shader.shader

gistfile1.txt

attribute vec3 aVertexPosition;
attribute vec3 aNormal;
attribute vec2 aTextureCoord;

uniform mat4 uProjection;
uniform mat4 uView;
uniform mat4 uWorld;
uniform mat3 uNormal;

uniform vec3 vLight;
uniform vec3 uViewDirection;

varying vec3 vNormal;
varying vec3 vVectorToLight;
varying vec3 vViewDirection;
varying vec2 vTextureCoord;
varying vec3 vTangent;
varying vec3 vBiTangent;
varying vec3 vHalfVector;

void main(void){
    vec4 vTransformedPosition =  uView * uWorld * vec4(aVertexPosition, 1.0);

    // Calculate vector from light
    vec3 vectorToLight = vec3(vec4(vLight.x, vLight.y, vLight.z, 1.0) - vTransformedPosition);
    vectorToLight = normalize(vectorToLight);

    // Transform tangent/bitangent/normal
    vTangent = normalize(uNormal * vec3(1,0,0));
    vNormal  = normalize(uNormal * aNormal);
    vBiTangent = cross(vTangent, vNormal);

    // Transform the light vector into texture space
    vVectorToLight = vec3(
                dot(vectorToLight, vTangent),
                dot(vectorToLight, vBiTangent),
                dot(vectorToLight, vNormal));
    vVectorToLight = normalize(vVectorToLight);

    // Transform the eye into texture space
    vViewDirection = vec3(
                dot(uViewDirection, vTangent),
                dot(uViewDirection, vBiTangent),
                dot(uViewDirection, vNormal));
    vViewDirection = normalize(vViewDirection);
    
    // Transform the half vector into texture space
    vHalfVector = normalize((vViewDirection + vVectorToLight) / 2.0);
    vHalfVector = vec3(
                dot(vHalfVector, vTangent),
                dot(vHalfVector, vBiTangent),
                dot(vHalfVector, vNormal));

    // And finally set the texture coords + position
    gl_Position =  uProjection *  vTransformedPosition;
    vTextureCoord = aTextureCoord;
}

gistfile2.txt

#ifdef GL_ES
precision highp float;
#endif

varying vec2 vTextureCoord;
varying vec3 vVectorToLight;
varying vec3 vViewDirection;
varying vec3 vNormal;
varying vec3 vTangent;
varying vec3 vBiTangent;
varying vec3 vHalfVector;

uniform sampler2D uBumpSampler;

void main(void) {

    // Sample the texture to get our new normal in texture space
    vec3 bumpNormal = (texture2D(uBumpSampler, vTextureCoord.st)).rgb * 2.0 - 1.0;

    // Calculate diffuse against bump map
    vec3 light = normalize(vVectorToLight);
    float diffuse  = clamp(dot(light, vNormal), 0.0, 1.0);
        
    // Calculate specular against bump map
    vec3 specular = vec3(0.0, 0.0, 1.0) * ( pow( dot(vHalfVector, vNormal), 20.0) );
    
    // Botch phong
    gl_FragColor = vec4(diffuse, diffuse, diffuse, 1.0) + vec4(specular, 1.0);
}