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@cloudwu cloudwu/ttfont.c

Last active Jun 29, 2020
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sample for stb truetype
#include <stdio.h>
#define HEIGHT 24
#define STB_TRUETYPE_IMPLEMENTATION
#define STBTT_STATIC
// gcc -Wall -Wno-unused-function -g ttfont.c -o ttfont.exe
// https://github.com/nothings/stb/blob/master/stb_truetype.h
#include "stb_truetype.h"
unsigned char ttf_buffer[1<<25];
#define MAXUNICODE 0x10FFFF
static int
utf8_decode(const char *o) {
static const unsigned int limits[] = {0xFF, 0x7F, 0x7FF, 0xFFFF};
const unsigned char *s = (const unsigned char *)o;
unsigned int c = s[0];
unsigned int res = 0; /* final result */
if (c < 0x80) /* ascii? */
res = c;
else {
int count = 0; /* to count number of continuation bytes */
while (c & 0x40) { /* still have continuation bytes? */
int cc = s[++count]; /* read next byte */
if ((cc & 0xC0) != 0x80) /* not a continuation byte? */
return -1; /* invalid byte sequence */
res = (res << 6) | (cc & 0x3F); /* add lower 6 bits from cont. byte */
c <<= 1; /* to test next bit */
}
res |= ((c & 0x7F) << (count * 5)); /* add first byte */
if (count > 3 || res > MAXUNICODE || res <= limits[count])
return -1; /* invalid byte sequence */
s += count; /* skip continuation bytes read */
}
return res;
}
int
main() {
stbtt_fontinfo font;
int i,j;
int c = utf8_decode("");
fread(ttf_buffer, 1, 1<<25, fopen("c:/windows/fonts/msyh.ttc", "rb"));
stbtt_InitFont(&font, ttf_buffer, stbtt_GetFontOffsetForIndex(ttf_buffer,0));
float scale = stbtt_ScaleForPixelHeight(&font, HEIGHT);
int x0,y0,x1,y1;
int ascent,baseline, decent;
stbtt_GetFontVMetrics(&font, &ascent,&decent,0);
baseline = (int) (ascent*scale);
int height = (int) ((ascent - decent)*scale);
printf("ascent = %d, decent = %d, baseline = %d, height = %d\n", ascent, decent, baseline, height);
stbtt_GetCodepointBitmapBox(&font, c, scale, scale, &x0, &y0, &x1, &y1);
printf("x0=%d y0=%d x1=%d y1=%d\n", x0, y0, x1, y1);
int w = x1-x0;
int h = y1-y0;
unsigned char bitmap[h][w];
stbtt_MakeCodepointBitmap(&font, &bitmap[0][0], w,h, w, scale, scale, c);
for (j=0; j < h; ++j) {
for (i=0; i < w; ++i) {
putchar(" .:ioVM@"[bitmap[j][i]>>5]);
}
putchar('\n');
}
return 0;
}
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