Oculus Rift lens distortion correction fragment shader snippet in GLSL

OculusPreWarp

// Exact distortion parameters (a, b, c) are not known yet, these are just placeholers
float a = 0.20f;
float b = 0.00f;
float c = 0.00f;
float d = 1 - (a + b + c);

// Calculate the source location "radius" (distance from the centre of the viewport)
// fragPos - xy position of the current fragment (destination) in NDC space [-1 1]^2
float destR = length(fragPos);
float srcR = a * pow(destR,4) + b * pow(destR,3) + c * pow(destR,2) + d * destR;

// Calculate the source vector (radial)
vec2 correctedRadial = normalize(fragPos) * srcR;

// Transform the coordinates (from [-1,1]^2 to [0, 1]^2)
vec2 uv = (correctedRadial/2.0f) + vec2(0.5f);

// Sample the texture at the source location
fragColor = texture(tex, uv);  

Hello is this full code?

Hi, sorry for replying so late. It's not a full code, just a snippet from the fragment shader. It will work if you declare and bind those variables correctly (fragPos, fragColor and tex).