Forked from 525c1e21-bd67-4735-ac99-b4b0e5262290/traverse.coffee
Created
September 9, 2012 19:30
-
-
Save Dav1dde/3686714 to your computer and use it in GitHub Desktop.
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
# smallest positive t such that s+t*ds is an integer | |
intbound = (s, ds) -> | |
if ds < 0 | |
intbound -s, -ds | |
else | |
s = mod s, 1 | |
return (1 - s) / ds | |
signum = (x) -> if x > 0 then 1 else (if x < 0 then -1 else 0) | |
mod = (value, modulus) -> (value % modulus + modulus) % modulus | |
wx = wy = wz = 128 | |
module.exports = raycast = (origin, direction, callback, radius = 30) -> | |
x = Math.floor origin[0] | |
y = Math.floor origin[1] | |
z = Math.floor origin[2] | |
[dx, dy, dz] = direction | |
stepX = signum dx | |
stepY = signum dy | |
stepZ = signum dz | |
tMaxX = intbound origin[0], dx | |
tMaxY = intbound origin[1], dy | |
tMaxZ = intbound origin[2], dz | |
tDeltaX = stepX / dx | |
tDeltaY = stepY / dy | |
tDeltaZ = stepZ / dz | |
face = vec3.create() | |
if dx is 0 and dy is 0 and dz is 0 | |
throw new Error 'Raycast in zero direction!' | |
radius /= Math.sqrt (dx * dx) + (dy * dy) + (dz * dz) | |
while true # ((if stepX > 0 then x < wx else x >= 0)) and ((if stepY > 0 then y < wy else y >= 0)) and ((if stepZ > 0 then z < wz else z >= 0)) | |
# check inside world | |
# unless x < 0 or y < 0 or z < 0 or x >= wx or y >= wy or z >= wz | |
break if callback x, y, z, face | |
if tMaxX < tMaxY | |
if tMaxX < tMaxZ | |
break if tMaxX > radius | |
x += stepX | |
tMaxX += tDeltaX | |
face[0] = -stepX | |
face[1] = 0 | |
face[2] = 0 | |
else | |
break if tMaxZ > radius | |
z += stepZ | |
tMaxZ += tDeltaZ | |
face[0] = 0 | |
face[1] = 0 | |
face[2] = -stepZ | |
else | |
if tMaxY < tMaxZ | |
break if tMaxY > radius | |
y += stepY | |
tMaxY += tDeltaY | |
face[0] = 0 | |
face[1] = -stepY | |
face[2] = 0 | |
else | |
break if tMaxZ > radius | |
z += stepZ | |
tMaxZ += tDeltaZ | |
face[0] = 0 | |
face[1] = 0 | |
face[2] = -stepZ |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment