/////////////
// GLOBALS //
/////////////
Texture2D shaderTexture : register(t0);
SamplerState SampleType : register(s0);
cbuffer SunLightBuffer
{
    float4 ambientColor;
    float4 diffuseColor;
    float3 lightDirection;
};

cbuffer SunLightColorBuffer
{
    float4 sunColor;
};

//////////////
// TYPEDEFS //
//////////////
struct PixelInputType
{
    float4 position : SV_POSITION;
    float2 tex : TEXCOORD0;
    float3 normal : NORMAL;
    float3 lightDir : TEXCOORD1;
};

////////////////////////////////////////////////////////////////////////////////
// Pixel Shader
////////////////////////////////////////////////////////////////////////////////
float4 SunLightPixelShader(PixelInputType input) : SV_TARGET
{
    float4 textureColor;
    float3 lightDir;
    float4 color;
    float lightIntensity;
    float4 colorArray;
    float4 colorSum;

    // Sample the pixel color from the texture using the sampler at this texture coordinate location.
    textureColor = shaderTexture.Sample(SampleType, input.tex);

    // Calculate the different amounts of light on this pixel based on the direction of the light.
    lightIntensity = saturate(dot(input.normal, input.lightDir));

    // Determine the diffuse color amount of the light.
    colorArray = diffuseColor * lightIntensity;

    // Initialize the sum of colors.
    colorSum = float4(0.0f, 0.0f, 0.0f, 1.0f);

    // Add the light color.
    colorSum.r += colorArray.r;
    colorSum.g += colorArray.g;
    colorSum.b += colorArray.b;

    // Multiply the texture pixel by the light color to get the final result.
    color = saturate(colorSum) * textureColor;

    return color;
}