/**
* Example Fragment Shader
* Sets the color and alpha of the pixel by setting gl_FragColor
*/

// Set the precision for data types used in this shader
precision highp float;
precision highp int;

// Default THREE.js uniforms available to both fragment and vertex shader
uniform mat4 modelMatrix;
uniform mat4 modelViewMatrix;
uniform mat4 projectionMatrix;
uniform mat4 viewMatrix;
uniform mat3 normalMatrix;

// Default uniforms provided by ShaderFrog.
uniform vec3 cameraPosition;
uniform float time;

// A uniform unique to this shader. You can modify it to the using the form
// below the shader preview. Any uniform you add is automatically given a form
uniform vec3 albedoColor;
uniform vec3 lightPosition;
uniform vec3 sunColor;
uniform float sunStrength;

uniform samplerCube iblCube;
uniform vec3 iblColor;
uniform float iblStrength;

uniform vec3 rimColor;
uniform float rimStrength;
uniform float rimWidth;

// Example varyings passed from the vertex shader
varying vec3 vPosition;
varying vec3 vNormal;
varying vec2 vUv;
varying vec2 vUv2;

void main()
{
    vec3 worldPosition = ( modelMatrix * vec4( vPosition, 1.0 )).xyz;

    vec3 worldNormal = normalize( vec3( modelMatrix * vec4( vNormal, 0.0 ) ) );
    vec3 lightVector = normalize( lightPosition - worldPosition );
    vec3 viewVector = normalize(cameraPosition - worldPosition);

    float rimndotv =  max(0.0, rimWidth - clamp(dot(worldNormal, viewVector), 0.0, 1.0));

    vec3 rimLight = rimndotv * rimColor * rimStrength;

    vec3 reflection = reflect(-viewVector, worldNormal);
    vec3 iblLight = iblColor * textureCube(iblCube, reflection).rgb * iblStrength;
    
    float ndotl = max(0.0, dot(worldNormal, lightVector));
    vec3 sunLight = sunColor * sunStrength * ndotl;

    vec3 finalLight = rimLight + iblLight + sunLight;

    // Fragment shaders set the gl_FragColor, which is a vector4 of
    // ( red, green, blue, alpha ).
    gl_FragColor = vec4( albedoColor * finalLight, 1.0 );

}