;

     pixman_composite_info_t info;

     int i;

     _pixman_image_validate (src);

     _pixman_image_validate (dest);

     dest_format = dest->common.extended_format_code;

     dest_flags = dest->common.flags;

     pixman_region32_init (&region);

     if (!_pixman_compute_composite_region32 (

 	    &region,

 	    src, NULL, dest,

 	    src_x - dest_x, src_y - dest_y, 0, 0, 0, 0,

 	    dest->bits.width, dest->bits.height))

     {

 	goto out;

     }

     info.op = op;

     info.src_image = src;

     info.dest_image = dest;

     info.src_flags = src->common.flags;

     info.dest_flags = dest->common.flags;

     for (i = 0; i < n_glyphs; ++i)

     {

 	glyph_t *glyph = (glyph_t *)glyphs[i].glyph;

 	pixman_image_t *glyph_img = glyph->image;

 	pixman_box32_t glyph_box;

 	pixman_box32_t *pbox;

 	uint32_t extra = FAST_PATH_SAMPLES_COVER_CLIP_NEAREST;

 	pixman_box32_t composite_box;

 	int n;

 	glyph_box.x1 = dest_x + glyphs[i].x - glyph->origin_x;

 	glyph_box.y1 = dest_y + glyphs[i].y - glyph->origin_y;

 	glyph_box.x2 = glyph_box.x1 + glyph->image->bits.width;

 	glyph_box.y2 = glyph_box.y1 + glyph->image->bits.height;

 	pbox = pixman_region32_rectangles (&region, &n);

 	info.mask_image = glyph_img;

 	while (n--)

 	{

 	    if (box32_intersect (&composite_box, pbox, &glyph_box))

 	    {

 		if (glyph_img->common.extended_format_code != glyph_format	||

 		    glyph_img->common.flags != glyph_flags)

 		{

 		    glyph_format = glyph_img->common.extended_format_code;

 		    glyph_flags = glyph_img->common.flags;

 		    _pixman_implementation_lookup_composite (

 			get_implementation(), op,

 			src->common.extended_format_code, src->common.flags,

 			glyph_format, glyph_flags | extra,

 			dest_format, dest_flags,

 			&implementation, &func);

 		}

 		info.src_x = src_x + composite_box.x1 - dest_x;

 		info.src_y = src_y + composite_box.y1 - dest_y;

 		info.mask_x = composite_box.x1 - (dest_x + glyphs[i].x - glyph->origin_x);

 		info.mask_y = composite_box.y1 - (dest_y + glyphs[i].y - glyph->origin_y);

 		info.dest_x = composite_box.x1;

 		info.dest_y = composite_box.y1;

 		info.width = composite_box.x2 - composite_box.x1;

 		info.height = composite_box.y2 - composite_box.y1;

 		info.mask_flags = glyph_flags;

 		func (implementation, &info);

 	    }

 	    pbox++;

 	}

 	pixman_list_move_to_front (&cache->mru, &glyph->mru_link);

     }

 out:

     pixman_region32_fini (&region);

 }

 static void

 add_glyphs (pixman_glyph_cache_t *cache,

 	    pixman_image_t *dest,

 	    int off_x, int off_y,

 	    int n_glyphs, const pixman_glyph_t *glyphs)

 {

     pixman_format_code_t glyph_format = PIXMAN_null;

     uint32_t glyph_flags = 0;

     pixman_composite_func_t func = NULL;

     pixman_implementation_t *implementation = NULL;

     pixman_format_code_t dest_format;

     uint32_t dest_flags;

     pixman_box32_t dest_box;

     pixman_composite_info_t info;

     pixman_image_t *white_img = NULL;

     pixman_bool_t white_src = FALSE;

     int i;

     _pixman_image_validate (dest);

     dest_format = dest->common.extended_format_code;

     dest_flags = dest->common.flags;

     info.op = PIXMAN_OP_ADD;

     info.dest_image = dest;

     info.src_x = 0;

     info.src_y = 0;

     info.dest_flags = dest_flags;

     dest_box.x1 = 0;

     dest_box.y1 = 0;

     dest_box.x2 = dest->bits.width;

     dest_box.y2 = dest->bits.height;

     for (i = 0; i < n_glyphs; ++i)

