//NormalMapping.fx
//FirstName: Igor
//LastName: Vermeulen
//Class 2DAE_GD05


//GLOBAL VARIABLES
//****************
float4x4 gMatrixWorldViewProj : WORLDVIEWPROJECTION;
float4x4 gMatrixWorld: WORLD;

float4 gColorAmbient: COLOR = float4(1.0,1.0,1.0,1.0);

float gAmbientIntensity<
	string UIName = "Ambient Intensity";
	string UIWidget = "Slider";
	float UIMin = 0.0;
	float UIMax = 1.0;
	float UIStep = 0.01;
> = 0.0f;

//Diffuse Map Variables
Texture2D gTextureDiffuse<
	string UIName = "Diffuse Texture";
	string ResourceName = "CobbleStone Textures/CobbleStone_DiffuseMap.dds";
	string ResourceType = "2D";
>;

//Light
float3 gLightDirection: DIRECTION<
	string UIName = "Light Direction";
	string Object = "TargetLight";
> = float3 (-0.57 , -0.57, 0.57);

float4 gColorDiffuse : COLOR = float4(1.0, 1.0, 1.0, 1.0);

//Normal map Variables
Texture2D m_normalMapTexture <
string UIName = "Normal Map";
string ResourceName = "CobbleStone Textures/CobbleStone_NormalMap.dds";
string ResourceType = "2D";
>;
SamplerState m_NormalMapSampler
{
Filter = MIN_MAG_MIP_POINT;
AddressU = WRAP;
AddressV = WRAP;
};
//STATES
//******
RasterizerState DisableCulling { CullMode = NONE; };

SamplerState gDiffuseSamplerState
{
	Filter = MIN_MAG_MIP_LINEAR;
	AddressU = WRAP;
	AddressV = WRAP;
};

struct VS_INPUT
{
	float3 Position: POSITION;
	float3 Normal: NORMAL;
	float2 TexCoord: TEXCOORD0;
	float3 tangent : TANGENT;
};

struct VS_OUTPUT
{
	float4 Position: SV_POSITION;
	float3 Normal: NORMAL;
	float2 TexCoord: TEXCOORD0;
	float3 tangent : TANGENT;
};

//MAIN VERTEX SHADER
//******************
VS_OUTPUT MainVS(VS_INPUT input)
{
	VS_OUTPUT output = (VS_OUTPUT)0;
	output.Position = mul(
					float4(input.Position,1.0),
					gMatrixWorldViewProj );

	output.Normal = normalize(mul(
		input.Normal,
		(float3x3)gMatrixWorld));

	output.TexCoord = input.TexCoord;

	output.tangent = normalize(mul(input.tangent,
	(float3x3)gMatrixWorld));
	return output;
}


//MAIN PIXEL SHADER
//*****************
float4 MainPS(VS_OUTPUT input) : SV_TARGET {
	float3 normal = normalize(input.Normal);
	float3 tangent = normalize(input.tangent);
	//
	float3 binormal = normalize(cross(tangent,normal));
	//
	float3x3 localAxis = {tangent,
							binormal,
							normal};
	//
	float3 sampledNormal = m_normalMapTexture.Sample(gDiffuseSamplerState, input.TexCoord);
	sampledNormal.x = (sampledNormal.x *2) -1;
	sampledNormal.y = (sampledNormal.y *2) -1;
	sampledNormal.z = (sampledNormal.z *2) -1;

	float3 newNormal = mul(sampledNormal,localAxis);

	//
	float4 finalColor = gTextureDiffuse.Sample(
		gDiffuseSamplerState, input.TexCoord);

	float diffuseIntensity = dot( newNormal, -gLightDirection);
	diffuseIntensity = saturate(diffuseIntensity);
	finalColor *= diffuseIntensity;
	finalColor += gColorAmbient * gAmbientIntensity;
	return finalColor;
}


//TECHNIQUES
//**********
technique10 DefaultTechnique {
	pass p0 {
		SetRasterizerState(DisableCulling);
		SetVertexShader(CompileShader(vs_4_0, MainVS()));
		SetPixelShader(CompileShader(ps_4_0, MainPS()));
	}
}