// Copyright 2006-2010 (C) - Frictional Games
//
// This file is part of HPL1 Engine
//
// For conditions of distribution and use, see copyright notice in LICENSE-shaders
//

///////////////////////////////////////////////////////
/// REFRACTION SPECIAL FRAGMENT PROGRAM /////////////////
///////////////////////////////////////////////////////

in vec2 vUv; //in object space
in vec4 vColor;

OUTPUT

uniform sampler2DRect tex0; //screenMap
uniform sampler2D tex1; //refractMap
uniform sampler2D tex2; //alphaMap

uniform vec2 screenSize;
uniform float t;
uniform float scale;

void main()
{
	float alpha = texture(tex2, vUv).x;
	vec2 uv2 = (gl_FragCoord.xy / screenSize);
	uv2.x += sin(t + uv2.y*10) * 0.001 * scale;
	uv2.y += sin(t + uv2.x*10) * 0.001 * scale;
	vec3 offset = vec3(((texture(tex1, uv2)*2.0) - vec4(1.0)) * alpha * vColor.w);

	outColor.xyz = (texture2DRect(tex0,gl_FragCoord.xy - offset.xy*scale)).xyz;
}