rt-thread/components/gui/src/font_fnt.c

/*
 * File      : font_fnt.c
 * This file is part of RT-Thread GUI Engine
 * COPYRIGHT (C) 2006 - 2017, RT-Thread Development Team
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Change Logs:
 * Date           Author       Notes
 * 2010-09-15     Bernard      first version
 */

 /*
 * rockbox fnt font engine
 */
#include <rtgui/font_fnt.h>
#include <rtgui/rtgui_system.h>

static void rtgui_fnt_font_draw_text(struct rtgui_font *font, struct rtgui_dc *dc, const char *text, rt_ubase_t len, struct rtgui_rect *rect);
static void rtgui_fnt_font_get_metrics(struct rtgui_font *font, const char *text, rtgui_rect_t *rect);
const struct rtgui_font_engine fnt_font_engine =
{
    RT_NULL,
    RT_NULL,
    rtgui_fnt_font_draw_text,
    rtgui_fnt_font_get_metrics
};

void rtgui_fnt_font_draw_text(struct rtgui_font *font, struct rtgui_dc *dc, const char *text, rt_ubase_t len, struct rtgui_rect *rect)
{
    int ch, i, j, c, width;
    rt_uint32_t position;
    struct fnt_font *fnt;
    rt_uint8_t *data_ptr;

    fnt = (struct fnt_font*)font->data;
    RT_ASSERT(fnt != RT_NULL);

    while (len)
    {
        /* get character */
        ch = *text;
        /* NOTE: we only support asc character right now */
        if (ch > 0x80)
        {
            text += 1;
            len -= 1;
            continue;
        }

        /* get position and width */
        if (fnt->offset == RT_NULL)
        {
            width = fnt->header.max_width;
            position = (ch - fnt->header.first_char) * width * ((fnt->header.height + 7)/8);
        }
        else
        {
            width = fnt->width[ch - fnt->header.first_char];
            position = fnt->offset[ch - fnt->header.first_char];
        }

        /* draw a character */
        data_ptr = (rt_uint8_t*)&fnt->bits[position];
        for (i = 0; i < width; i ++) /* x */
        {
            for (j = 0; j < 8; j ++) /* y */
            {
                for (c = 0; c < (fnt->header.height + 7)/8; c ++)
                {
                    /* check drawable region */
                    if ((rect->x1 + i > rect->x2) || (rect->y1 + c * 8 + j > rect->y2))
                        continue;

                    if (data_ptr[i + c * width] & (1 << j))
                        rtgui_dc_draw_point(dc, rect->x1 + i, rect->y1 + c * 8 + j);
                }
            }
        }

        rect->x1 += width;
        text += 1;
        len -= 1;
    }
}

void rtgui_fnt_font_get_metrics(struct rtgui_font *font, const char *text, rtgui_rect_t *rect)
{
    int ch;
    struct fnt_font *fnt;

    fnt = (struct fnt_font*)font->data;
    RT_ASSERT(fnt != RT_NULL);

    rt_memset(rect, 0x00, sizeof(rtgui_rect_t));
    rect->y2 = fnt->header.height;

    while (*text)
    {
        if (fnt->width == RT_NULL)
        {
            /* fixed width font */
            rect->x2 += fnt->header.max_width;
        }
        else
        {
            ch = *text;
            /* NOTE: we only support asc character right now */
            if (ch > 0x80)
            {
                text += 1;
                continue;
            }

            rect->x2 += fnt->width[ch - fnt->header.first_char];
        }

        text += 1;
    }
}

#ifdef RTGUI_USING_FNT_FILE
#include <dfs_posix.h>

rt_inline int readbyte(int fd, unsigned char *cp)
{
    unsigned char buf[1];

    if (read(fd, buf, 1) != 1)
        return 0;
    *cp = buf[0];
    return 1;
}

rt_inline int readshort(int fd, unsigned short *sp)
{
    unsigned char buf[2];

    if (read(fd, buf, 2) != 2)
        return 0;
    *sp = buf[0] | (buf[1] << 8);
    return 1;
}

