first commit

font.c

@@ -0,0 +1,87 @@
+#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;
+};
+
+static stbtt_fontinfo font;
+static uchar *fontdata;
+static float scale;
+static Glyph cache[Nglyphs];
+static u32int blendtab[2][256];
+
+static u32int
+blend(u32int bg, int a)
+{
+	int r, g, b, inv;
+
+	inv = 255 - a;
+	r = (bg >> 16 & 0xff) * inv / 255;
+	g = (bg >> 8 & 0xff) * inv / 255;
+	b = (bg & 0xff) * inv / 255;
+	return (r << 16) | (g << 8) | b;
+}
+
+void
+fontinit(char *path)
+{
+	int fd, a;
+	long sz, n;
+
+	fd = open(path, OREAD);
+	if(fd < 0)
+		die("can't open font: %s", path);
+	sz = seek(fd, 0, 2);
+	seek(fd, 0, 0);
+	fontdata = emalloc(sz);
+	n = readn(fd, fontdata, sz);
+	close(fd);
+	if(n != sz)
+		die("can't read font: %s", path);
+	if(!stbtt_InitFont(&font, fontdata, stbtt_GetFontOffsetForIndex(fontdata, 0)))
+		die("can't init font: %s", path);
+	scale = stbtt_ScaleForPixelHeight(&font, Fontsz);
+	for(a = 0; a < 256; a++){
+		blendtab[0][a] = blend(Colbg, a);
+		blendtab[1][a] = blend(Colsel, a);
+	}
+}
+
+void
+putfont(u32int *buf, int w, int h, int px, int py, Rune r)
+{
+	Glyph *g;
+	int i, j, x, y, a, sel;
+	u32int *p;
+
+	if(r >= Nglyphs)
+		return;
+	g = &cache[r];
+	if(g->bmp == nil){
+		g->bmp = stbtt_GetCodepointBitmap(&font, scale, scale, r, &g->w, &g->h, &g->ox, &g->oy);
+		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){
+				p = &buf[y * w + x];
+				sel = (*p == Colsel) ? 1 : 0;
+				*p = blendtab[sel][a];
+			}
+		}
+	}
+}