rockbox/tools/convbdf.c

/*
 * Convert BDF files to C source and/or Rockbox .fnt file format
 *
 * Copyright (c) 2002 by Greg Haerr <greg@censoft.com>
 *
 * What fun it is converting font data...
 *
 * 09/17/02    Version 1.0
 */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>

#define ROTATE /* define this for the new, rotated format */

/* BEGIN font.h*/
/* loadable font magic and version #*/
#ifdef ROTATE
#define VERSION     "RB12" /* newer version */
#else
#define VERSION     "RB11"
#endif

/*
 * bitmap_t helper macros
 */
typedef unsigned short bitmap_t; /* bitmap image unit size*/

/* Number of words to hold a pixel line of width x pixels */
#define BITMAP_BITSPERIMAGE     (sizeof(bitmap_t) * 8)
#define BITMAP_WORDS(x)         (((x)+BITMAP_BITSPERIMAGE-1)/BITMAP_BITSPERIMAGE)
#define BITMAP_BYTES(x)         (BITMAP_WORDS(x)*sizeof(bitmap_t))
#define BITMAP_BITVALUE(n)      ((bitmap_t) (((bitmap_t) 1) << (n)))
#define BITMAP_FIRSTBIT         (BITMAP_BITVALUE(BITMAP_BITSPERIMAGE - 1))
#define BITMAP_TESTBIT(m)       ((m) & BITMAP_FIRSTBIT)
#define BITMAP_SHIFTBIT(m)      ((bitmap_t) ((m) << 1))


/* builtin C-based proportional/fixed font structure */
/* based on The Microwindows Project http://microwindows.org */
struct font {
    int     maxwidth;   /* max width in pixels */
    int     height;     /* height in pixels */
    int     ascent;     /* ascent (baseline) height */
    int     firstchar;  /* first character in bitmap */
    int     size;       /* font size in glyphs ('holes' included) */
    bitmap_t*   bits;       /* 16-bit right-padded bitmap data */
    int*    offset;     /* offsets into bitmap data */
    unsigned char* width;   /* character widths or NULL if fixed */
    int     defaultchar;    /* default char (not glyph index) */
    int     bits_size;  /* # words of bitmap_t bits */
    
    /* unused by runtime system, read in by convbdf */
    int     nchars;     /* number of different glyphs */
    unsigned int* offrot;   /* offsets into rotated bitmap data */
    char*   name;       /* font name */
    char*   facename;   /* facename of font */
    char*   copyright;  /* copyright info for loadable fonts */
    int     pixel_size;
    int     descent;
    int     fbbw, fbbh, fbbx, fbby;

    /* Max 'overflow' of a char's ascent (descent) over the font's one */
    int max_over_ascent, max_over_descent;
    
    /* The number of clipped ascents/descents/total */
    int num_clipped_ascent, num_clipped_descent, num_clipped;
};
/* END font.h*/

#define isprefix(buf,str)   (!strncmp(buf, str, strlen(str)))
#define strequal(s1,s2)     (!strcmp(s1, s2))

#define MAX(a,b)            ((a) > (b) ? (a) : (b))
#define MIN(a,b)            ((a) < (b) ? (a) : (b))

int gen_c = 0;
int gen_h = 0;
int gen_fnt = 0;
int gen_map = 1;
int start_char = 0;
int limit_char = 65535;
int oflag = 0;
char outfile[256];

void usage(void);
void getopts(int *pac, char ***pav);
int convbdf(char *path);

void free_font(struct font* pf);
struct font* bdf_read_font(char *path);
int bdf_read_header(FILE *fp, struct font* pf);
int bdf_read_bitmaps(FILE *fp, struct font* pf);
char * bdf_getline(FILE *fp, char *buf, int len);
bitmap_t bdf_hexval(unsigned char *buf, int ndx1, int ndx2);
void bitmap_buf_alloc(struct font* pf);

int gen_c_source(struct font* pf, char *path);
int gen_h_header(struct font* pf, char *path);
int gen_fnt_file(struct font* pf, char *path);

void
usage(void)
{
    char help[] = {
    "Usage: convbdf [options] [input-files]\n"
    "       convbdf [options] [-o output-file] [single-input-file]\n"
    "Options:\n"
    "    -c     Convert .bdf to .c source file\n"
    "    -h     Convert .bdf to .h header file (to create sysfont.h)\n"
    "    -f     Convert .bdf to .fnt font file\n"
    "    -s N   Start output at character encodings >= N\n"
    "    -l N   Limit output to character encodings <= N\n"
    "    -n     Don't generate bitmaps as comments in .c file\n"
    };

    fprintf(stderr, "%s", help);
}

/* parse command line options*/
void getopts(int *pac, char ***pav)
{
    char *p;
    char **av;
    int ac;
    
