[Shader] Changing Sprite Colour Palette

Questions & Answers
1

Hello All,

I’m trying to create a shader which will change the colours on a sprite based on the palette that I pass in, for example;

198277-examples.png
198277-examples.png762×290 9.3 KB

But instead, what I am getting is this
198278-results.png

This is my first time working on a shader, if anyone could point me in the right direction, I would be extremely grateful

Thanks

Shader "Custom/bitty_shader"
{
     Properties
     {
        _Color ("Main Color", Color) = (1,1,1,1)
        _MainTex ("Base (RGB)", 2D) = "white" {}
        _DefaultPaletteTex ("Default Palette (RGB)", 2D) = "white"
        _CustomPaletteTex ("Custom Palette (RGB)", 2D) = "white"
     }
     SubShader
     {
        Lighting Off
        LOD 200
 
        CGPROGRAM
        #pragma surface surf Lambert
 
        fixed4 _Color;
        sampler2D _MainTex;
        sampler2D _DefaultPaletteTex;
        sampler2D _CustomPaletteTex;
      
        float4 _DefaultPaletteTex_TexelSize;
        float4 _CustomPaletteTex_TexelSize;
      
        struct Input {
          float2 uv_MainTex;
        };
 
        void surf (Input IN, inout SurfaceOutput o) {
            o.Alpha = 0;
          
            for(int _DefaultPalette_x = 0; _DefaultPalette_x < _DefaultPaletteTex_TexelSize.z; _DefaultPalette_x++)
            {
                for(int _DefaultPalette_y = 0; _DefaultPalette_y < _DefaultPaletteTex_TexelSize.w; _DefaultPalette_y++)
                {
                    fixed4 main = tex2D(_MainTex, IN.uv_MainTex);
                    fixed4 palette = tex2D(_DefaultPaletteTex, float2(_DefaultPalette_x, _DefaultPalette_y));
                    if(main.r == palette.r && main.g == palette.g && main.b == palette.b)
                    {
                        fixed4 c = tex2D(_CustomPaletteTex, float2(_DefaultPalette_x, _DefaultPalette_y));
                        o.Albedo = c.rgb;
                        o.Alpha = 255;
                    }
                }
            }  
        }
        ENDCG
     }
  FallBack "Diffuse"
}
2

Figured it out.

float4 frag(Fragment IN) : COLOR
            {
			    for(float _DefaultPalette_x = 0; _DefaultPalette_x < 1; _DefaultPalette_x += 0.125)
			    {
				    for(float _DefaultPalette_y = 0; _DefaultPalette_y < 1; _DefaultPalette_y += 0.125)
				    {
                        float4 main = tex2D(_MainTex, IN.uv_MainTex);
                        float4 palette = tex2D(_DefaultPaletteTex, float2(_DefaultPalette_x, _DefaultPalette_y));

					    if(main.r == palette.r && main.g == palette.g && main.b == palette.b)
					    {
						    float4 c = tex2D(_CustomPaletteTex, float2(_DefaultPalette_x, _DefaultPalette_y));
                            if(c.a > 0)
                            {
					            return c;
                            }
                        }
				    }
			    }
                float4 c = 0;
                return c;
            }