/**
 * Kepler - Core
 * Copyright (c) 2010 kaj dijkstra STUDIOS
 * All rights reserved.
 */
  
/**
 * Author: Kaj Dijksta
 */
 
    attribute vec3 position;
    attribute vec2 uv;
	
    uniform mat4 viewProjection;

    varying vec2 v_textureCoord;

    void main(void) {
	
        v_textureCoord = uv;
		gl_Position = viewProjection * vec4(position, 1.0);
		
    }
	
	// #keplerEngine - Split
	
	precision highp float;

	uniform sampler2D colorSampler;
	uniform float exposure;
	
	varying vec2 v_textureCoord;

	vec3 HDR_ACES(const vec3 x) {
		// Narkowicz 2015, "ACES Filmic Tone Mapping Curve"
		const float a = 2.51;
		const float b = 0.03;
		const float c = 2.43;
		const float d = 0.59;
		const float e = 0.14;
		return (x * (a * x + b)) / (x * (c * x + d) + e);
	}

	vec3 tonemap(const vec3 x) {
		return HDR_ACES(x);
	}
	
	float linearToSRGB(float c) {
		return (c <= 0.0031308) ? c * 12.92 : (pow(abs(c), 1.0 / 2.4) * 1.055) - 0.055;
	}

	vec3 linearToSRGB(vec3 c) {
		return vec3(linearToSRGB(c.r), linearToSRGB(c.g), linearToSRGB(c.b));
	}
	
	void main() {
		
		vec3 pbr = texture2D( colorSampler, v_textureCoord ).rgb;
			gl_FragColor = vec4( pbr , 1.0 );
		//pbr.rgb *= exposure;
	
		//if(v_textureCoord.x < 0.5) {
		//	gl_FragColor = vec4( linearToSRGB( tonemap(pbr) ), 1.0 );
		//} else {
		//	gl_FragColor = vec4( 
		//}
		
	}