source: code/archive/skybox/Media/materials/programs/OldTV.cg @ 10022

sampler Image: register(s0);
sampler Rand: register(s1);
sampler Noise: register(s2);

float4 OldTV_ps(float2 pos: TEXCOORD1, float2 img: TEXCOORD0,
    uniform float distortionFreq: register(c3),
    uniform float distortionScale: register(c4),
    uniform float distortionRoll: register(c5),
    uniform float interference: register(c7),
    uniform float frameLimit: register(c8),
    uniform float frameShape: register(c0),
    uniform float frameSharpness: register(c1),
    uniform float time_0_X: register(c2),
    uniform float sin_time_0_X: register(c6)

) : COLOR {
   // Define a frame shape
   float f = (1 - pos.x * pos.x) * (1 - pos.y * pos.y);
   float frame = saturate(frameSharpness * (pow(f, frameShape) - frameLimit));

   // Interference ... just a texture filled with rand()
   float rand = tex3D(Rand, float3(1.5 * pos, time_0_X)) - 0.2;

   // Some signed noise for the distortion effect
   float noisy = tex3D(Noise, float3(0, 0.5 * pos.y, 0.1 * time_0_X)) - 0.5;

   // Repeat a 1 - x^2 (0 < x < 1) curve and roll it with sinus.
   float dst = frac(pos.y * distortionFreq + distortionRoll * sin_time_0_X);
   dst *= (1 - dst);
   // Make sure distortion is highest in the center of the image
   dst /= 1 + distortionScale * abs(pos.y);

   // ... and finally distort
   img.x += distortionScale * noisy * dst;
   float4 image = tex2D(Image, img);

   // Combine frame, distorted image and interference
   return frame * (interference * rand + image);
}