// input
struct vtxin 
{
  float4 position: POSITION;
  float3 normal: NORMAL;
  float4 color: COLOR0;
  float4 texCoord: TEXCOORD0;
};

// vtx output
struct vtxout
{
  float4 position: POSITION; // eye space
  float4 texCoord: TEXCOORD0;    

  float4 color: COLOR0;  
  float4 eyePos: TEXCOORD1; // eye position
  float3 normal: TEXCOORD2;
};


// fragment input
struct fragin
{
	float4 color: COLOR0;  
	//float4 position: POSITION;
	float4 texCoord: TEXCOORD0;    

	float4 winPos: WPOS;
	float4 eyePos: TEXCOORD1; // eye position
	float3 normal: TEXCOORD2;
};


struct pixel
{
	float4 col: COLOR0;
	float3 norm: COLOR1;
	float3 pos: COLOR2;
};


#pragma position_invariant vtx

vtxout vtx(vtxin IN)
{
	vtxout OUT;

	OUT.color = IN.color;
	OUT.texCoord = IN.texCoord;

	// transform the vertex position into eye space
	OUT.eyePos = mul(glstate.matrix.modelview[0], IN.position);
	// transform the vertex position into post projection space
	OUT.position = mul(glstate.matrix.mvp, IN.position);

	OUT.normal = IN.normal;

	return OUT;
}

//#pragma position_invariant fragtex

pixel fragtex(fragin IN, 
			  uniform sampler2D tex
			  )
{
	float4 texColor = tex2D(tex, IN.texCoord.xy);

	// account for alpha blending
	if (texColor.w < 0.5f) discard;

	pixel pix;

	// save color in first render target
	// hack: use combination of emmisive + diffuse (emmisive used as constant ambient term)
	pix.col = (glstate.material.emission + glstate.material.diffuse) * texColor; 
	// save world space normal in rt
	pix.norm = IN.normal;

	// hack: squeeze some information about ambient into the texture
	//pix.col.w = glstate.material.emission.x;

	// compute eye linear depth
	pix.col.w = length(IN.eyePos.xyz);

	return pix;
}


pixel frag(fragin IN)
{
	pixel pix;

	// hack: use comination of emmisive + diffuse (emmisive used as constant ambient term)
	pix.col = glstate.material.diffuse + glstate.material.emission;

	pix.norm = IN.normal;

	pix.col.w = length(IN.eyePos.xyz);

	// hack: squeeze some information about the ambient term into the target
	//pix.col.w = glstate.material.emission.x;

	return pix;
}