| 67 |
|
bound(a,x,b) : if(a-x, a, if(x-b, b, x)); |
| 68 |
|
Acos(x) : acos(bound(-1,x,1)); |
| 69 |
|
Asin(x) : asin(bound(-1,x,1)); |
| 70 |
+ |
Atan2(y,x) : if(x*x+y*y, atan2(y,x), 0); |
| 71 |
|
Exp(x) : if(-x-100, 0, exp(x)); |
| 72 |
|
Sqrt(x) : if(x, sqrt(x), 0); |
| 73 |
|
|
| 97 |
|
red(r,g,b) = if(r,r,0); |
| 98 |
|
green(r,g,b) = if(g,g,0); |
| 99 |
|
blue(r,g,b) = if(b,b,0); |
| 100 |
< |
grey(r,g,b) = .3*r + .59*g + .11*b; |
| 100 |
> |
grey(r,g,b) = noneg(.263*r + .655*g + .082*b); |
| 101 |
|
clip_r(r,g,b) = bound(0,r,1); |
| 102 |
|
clip_g(r,g,b) = bound(0,g,1); |
| 103 |
|
clip_b(r,g,b) = bound(0,b,1); |
| 104 |
< |
clipgrey(r,g,b) = bound(0,grey(r,g,b),1); |
| 104 |
> |
clipgrey(r,g,b) = min(grey(r,g,b),1); |
| 105 |
|
|
| 106 |
|
dot(v1,v2) : v1(1)*v2(1) + v1(2)*v2(2) + v1(3)*v2(3); |
| 107 |
|
cross(i,v1,v2) : select(i, v1(2)*v2(3) - v1(3)*v2(2), |
| 139 |
|
(1+t*(1.432788+t*(.189269+t*.001308))) ; |
| 140 |
|
un1`private(p) : un2`private(sqrt(-2*log(p))) ; |
| 141 |
|
|
| 142 |
< |
unif2norm(p) : if( .5-p, un1`private(p), -un1`private(1-p) ) ; |
| 142 |
> |
unif2norm(p) : if( .5-p, -un1`private(p), un1`private(1-p) ) ; |
| 143 |
|
|
| 144 |
|
nrand(x) = unif2norm(rand(x)); |
| 145 |
|
|
| 146 |
|
{ Local (u,v) coordinates for planar surfaces } |
| 147 |
|
crosslen`private = Nx*Nx + Ny*Ny; |
| 148 |
< |
{ U is distance from origin in XY-plane } |
| 148 |
> |
{ U is distance from projected Z-axis } |
| 149 |
|
U = if( crosslen`private - FTINY, |
| 150 |
|
(Py*Nx - Px*Ny)/crosslen`private, |
| 151 |
|
Px); |