    ac = *pac;
    av = *pav;
    while (ac > 0 && av[0][0] == '-') {
        p = &av[0][1]; 
        while( *p)
            switch(*p++) {
            case ' ':           /* multiple -args on av[]*/
                while( *p && *p == ' ')
                    p++;
                if( *p++ != '-')    /* next option must have dash*/
                    p = "";
                break;          /* proceed to next option*/
            case 'c':           /* generate .c output*/
                gen_c = 1;
                break;
            case 'h':           /* generate .h output*/
                gen_h = 1;
                break;
            case 'f':           /* generate .fnt output*/
                gen_fnt = 1;
                break;
            case 'n':           /* don't gen bitmap comments*/
                gen_map = 0;
                break;
            case 'o':           /* set output file*/
                oflag = 1;
                if (*p) {
                    strcpy(outfile, p);
                    while (*p && *p != ' ')
                        p++;
                }
                else {
                    av++; ac--;
                    if (ac > 0)
                        strcpy(outfile, av[0]);
                }
                break;
            case 'l':           /* set encoding limit*/
                if (*p) {
                    limit_char = atoi(p);
                    while (*p && *p != ' ')
                        p++;
                }
                else {
                    av++; ac--;
                    if (ac > 0)
                        limit_char = atoi(av[0]);
                }
                break;
            case 's':           /* set encoding start*/
                if (*p) {
                    start_char = atoi(p);
                    while (*p && *p != ' ')
                        p++;
                }
                else {
                    av++; ac--;
                    if (ac > 0)
                        start_char = atoi(av[0]);
                }
                break;
            default:
                fprintf(stderr, "Unknown option ignored: %c\r\n", *(p-1));
            }
        ++av; --ac;
    }
    *pac = ac;
    *pav = av;
}

/* remove directory prefix and file suffix from full path */
char *basename(char *path)
{
    char *p, *b;
    static char base[256];

    /* remove prepended path and extension */
    b = path;
    for (p=path; *p; ++p) {
        if (*p == '/')
            b = p + 1;
    }
    strcpy(base, b);
    for (p=base; *p; ++p) {
        if (*p == '.') {
            *p = 0;
            break;
        }
    }
    return base;
}

int convbdf(char *path)
{
    struct font* pf;
    int ret = 0;

    pf = bdf_read_font(path);
    if (!pf)
        exit(1);
    
    if (gen_c) {
        if (!oflag) {
            strcpy(outfile, basename(path));
            strcat(outfile, ".c");
        }
        ret |= gen_c_source(pf, outfile);
    }
    
    if (gen_h) {
        if (!oflag) {
            strcpy(outfile, basename(path));
            strcat(outfile, ".h");
        }
        ret |= gen_h_header(pf, outfile);
    }

    if (gen_fnt) {
        if (!oflag) {
            strcpy(outfile, basename(path));
            strcat(outfile, ".fnt");
        }
        ret |= gen_fnt_file(pf, outfile);
    }

    free_font(pf);
    return ret;
}

int main(int ac, char **av)
{
    int ret = 0;

    ++av; --ac;     /* skip av[0] */
    getopts(&ac, &av);  /* read command line options */

    if (ac < 1 || (!gen_c && !gen_h && !gen_fnt)) {
        usage();
        exit(1);
    }
    if (oflag) {
        if (ac > 1 || (gen_c && gen_fnt) || (gen_c && gen_h) || (gen_h && gen_fnt)) {
            usage();
            exit(1);
        }
    }
    
    while (ac > 0) {
        ret |= convbdf(av[0]);
        ++av; --ac;
    }
    
    exit(ret);
}

/* free font structure */
void free_font(struct font* pf)
{
    if (!pf)
        return;
    if (pf->name)
        free(pf->name);
    if (pf->facename)
        free(pf->facename);
    if (pf->bits)
        free(pf->bits);
    if (pf->offset)
        free(pf->offset);
    if (pf->offrot)
        free(pf->offrot);
    if (pf->width)
        free(pf->width);
    free(pf);
}

/* build incore structure from .bdf file */
struct font* bdf_read_font(char *path)
{
    FILE *fp;
    struct font* pf;

    fp = fopen(path, "rb");
    if (!fp) {
        fprintf(stderr, "Error opening file: %s\n", path);
        return NULL;
    }
    
    pf = (struct font*)calloc(1, sizeof(struct font));
    if (!pf)
        goto errout;
    memset(pf, 0, sizeof(struct font));
    
    pf->name = strdup(basename(path));

    if (!bdf_read_header(fp, pf)) {
        fprintf(stderr, "Error reading font header\n");
        goto errout;
    }

    pf->max_over_ascent = pf->max_over_descent = 0;
    pf->num_clipped_ascent = pf->num_clipped_descent = pf->num_clipped = 0;

    if (!bdf_read_bitmaps(fp, pf)) {
        fprintf(stderr, "Error reading font bitmaps\n");
        goto errout;
    }
    
    if (pf->num_clipped > 0) {
        fprintf(stderr, "Warning: %d characters out of %d were clipped "
                "(%d at ascent, %d at descent)\n",
                pf->num_clipped, pf->nchars,
                pf->num_clipped_ascent, pf->num_clipped_descent);
        fprintf(stderr, "         max overflows: ascent: %d, descent: %d\n",
                pf->max_over_ascent, pf->max_over_descent);
    }

    fclose(fp);
    return pf;

 errout:
    fclose(fp);
    free_font(pf);
    return NULL;
}

/* read bdf font header information, return 0 on error */
int bdf_read_header(FILE *fp, struct font* pf)
{
    int encoding;
    int firstchar = 65535;
    int lastchar = -1;
    char buf[256];
    char facename[256];
    char copyright[256];

