Shader "Custom/Pixelgon"
{
  Properties
  {
    _MainTex ("Texture", 2D) = "" {}
    _Shade ("Shade", Float) = 1
  }
  SubShader
  {
    Tags { "RenderType"="Transparent" }

    Cull Off

    Pass
    {
      CGPROGRAM
      #pragma vertex vert
      #pragma fragment frag

      #include "UnityCG.cginc"

      sampler2D _MainTex;
      float4 _MainTex_ST;
      float _Shade;

      struct meshdata
      {
        float4 vertex : POSITION;
        float3 normal : NORMAL;
        float2 uv : TEXCOORD0;
        float4 color : COLOR;
      };

      struct v2f
      {
        float4 vertex : SV_POSITION;
        float4 worldPos : TEXCOORD1;
        float3 normal : TEXCOORD2;
        float2 uv : TEXCOORD0;
        float4 color : COLOR;
      };

      float DeRez(float value)
      {
        return float(round(value * 420)) / 420;
      }

      float3 hsv2rgb(float3 c)
      {
        c = float3(c.x, clamp(c.yz, 0.0, 1.0));
        float4 K = float4(1.0, 2.0 / 3.0, 1.0 / 3.0, 3.0);
        float3 p = abs(frac(c.xxx + K.xyz) * 6.0 - K.www);
        return c.z * lerp(K.xxx, clamp(p - K.xxx, 0.0, 1.0), c.y);
      }

      v2f vert (meshdata v)
      {
        v2f o;
        v.vertex.x = DeRez(v.vertex.x);
        v.vertex.y = DeRez(v.vertex.y);
        v.vertex.z = DeRez(v.vertex.z);
        o.vertex = UnityObjectToClipPos(v.vertex);
        o.worldPos = mul(unity_ObjectToWorld, v.vertex);
        o.normal = UnityObjectToWorldNormal(v.normal);
        o.uv = TRANSFORM_TEX(v.uv, _MainTex);
        o.color = v.color * _Shade;
        return o;
      }

      float4 frag (v2f i) : SV_Target
      {
        float4 col = tex2D(_MainTex, i.uv);
        clip(col.a - 0.5);
        
        // float shade = clamp(1.5 + dot(i.normal, float3(0, -1, 0)), 0, 1);
        // col.r *= 1.5 - shade;
        // col.g *= 1.5 - shade;
        // col.b *= shade;

        if (saturate(dot(normalize(UnityWorldSpaceViewDir(i.worldPos)), i.normal)) < 0.333)
        {
          col *= 0.9;
        }
        // col *= float4(hsv2rgb(float3(saturate(dot(normalize(UnityWorldSpaceViewDir(i.worldPos)), i.normal)), 1, 1)), 1);
        return col * i.color;
      }
      ENDCG
    }
  }

  Fallback "Legacy Shaders/Transparent/Cutout/Soft Edge Unlit"
}