1 files changed, 52 insertions, 0 deletions
diff --git a/src/user/app/vterm/font.c b/src/user/app/vterm/font.c
new file mode 100644
index 0000000..d9a4e3c
--- /dev/null
+++ b/src/user/app/vterm/font.c
@@ -0,0 +1,52 @@
+#include "vterm.h"
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+struct psf font;
+void *font_data;
+
+void font_load(const char *path) {
+	FILE *f = fopen(path, "r");
+	if (!f) {
+		eprintf("couldn't open font \"%s\"", path);
+		exit(1);
+	}
+
+	const size_t cap = 8 * 1024; // TODO get file size
+	void *buf = malloc(cap);
+	if (!buf) {
+		eprintf("out of memory");
+		exit(1);
+	}
+	fread(buf, 1, cap, f);
+	if (ferror(f)) {
+		eprintf("error reading file");
+		exit(1);
+	}
+	fclose(f);
+
+	if (memcmp(buf, "\x72\xb5\x4a\x86", 4)) {
+		eprintf("invalid psf header");
+		exit(1);
+	}
+	memcpy(&font, buf, sizeof font);
+	font_data = buf + font.glyph_offset;
+}
+
+void font_blit(uint32_t glyph, int x, int y) {
+	if (glyph >= font.glyph_amt) glyph = 0;
+
+	dirty_mark(x, y);
+
+	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;
+		}
+	}
+}