//------------------------------------
float4x4 WorldViewProj : WorldViewProjection;
float4x4 World   : World;
float4x4 WorldInverseTranspose : WorldInverseTranspose;
float4x4 ViewInverse : ViewInverse;

texture NormalMap : Diffuse
<
    string ResourceName = "LowPolyNormalsMap.tga";
>;

texture TextureMap : Diffuse
<
    string ResourceName = "Texture.tga";
>;

float4 lightDir : Direction
<
    string Object = "DirectionalLight";
    string Space = "World";
> = {1.0f, -1.0f, 1.0f, 0.0f};

float3 lightColor : Diffuse
<
    string UIName = "Diffuse Light Color";
    string Object = "DirectionalLight";
> = {1.0f, 1.0f, 1.0f};

float4 lightAmbient : Ambient
<
    string UIWidget = "Ambient Light Color";
    string Space = "material";
> = {0.0f, 0.0f, 0.0f, 1.0f};

//------------------------------------
struct AppInput {
    float4 Pos			: POSITION;
    float3 Normal		: NORMAL;
    float3 Tangent 		: TANGENT;
    float2 TexCoords	: TEXCOORD;
};

struct PSInput {
    float4 Pos			: POSITION;
    float2 TexCoords	: TEXCOORD0;
    float2 TexCoords2	: TEXCOORD1;
    float3 Light		: TEXCOORD2;
    float3 Normal		: TEXCOORD3;
};


//------------------------------------
PSInput VS( AppInput In ) 
{
    PSInput Out;
    Out.Pos = mul( In.Pos, WorldViewProj );
    Out.TexCoords = In.TexCoords;
    Out.TexCoords2 = In.TexCoords;
    
    float3x3 WorldToTangent;
    WorldToTangent[0] = mul( In.Tangent, World );
    WorldToTangent[1] = mul( cross( In.Tangent, In.Normal ), World );
    WorldToTangent[2] = mul( In.Normal, World );
    
    Out.Light = normalize( mul( WorldToTangent, -lightDir ) );
    Out.Normal = normalize( mul( WorldToTangent, WorldToTangent[2] ) );
    
    return Out;
}

//------------------------------------
sampler NormalMapSampler = sampler_state 
{
    texture = <NormalMap>;
    AddressU  = CLAMP;        
    AddressV  = CLAMP;
    AddressW  = CLAMP;
    MIPFILTER = LINEAR;
    MINFILTER = LINEAR;
    MAGFILTER = LINEAR;
};

sampler TextureMapSampler = sampler_state 
{
    texture = <TextureMap>;
    AddressU  = CLAMP;        
    AddressV  = CLAMP;
    AddressW  = CLAMP;
    MIPFILTER = LINEAR;
    MINFILTER = LINEAR;
    MAGFILTER = LINEAR;
};

//-----------------------------------
float4 PS( PSInput In ): COLOR
{
	float3 Normal = ( 2 * tex2D( NormalMapSampler, In.TexCoords ) ) - 1;
	float4 Texture = tex2D( TextureMapSampler, In.TexCoords2 );
	
	float SelfShadow = saturate( 4 * dot( In.Normal, In.Light ) );
	float NormalMapDiffuse = saturate( dot( Normal, In.Light ) );
	return SelfShadow * float4( lightColor * NormalMapDiffuse * Texture , 1.0f );
}

//-----------------------------------
technique Diffuse
{
    pass p0 
    {
		VertexShader = compile vs_1_1 VS();
		PixelShader  = compile ps_1_1 PS();
    }
}