rt_inline int readlong(int fd, rt_uint32_t *lp)
{
    unsigned char buf[4];

    if (read(fd, buf, 4) != 4)
        return 0;
    *lp = buf[0] | (buf[1] << 8) | (buf[2] << 16) | (buf[3] << 24);
    return 1;
}

rt_inline int readstr(int fd, char *buf, int count)
{
    return read(fd, buf, count);
}

struct rtgui_font *fnt_font_create(const char* filename, const char* font_family)
{
    int fd = -1;
    rt_uint32_t index;
    struct rtgui_font *font = RT_NULL;
    struct fnt_font *fnt = RT_NULL;
    struct fnt_header *fnt_header;

    fd = open(filename, O_RDONLY, 0);
    if (fd < 0)
    {
        goto __exit;
    }

    font = (struct rtgui_font*) rtgui_malloc (sizeof(struct rtgui_font));
    if (font == RT_NULL) goto __exit;
    fnt = (struct fnt_font*) rtgui_malloc (sizeof(struct fnt_font));
    if (fnt == RT_NULL) goto __exit;
    rt_memset(fnt, 0x00, sizeof(struct fnt_font));
    font->data = (void*)fnt;

    fnt_header = &(fnt->header);
    if (readstr(fd, fnt_header->version, 4) != 4) goto __exit;
    if (!readshort(fd, &fnt_header->max_width)) goto __exit;
    if (!readshort(fd, &fnt_header->height)) goto __exit;
    if (!readshort(fd, &fnt_header->ascent)) goto __exit;
    if (!readshort(fd, &fnt_header->depth)) goto __exit;

    if (!readlong(fd, &fnt_header->first_char)) goto __exit;
    if (!readlong(fd, &fnt_header->default_char)) goto __exit;
    if (!readlong(fd, &fnt_header->size)) goto __exit;
    if (!readlong(fd, &fnt_header->nbits)) goto __exit;
    if (!readlong(fd, &fnt_header->noffset)) goto __exit;
    if (!readlong(fd, &fnt_header->nwidth)) goto __exit;

    fnt->bits = (MWIMAGEBITS*) rtgui_malloc (fnt_header->nbits * sizeof(MWIMAGEBITS));
    if (fnt->bits == RT_NULL) goto __exit;
    /* read data */
    if (readstr(fd, &(fnt->bits[0]), fnt_header->nbits) != fnt_header->nbits) goto __exit;

    /* check boundary */
    if (fnt_header->nbits & 0x01)
    {
        rt_uint16_t pad;
        readshort(fd, &pad);
        pad = pad; /* skip warning */
    }

    if (fnt_header->noffset != 0)
    {
        fnt->offset = rtgui_malloc (fnt_header->noffset * sizeof(rt_uint32_t));
        if (fnt->offset == RT_NULL) goto __exit;

        for (index = 0; index < fnt_header->noffset; index ++)
        {
            if (!readshort(fd, &(fnt->offset[index]))) goto __exit;
        }
    }

    if (fnt_header->nwidth != 0)
    {
        fnt->width = rtgui_malloc (fnt_header->nwidth * sizeof(rt_uint8_t));
        if (fnt->width == RT_NULL) goto __exit;

        for (index = 0; index < fnt_header->nwidth; index ++)
        {
            if (!readbyte(fd, &(fnt->width[index]))) goto __exit;
        }
    }

    close(fd);

    font->family = rt_strdup(font_family);
    font->height = fnt->header.height;
    font->refer_count = 0;
    font->engine = &fnt_font_engine;

    /* add to system */
    rtgui_font_system_add_font(font);

    return font;

__exit:
    if (fd >= 0) close(fd);
    if (fnt != RT_NULL)
    {
        if (fnt->bits != RT_NULL) rtgui_free(fnt->bits);
        if (fnt->offset != RT_NULL) rtgui_free(fnt->offset);
        if (fnt->width != RT_NULL) rtgui_free(fnt->width);

        rtgui_free(fnt);
    }

    if (font != RT_NULL)
    {
        rtgui_free(font);
    }
    return RT_NULL;
}
#endif