    /* set certain values to errors for later error checking */
    pf->defaultchar = -1;
    pf->ascent = -1;
    pf->descent = -1;

    for (;;) {
        if (!bdf_getline(fp, buf, sizeof(buf))) {
            fprintf(stderr, "Error: EOF on file\n");
            return 0;
        }
        if (isprefix(buf, "FONT ")) {       /* not required */
            if (sscanf(buf, "FONT %[^\n]", facename) != 1) {
                fprintf(stderr, "Error: bad 'FONT'\n");
                return 0;
            }
            pf->facename = strdup(facename);
            continue;
        }
        if (isprefix(buf, "COPYRIGHT ")) {  /* not required */
            if (sscanf(buf, "COPYRIGHT \"%[^\"]", copyright) != 1) {
                fprintf(stderr, "Error: bad 'COPYRIGHT'\n");
                return 0;
            }
            pf->copyright = strdup(copyright);
            continue;
        }
        if (isprefix(buf, "DEFAULT_CHAR ")) {   /* not required */
            if (sscanf(buf, "DEFAULT_CHAR %d", &pf->defaultchar) != 1) {
                fprintf(stderr, "Error: bad 'DEFAULT_CHAR'\n");
                return 0;
            }
        }
        if (isprefix(buf, "FONT_DESCENT ")) {
            if (sscanf(buf, "FONT_DESCENT %d", &pf->descent) != 1) {
                fprintf(stderr, "Error: bad 'FONT_DESCENT'\n");
                return 0;
            }
            continue;
        }
        if (isprefix(buf, "FONT_ASCENT ")) {
            if (sscanf(buf, "FONT_ASCENT %d", &pf->ascent) != 1) {
                fprintf(stderr, "Error: bad 'FONT_ASCENT'\n");
                return 0;
            }
            continue;
        }
        if (isprefix(buf, "FONTBOUNDINGBOX ")) {
            if (sscanf(buf, "FONTBOUNDINGBOX %d %d %d %d",
                       &pf->fbbw, &pf->fbbh, &pf->fbbx, &pf->fbby) != 4) {
                fprintf(stderr, "Error: bad 'FONTBOUNDINGBOX'\n");
                return 0;
            }
            continue;
        }
        if (isprefix(buf, "CHARS ")) {
            if (sscanf(buf, "CHARS %d", &pf->nchars) != 1) {
                fprintf(stderr, "Error: bad 'CHARS'\n");
                return 0;
            }
            continue;
        }

        /*
         * Reading ENCODING is necessary to get firstchar/lastchar
         * which is needed to pre-calculate our offset and widths
         * array sizes.
         */
        if (isprefix(buf, "ENCODING ")) {
            if (sscanf(buf, "ENCODING %d", &encoding) != 1) {
                fprintf(stderr, "Error: bad 'ENCODING'\n");
                return 0;
            }
            if (encoding >= 0 &&
                encoding <= limit_char && 
                encoding >= start_char) {

                if (firstchar > encoding)
                    firstchar = encoding;
                if (lastchar < encoding)
                    lastchar = encoding;
            }
            continue;
        }
        if (strequal(buf, "ENDFONT"))
            break;
    }

    /* calc font height*/
    if (pf->ascent < 0 || pf->descent < 0 || firstchar < 0) {
        fprintf(stderr, "Error: Invalid BDF file, requires FONT_ASCENT/FONT_DESCENT/ENCODING\n");
        return 0;
    }
    pf->height = pf->ascent + pf->descent;

    /* calc default char */
    if (pf->defaultchar < 0 || 
        pf->defaultchar < firstchar || 
        pf->defaultchar > limit_char ||
        pf->defaultchar > lastchar)
        pf->defaultchar = firstchar;

    /* calc font size (offset/width entries) */
    pf->firstchar = firstchar;
    pf->size = lastchar - firstchar + 1;
    if (pf->size < pf->nchars) {
        fprintf(stderr, "Error: NCHARS and max code mismatch\n");
        return 0;
    }
    
    /* use the font boundingbox to get initial maxwidth */
    /*maxwidth = pf->fbbw - pf->fbbx;*/
    pf->maxwidth = pf->fbbw;
    bitmap_buf_alloc(pf); /* Allocate bitmaps */

    pf->offset = (int *)malloc(pf->size * sizeof(int));
    pf->offrot = (unsigned int *)malloc(pf->size * sizeof(unsigned int));
    pf->width = (unsigned char *)malloc(pf->size * sizeof(unsigned char));
    
    if (!pf->bits || !pf->offset || !pf->offrot || !pf->width) {
        fprintf(stderr, "Error: no memory for font load\n");
        return 0;
    }

    return 1;
}

/* read bdf font bitmaps, return 0 on error */
int bdf_read_bitmaps(FILE *fp, struct font* pf)
{
    int ofs = 0;
    int ofr = 0;
    int i, k, encoding, width;
    int bbw, bbh, bbx, bby;
    int proportional = 0;
    int encodetable = 0;
    int l;
    char buf[256];
    bitmap_t *ch_bitmap;
    int ch_words;

