Move main module to c++

src/modules/main/font.cpp

@@ -0,0 +1,81 @@
+#include "font.h"
+#include "screen.h"
+
+/* PSF2 header format
+ * Taken from the Linux KBD documentation
+ * http://www.win.tue.nl/~aeb/linux/kbd/font-formats-1.html
+ */
+
+const static uint8_t magic[] = {0x72, 0xb5, 0x4a, 0x86};
+
+/* bits used in flags */
+enum psf2_flags {
+	psf2_has_unicode = 0x00000001
+};
+
+/* max version recognized so far */
+#define PSF2_MAXVERSION 0
+
+/* UTF8 separators */
+#define PSF2_SEPARATOR  0xFF
+#define PSF2_STARTSEQ   0xFE
+
+struct psf2_header {
+	uint8_t magic[4];
+	uint32_t version;
+	uint32_t header_size;   // offset of bitmaps in file
+	uint32_t flags;
+	uint32_t length;        // number of glyphs
+	uint32_t charsize;      // number of bytes for each character
+	uint32_t height, width; // max dimensions of glyphs
+};
+
+int
+font_init(void *header, struct font *font)
+{
+	struct psf2_header *psf2 = (struct psf2_header *)header;
+	for (int i = 0; i < sizeof(magic); ++i) {
+		if (psf2->magic[i] != magic[i]) {
+			return 1;
+		}
+	}
+
+	if (font == 0)
+		return 2;
+
+	font->height = psf2->height;
+	font->width = psf2->width;
+	font->charsize = psf2->charsize;
+	font->count = psf2->length;
+	font->data = (uint8_t *)header + psf2->header_size;
+	return 0;
+}
+
+int
+font_draw(
+	struct font *f,
+    struct screen *s,
+    uint32_t glyph,
+	uint32_t color,
+    uint32_t x,
+    uint32_t y)
+{
+	const uint32_t height = f->height;
+	const uint32_t width = f->width;
+	const uint32_t bwidth = (width+7)/8;
+	uint8_t *data = f->data + (glyph * f->charsize);
+
+	for (int dy = 0; dy < f->height; ++dy) {
+		for (int dx = 0; dx < bwidth; ++dx) {
+			uint8_t byte = data[dy * bwidth + dx];
+			for (int i = 0; i < 8; ++i) {
+				if (dx*8 + i >= width) continue;
+				const uint8_t mask = 1 << (7-i);
+				uint32_t c = (byte & mask) ? color : 0;
+				screen_pixel(s, x + dx*8 + i, y + dy, c);
+			}
+		}
+	}
+	return 0;
+}
+