stb/tools/easy_font_maker.c

   1 // This program was used to encode the data for stb_simple_font.h
   2
   3 #define STB_DEFINE
   4 #include "stb.h"
   5 #define STB_IMAGE_IMPLEMENTATION
   6 #include "stb_image.h"
   7
   8 int w,h;
   9 uint8 *data;
  10
  11 int last_x[2], last_y[2];
  12 int num_seg[2], non_empty;
  13 #if 0
  14 typedef struct
  15 {
  16    unsigned short first_segment;
  17    unsigned char advance;
  18 } chardata;
  19
  20 typedef struct
  21 {
  22    unsigned char x:4;
  23    unsigned char y:4;
  24    unsigned char len:3;
  25    unsigned char dir:1;
  26 } segment;
  27
  28 segment *segments;
  29
  30 void add_seg(int x, int y, int len, int horizontal)
  31 {
  32    segment s;
  33    s.x = x;
  34    s.y = y;
  35    s.len = len;
  36    s.dir = horizontal;
  37    assert(s.x == x);
  38    assert(s.y == y);
  39    assert(s.len == len);
  40    stb_arr_push(segments, s);
  41 }
  42 #else
  43 typedef struct
  44 {
  45    unsigned char first_segment:8;
  46    unsigned char first_v_segment:8;
  47    unsigned char advance:5;
  48    unsigned char voff:1;
  49 } chardata;
  50
  51 #define X_LIMIT 1
  52 #define LEN_LIMIT 7
  53
  54 typedef struct
  55 {
  56    unsigned char dx:1;
  57    unsigned char y:4;
  58    unsigned char len:3;
  59 } segment;
  60
  61 segment *segments;
  62 segment *vsegments;
  63
  64 void add_seg(int x, int y, int len, int horizontal)
  65 {
  66    segment s;
  67
  68    while (x - last_x[horizontal] > X_LIMIT) {
  69       add_seg(last_x[horizontal] + X_LIMIT, 0, 0, horizontal);
  70    }
  71    while (len > LEN_LIMIT) {
  72       add_seg(x, y, LEN_LIMIT, horizontal);
  73       len -= LEN_LIMIT;
  74       x += LEN_LIMIT*horizontal;
  75       y += LEN_LIMIT*!horizontal;
  76    }
  77
  78    s.dx = x - last_x[horizontal];
  79    s.y = y;
  80    s.len = len;
  81    non_empty += len != 0;
  82    //assert(s.x == x);
  83    assert(s.y == y);
  84    assert(s.len == len);
  85    ++num_seg[horizontal];
  86    if (horizontal)
  87       stb_arr_push(segments, s);
  88    else
  89       stb_arr_push(vsegments, s);
  90    last_x[horizontal] = x;
  91 }
  92
  93 void print_segments(segment *s)
  94 {
  95    int i, hpos;
  96    printf("   ");
  97    hpos = 4;
  98    for (i=0; i < stb_arr_len(s); ++i) {
  99       // repack for portability
 100       unsigned char seg = s[i].len + s[i].dx*8 + s[i].y*16;
 101       hpos += printf("%d,", seg);
 102       if (hpos > 72 && i+1 < stb_arr_len(s)) {
 103          hpos = 4;
 104          printf("\n    ");
 105       }
 106    }
 107    printf("\n");
 108 }
 109
 110 #endif
 111
 112 chardata charinfo[128];
 113
 114 int parse_char(int x, chardata *c, int offset)
 115 {
 116    int start_x = x, end_x, top_y = 0, y;
 117
 118    c->first_segment = stb_arr_len(segments);
 119    c->first_v_segment = stb_arr_len(vsegments) - offset;
 120    assert(c->first_segment == stb_arr_len(segments));
 121    assert(c->first_v_segment + offset == stb_arr_len(vsegments));
 122
 123    // find advance distance
 124    end_x = x+1;
 125    while (data[end_x*3] == 255)
 126       ++end_x;
 127    c->advance = end_x - start_x + 1;
 128
 129    last_x[0] = last_x[1] = 0;
 130    last_y[0] = last_y[1] = 0;
 131
 132    for (y=2; y < h; ++y) {
 133       for (x=start_x; x < end_x; ++x) {
 134          if (data[y*3*w+x*3+1] < 255) {
 135             top_y = y;
 136             break;
 137          }
 138       }
 139       if (top_y)
 140          break;
 141    }
 142    c->voff = top_y > 2;
 143    if (top_y > 2)
 144       top_y = 3;
 145
 146    for (x=start_x; x < end_x; ++x) {
 147       int y;
 148       for (y=2; y < h; ++y) {
 149          if (data[y*3*w+x*3+1] < 255) {
 150             if (data[y*3*w+x*3+0] == 255) { // red
 151                int len=0;
 152                while (y+len < h && data[(y+len)*3*w+x*3+0] == 255 && data[(y+len)*3*w+x*3+1] == 0) {
 153                   data[(y+len)*3*w+x*3+0] = 0;
 154                   ++len;
 155                }
 156                add_seg(x-start_x,y-top_y,len,0);
 157             }
 158             if (data[y*3*w+x*3+2] == 255) { // blue
 159                int len=0;
 160                while (x+len < end_x && data[y*3*w+(x+len)*3+2] == 255 && data[y*3*w+(x+len)*3+1] == 0) {
 161                   data[y*3*w+(x+len)*3+2] = 0;
 162                   ++len;
 163                }
 164                add_seg(x-start_x,y-top_y,len,1);
 165             }
 166          }
 167       }
 168    }
 169    return end_x;
 170 }
 171
 172
 173 int main(int argc, char **argv)
 174 {
 175    int c, x=0;
 176    data = stbi_load("easy_font_raw.png", &w, &h, 0, 3);
 177    for (c=32; c < 127; ++c) {
 178       x = parse_char(x, &charinfo[c], 0);
 179       printf("%3d -- %3d %3d\n", c, charinfo[c].first_segment, charinfo[c].first_v_segment);
 180    }
 181    printf("===\n");
 182    printf("%d %d %d\n", num_seg[0], num_seg[1], non_empty);
 183    printf("%d\n", sizeof(segments[0]) * stb_arr_len(segments));
 184    printf("%d\n", sizeof(segments[0]) * stb_arr_len(segments) + sizeof(segments[0]) * stb_arr_len(vsegments) + sizeof(charinfo[32])*95);
 185
 186    printf("struct {\n"
 187           "    unsigned char advance;\n"
 188           "    unsigned char h_seg;\n"
 189           "    unsigned char v_seg;\n"
 190           "} stb_easy_font_charinfo[96] = {\n");
 191    charinfo[c].first_segment = stb_arr_len(segments);
 192    charinfo[c].first_v_segment = stb_arr_len(vsegments);
 193    for (c=32; c < 128; ++c) {
 194       if ((c & 3) == 0) printf("    ");
 195       printf("{ %2d,%3d,%3d },",
 196          charinfo[c].advance + 16*charinfo[c].voff,
 197          charinfo[c].first_segment,
 198          charinfo[c].first_v_segment);
 199       if ((c & 3) == 3) printf("\n"); else printf("  ");
 200    }
 201    printf("};\n\n");
 202
 203    printf("unsigned char stb_easy_font_hseg[%d] = {\n", stb_arr_len(segments));
 204       print_segments(segments);
 205    printf("};\n\n");
 206
 207    printf("unsigned char stb_easy_font_vseg[%d] = {\n", stb_arr_len(vsegments));
 208       print_segments(vsegments);
 209    printf("};\n");
 210    return 0;
 211 }