    /* reset file pointer */
    fseek(fp, 0L, SEEK_SET);

    /* initially mark offsets as not used */
    for (i=0; i<pf->size; ++i)
        pf->offset[i] = -1;

    for (;;) {
        if (!bdf_getline(fp, buf, sizeof(buf))) {
            fprintf(stderr, "Error: EOF on file\n");
            return 0;
        }
        if (isprefix(buf, "STARTCHAR")) {
            encoding = width = -1;
            bbw = pf->fbbw;
            bbh = pf->fbbh;
            bbx = pf->fbbx;
            bby = pf->fbby;
            continue;
        }
        if (isprefix(buf, "ENCODING ")) {
            if (sscanf(buf, "ENCODING %d", &encoding) != 1) {
                fprintf(stderr, "Error: bad 'ENCODING'\n");
                return 0;
            }
            if (encoding < start_char || encoding > limit_char)
                encoding = -1;
            continue;
        }
        if (isprefix(buf, "DWIDTH ")) {
            if (sscanf(buf, "DWIDTH %d", &width) != 1) {
                fprintf(stderr, "Error: bad 'DWIDTH'\n");
                return 0;
            }
            /* use font boundingbox width if DWIDTH <= 0 */
            if (width <= 0)
                width = pf->fbbw - pf->fbbx;
            continue;
        }
        if (isprefix(buf, "BBX ")) {
            if (sscanf(buf, "BBX %d %d %d %d", &bbw, &bbh, &bbx, &bby) != 4) {
                fprintf(stderr, "Error: bad 'BBX'\n");
                return 0;
            }
            continue;
        }
        if (strequal(buf, "BITMAP") || strequal(buf, "BITMAP ")) {
            int overflow_asc, overflow_desc;
            int bbh_orig, bby_orig, y;

            if (encoding < 0)
                continue;

            /* set bits offset in encode map*/
            if (pf->offset[encoding-pf->firstchar] != -1) {
                fprintf(stderr, "Error: duplicate encoding for character %d (0x%02x), ignoring duplicate\n",
                        encoding, encoding);
                continue;
            }
            pf->offset[encoding-pf->firstchar] = ofs;
            pf->offrot[encoding-pf->firstchar] = ofr;

            /* calc char width */
            if (bbx < 0) {
                /* Rockbox can't render overlapping glyphs */
                width -= bbx;
                bbx = 0;
            }
            if (width > pf->maxwidth) {
                pf->maxwidth = width;
                bitmap_buf_alloc(pf); /* Re-allocate bitmaps since the maxwidth has grown */
            }
            pf->width[encoding-pf->firstchar] = width;

            ch_bitmap = pf->bits + ofs;
            ch_words = BITMAP_WORDS(width);
            memset(ch_bitmap, 0, BITMAP_BYTES(width) * pf->height); /* clear bitmap */

#define BM(row,col) (*(ch_bitmap + ((row)*ch_words) + (col)))
#define BITMAP_NIBBLES  (BITMAP_BITSPERIMAGE/4)

            bbh_orig = bbh;
            bby_orig = bby;

            overflow_asc = bby + bbh - pf->ascent;
            if (overflow_asc > 0) {
                pf->num_clipped_ascent++;
                if (overflow_asc > pf->max_over_ascent) {
                    pf->max_over_ascent = overflow_asc;
                }
                bbh = MAX(bbh - overflow_asc, 0); /* Clipped -> decrease the height */
                fprintf(stderr, "Warning: character %d goes %d pixel(s)"
                        " beyond the font's ascent, it will be clipped\n",
                        encoding, overflow_asc);
            }
            overflow_desc = -bby - pf->descent;
            if (overflow_desc > 0) {
                pf->num_clipped_descent++;
                if (overflow_desc > pf->max_over_descent) {
                    pf->max_over_descent = overflow_desc;
                }
                bby += overflow_desc;
                bbh = MAX(bbh - overflow_desc, 0); /* Clipped -> decrease the height */
                fprintf(stderr, "Warning: character %d goes %d pixel(s)"
                        " beyond the font's descent, it will be clipped\n",
                        encoding, overflow_desc);
            }
            if (overflow_asc > 0 || overflow_desc > 0) {
                pf->num_clipped++;
            }

            y = bby_orig + bbh_orig; /* 0-based y within the char */
            
            /* read bitmaps */
            for (i=0; ; ++i) {
                int hexnibbles;

