1 files changed, 76 insertions, 0 deletions
diff --git a/src/cmd/vterm/font.c b/src/cmd/vterm/font.c
new file mode 100644
index 0000000..777b094
--- /dev/null
+++ b/src/cmd/vterm/font.c
@@ -0,0 +1,76 @@
+#include "vterm.h"
+#include <err.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+struct psf2 font;
+void *font_data;
+
+void font_load(const char *path) {
+	FILE *f = fopen(path, "r");
+	if (!f) {
+		err(1, "couldn't open font \"%s\"", path);
+	}
+
+	void *buf;
+	long buflen;
+
+	fseek(f, 0, SEEK_END);
+	buflen = ftell(f);
+	if (buflen < 0) {
+		errx(1, "can't get the size of \"%s\"", path);
+	}
+
+	buf = malloc(buflen);
+	if (!buf) {
+		err(1, "out of memory");
+	}
+
+	fseek(f, 0, SEEK_SET);
+	fread(buf, 1, buflen, f);
+	if (ferror(f)) {
+		err(1, "error reading font");
+	}
+	fclose(f);
+
+	if (!memcmp(buf, "\x72\xb5\x4a\x86", 4)) {
+		memcpy(&font, buf, sizeof font);
+		font_data = buf + font.glyph_offset;
+	} else if (!memcmp(buf, "\x36\x04", 2)) {
+		struct psf1 *hdr = buf;
+		font = (struct psf2){
+			.glyph_amt = 256,
+			.glyph_size = hdr->h,
+			.h = hdr->h,
+			.w = 8,
+		};
+		font_data = buf + 4;
+	} else {
+		errx(1, "invalid psf header");
+	}
+}
+
+void font_blit(uint32_t glyph, int x, int y) {
+	if (glyph >= font.glyph_amt) glyph = 0;
+	if (x < 0 || (x+1) * font.w >= fb.width ||
+		y < 0 || (y+1) * font.h >= fb.height)
+	{
+		return;
+	}
+
+	dirty_mark(&dirty, x * font.w, y * font.h);
+	dirty_mark(&dirty, (x+1) * font.w - 1, (y+1) * font.h - 1);
+
+	char *bitmap = font_data + font.glyph_size * glyph;
+	for (size_t i = 0; i < font.w; i++) {
+		for (size_t j = 0; j < font.h; j++) {
+			size_t idx = j * font.w + i;
+			char byte = bitmap[idx / 8];
+			byte >>= (7-(idx&7));
+			byte &= 1;
+			*((uint32_t*)&fb.b[fb.pitch * (y * font.h + j) + 4 * (x * font.w + i)]) = byte * 0xB0B0B0;
+		}
+	}
+	return;
+}