Shader source

Shader "Custom/ColourBleedShader"
{
	Properties
	{
		_MainTex ("Texture", 2D) = "white" {}
	}
	SubShader
	{

		Pass
		{
			Blend One OneMinusSrcAlpha
			CGPROGRAM
			#pragma vertex vert
			#pragma fragment frag

			#include "UnityCG.cginc"

			struct appdata
			{
				float4 vertex : POSITION;
				float2 uv : TEXCOORD0;
			};

			struct v2f
			{
				float2 uv : TEXCOORD0;
				float4 vertex : SV_POSITION;
			};

			sampler2D _MainTex;
			float4 _MainTex_TexelSize;

			v2f vert (appdata v)
			{
				v2f o;
				o.vertex = mul(UNITY_MATRIX_MVP, v.vertex);
				o.uv = v.uv;
				return o;
			}

			float4 colorBleed (v2f i, sampler2D mainTexture, float4 texelSize)
			{
				fixed4 tex = tex2D(_MainTex, i.uv);

				float2 RoffsetUV = float2(i.uv.x - texelSize.x*2, i.uv.y);
				float2 BoffsetUV = float2(i.uv.x + texelSize.x*2, i.uv.y);

				fixed4 rTex = tex2D(_MainTex, RoffsetUV);
				fixed4 bTex = tex2D(_MainTex, BoffsetUV);

				rTex = float4 (rTex.r, 0, 0, 0.5);
				bTex = float4 (0, 0, bTex.b, 0.5);
				tex = float4 (0, tex.g, 0, 0.5);

				float2 myuv = float2(i.uv.x+_MainTex_TexelSize.x*5, i.uv.y+_MainTex_TexelSize.x*20);
				fixed4 endTex = float4 (rTex + bTex + tex);

				return endTex;

			}

			fixed4 frag (v2f i) : SV_Target
			{

				float4 finalTex = colorBleed(i, _MainTex, _MainTex_TexelSize);

				return finalTex;

				//TODO: make picture a bit blurrier, add grain effect, scanlines? CRT screen bend?


			}
			ENDCG
		}
	}
}