libcaca/tools/sortchars.c

/*
 *  sortchars     analyse ASCII characters
 *  Copyright (c) 2007 Sam Hocevar <sam@zoy.org>
 *                All Rights Reserved
 *
 *  $Id$
 *
 *  This program is free software. It comes without any warranty, to
 *  the extent permitted by applicable law. You can redistribute it
 *  and/or modify it under the terms of the Do What The Fuck You Want
 *  To Public License, Version 2, as published by Sam Hocevar. See
 *  http://sam.zoy.org/wtfpl/COPYING for more details.
 */

#include "config.h"
#include "common.h"
#if !defined(__KERNEL__)
#   if defined(HAVE_INTTYPES_H)
#      include <inttypes.h>
#   endif
#   include <stdio.h>
#   include <string.h>
#   include <stdlib.h>
#endif
#include "cucul.h"

#define GLYPHS 0x7f
#define FONT 1 /* 0 or 1 */
#define DX 2
#define DY 3
#define RANGEBITS 2
#define RANGE (1 << RANGEBITS)
#define FULLRANGE (1 << (RANGEBITS * DX * DY))

int total[GLYPHS][DX][DY];
int16_t allbits[GLYPHS];
int bestchar[FULLRANGE];

static int curve[17] = /* 17 instead of 16 */
{
    0, 4, 6, 8, 9, 10, 11, 12, 12, 13, 13, 14, 14, 15, 15, 15, 15
};

static int distance(uint16_t, uint16_t);

int main(int argc, char *argv[])
{
    int count[DX][DY];
    char utf8[7];
    cucul_canvas_t *cv;
    cucul_font_t *f;
    char const * const * fonts;
    uint8_t *img;
    unsigned int w, h, x, y;
    int ret, i, max;

    /* Load a libcucul internal font */
    fonts = cucul_get_font_list();
    if(fonts[FONT] == NULL)
    {
        fprintf(stderr, "error: libcucul was compiled without any fonts\n");
        return -1;
    }
    f = cucul_load_font(fonts[FONT], 0);
    if(f == NULL)
    {
        fprintf(stderr, "error: could not load font \"%s\"\n", fonts[0]);
        return -1;
    }

    cv = cucul_create_canvas(1, 1);
    cucul_set_color_ansi(cv, CUCUL_WHITE, CUCUL_BLACK);

    /* Create our bitmap buffer (32-bit ARGB) */
    w = cucul_get_font_width(f);
    h = cucul_get_font_height(f);
    img = malloc(4 * w * h);

    /* Zero our structures */
    for(y = 0; y < DY; y++)
        for(x = 0; x < DX; x++)
            count[x][y] = 0;

    for(y = 0; y < h; y++)
        for(x = 0; x < w; x++)
            count[x * DX / w][y * DY / h]++;

    for(i = 0x20; i < GLYPHS; i++)
        for(y = 0; y < DY; y++)
            for(x = 0; x < DX; x++)
                total[GLYPHS][x][y] = 0;

    /* Draw all glyphs and count their pixels */
    for(i = 0x20; i < GLYPHS; i++)
    {
        cucul_put_char(cv, 0, 0, i);

        /* Render the canvas onto our image buffer */
        cucul_render_canvas(cv, f, img, w, h, 4 * w);

        for(y = 0; y < h * DY; y++)
            for(x = 0; x < w * DX; x++)
                total[i][x / w][y / h]
                  += img[(w * (y / DY) + (x / DX)) * 4 + 1];
    }

    /* Compute max pixel value */
    max = 0;
    for(i = 0x20; i < GLYPHS; i++)
        for(y = 0; y < DY; y++)
            for(x = 0; x < DX; x++)
            {
                int val = total[i][x][y] * 256 / count[x][y];
                if(val > max)
                    max = val;
            }

    /* Compute bits for all glyphs */
    for(i = 0x20; i < GLYPHS; i++)
    {
        int bits = 0;

        if(i >= 0x7f && i <= 0x9f)
        {
            allbits[i] = 0;
            continue;
        }

        for(y = 0; y < DY; y++)
        {
            for(x = 0; x < DX; x++)
            {
                int t = total[i][x][y] * 16 * 256 / (count[x][y] * max);
                bits *= RANGE;
                bits |= curve[t] / (16 / RANGE);
            }
        }

        allbits[i] = bits;
    }

    /* Find a glyph for all combinations */
    for(i = 0; i < FULLRANGE; i++)
    {
        int j, mindist = 0x1000, best = 0;

        for(j = 0x20; j < GLYPHS; j++)
        {
            int d = distance(i, allbits[j]);
            if(d < mindist)
            {
                best = j;
                mindist = d;
                if(d == 0)
                    break;
            }
        }

        bestchar[i] = best;
    }

    /* Print results */
    printf("/* Generated by sortchars.c */\n");
    printf("static char const lookup_ascii[%i] =\n{\n    ", FULLRANGE);
    for(i = 0; i < FULLRANGE; i++)
    {
        ret = cucul_utf32_to_utf8(utf8, bestchar[i]);
        utf8[ret] = '\0';
        printf("%i, ", bestchar[i]);
        if((i % 16) == 15 && i != FULLRANGE - 1)
            printf("\n    ");
    }
    printf("\n};\n");

    cucul_free_canvas(cv);

    return 0;
}

static int distance(uint16_t a, uint16_t b)
{
    int i, d = 0;

    for(i = 0; i < DX * DY; i++)
    {
        int x = (int)(a & (RANGE - 1)) - (int)(b & (RANGE - 1));
        d += x * x;
        a /= RANGE;
        b /= RANGE;
    }

    return d;
}