Files
jsix_import/src/modules/main/font.cpp
2018-04-08 12:44:09 -07:00

82 lines
1.8 KiB
C++

#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;
}