                if (!bdf_getline(fp, buf, sizeof(buf))) {
                    fprintf(stderr, "Error: EOF reading BITMAP data for character %d\n",
                            encoding);
                    return 0;
                }
                if (isprefix(buf, "ENDCHAR"))
                    break;
                
                y--;
                if ((y >= pf->ascent) || (y < -pf->descent)) {
                    /* We're beyond the area that Rockbox can render -> clip */
                    --i; /* This line doesn't count */
                    continue;
                }

                hexnibbles = strlen(buf);
                for (k=0; k<ch_words; ++k) {
                    int ndx = k * BITMAP_NIBBLES;
                    int padnibbles = hexnibbles - ndx;
                    bitmap_t value;
                    
                    if (padnibbles <= 0)
                        break;
                    if (padnibbles >= (int)BITMAP_NIBBLES)
                        padnibbles = 0;

                    value = bdf_hexval((unsigned char *)buf,
                                       ndx, ndx+BITMAP_NIBBLES-1-padnibbles);
                    value <<= padnibbles * BITMAP_NIBBLES;

                    BM(pf->height - pf->descent - bby - bbh + i, k) |=
                        value >> bbx;
                    /* handle overflow into next image word */
                    if (bbx) {
                        BM(pf->height - pf->descent - bby - bbh + i, k+1) =
                            value << (BITMAP_BITSPERIMAGE - bbx);
                    }
                }
            }

            ofs += BITMAP_WORDS(width) * pf->height;
            ofr += pf->width[encoding-pf->firstchar] * ((pf->height+7)/8);

            continue;
        }
        if (strequal(buf, "ENDFONT"))
            break;
    }

    /* change unused width values to default char values */
    for (i=0; i<pf->size; ++i) {
        int defchar = pf->defaultchar - pf->firstchar;

        if (pf->offset[i] == -1)
            pf->width[i] = pf->width[defchar];
    }

    /* determine whether font doesn't require encode table */
#ifdef ROTATE
    l = 0;
    for (i=0; i<pf->size; ++i) {
        if ((int)pf->offrot[i] != l) {
            encodetable = 1;
            break;
        }
        l += pf->maxwidth * ((pf->height + 7) / 8);
    }
#else
    l = 0;
    for (i=0; i<pf->size; ++i) {
        if (pf->offset[i] != l) {
            encodetable = 1;
            break;
        }
        l += BITMAP_WORDS(pf->width[i]) * pf->height;
    }
#endif
    if (!encodetable) {
        free(pf->offset);
        pf->offset = NULL;
    }

    /* determine whether font is fixed-width */
    for (i=0; i<pf->size; ++i) {
        if (pf->width[i] != pf->maxwidth) {
            proportional = 1;
            break;
        }
    }
    if (!proportional) {
        free(pf->width);
        pf->width = NULL;
    }

    /* reallocate bits array to actual bits used */
    if (ofs < pf->bits_size) {
        pf->bits = realloc(pf->bits, ofs * sizeof(bitmap_t));
        pf->bits_size = ofs;
    }

#ifdef ROTATE
    pf->bits_size = ofr; /* always update, rotated is smaller */
#endif

    return 1;
}

/* read the next non-comment line, returns buf or NULL if EOF */
char *bdf_getline(FILE *fp, char *buf, int len)
{
    int c;
    char *b;

    for (;;) {
        b = buf;
        while ((c = getc(fp)) != EOF) {
            if (c == '\r')
                continue;
            if (c == '\n')
                break;
            if (b - buf >= (len - 1))
                break;
            *b++ = c;
        }
        *b = '\0';
        if (c == EOF && b == buf)
            return NULL;
        if (b != buf && !isprefix(buf, "COMMENT"))
            break;
    }
    return buf;
}
 
/*
   Calculates the necessary size of the bit buffer to hold all the
   bitmaps for the glyphs in the font. Shoud be called every time
   the max width of the font grows. Font height, the max width and
   the number of chars in the font must have been already set.
*/
void bitmap_buf_alloc(struct font* pf)
{
    pf->bits_size = pf->size * BITMAP_WORDS(pf->maxwidth) * pf->height;
    pf->bits = (bitmap_t *)realloc(pf->bits, pf->bits_size * sizeof(bitmap_t));
}


/* return hex value of portion of buffer*/
bitmap_t bdf_hexval(unsigned char *buf, int ndx1, int ndx2)
{
    bitmap_t val = 0;
    int i, c;

    for (i=ndx1; i<=ndx2; ++i) {
        c = buf[i];
        if (c >= '0' && c <= '9')
            c -= '0';
        else 
            if (c >= 'A' && c <= 'F')
                c = c - 'A' + 10;
            else 
                if (c >= 'a' && c <= 'f')
                    c = c - 'a' + 10;
                else 
                    c = 0;
        val = (val << 4) | c;
    }
    return val;
}

