Documentation from code comments

wrapper for material color properties and other settings

customUniforms: adds some uniforms to the shader so they can be accessed from the postFragment function

postFragment: Adds a function to the material shader that will get executed after all lighting and material calculations

The source passed has to include a function with the signature:

vec4 postFragment(vec4 localColor){ return localColor; }

which will receive the final color after calculating all the lights and material and can modify it and return a new color

The function has access to the following variables:

vec2 v_texcoord;          // texture coordinate
vec3 v_normal;            // normal at this fragment
vec3 v_transformedNormal; // normal multiplied by the normal matrix
vec3 v_eyePosition;       // position of this fragment in eye coordinates
vec3 v_worldPosition;     // position of this fragment in world coordinates
vec4 v_color;             // color interpolated from the vertex colors
SAMPLER tex0;             // the bound texture if there's any

vec4 mat_ambient;         // material ambient color
vec4 mat_diffuse;         // material diffuse color
vec4 mat_specular;        // material specular
vec4 mat_emissive;        // material emissive
float mat_shininess;      // material shininess

vec4 global_ambient;      // global ambient light
mat4 modelViewMatrix;     // model view matrix
mat4 projectionMatrix;    // projection matrix
mat4 textureMatrix;       // texture matrix
mat4 modelViewProjectionMatrix; // model view projection matrix

MAX_LIGHTS                // the total number of lights in the scen

And an array of lights each light has the following properties:

float lights[i].enabled;
vec4 lights[i].ambient;
float lights[i].type;     // 0 = pointlight
                          // 1 = directionlight
                          // 2 = spotlight
                          // 3 = area
vec4 lights[i].position;  // where are we
vec4 lights[i].diffuse;   // how diffuse
vec4 lights[i].specular;  // what kinda specular stuff we got going on?

// attenuation, how the light attenuates with the distance
float lights[i].constantAttenuation;
float lights[i].linearAttenuation;
float lights[i].quadraticAttenuation;

// only for spot
float lights[i].spotCutoff;
float lights[i].spotCosCutoff;
float lights[i].spotExponent;

// spot and area
vec3 lights[i].spotDirection;

// only for directional
vec3 lights[i].halfVector;

// only for area
float lights[i].width;
float lights[i].height;
vec3 lights[i].right;
vec3 lights[i].up;