mpv/libass/ass_cache.c

#include "config.h"

#include <ft2build.h>
#include FT_FREETYPE_H

#include <assert.h>

#include "mp_msg.h"
#include "ass_fontconfig.h"
#include "ass_cache.h"


typedef struct face_cache_item_s {
	face_desc_t desc;
	char* path;
	int index;
	FT_Face face;
} face_cache_item_t;

#define MAX_FACE_CACHE_SIZE 100

static face_cache_item_t* face_cache;
static int face_cache_size;

extern int no_more_font_messages;

static int font_compare(face_desc_t* a, face_desc_t* b) {
	if (strcmp(a->family, b->family) != 0)
		return 0;
	if (a->bold != b->bold)
		return 0;
	if (a->italic != b->italic)
		return 0;
	return 1;
}

/**
 * \brief Get a face object, either from cache or created through FreeType+FontConfig.
 * \param library FreeType library object
 * \param fontconfig_priv fontconfig private data
 * \param desc required face description
 * \param face out: the face object
*/ 
int ass_new_face(FT_Library library, void* fontconfig_priv, face_desc_t* desc, /*out*/ FT_Face* face)
{
	FT_Error error;
	int i;
	char* path;
	int index;
	face_cache_item_t* item;
	
	for (i=0; i<face_cache_size; ++i)
		if (font_compare(desc, &(face_cache[i].desc))) {
			*face = face_cache[i].face;
			return 0;
		}

	if (face_cache_size == MAX_FACE_CACHE_SIZE) {
		mp_msg(MSGT_GLOBAL, MSGL_FATAL, "Too many fonts\n");
		return 1;
	}

	path = fontconfig_select(fontconfig_priv, desc->family, desc->bold, desc->italic, &index);
	
	error = FT_New_Face(library, path, index, face);
	if (error) {
		if (!no_more_font_messages)
			mp_msg(MSGT_GLOBAL, MSGL_WARN, "Error opening font: %s, %d\n", path, index);
		no_more_font_messages = 1;
		return 1;
	}
	
	item = face_cache + face_cache_size;
	item->path = strdup(path);
	item->index = index;
	item->face = *face;
	memcpy(&(item->desc), desc, sizeof(face_desc_t));
	face_cache_size++;
	return 0;
}

void ass_face_cache_init(void)
{
	face_cache = calloc(MAX_FACE_CACHE_SIZE, sizeof(face_cache_item_t));
	face_cache_size = 0;
}

void ass_face_cache_done(void)
{
	int i;
	for (i = 0; i < face_cache_size; ++i) {
		face_cache_item_t* item = face_cache + i;
		if (item->face) FT_Done_Face(item->face);
		if (item->path) free(item->path);
		// FIXME: free desc ?
	}
	free(face_cache);
	face_cache_size = 0;
}

//---------------------------------
// glyph cache

#define GLYPH_HASH_SIZE (0xFFFF + 13)

typedef struct glyph_hash_item_s {
	glyph_hash_key_t key;
	glyph_hash_val_t val;
	struct glyph_hash_item_s* next;
} glyph_hash_item_t;

typedef glyph_hash_item_t* glyph_hash_item_p;

static glyph_hash_item_p* glyph_hash_root;
static int glyph_hash_size;

static int glyph_compare(glyph_hash_key_t* a, glyph_hash_key_t* b) {
	if (memcmp(a, b, sizeof(glyph_hash_key_t)) == 0)
		return 1;
	else
		return 0;
}

static unsigned glyph_hash(glyph_hash_key_t* key) {
	unsigned val = 0;
	unsigned i;
	for (i = 0; i < sizeof(key->face); ++i)
		val += *(unsigned char *)(&(key->face) + i);
	val <<= 21;
	
	if (key->bitmap)   val &= 0x80000000;
	val += key->index;
	val += key->size << 8;
	val += key->outline << 3;
	val += key->advance.x << 10;
	val += key->advance.y << 16;
	val += key->bold << 1;
	val += key->italic << 20;
	return val;
}

/**
 * \brief Add a glyph to glyph cache.
 * \param key hash key
 * \param val hash val: 2 bitmap glyphs + some additional info
*/ 
void cache_add_glyph(glyph_hash_key_t* key, glyph_hash_val_t* val)
{
	unsigned hash = glyph_hash(key);
	glyph_hash_item_t** next = glyph_hash_root + (hash % GLYPH_HASH_SIZE);
	while (*next) {
		if (glyph_compare(key, &((*next)->key)))
			return;
		next = &((*next)->next);
		assert(next);
	}
	(*next) = malloc(sizeof(glyph_hash_item_t));
//	(*next)->desc = glyph_key_copy(key, &((*next)->key));
	memcpy(&((*next)->key), key, sizeof(glyph_hash_key_t));
	memcpy(&((*next)->val), val, sizeof(glyph_hash_val_t));
	(*next)->next = 0;

	glyph_hash_size ++;
/*	if (glyph_hash_size  && (glyph_hash_size % 25 == 0)) {
		printf("\nGlyph cache: %d entries, %d bytes\n", glyph_hash_size, glyph_hash_size * sizeof(glyph_hash_item_t));
	} */
}

/**
 * \brief Get a glyph from glyph cache.
 * \param key hash key
 * \return requested hash val or 0 if not found
*/ 
glyph_hash_val_t* cache_find_glyph(glyph_hash_key_t* key)
{
	unsigned hash = glyph_hash(key);
	glyph_hash_item_t* item = glyph_hash_root[hash % GLYPH_HASH_SIZE];
	while (item) {
		if (glyph_compare(key, &(item->key))) {
			return &(item->val);
		}
		item = item->next;
	}
	return 0;
}

void ass_glyph_cache_init(void)
{
	glyph_hash_root = calloc(GLYPH_HASH_SIZE, sizeof(glyph_hash_item_p));
	glyph_hash_size = 0;
}

void ass_glyph_cache_done(void)
{
	int i;
	for (i = 0; i < GLYPH_HASH_SIZE; ++i) {
		glyph_hash_item_t* item = glyph_hash_root[i];
		while (item) {
			glyph_hash_item_t* next = item->next;
			if (item->val.glyph) FT_Done_Glyph(item->val.glyph);
			if (item->val.outline_glyph) FT_Done_Glyph(item->val.outline_glyph);
			free(item);
			item = next;
		}
	}
	free(glyph_hash_root);
	glyph_hash_size = 0;
}

void ass_glyph_cache_reset(void)
{
	ass_glyph_cache_done();
	ass_glyph_cache_init();
}