// The original retro pixel shader
  Texture2D shaderTexture;
  SamplerState samplerState;
  
  cbuffer PixelShaderSettings {
    float  Time;
    float  Scale;
    float2 Resolution;
    float4 Background;
  };
  
  float4 main(float4 pos : SV_POSITION, float2 tex : TEXCOORD) : SV_TARGET
  {
    // Read the color value at the current texture coordinate (tex)
    //  float4 is tuple of 4 floats, rgba
    float4 color = shaderTexture.Sample(samplerState, tex);
    
    // Vertical scroll
    tex.y+= Time;
    color.rg = tex * 0.5f;
    
    // Return the final color
    return color;
  }