i'm using a curved screen of 250 cm by 500 cm  with an angle of 160 degrees and i want to bend the output of Processing, so that it fits. I've found a fisheye exemple of GLgraphics and i want to change this to my arc-ed screen. How can i do this correctly?

2. uniform sampler2D texture0;
3. uniform float aperture;
4. 
   
5. const float PI = 3.1415926535;
6. 
   
7. void main(void) {    
8.   float apertureHalf = 0.5 * aperture * (PI / 180.0);
9.   
10.   // This factor ajusts the coordinates in the case that
11.   // the aperture angle is less than 180 degrees, in which
12.   // case the area displayed is not the entire half-sphere.
13.   float maxFactor = sin(apertureHalf);
14.   
15.   vec2 pos = 2.0 * gl_TexCoord[0].st - 1.0;
16.   
17.   float l = length(pos);
18.   if (l > 1.0) {
19.     gl_FragColor = vec4(0, 0, 0, 1);  
20.   } else {
21.     float x = maxFactor * pos.x;
22.     float y = maxFactor * pos.y;
23.     
24.     float n = length(vec2(x, y));
25.     
26.     float z = sqrt(1.0 - n * n);
27.   
28.     float r = atan(n, z) / PI; 
29.   
30.     float phi = atan(y, x);
31. 
    
32.     float u = r * cos(phi) + 0.5;
33.     float v = r * sin(phi) + 0.5;
34.   
35.     gl_FragColor = texture2D(texture0, vec2(u, v));
36.   }
37. }