/*

 * 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;

}

#if defined(__GNUC__) && !defined(__x86_64__) && !defined(__amd64__)

__attribute__((__force_align_arg_pointer__))

#endif

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.

 */

#if defined(__GNUC__) && !defined(__x86_64__) && !defined(__amd64__)

__attribute__((__force_align_arg_pointer__))

#endif

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);

}