ttf2dumbfont.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <ft2build.h>
#include FT_FREETYPE_H

#include "dumbfont.h"

#define PROGNAME "ttf2dumbfont"
#define NCODEPOINT 256
#define MAXIMAGEBYTESIZE (64 * 64 / 8)
#define UNISIGSIZE 32

static unsigned char pixels[NCODEPOINT * MAXIMAGEBYTESIZE];

static void
usage(void)
{
    fprintf(stderr, "usage: %s %s\n", PROGNAME, "<ttf-file> 8|16|32|64");
    exit(1);
}

int
main(int argc, char **argv)
{
    static unsigned char imagebytes[MAXIMAGEBYTESIZE];
    const char *ttf_file;
    const unsigned char *unisig;
    FT_Library library;
    FT_Face face;
    FT_GlyphSlot glyph;
    FT_Bitmap *bitmap;
    size_t imagebytesize;
    int side, baseline, codepoint, yphys, xphys, y, x;
    unsigned int ibyte, ibit;
    int bestbaseline, leastmissing;

    binary_stdout();
    if (argc != 3) {
        usage();
    }
    ttf_file = argv[1];
    switch ((side = atoi(argv[2]))) {
    case 8:
        unisig = unisig8;
        break;
    case 16:
        unisig = unisig16;
        break;
    case 32:
        unisig = unisig32;
        break;
    case 64:
        unisig = unisig64;
        break;
    default:
        usage();
    }
    imagebytesize = side * side / 8;
    if (FT_Init_FreeType(&library)) {
        die("FT_Init_FreeType");
    }
    if (FT_New_Face(library, ttf_file, 0, &face)) {
        die("FT_New_Face");
    }
    if (FT_Set_Pixel_Sizes(face, side, side)) {
        die("FT_Set_Pixel_Sizes");
    }
    bestbaseline = 0;
    leastmissing = 65535;
    for (baseline = side - 1; baseline >= 0; baseline--) {
        int missingpixels = 0;
        for (codepoint = 0; codepoint < NCODEPOINT; codepoint++) {
            if (FT_Load_Char(face, codepoint, FT_LOAD_RENDER)) {
                die("FT_Load_Char");
            }
            glyph = face->glyph;
            bitmap = &glyph->bitmap;
            for (yphys = 0; yphys < (int)bitmap->rows; yphys++) {
                for (xphys = 0; xphys < (int)bitmap->width; xphys++) {
                    if (bitmap->buffer[yphys * bitmap->pitch + xphys]) {
                        x = xphys + (int)glyph->bitmap_left;
                        y = yphys + side - baseline - (int)glyph->bitmap_top;
                        if (!((x >= 0) && (x < side) && (y >= 0) &&
                                (y < side))) {
                            missingpixels++;
                        }
                    }
                }
            }
        }
        if (leastmissing > missingpixels) {
            leastmissing = missingpixels;
            bestbaseline = baseline;
        }
    }
    baseline = bestbaseline;
    fprintf(stderr, "automatically selected baseline %d\n", baseline);
    for (codepoint = 0; codepoint < NCODEPOINT; codepoint++) {
        if (FT_Load_Char(face, codepoint, FT_LOAD_RENDER)) {
            die("FT_Load_Char");
        }
        glyph = face->glyph;
        bitmap = &glyph->bitmap;
        memset(imagebytes, 0, sizeof(imagebytes));
        for (yphys = 0; yphys < (int)bitmap->rows; yphys++) {
            for (xphys = 0; xphys < (int)bitmap->width; xphys++) {
                if (bitmap->buffer[yphys * bitmap->pitch + xphys]) {
                    x = xphys + (int)glyph->bitmap_left;
                    y = yphys + side - baseline - (int)glyph->bitmap_top;
                    if ((x >= 0) && (x < side) && (y >= 0) && (y < side)) {
                        ibyte = y * (side / 8) + (x / 8);
                        ibit = x % 8;
                        imagebytes[ibyte] |= 1 << ibit;
                    }
                }
            }
        }
        memcpy(pixels + imagebytesize * codepoint, imagebytes, imagebytesize);
    }
    if ((1 != fwrite(unisig, UNISIGSIZE, 1, stdout)) ||
        (1 != fwrite(pixels, NCODEPOINT * imagebytesize, 1, stdout))) {
        die("cannot write to stdout");
    }
    return 0;
}