font_hz_file.c

/*
 * Cached HZ font engine
 */
#include <rtgui/dc.h>
#include <rtgui/font.h>
#include <rtgui/tree.h>
#include <rtgui/rtgui_system.h>
#include <dfs_posix.h>

#define HZ_DATA_SIZE    (2 * 16)
#define HZ_CACHE_MAX    64
SPLAY_HEAD(cache_tree, hz_cache);
struct hz_cache
{
    SPLAY_ENTRY(hz_cache) hz_node;

    rt_uint16_t hz_id;
};

struct rtgui_hz_file_font
{
    struct cache_tree cache_root;
    rt_uint16_t cache_size;

    /* font size */
    rt_uint16_t font_size;

    /* file descriptor */
    int fd;

    /* font file name */
    const char* font_fn;
};

static int _font_cache_compare(struct hz_cache* node1, struct hz_cache* node2);

static void rtgui_hz_file_font_load(struct rtgui_font* font);
static void rtgui_hz_file_font_draw_text(struct rtgui_font* font, struct rtgui_dc* dc, const rt_uint8_t* text, rt_ubase_t len, struct rtgui_rect* rect);
static void rtgui_hz_file_font_get_metrics(struct rtgui_font* font, const rt_uint8_t* text, rtgui_rect_t* rect);
struct rtgui_font_engine rtgui_hz_file_font_engine =
{
	RT_NULL,
	rtgui_hz_file_font_load,
	rtgui_hz_file_font_draw_text,
	rtgui_hz_file_font_get_metrics
};

SPLAY_PROTOTYPE(cache_tree, hz_cache, hz_node, _font_cache_compare);
SPLAY_GENERATE (cache_tree, hz_cache, hz_node, _font_cache_compare);

static int _font_cache_compare(struct hz_cache* cache_1, struct hz_cache* cache_2)
{
    if (cache_1->hz_id > cache_2->hz_id) return 1;
    if (cache_1->hz_id < cache_2->hz_id) return -1;

    return 0;
}

static rt_uint8_t* _font_cache_get(struct rtgui_hz_file_font* font, rt_uint16_t hz_id)
{
    rt_uint32_t seek;
    struct hz_cache *cache, search;

    search.hz_id = hz_id;
    cache = SPLAY_FIND(cache_tree, &(font->cache_root), &search);
    if (cache != RT_NULL)
    {
        /* find it */
        return (rt_uint8_t*)(cache + 1);
    }

    /* can not find it, load to cache */
    cache = (struct hz_cache*) rtgui_malloc(sizeof(struct hz_cache) + HZ_DATA_SIZE);
    if (cache == RT_NULL) return RT_NULL; /* no memory yet */

    cache->hz_id = hz_id;
    seek = 94 * ((hz_id & 0xff - 0xA0) - 1) + ((hz_id >> 8) - 0xA0);
    seek = seek * HZ_DATA_SIZE;

    /* read hz font data */
    if ((lseek(font->fd, seek, SEEK_SET) < 0) ||
        read(font->fd, (char*)(cache + 1), HZ_DATA_SIZE) !=
        HZ_DATA_SIZE)
    {
        rtgui_free(cache);
        return RT_NULL;
    }

    /* insert to cache */
    SPLAY_INSERT(cache_tree, &(font->cache_root), cache);

    if (font->cache_size > HZ_CACHE_MAX)
    {
        /* remove a cache */
        struct hz_cache* left;
        left = SPLAY_LEFT(font->cache_root.sph_root, hz_node);
        while (SPLAY_LEFT(left, hz_node) != RT_NULL) left = SPLAY_LEFT(left, hz_node);

        /* remove the left node */
        SPLAY_REMOVE(cache_tree, &(font->cache_root), left);
    }

    return (rt_uint8_t*)(cache + 1);
}

static void rtgui_hz_file_font_load(struct rtgui_font* font)
{
    struct rtgui_hz_file_font* hz_file_font = (struct rtgui_hz_file_font*)font;
    RT_ASSERT(hz_file_font != RT_NULL);

    hz_file_font->fd = open(hz_file_font->font_fn, O_RDONLY, 0);
}

static void rtgui_hz_file_font_draw_text(struct rtgui_font* font, struct rtgui_dc* dc, const rt_uint8_t* text, rt_ubase_t len, struct rtgui_rect* rect)
{
	rt_base_t h;
	rt_uint8_t* str;
    struct rtgui_hz_file_font* hz_file_font = (struct rtgui_hz_file_font*)font;
    RT_ASSERT(hz_file_font != RT_NULL);

	/* drawing height */
	h = (hz_file_font->font_size + rect->y1 > rect->y2)?
        rect->y2 - rect->y1 : hz_file_font->font_size;

	str = (rt_uint8_t*)text;

	while (len > 0 && rect->x1 < rect->x2)
	{
		const rt_uint8_t* font_ptr;
		register rt_base_t i, j, k;

		/* get font pixel data */
		font_ptr = _font_cache_get(hz_file_font, *(rt_uint16_t*)str);

		/* draw word */
		for (i=0; i < h; i ++)
		{
			for (j=0; j < 2; j++)
				for (k=0; k < 8; k++)
				{
					if ( ((font_ptr[i*2 + j] >> (7-k)) & 0x01) != 0 &&
						(rect->x1 + 8 * j + k < rect->x2))
					{
						rtgui_dc_draw_point(dc, rect->x1 + 8*j + k, rect->y1 + i);
					}
				}
		}

		/* move x to next character */
		rect->x1 += hz_file_font->font_size;
		str += 2;
		len -= 2;
	}
}

static void rtgui_hz_file_font_get_metrics(struct rtgui_font* font, const rt_uint8_t* text, rtgui_rect_t* rect)
{
    struct rtgui_hz_file_font* hz_file_font = (struct rtgui_hz_file_font*)font;
    RT_ASSERT(hz_file_font != RT_NULL);

	/* set metrics rect */
	rect->x1 = rect->y1 = 0;
	rect->x2 = (rt_int16_t)(hz_file_font->font_size/2 * rt_strlen((const char*)text));
	rect->y2 = hz_file_font->font_size;
}