#ifdef GL_ES
precision highp float;
#endif

uniform vec4 uLens;
uniform vec2 uFov;

uniform sampler2D uSampler;

varying vec3 vPosition;
varying vec2 vTextureCoord;

vec2 TextureCoord2GLCoord(vec2 textureCoord) {
	return (textureCoord - vec2(0.5, 0.5)) * 2.0;
}
vec2 GLCoord2TextureCoord(vec2 glCoord) {
	return glCoord / 2.0 + vec2(0.5, 0.5);
}

void main(void){
	vec2 vMapping = vec2(vTextureCoord.x, 1.0 - vTextureCoord.y);
	vMapping = TextureCoord2GLCoord(vMapping);

	//TOD insert Code
	float F = uLens.x/ uLens.w;

	float seta = length(vMapping) / F;

	vMapping = sin(seta) * F / length(vMapping) * vMapping;

	vMapping *= uLens.w * 1.414;

	vMapping = GLCoord2TextureCoord(vMapping);

	vec4 texture = texture2D(uSampler, vMapping);
	if(vMapping.x > 0.99 || vMapping.x < 0.01 || vMapping.y > 0.99 || vMapping.y < 0.01){
		texture = vec4(0.0, 0.0, 0.0, 1.0);
	} 
	gl_FragColor = texture;
}