You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
90 lines
2.0 KiB
90 lines
2.0 KiB
fn draw-circle screen: (addr screen), cx: int, cy: int, radius: int, color: int { |
|
var x: int |
|
var y: int |
|
var err: int |
|
# x = -r |
|
var tmp/eax: int <- copy radius |
|
tmp <- negate |
|
copy-to x, tmp |
|
# err = 2 - 2*r |
|
tmp <- copy radius |
|
tmp <- shift-left 1 |
|
tmp <- negate |
|
tmp <- add 2 |
|
copy-to err, tmp |
|
# |
|
var tmpx/ecx: int <- copy 0 |
|
var tmpy/edx: int <- copy 0 |
|
{ |
|
# pixel(cx-x, cy+y) |
|
tmpx <- copy cx |
|
tmpx <- subtract x |
|
tmpy <- copy cy |
|
tmpy <- add y |
|
pixel screen, tmpx, tmpy, color |
|
# pixel(cx-y, cy-x) |
|
tmpx <- copy cx |
|
tmpx <- subtract y |
|
tmpy <- copy cy |
|
tmpy <- subtract x |
|
pixel screen, tmpx, tmpy, color |
|
# pixel(cx+x, cy-y) |
|
tmpx <- copy cx |
|
tmpx <- add x |
|
tmpy <- copy cy |
|
tmpy <- subtract y |
|
pixel screen, tmpx, tmpy, color |
|
# pixel(cx+y, cy+x) |
|
tmpx <- copy cx |
|
tmpx <- add y |
|
tmpy <- copy cy |
|
tmpy <- add x |
|
pixel screen, tmpx, tmpy, color |
|
# r = err |
|
tmp <- copy err |
|
copy-to radius, tmp |
|
# if (r <= y) { ++y; err += (y*2 + 1); } |
|
{ |
|
tmpy <- copy y |
|
compare radius, tmpy |
|
break-if-> |
|
increment y |
|
tmpy <- copy y |
|
tmpy <- shift-left 1 |
|
tmpy <- increment |
|
add-to err, tmpy |
|
} |
|
# if (r > x || err > y) { ++x; err += (x*2 + 1); } |
|
$draw-circle:second-check: { |
|
{ |
|
tmpx <- copy x |
|
compare radius, tmpx |
|
break-if-> |
|
tmpy <- copy y |
|
compare err, tmpy |
|
break-if-> |
|
break $draw-circle:second-check |
|
} |
|
increment x |
|
tmpx <- copy x |
|
tmpx <- shift-left 1 |
|
tmpx <- increment |
|
add-to err, tmpx |
|
} |
|
# loop termination condition |
|
compare x, 0 |
|
loop-if-< |
|
} |
|
} |
|
|
|
fn draw-disc screen: (addr screen), cx: int, cy: int, radius: int, color: int, border-color: int { |
|
var r/eax: int <- copy 0 |
|
{ |
|
compare r, radius |
|
break-if->= |
|
draw-circle screen, cx cy, r, color |
|
r <- increment |
|
loop |
|
} |
|
draw-circle screen, cx cy, r, border-color |
|
}
|
|
|