Weitere Projekt-Dokumentation - von Johannes Singler

Abbildung 9: Die Hilfstextur für den WireWorld-Zellularautomaten.
//Declare pixel shader version
ps.2.0
dcl_2d s0 //cell state, point sampling
dcl_2d s1 //cell state, bilinear filtering
dcl_2d s5 //decision support texture, point sampling
dcl t0.xy //current cell
dcl t1.xy //4 texture coordinates to sample 4 neighbors
dcl t2.xy
dcl t3.xy
dcl t4.xy
//r: 0 = non-red, 1 = red
//b: 0 = black, non-conductor; 1/4 = red, electron head,
// 1/2 = blue, electron tail, 3/4 = white, conductor
//Multiplicative factor to isolate blue
// RGBA
def c0, 0.5, 0.5, 0.5, 0.5
//Additive factor to bias the red-green slightly (to avoid problems with tight texture coordinates)
def c1, 0.01, 0.01, 0.0, 0.0
//Weights for neighbor pixels, 1/16 * 2
def c2, 0.125, 0.0, 0.0, 0.0
//offset for nicer colors
def c3, 0.0, 0.5, 0.0, 0.0
//get colors from 5 texture stages
texld r0, t0, s0 //this cell
texld r1, t1, s1 //straight neighbors
texld r2, t2, s1
texld r3, t3, s1
texld r4, t4, s1
mov r6, c1 //initialize with bias
mad r6.g, r0.b, c0, r6.g //mask out blue and put it in green
//and add the average of the neighbors according to weights in constant mem:
//r6 = fac * r1 + fac * r2 + fac * r3 + fac * r4
mad r6.r, c2, r1.r, r6
mad r6.r, c2, r2.r, r6
mad r6.r, c2, r3.r, r6
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