///////depth map
struct VS_OUT
{
	float4 hPosition	: POSITION;
	float4 Position	: TEXCOORD0;
};

VS_OUT hDepthVS(float4 position : POSITION,	
		uniform float4x4 worldView,
		uniform float4x4 worldViewProj)
{
  
  VS_OUT OUT;
  OUT.hPosition = mul(worldViewProj, position);
  OUT.Position = mul(worldView, position);
  OUT.Position.z *= -1.0;
  return OUT;
}



float4 DepthPS(VS_OUT IN ):COLOR
{
	float dist = length(IN.Position.xyz);
	return float4(dist, dist, dist, 1);	
}

///////////////Shadow

struct VS_OUT_SHADOW
{
	float4 hPosition	: POSITION;
	float4 Position		: TEXCOORD0;
};

VS_OUT_SHADOW depthShadowVS(float4 position : POSITION,	
		uniform float4x4 world,
		uniform float4x4 worldViewProj)
{
  VS_OUT_SHADOW OUT;
  OUT.hPosition = mul(worldViewProj, position);
  OUT.Position = mul(world, position);
  return OUT;
}


float4 depthShadowPS(VS_OUT_SHADOW IN,
					uniform float4x4 lightView,
					uniform float4x4 lightViewProj,
					uniform sampler2D depthShadowMap ):COLOR
{
	float bias = 0.0;
	float4 shadowColor = float4(0.4, 0.4, 0.4, 1.0);

	float4 light = 1;
	
	float4 lightCamPos = mul(lightView, IN.Position);
	float d = length(lightCamPos.xyz);
	
	float4 lightScreenPos = mul(lightViewProj, IN.Position);
	lightScreenPos = lightScreenPos / lightScreenPos.w ;
	float dist = length(lightScreenPos.xy);
	
	if(dist < 1.0 && lightCamPos.z < 0)
	{
		lightScreenPos = ( lightScreenPos + 1.0 ) / 2.0;
		lightScreenPos.y = 1.0 - lightScreenPos.y;
		float4 storedDepth = tex2D(depthShadowMap, lightScreenPos.xy);
			
		
		if(storedDepth.r + bias < d)
			light = shadowColor;
		if(storedDepth.r == 0)
			light = 1;			
	}
	else
		light = 1;
		
	return light;	
}