diff options
Diffstat (limited to 'img.mu')
| -rw-r--r-- | img.mu | 66 |
1 files changed, 32 insertions, 34 deletions
diff --git a/img.mu b/img.mu index 2ae8e8d7..db9cff4e 100644 --- a/img.mu +++ b/img.mu @@ -27,19 +27,10 @@ fn main screen: (addr screen), keyboard: (addr keyboard), data-disk: (addr disk) var img-storage: image var img/esi: (addr image) <- address img-storage load-image img, data-disk - render-image screen, img, 0/x, 0/y, 0x100/width, 0x100/height -#? render-image screen, img, 0x20/x, 0x180/y, 0x12c/width=300, 0xc8/height=200 -#? render-pgm-image screen, img, 0x220/x, 0x180/y, 0x12c/width=300, 0xc8/height=200 -#? render-image screen, img, 0x320/x, 0x280/y, 0x60/width=96, 0x1c/height=28 - -#? render-pgm-image screen, img, 0x1c0/x, 0x100/y, 0x12c/width=300, 0xc8/height=200 -#? draw-box-on-real-screen 0x1bf/x, 0x102/y, 0x1c4/x, 0x104/y, 4/fg -#? render-image screen, img, 0x80/x, 0x100/y, 0x12c/width=300, 0xc8/height=200 - -#? set-cursor-position 0/screen, 0/x 2/y -#? render-pgm-image screen, img, 0x200/x, 0x100/y, 0x200/width, 0x200/height -#? render-image screen, img, 0/x, 0x100/y, 0x200/width, 0x200/height - +#? render-image screen, img, 0/x, 0/y, 0x300/width, 0x300/height + render-image screen, img, 0x20/x, 0x80/y, 0x258/width=600, 0x190/height=400 +#? render-image screen, img, 0x20/x, 0x80/y, 0x12c/width=300, 0xc8/height=200 +#? render-pgm-image screen, img, 0x220/x, 0x80/y, 0x12c/width=300, 0xc8/height=200 } fn load-image self: (addr image), data-disk: (addr disk) { @@ -501,34 +492,41 @@ fn dither-pgm-unordered _src: (addr image), _dest: (addr image) { } fn compute-greyscale-color-and-error errors: (addr array int), initial-color: byte, x: int, y: int, width: int -> _/eax: byte, _/esi: int { + # pseudocode: + # error += (initial-color << 16) + # nearest-color = nearest(error >> 16) + # error -= (nearest-color << 16) + # return nearest-color >> 4 + 16, error var error/esi: int <- _read-dithering-error errors, x, y, width - # error += initial-color << 16 - var color-int/eax: int <- copy initial-color - color-int <- shift-left 0x10 # we have 32 bits; we'll use 16 bits for the fraction and leave 8 for unanticipated overflow - error <- add color-int - # tmp = max(error, 0) - var tmp/eax: int <- copy error - { - compare tmp, 0 + # error += (initial-color << 16) + var tmp/eax: int <- copy initial-color + tmp <- shift-left 0x10 # we have 32 bits; we'll use 16 bits for the fraction and leave 8 for unanticipated overflow + error <- add tmp + # nearest-color = nearest(error >> 16) + var nearest-color/ecx: int <- copy error + nearest-color <- shift-right-signed 0x10 + { + compare nearest-color, 0 break-if->= - tmp <- copy 0 + nearest-color <- copy 0 } - # round tmp to nearest multiple of 0x100000 + # . round to nearest multiple of 0x10 { - var tmp2/ecx: int <- copy tmp - tmp2 <- and 0xfffff - compare tmp2, 0x80000 + var tmp/eax: int <- copy nearest-color + tmp <- and 0xf + compare tmp, 8 break-if-< - tmp <- add 0x80000 + nearest-color <- add 8 } - tmp <- and 0xf00000 - # error -= tmp + nearest-color <- and 0xf0 + # error -= (nearest-color << 16) + var tmp/eax: int <- copy nearest-color + tmp <- shift-left 0x10 error <- subtract tmp - # color = tmp >> 20 + 16 - var color/eax: int <- copy tmp - color <- shift-right-signed 0x14 - color <- add 0x10 - var color-byte/eax: byte <- copy-byte color + # return (nearest-color >> 4 + 16), error + nearest-color <- shift-right 4 + nearest-color <- add 0x10 + var color-byte/eax: byte <- copy-byte nearest-color return color-byte, error } |