SamplerState SampleType;

struct LayerData
{
    uint blendMode;
    uint type;
    float4 color;
};

cbuffer PerFrameBuffer
{
    matrix worldMatrix;
    matrix viewMatrix;
    matrix projectionMatrix;
    uint2 numTextures;
};

Texture2D textures[126];
StructuredBuffer<LayerData> textureData;

struct VertexInputType
{
    float4 position : POSITION;
    float2 tex : TEXCOORD0;
};

struct PixelInputType
{
    float4 position : SV_POSITION;
    float2 tex : TEXCOORD0;
};

float4 TexturePixelShader(PixelInputType input) : SV_TARGET
{
    float4 source = textures[0].Sample(SampleType, input.tex);
    uint count = numTextures.x;
    for(uint i = 0; i < count; ++i)
    {
        float4 layer = textures[i+1].Sample(SampleType, input.tex);

        switch(textureData[i].type)
        {
            case 0:
            source = source + source.a * layer;
            break;
            case 1:
            source = source + source.a * layer.r * textureData[i].color;
            break;
        }
    }

    return source;
}

PixelInputType TextureVertexShader(VertexInputType input)
{
    PixelInputType output;

    // Change the position vector to be 4 units for proper matrix calculations.
    input.position.w = 1.0f;

    // Calculate the position of the vertex against the world, view, and projection matrices.
    output.position = mul(input.position, worldMatrix);
    output.position = mul(output.position, viewMatrix);
    output.position = mul(output.position, projectionMatrix);

    // Store the texture coordinates for the pixel shader.
    output.tex = input.tex;

    return output;
}