PixelShader

Texture2D diffTexture : register(t0);
Texture2D ambientTexture : register(t1);
Texture2D specularTexture : register(t2);
Texture2D normalTexture: register(t3);
Texture2D worldPosTexture: register(t4);
SamplerState pointSampler : register(s0);

cbuffer LightConstantBuffer
{
    matrix worldMatrix;
    matrix viewMatrix;
    matrix projectionMatrix;
    matrix lightViewMatrix;
    matrix lightProjectionMatrix;

    float4 camPos;
    float4 lightPos;
};

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

float4 main(PSInput input) : SV_TARGET
{
    float4 diffColor;
    float4 ambientColor;
    float4 specColor;
    float4 normal;
    float4 worldPos;
    float4 outputColor;
    float2 textCoords = float2(input.position.x / 800, input.position.y / 600);

    float lightIntensity = 0.0f;

    //Sample the diffuse texture from deferred render
    diffColor = diffTexture.Sample(pointSampler, textCoords);

    //Sample the ambient texture from deferred render
    ambientColor = ambientTexture.Sample(pointSampler, textCoords);

    //Sample the specual texture from deferred render
    specColor = specularTexture.Sample(pointSampler, textCoords);

    //Sample the normal texture from deferred render
    normal = normalTexture.Sample(pointSampler, textCoords);

    //Sample the texture with positions in world space from deferred render
    worldPos = worldPosTexture.Sample(pointSampler, textCoords);

    //Create the normalized vector from position to light source
    float3 outVec = normalize(lightPos.xyz - (worldPos).xyz);

    //Create the normalized reflection vector
    float3 refVec = normalize(reflect(-outVec, normal));

    //Creathe the normalized vector from position to camera
    float3 viewDir = normalize(camPos - worldPos).xyz;

    float specIntesity = saturate(dot(refVec, viewDir));
    float shineFactor = 5.0f;
    float lightSpecular = 0.65f;

    //Calculate the specular part
    float4 specular = float4(specColor.rgb * lightSpecular * max(pow(specIntesity, shineFactor), 0.0f), 1.0f);

    lightIntensity = dot(normal, outVec);
    if (lightIntensity < 0) {
        lightIntensity = 0;
    }

    //Combine everything for the output color
    outputColor = saturate(((diffColor.rgba + specular.rgba) * lightIntensity * 0.8f) + ((ambientColor.rgba) * 0.2f));

    //return float4(input.tex.x, input.tex.y, 0.0f, 1.0f);
    //return float4(input.position.x / 800, input.position.y / 600, 0.0f, 1.0f);
    return outputColor;
}