struct VertexToPixel
{
    float4 Position     : POSITION;
    float4 Color        : COLOR0;
    float LightingFactor: TEXCOORD0;
    float2 TextureCoords: TEXCOORD1;
};

struct PixelToFrame
{
    float4 Color : COLOR0;
};

//------- Constants --------
float4x4 xView;
float4x4 xProjection;
float4x4 xWorld;
float3 xLightDirection;
float xAmbient;
bool xEnableLighting;
bool xShowNormals;
float3 xCamPos;
float3 xCamUp;
float xPointSpriteSize;

//------- Texture Samplers --------

Texture xTexture;
sampler TextureSampler = sampler_state { texture = ; magfilter = LINEAR; minfilter = LINEAR; mipfilter=LINEAR; AddressU = mirror; AddressV = mirror;};

//------- Technique: Pretransformed --------

VertexToPixel PretransformedVS( float4 inPos : POSITION, float4 inColor: COLOR)
{
    VertexToPixel Output = (VertexToPixel)0;

    Output.Position = inPos;
    Output.Color = inColor;

    return Output;
}

PixelToFrame PretransformedPS(VertexToPixel PSIn)
{
    PixelToFrame Output = (PixelToFrame)0;

    Output.Color = PSIn.Color;

    return Output;
}

technique Pretransformed
{
    pass Pass0
    {
        VertexShader = compile vs_2_0 PretransformedVS();
        PixelShader  = compile ps_2_0 PretransformedPS();
    }
}

//------- Technique: Colored --------

VertexToPixel ColoredVS( float4 inPos : POSITION, float3 inNormal: NORMAL, float4 inColor: COLOR)
{
    VertexToPixel Output = (VertexToPixel)0;
    float4x4 preViewProjection = mul (xView, xProjection);
    float4x4 preWorldViewProjection = mul (xWorld, preViewProjection);

    Output.Position = mul(inPos, preWorldViewProjection);
    Output.Color = inColor;

    float3 Normal = normalize(mul(normalize(inNormal), xWorld));
    Output.LightingFactor = 1;
    if (xEnableLighting)
        Output.LightingFactor = dot(Normal, -xLightDirection);

    return Output;
}

PixelToFrame ColoredPS(VertexToPixel PSIn)
{
    PixelToFrame Output = (PixelToFrame)0;

    Output.Color = PSIn.Color;
    Output.Color.rgb *= saturate(PSIn.LightingFactor) + xAmbient;

    return Output;
}

technique Colored
{
    pass Pass0
    {
        VertexShader = compile vs_2_0 ColoredVS();
        PixelShader  = compile ps_2_0 ColoredPS();
    }
}

//------- Technique: ColoredNoShading --------

VertexToPixel ColoredNoShadingVS( float4 inPos : POSITION, float4 inColor: COLOR)
{
    VertexToPixel Output = (VertexToPixel)0;
    float4x4 preViewProjection = mul (xView, xProjection);
    float4x4 preWorldViewProjection = mul (xWorld, preViewProjection);

    Output.Position = mul(inPos, preWorldViewProjection);
    Output.Color = inColor;

    return Output;
}

PixelToFrame ColoredNoShadingPS(VertexToPixel PSIn)
{
    PixelToFrame Output = (PixelToFrame)0;

    Output.Color = PSIn.Color;

    return Output;
}

technique ColoredNoShading
{
    pass Pass0
    {
        VertexShader = compile vs_2_0 ColoredNoShadingVS();
        PixelShader  = compile ps_2_0 ColoredNoShadingPS();
    }
}


//------- Technique: Textured --------

VertexToPixel TexturedVS( float4 inPos : POSITION, float3 inNormal: NORMAL, float2 inTexCoords: TEXCOORD0)
{
    VertexToPixel Output = (VertexToPixel)0;
    float4x4 preViewProjection = mul (xView, xProjection);
    float4x4 preWorldViewProjection = mul (xWorld, preViewProjection);

    Output.Position = mul(inPos, preWorldViewProjection);
    Output.TextureCoords = inTexCoords;

    float3 Normal = normalize(mul(normalize(inNormal), xWorld));
    Output.LightingFactor = 1;
    if (xEnableLighting)
        Output.LightingFactor = dot(Normal, -xLightDirection);

    return Output;
}

PixelToFrame TexturedPS(VertexToPixel PSIn)
{
    PixelToFrame Output = (PixelToFrame)0;

    Output.Color = tex2D(TextureSampler, PSIn.TextureCoords);
    Output.Color.rgb *= saturate(PSIn.LightingFactor) + xAmbient;

    return Output;
}

technique Textured
{
    pass Pass0
    {
        VertexShader = compile vs_2_0 TexturedVS();
        PixelShader  = compile ps_2_0 TexturedPS();
    }
}

//------- Technique: TexturedNoShading --------

VertexToPixel TexturedNoShadingVS( float4 inPos : POSITION, float3 inNormal: NORMAL, float2 inTexCoords: TEXCOORD0)
{
    VertexToPixel Output = (VertexToPixel)0;
    float4x4 preViewProjection = mul (xView, xProjection);
    float4x4 preWorldViewProjection = mul (xWorld, preViewProjection);

    Output.Position = mul(inPos, preWorldViewProjection);
    Output.TextureCoords = inTexCoords;

    return Output;
}

PixelToFrame TexturedNoShadingPS(VertexToPixel PSIn)
{
    PixelToFrame Output = (PixelToFrame)0;

    Output.Color = tex2D(TextureSampler, PSIn.TextureCoords);

    return Output;
}

technique TexturedNoShading
{
    pass Pass0
    {
        VertexShader = compile vs_2_0 TexturedNoShadingVS();
        PixelShader  = compile ps_2_0 TexturedNoShadingPS();
    }
}

//------- Technique: PointSprites --------

VertexToPixel PointSpriteVS(float3 inPos: POSITION0, float2 inTexCoord: TEXCOORD0)
{
    VertexToPixel Output = (VertexToPixel)0;

    float3 center = mul(inPos, xWorld);
    float3 eyeVector = center - xCamPos;

    float3 sideVector = cross(eyeVector,xCamUp);
    sideVector = normalize(sideVector);
    float3 upVector = cross(sideVector,eyeVector);
    upVector = normalize(upVector);

    float3 finalPosition = center;
    finalPosition += (inTexCoord.x-0.5f)*sideVector*0.5f*xPointSpriteSize;
    finalPosition += (0.5f-inTexCoord.y)*upVector*0.5f*xPointSpriteSize;

    float4 finalPosition4 = float4(finalPosition, 1);

    float4x4 preViewProjection = mul (xView, xProjection);
    Output.Position = mul(finalPosition4, preViewProjection);

    Output.TextureCoords = inTexCoord;

    return Output;
}

PixelToFrame PointSpritePS(VertexToPixel PSIn) : COLOR0
{
    PixelToFrame Output = (PixelToFrame)0;
    Output.Color = tex2D(TextureSampler, PSIn.TextureCoords);
    return Output;
}

technique PointSprites
{
    pass Pass0
    {
        VertexShader = compile vs_2_0 PointSpriteVS();
        PixelShader  = compile ps_2_0 PointSpritePS();
    }
}