Ch8GrayscaleImageEffect.shader

Shader "CookbookShaders/Ch08/GrayscaleImageEffect.shader"
{
	Properties
	{
		_MainTex ("Base (RGB)", 2D) = "white" {}
		_LuminosityAmount ("GrayScale Amount", Range(0.0, 1.0)) = 1.0
	}

	SubShader
	{
		Pass
		{
			CGPROGRAM
			#pragma vertex vert_img
			#pragma fragment frag
			#pragma fragmentoption ARB_precision_hint_fastest
			#include "UnityCG.cginc"

			// declare corresponding CGPROGRAM variables
			uniform sampler2D _MainTex;
			fixed _LuminosityAmount;

			fixed4 frag(v2f_img i) : COLOR
			{
				// Get the colors from the RenderTexture and the UVs from the v2f_img struct
				fixed4 renderTex = tex2D(_MainTex, i.uv);

				// Apply the luminosity values to our render texture
				float luminosity = 0.299 * renderTex.r + 0.587 * renderTex.g + 0.114 * renderTex.b;
				fixed4 finalColor = lerp(renderTex, luminosity, _LuminosityAmount);

				return finalColor;
			}

			ENDCG
		}
	}
}