/*
 * Take an bitmap_t bitmap and convert to Rockbox format.
 * Used for converting font glyphs for the time being.
 * Can use for standard X11 and Win32 images as well.
 * See format description in lcd-recorder.c
 *
 * Doing it this way keeps fonts in standard formats,
 * as well as keeping Rockbox hw bitmap format.
 */
int rotleft(unsigned char *dst, /* output buffer */
            size_t dstlen,      /* buffer size */
            bitmap_t *src, unsigned int width, unsigned int height)
{
    unsigned int i,j;
    unsigned int src_words;     /* # words of input image */
    unsigned int dst_mask;      /* bit mask for destination */
    bitmap_t src_mask;          /* bit mask for source */

    /* calc words of input image*/
    src_words = BITMAP_WORDS(width) * height;

    if(((height + 7) / 8) * width > dstlen) {
        fprintf(stderr, "%s:%d %d x %d overflows %ld bytes buffer, needs %d\n",
                __FILE__, __LINE__, width, height, (unsigned long)dstlen,
                ((height + 7) / 8) * width );
        return 0;
    }
    
    /* clear background*/
    memset(dst, 0, ((height + 7) / 8) * width);

    dst_mask = 1;

    for (i=0; i < src_words; i++) {

        /* calc src input bit*/
        src_mask = 1 << (sizeof (bitmap_t) * 8 - 1);
        
        /* for each input column...*/
        for(j=0; j < width; j++) {

            if (src_mask == 0) /* input word done? */
            {
                src_mask = 1 << (sizeof (bitmap_t) * 8 - 1);
                i++;    /* next input word */
            }

            /* if set in input, set in rotated output */
            if (src[i] & src_mask)
                dst[j] |= dst_mask;

            src_mask >>= 1;    /* next input bit */
        }

        dst_mask <<= 1;          /* next output bit (row) */
        if (dst_mask > (1 << 7)) /* output bit > 7? */
        {
            dst_mask = 1;
            dst += width;        /* next output byte row */
        }
    }
    return ((height + 7) / 8) * width; /* return result size in bytes */
}


/* generate C source from in-core font*/
int gen_c_source(struct font* pf, char *path)
{
    FILE *ofp;
    int i, ofr = 0;
    time_t t = time(0);
#ifndef ROTATE
    int did_syncmsg = 0;
    bitmap_t *ofs = pf->bits;
#endif
    char buf[256];
    char obuf[256];
    char hdr1[] = {
        "/* Generated by convbdf on %s. */\n"
        "#include \"font.h\"\n"
        "#ifdef HAVE_LCD_BITMAP\n"
        "\n"
        "/* Font information:\n"
        "   name: %s\n"
        "   facename: %s\n"
        "   w x h: %dx%d\n"
        "   size: %d\n"
        "   ascent: %d\n"
        "   descent: %d\n"
        "   first char: %d (0x%02x)\n"
        "   last char: %d (0x%02x)\n"
        "   default char: %d (0x%02x)\n"
        "   proportional: %s\n"
        "   %s\n"
        "*/\n"
        "\n"
        "/* Font character bitmap data. */\n"
        "static const unsigned char _font_bits[] = {\n"
    };

    ofp = fopen(path, "w");
    if (!ofp) {
        fprintf(stderr, "Can't create %s\n", path);
        return 1;
    }

    strcpy(buf, ctime(&t));
    buf[strlen(buf)-1] = 0;

    fprintf(ofp, hdr1, buf, 
            pf->name,
            pf->facename? pf->facename: "",
            pf->maxwidth, pf->height,
            pf->size,
            pf->ascent, pf->descent,
            pf->firstchar, pf->firstchar,
            pf->firstchar+pf->size-1, pf->firstchar+pf->size-1,
            pf->defaultchar, pf->defaultchar,
            pf->width? "yes": "no",
            pf->copyright? pf->copyright: "");

    /* generate bitmaps*/
    for (i=0; i<pf->size; ++i) {
        int x;
        int bitcount = 0;
        int width = pf->width ? pf->width[i] : pf->maxwidth;
        int height = pf->height;
        bitmap_t *bits;
        bitmap_t bitvalue=0;

        /* Skip missing glyphs */
        if (pf->offset && (pf->offset[i] == -1))
            continue;

        bits = pf->bits + (pf->offset? (int)pf->offset[i]: (pf->height * i));

        fprintf(ofp, "\n/* Character %d (0x%02x):\n   width %d",
                i+pf->firstchar, i+pf->firstchar, width);

        if (gen_map) {
            fprintf(ofp, "\n   +");
            for (x=0; x<width; ++x) fprintf(ofp, "-");
            fprintf(ofp, "+\n");

            x = 0;
            while (height > 0) {
                if (x == 0) fprintf(ofp, "   |");

                if (bitcount <= 0) {
                    bitcount = BITMAP_BITSPERIMAGE;
                    bitvalue = *bits++;
                }

                fprintf(ofp, BITMAP_TESTBIT(bitvalue)? "*": " ");

                bitvalue = BITMAP_SHIFTBIT(bitvalue);
                --bitcount;
                if (++x == width) {
                    fprintf(ofp, "|\n");
                    --height;
                    x = 0;
                    bitcount = 0;
                }
            }
            fprintf(ofp, "   +");
            for (x=0; x<width; ++x)
                fprintf(ofp, "-");
            fprintf(ofp, "+ */\n");
        }
        else
            fprintf(ofp, " */\n");

