snoti/font.c
2025-12-30 22:46:42 +09:00

126 lines
2.6 KiB
C

#define STB_TRUETYPE_IMPLEMENTATION
#include "stb_truetype.h"
#include "dat.h"
#include "fn.h"
typedef struct Glyph Glyph;
struct Glyph
{
uchar *bmp;
int w, h, ox, oy;
};
enum { Maxfonts = 4 };
static stbtt_fontinfo fonts[Maxfonts];
static uchar *fontdata[Maxfonts];
static float scale[Maxfonts];
static int nfonts;
static Glyph cache[Nglyphs];
static u32int blendtab[256];
static u32int
blend(u32int bg, u32int fg, int a)
{
int br, bg_, bb, fr, fg_, fb, r, g, b, inv;
inv = 255 - a;
br = (bg >> 16) & 0xff;
bg_ = (bg >> 8) & 0xff;
bb = bg & 0xff;
fr = (fg >> 16) & 0xff;
fg_ = (fg >> 8) & 0xff;
fb = fg & 0xff;
r = (br * inv + fr * a) / 255;
g = (bg_ * inv + fg_ * a) / 255;
b = (bb * inv + fb * a) / 255;
return (r << 16) | (g << 8) | b;
}
static void
loadfont(char *path)
{
int fd;
long sz, n;
if(nfonts >= Maxfonts)
die("too many fonts");
fd = open(path, OREAD);
if(fd < 0)
die("can't open font: %s", path);
sz = seek(fd, 0, 2);
seek(fd, 0, 0);
fontdata[nfonts] = emalloc(sz);
n = readn(fd, fontdata[nfonts], sz);
close(fd);
if(n != sz)
die("can't read font: %s", path);
if(!stbtt_InitFont(&fonts[nfonts], fontdata[nfonts], stbtt_GetFontOffsetForIndex(fontdata[nfonts], 0)))
die("can't init font: %s", path);
scale[nfonts] = stbtt_ScaleForPixelHeight(&fonts[nfonts], Fontsz);
nfonts++;
}
void
fontinit(char *dir)
{
int fd, n, i, a;
Dir *d;
char path[256], *p;
fd = open(dir, OREAD);
if(fd < 0)
die("can't open font dir: %s", dir);
n = dirreadall(fd, &d);
close(fd);
if(n < 0)
die("can't read font dir: %s", dir);
for(i = 0; i < n; i++){
p = strrchr(d[i].name, '.');
if(p != nil && (strcmp(p, ".ttf") == 0 || strcmp(p, ".otf") == 0)){
snprint(path, sizeof path, "%s/%s", dir, d[i].name);
loadfont(path);
}
}
free(d);
if(nfonts == 0)
die("no fonts in %s", dir);
for(a = 0; a < 256; a++)
blendtab[a] = blend(Colbg, Colfg, a);
}
void
putfont(u32int *buf, int w, int h, int px, int py, Rune r)
{
Glyph *g;
int i, j, x, y, a, f;
if(r >= Nglyphs)
return;
g = &cache[r];
if(g->bmp == nil){
for(f = 0; f < nfonts; f++){
if(stbtt_FindGlyphIndex(&fonts[f], r) == 0)
continue;
g->bmp = stbtt_GetCodepointBitmap(&fonts[f], scale[f], scale[f], r, &g->w, &g->h, &g->ox, &g->oy);
if(g->bmp != nil)
break;
}
if(g->bmp == nil)
return;
}
for(j = 0; j < g->h; j++){
y = py + j + g->oy + Fontsz - Fontbase;
if(y < 0 || y >= h)
continue;
for(i = 0; i < g->w; i++){
x = px + i + g->ox;
if(x < 0 || x >= w)
continue;
a = g->bmp[j * g->w + i];
if(a > 0)
buf[y * w + x] = blendtab[a];
}
}
}