     {

 	glyph_t *glyph = (glyph_t *)glyphs[i].glyph;

 	pixman_image_t *glyph_img = glyph->image;

 	pixman_box32_t glyph_box;

 	pixman_box32_t composite_box;

 	if (glyph_img->common.extended_format_code != glyph_format	||

 	    glyph_img->common.flags != glyph_flags)

 	{

 	    pixman_format_code_t src_format, mask_format;

 	    glyph_format = glyph_img->common.extended_format_code;

 	    glyph_flags = glyph_img->common.flags;

 	    if (glyph_format == dest->bits.format)

 	    {

 		src_format = glyph_format;

 		mask_format = PIXMAN_null;

 		info.src_flags = glyph_flags | FAST_PATH_SAMPLES_COVER_CLIP_NEAREST;

 		info.mask_flags = FAST_PATH_IS_OPAQUE;

 		info.mask_image = NULL;

 		white_src = FALSE;

 	    }

 	    else

 	    {

 		if (!white_img)

 		{

 		    static const pixman_color_t white = { 0xffff, 0xffff, 0xffff, 0xffff };

 		    if (!(white_img = pixman_image_create_solid_fill (&white)))

 			goto out;

 		    _pixman_image_validate (white_img);

 		}

 		src_format = PIXMAN_solid;

 		mask_format = glyph_format;

 		info.src_flags = white_img->common.flags;

 		info.mask_flags = glyph_flags | FAST_PATH_SAMPLES_COVER_CLIP_NEAREST;

 		info.src_image = white_img;

 		white_src = TRUE;

 	    }

 	    _pixman_implementation_lookup_composite (

 		get_implementation(), PIXMAN_OP_ADD,

 		src_format, info.src_flags,

 		mask_format, info.mask_flags,

 		dest_format, dest_flags,

 		&implementation, &func);

 	}

 	glyph_box.x1 = glyphs[i].x - glyph->origin_x + off_x;

 	glyph_box.y1 = glyphs[i].y - glyph->origin_y + off_y;

 	glyph_box.x2 = glyph_box.x1 + glyph->image->bits.width;

 	glyph_box.y2 = glyph_box.y1 + glyph->image->bits.height;

 	if (box32_intersect (&composite_box, &glyph_box, &dest_box))

 	{

 	    int src_x = composite_box.x1 - glyph_box.x1;

 	    int src_y = composite_box.y1 - glyph_box.y1;

 	    if (white_src)

 		info.mask_image = glyph_img;

 	    else

 		info.src_image = glyph_img;

 	    info.mask_x = info.src_x = src_x;

 	    info.mask_y = info.src_y = src_y;

 	    info.dest_x = composite_box.x1;

 	    info.dest_y = composite_box.y1;

 	    info.width = composite_box.x2 - composite_box.x1;

 	    info.height = composite_box.y2 - composite_box.y1;

 	    func (implementation, &info);

 	    pixman_list_move_to_front (&cache->mru, &glyph->mru_link);

 	}

     }

 out:

     if (white_img)

 	pixman_image_unref (white_img);

 }

 /* Conceptually, for each glyph, (white IN glyph) is 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 (mask_x, mask_y) in the infinite mask and (src_x, src_y) in the source

  * image are both aligned with (dest_x, dest_y) in the destination image. Then

  * these three images are composited within 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,

 			 const pixman_glyph_t  *glyphs)

 {

     pixman_image_t *mask;

     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);

     }

     add_glyphs (cache, mask, - mask_x, - mask_y, n_glyphs, glyphs);

     pixman_image_composite32 (op, src, mask, dest,

 			      src_x, src_y,

 			      0, 0,

 			      dest_x, dest_y,

 			      width, height);

     pixman_image_unref (mask);

 }