        bits = pf->bits + (pf->offset? (int)pf->offset[i]: (pf->height * i));
#ifdef ROTATE /* pre-rotated into Rockbox bitmap format */
        {
          unsigned char bytemap[512];
          int y8, ix=0;
          
          int size = rotleft(bytemap, sizeof(bytemap), bits, width,
                             pf->height);
          for (y8=0; y8<pf->height; y8+=8) /* column rows */
          {
            for (x=0; x<width; x++) {
                fprintf(ofp, "0x%02x, ", bytemap[ix]);
                ix++;
            }
            fprintf(ofp, "\n");
          }

        /* update offrot since bits are now in sorted order */
        pf->offrot[i] = ofr;
        ofr += size;

        }
#else
        for (x=BITMAP_WORDS(width)*pf->height; x>0; --x) {
            fprintf(ofp, "0x%04x,\n", *bits);
            if (!did_syncmsg && *bits++ != *ofs++) {
                fprintf(stderr, "Warning: found encoding values in non-sorted order (not an error).\n");
                did_syncmsg = 1;
            }
        }
#endif
    }
    fprintf(ofp, "};\n\n");

    if (pf->offset) {
        /* output offset table*/
        fprintf(ofp, "/* Character->glyph mapping. */\n"
                "static const unsigned short _sysfont_offset[] = {\n");

        for (i=0; i<pf->size; ++i) {
            if (pf->offset[i] == -1) {
                pf->offset[i] = pf->offset[pf->defaultchar - pf->firstchar];
                pf->offrot[i] = pf->offrot[pf->defaultchar - pf->firstchar];
            }
            fprintf(ofp, "  %d,\t/* (0x%02x) */\n", 
#ifdef ROTATE
                    pf->offrot[i], i+pf->firstchar);
#else
                    pf->offset[i], i+pf->firstchar);
#endif
        }
        fprintf(ofp, "};\n\n");
    }

    /* output width table for proportional fonts*/
    if (pf->width) {
        fprintf(ofp, "/* Character width data. */\n"
                "static const unsigned char _sysfont_width[] = {\n");

        for (i=0; i<pf->size; ++i)
            fprintf(ofp, "  %d,\t/* (0x%02x) */\n", 
                    pf->width[i], i+pf->firstchar);
        fprintf(ofp, "};\n\n");
    }

    /* output struct font struct*/
    if (pf->offset)
        sprintf(obuf, "_sysfont_offset,");
    else
        sprintf(obuf, "0,  /* no encode table */");

    if (pf->width)
        sprintf(buf, "_sysfont_width,  /* width */");
    else
        sprintf(buf, "0,  /* fixed width */");

    fprintf(ofp,    "/* Exported structure definition. */\n"
            "const struct font sysfont = {\n"
            "  %d,  /* maxwidth */\n"
            "  %d,  /* height */\n"
            "  %d,  /* ascent */\n"
            "  %d,  /* firstchar */\n"
            "  %d,  /* size */\n"
            "  _font_bits, /* bits */\n"
            "  %s  /* offset */\n"
            "  %s\n"
            "  %d,  /* defaultchar */\n"
            "  %d   /* bits_size */\n"
            "};\n"
            "#endif /* HAVE_LCD_BITMAP */\n",
            pf->maxwidth, pf->height,
            pf->ascent,
            pf->firstchar,
            pf->size,
            obuf,
            buf,
            pf->defaultchar,
            pf->bits_size);

    return 0;
}

/* generate C header from in-core font*/
int gen_h_header(struct font* pf, char *path)
{
    FILE *ofp;
    time_t t = time(0);
    char buf[256];
    char *hdr1 =
        "/* Generated by convbdf on %s. */\n"
        "#ifdef HAVE_LCD_BITMAP\n"
        "\n"
        "/* Font information*/\n"
        "#define SYSFONT_NAME           %s\n"
        "#define SYSFONT_FACENAME       %s\n"
        "#define SYSFONT_WIDTH          %d\n"
        "#define SYSFONT_HEIGHT         %d\n"
        "#define SYSFONT_SIZE           %d\n"
        "#define SYSFONT_ASCENT         %d\n";
    char *hdr2 =
        "#define SYSFONT_DESCENT        %d\n"
        "#define SYSFONT_FIRST_CHAR     %d\n"
        "#define SYSFONT_LAST_CHAR      %d\n"
        "#define SYSFONT_DEFAULT_CHAR   %d\n"
        "#define SYSFONT_PROPORTIONAL   %d\n"
        "#define SYSFONT_COPYRIGHT      %s\n"
        "#define SYSFONT_BITS_SIZE      %d\n"
        "\n"
        "#endif\n";

    ofp = fopen(path, "w");
    if (!ofp) {
        fprintf(stderr, "Can't create %s\n", path);
        return 1;
    }

    strcpy(buf, ctime(&t));
    buf[strlen(buf)-1] = 0;

