water_fragment.cg

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void main(float3 incident         : TEXCOORD0,
		  float3 normal           : TEXCOORD1,
		  float2 screen_coord     : TEXCOORD2,
		  float3 T : TEXCOORD3,
		  float reflection_factor : COLOR,

		  out float4 color : COLOR,

		  uniform sampler2D background : TEXUNIT0,
		  uniform samplerCUBE environmentMap : TEXUNIT1)
{
	//float3 i_proj = mul((float3x3)modelViewProj, incident);
	//float3 n_proj = mul((float3x3)modelViewProj, N);

	incident = normalize(incident);
	normal = normalize(normal);
//	float eta_ratio = 1.333;
	float eta_ratio = 1.1;

	float3 rvec = refract(incident, normal, eta_ratio);
	//rvec = normalize(T);
//	float2 refract_coord = clamp(screen_coord + 0.3*(rvec.xy/abs(rvec.z) - incident.xy/abs(incident.z)), -1, 1);
//	float2 refract_coord = screen_coord + 0.3*(rvec.xy/abs(rvec.z) - incident.xy/abs(incident.z));
	//float2 refract_coord = 0.5*(rvec.xy/abs(rvec.z) + float2(1, 1));//screen_coord + 0.3*(rvec.xy/abs(rvec.z) - incident.xy/abs(incident.z));

	float4 refract_color;
	if ((rvec.x == 0) && (rvec.y == 0) && (rvec.z == 0))
		//rvec = incident;
		//refract_color = float4(0, 0, 0, 0);
		reflection_factor = 1;

	//refract_coord = screen_coord;

	float4 reflect_color = texCUBE(environmentMap, reflect(incident, normal));


	float4 norefract_color = tex2D(background, screen_coord);
	if (norefract_color.w > 0)
	{
		refract_color = 0.6*norefract_color;
	}
	else
	{
		refract_color = texCUBE(environmentMap, rvec);//refract(incident, normal, eta_ratio));
	//	refract_color = tex2D(background, refract_coord);
	}



	// Reflection color
//	float4 reflect_color = texCUBE(environmentMap, reflect(incident, N));
	//float4 reflect_color = texCUBE(environmentMap, normalize(R));

	//reflect_color = float4(1, 0, 0, 0);
	color = lerp(refract_color, reflect_color, reflection_factor);
	//color = reflection_factor;


	//color = float4(0.1, 0.1, dot(normal, normalize(float3(1, 1, -1))), 0);
	//color = dot(normal, normalize(float3(1, 1, -1)));
}