source: data/data_extern/programs/GLSL120/Example_FresnelFp.glsl @ 12232

#version 120

uniform vec4 tintColour;
uniform float noiseScale;
uniform float fresnelBias;
uniform float fresnelScale;
uniform float fresnelPower;
uniform sampler2D noiseMap;
uniform sampler2D reflectMap;
uniform sampler2D refractMap;

varying vec3 noiseCoord;
varying vec4 projectionCoord;
varying vec3 eyeDir;
varying vec3 oNormal;

// Fragment program for distorting a texture using a 3D noise texture
void main()
{
        // Do the tex projection manually so we can distort _after_
        vec2 final = projectionCoord.xy / projectionCoord.w;

        // Noise
        vec3 noiseNormal = (texture2D(noiseMap, (noiseCoord.xy / 5.0)).rgb - 0.5).rbg * noiseScale;
        final += noiseNormal.xz;

        // Fresnel
        //normal = normalize(normal + noiseNormal.xz);
        float fresnel = fresnelBias + fresnelScale * pow(1.0 + dot(eyeDir, oNormal), fresnelPower);

        // Reflection / refraction
        vec4 reflectionColour = texture2D(reflectMap, final);
        vec4 refractionColour = texture2D(refractMap, final) + tintColour;

        // Final colour
        gl_FragColor = mix(refractionColour, reflectionColour, fresnel);
}