    fprintf(ofp, hdr1, buf,
            pf->name,
            pf->facename? pf->facename: "",
            pf->maxwidth,
            pf->height,
            pf->size,
            pf->ascent);

    fprintf(ofp, hdr2, 
            pf->descent,
            pf->firstchar,
            pf->firstchar+pf->size-1,
            pf->defaultchar,
            pf->width? 1: 0,
            pf->copyright? pf->copyright: "",
            pf->bits_size);

    return 0;
}

static int writebyte(FILE *fp, unsigned char c)
{
    return putc(c, fp) != EOF;
}

static int writeshort(FILE *fp, unsigned short s)
{
    putc(s, fp);
    return putc(s>>8, fp) != EOF;
}

static int writeint(FILE *fp, unsigned int l)
{
    putc(l, fp);
    putc(l>>8, fp);
    putc(l>>16, fp);
    return putc(l>>24, fp) != EOF;
}

static int writestr(FILE *fp, char *str, int count)
{
    return (int)fwrite(str, 1, count, fp) == count;
}

#ifndef ROTATE
static int writestrpad(FILE *fp, char *str, int totlen)
{
    int ret;

    while (str && *str && totlen > 0) {
        if (*str) {
            ret = putc(*str++, fp);
            --totlen;
        }
    }
    while (--totlen >= 0)
        ret = putc(' ', fp);
    return ret;
}
#endif

/* generate .fnt format file from in-core font*/
int gen_fnt_file(struct font* pf, char *path)
{
    FILE *ofp;
    int i;
#ifdef ROTATE
    int ofr = 0;
#endif

    ofp = fopen(path, "wb");
    if (!ofp) {
        fprintf(stderr, "Can't create %s\n", path);
        return 1;
    }

    /* write magic and version #*/
    writestr(ofp, VERSION, 4);
#ifndef ROTATE
    /* internal font name*/
    writestrpad(ofp, pf->name, 64);

    /* copyright*/
    writestrpad(ofp, pf->copyright, 256);
#endif
    /* font info*/
    writeshort(ofp, pf->maxwidth);
    writeshort(ofp, pf->height);
    writeshort(ofp, pf->ascent);
    writeshort(ofp, 0);
    writeint(ofp, pf->firstchar);
    writeint(ofp, pf->defaultchar);
    writeint(ofp, pf->size);

    /* variable font data sizes*/
    writeint(ofp, pf->bits_size);         /* # words of bitmap_t*/
    writeint(ofp, pf->offset? pf->size: 0);  /* # ints of offset*/
    writeint(ofp, pf->width? pf->size: 0);    /* # bytes of width*/
    /* variable font data*/
#ifdef ROTATE
    for (i=0; i<pf->size; ++i)
    {
        bitmap_t* bits;
        int width = pf->width ? pf->width[i] : pf->maxwidth;
        int size;  
        unsigned char bytemap[512];

        /* Skip missing glyphs */
        if (pf->offset && (pf->offset[i] == -1))
            continue;

        bits = pf->bits + (pf->offset? (int)pf->offset[i]: (pf->height * i));

        size = rotleft(bytemap, sizeof(bytemap), bits, width, pf->height);
        writestr(ofp, (char *)bytemap, size);

        /* update offrot since bits are now in sorted order */
        pf->offrot[i] = ofr;
        ofr += size;
    }

    if ( pf->bits_size < 0xFFDB )
    {
        /* bitmap offset is small enough, use unsigned short for offset */
        if (ftell(ofp) & 1)
            writebyte(ofp, 0);          /* pad to 16-bit boundary*/
    }
    else
    {
        /* bitmap offset is large then 64K, use unsigned int for offset */
        while (ftell(ofp) & 3)
            writebyte(ofp, 0);          /* pad to 32-bit boundary*/
    }

    if (pf->offset)
    {
        for (i=0; i<pf->size; ++i)
        {
            if (pf->offset[i] == -1) {
                pf->offrot[i] = pf->offrot[pf->defaultchar - pf->firstchar];
            }
            if ( pf->bits_size < 0xFFDB )
                writeshort(ofp, pf->offrot[i]);
            else
                writeint(ofp, pf->offrot[i]);
        }
    }

    if (pf->width)
        for (i=0; i<pf->size; ++i)
            writebyte(ofp, pf->width[i]);
#else
    for (i=0; i<pf->bits_size; ++i)
        writeshort(ofp, pf->bits[i]);
    if (ftell(ofp) & 2)
        writeshort(ofp, 0);     /* pad to 32-bit boundary*/

    if (pf->offset)
        for (i=0; i<pf->size; ++i) {
            if (pf->offset[i] == (unsigned int)-1) {
                pf->offset[i] = pf->offset[pf->defaultchar - pf->firstchar];
            }
            writeint(ofp, pf->offset[i]);
        }

    if (pf->width)
        for (i=0; i<pf->size; ++i)
            writebyte(ofp, pf->width[i]);
#endif
    fclose(ofp);
    return 0;
}