BloomStencilShader

struct Vertex
{
    float4 pos : POSITION;
    float2 tex : TEXTURE;
    float3 norm : NORMAL;
};

struct PixelShaderArgs
{
    float4 pos : SV_POSITION;
    float2 col : TEXTURE;
    float3 norm : NORMAL;
};

struct BloomShaderData
{
    float Threshold;
    float Intensity;
    float Padding1;
    float Padding2;
};

Texture2D ShaderTexture : register(t0);
SamplerState Sampler : register(s0);
float4x4 localMatrix : register(b0);

cbuffer BloomShaderDataBuffer : register(b1)
{
    BloomShaderData BloomData;
};

PixelShaderArgs VertexShaderMain(Vertex vertex)
{
    PixelShaderArgs output;
    output.pos = vertex.pos;
    output.col = vertex.tex;
    return output;
}

float4 PixelShaderMain(PixelShaderArgs pixelShaderArgs) : SV_Target
{
    float4 diffuse = ShaderTexture.Sample(Sampler, pixelShaderArgs.col);
    float luminosity = (diffuse.r * 0.2126) + (diffuse.g * 0.7152) + (diffuse.b * 0.0722);
    if (luminosity > BloomData.Threshold)
    {
        return diffuse;
    }
    else
    {
        return float4(0, 0, 0, 0);
    }
}