diff options
| -rw-r--r-- | framebuffer.lua | 55 |
1 files changed, 55 insertions, 0 deletions
diff --git a/framebuffer.lua b/framebuffer.lua new file mode 100644 index 0000000..6b588b2 --- /dev/null +++ b/framebuffer.lua @@ -0,0 +1,55 @@ +local fb = {} + +fb.w = 0 +fb.h = 0 +fb.x = 0 +fb.y = 0 +fb.buf = nil + +function fb.init(w, h) + fb.w = w + fb.h = h + fb.x = 0 + fb.y = 0 + fb.buf = {} +end + +function fb.scroll() + for x = 0, fb.w-1 do + for y = 1, fb.h/8-1 do + fb.buf[x*(fb.h/8) + y-1 + 1] = fb.buf[x*(fb.h/8) + y + 1] or nil + end + fb.buf[x*(fb.h/8) + fb.h/8] = nil + end + fb.y = fb.y - 8 +end + +function fb.put(font, c) + if c == 10 then + fb.x = 0 + fb.y = fb.y + font.height + return + end + if c < 32 or c > 126 then + c = 0x3f + end + if fb.y >= fb.h then + fb.scroll() + end + local glyph = font.glyphs[c - 31] + for i = 1, table.getn(glyph) do + fb.buf[fb.y/8 + (fb.x + i-1) * (fb.h/8) + 1] = glyph[i] + end + fb.x = fb.x + table.getn(glyph) + 2 + if fb.x > fb.w then + fb.put(font, 10) + end +end + +function fb.print(font, str) + for i = 1, string.len(str) do + fb.put(font, string.byte(str, i)) + end +end + +return fb |