Shadow Shader

cbuffer ConstantBuffer
{
    matrix worldMatrix;
    matrix viewMatrix;
    matrix projectionMatrix;
    matrix lightViewMatrix;
    matrix lightProjectionMatrix;
};

struct VS_OUTPUT
{
    float4 pos : SV_POSITION;
    float2 texCoord : TEXCOORD0;
    float4 lightViewPosition : TEXCOORD1;
    float4 worldPosition : POSITION;
};
VS_OUTPUT VS(float4 position : POSITION, float2 texCoord : TEXCOORD)
{
   position.w = 1.0f;

    VS_OUTPUT output;
    output.pos = mul(worldMatrix, position);
    output.pos = mul(viewMatrix, output.pos);
    output.pos = mul(projectionMatrix, output.pos);
    output.texCoord = texCoord;

    output.lightViewPosition = mul(position, worldMatrix);
    output.lightViewPosition = mul(output.lightViewPosition, lightViewMatrix);
    output.lightViewPosition = mul(output.lightViewPosition, lightProjectionMatrix);

    output.worldPosition = mul(position, worldMatrix);

    return output;
}

Texture2D texture2d;
SamplerState samplerState;

float4 PS(VS_OUTPUT input) : SV_TARGET
{
    input.lightViewPosition.xyz /= input.lightViewPosition.w;

    float4 ambient = float4(0.1f,0.1f,0.1f,1.0f);
    float2 projectTexCoord;

    projectTexCoord.x = input.lightViewPosition.x / 2.0f + 0.5f;
    projectTexCoord.y = -input.lightViewPosition.y / 2.0f + 0.5f;

    float3 normal = float3(0.0f,1.0f,0.0f);
    float3 lightPos = normalize(float3(0.0f,3.0f,-3.0f) - input.worldPosition);

    if((saturate(projectTexCoord.x) == projectTexCoord.x) && (saturate(projectTexCoord.y) == projectTexCoord.y))
    {
       float depthValue = texture2d.Sample(samplerState, projectTexCoord).r;
       float lightDepthValue = input.lightViewPosition.z;

       if(depthValue > lightDepthValue)
       {
           float lightIntensity = saturate(dot(normal, lightPos));

            if(lightIntensity > 0.0f)
            {
               return float4(1.0f,1.0f,1.0f,1.0f) * lightIntensity;
            }
       }
    }

    return float4(0.0f,0.0f,0.0f,1.0f);
}