Unity 自作タイルマップシステム用のシェーダー

Shader "Custom/AutoTileMap"{
    Properties{
        _MainTex("Base (RGB)", 2D) = "white" {}
        _TileSize("TileSize", Int) = 16
    }
    SubShader{
        //Lighting Off
        pass {
            Tags{ "LightMode" = "Vertex" }

            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            //#pragma target 3.0
            #include "UnityCG.cginc"

            sampler2D _MainTex;
            half4 _MainTex_TexelSize;
            int _TileSize;
            int _Layer;
            half _TexTileSize;
            half _OneBrightness;

            struct VertOut {
                float4 pos : POSITION;
                float2 uv : TEXCOORD0;
                half brightness : TEXCOORD1;
                half2 light_dist0 : TEXCOORD2;
                half2 light_dist1 : TEXCOORD3;
                half2 light_dist2 : TEXCOORD4;
                half2 light_dist3 : TEXCOORD5;
                half2 light_dist4 : TEXCOORD6;
                half2 light_dist5 : TEXCOORD7;
                half2 light_dist6 : TEXCOORD8;
                half2 light_dist7 : TEXCOORD9;
            };

            // 頂点シェーダ
            VertOut vert(appdata_full v) {
                VertOut o;
                o.pos = mul(UNITY_MATRIX_MVP, v.vertex);
                o.uv = v.texcoord;

                if (o.uv.x < -_TexTileSize) {// 無
                    o.pos.x = 0;
                } else {
                    if (o.uv.x > 1) {// タイルアニメーション
                        half animsize = floor(o.uv.x + 1);
                        o.uv.x = o.uv.x - floor(o.uv.x);
                        o.uv.x += (_MainTex_TexelSize.x * _TileSize) * floor((_Time.y * 2) % animsize);
                    }

                    o.brightness = 1;
                    if (o.uv.y > 1) {// 明るさ
                        o.brightness = 1.0 - _OneBrightness * floor(o.uv.y);
                        o.uv.y = o.uv.y - floor(o.uv.y);
                    }

                    // ライト距離
                    half2 vp = mul(UNITY_MATRIX_M, v.vertex).xy;
                    half2 lp;
                    lp = mul(UNITY_MATRIX_I_V, unity_LightPosition[0]).xy;
                    lp.x = floor(lp.x) + 0.5;
                    lp.y = floor(lp.y) + 0.5;
                    o.light_dist0 = half2(vp.x - lp.x - 0.5, vp.y - lp.y - 0.5);

                    lp = mul(UNITY_MATRIX_I_V, unity_LightPosition[1]).xy;
                    lp.x = floor(lp.x) + 0.5;
                    lp.y = floor(lp.y) + 0.5;
                    o.light_dist1 = half2(vp.x - lp.x - 0.5, vp.y - lp.y - 0.5);

                    lp = mul(UNITY_MATRIX_I_V, unity_LightPosition[2]).xy;
                    lp.x = floor(lp.x) + 0.5;
                    lp.y = floor(lp.y) + 0.5;
                    o.light_dist2 = half2(vp.x - lp.x - 0.5, vp.y - lp.y - 0.5);

                    lp = mul(UNITY_MATRIX_I_V, unity_LightPosition[3]).xy;
                    lp.x = floor(lp.x) + 0.5;
                    lp.y = floor(lp.y) + 0.5;
                    o.light_dist3 = half2(vp.x - lp.x - 0.5, vp.y - lp.y - 0.5);

                    lp = mul(UNITY_MATRIX_I_V, unity_LightPosition[4]).xy;
                    lp.x = floor(lp.x) + 0.5;
                    lp.y = floor(lp.y) + 0.5;
                    o.light_dist4 = half2(vp.x - lp.x - 0.5, vp.y - lp.y - 0.5);

                    lp = mul(UNITY_MATRIX_I_V, unity_LightPosition[5]).xy;
                    lp.x = floor(lp.x) + 0.5;
                    lp.y = floor(lp.y) + 0.5;
                    o.light_dist5 = half2(vp.x - lp.x - 0.5, vp.y - lp.y - 0.5);

                    lp = mul(UNITY_MATRIX_I_V, unity_LightPosition[6]).xy;
                    lp.x = floor(lp.x) + 0.5;
                    lp.y = floor(lp.y) + 0.5;
                    o.light_dist6 = half2(vp.x - lp.x - 0.5, vp.y - lp.y - 0.5);

                    lp = mul(UNITY_MATRIX_I_V, unity_LightPosition[7]).xy;
                    lp.x = floor(lp.x) + 0.5;
                    lp.y = floor(lp.y) + 0.5;
                    o.light_dist7 = half2(vp.x - lp.x - 0.5, vp.y - lp.y - 0.5);
                }
                return o;
            }

            // ピクセルシェーダ
            fixed4 frag(VertOut input) : COLOR {
                fixed4 c = tex2D(_MainTex, input.uv);
                if (input.uv.x < 0) { return fixed4(0, 0, 0, 1); }// 黒
                if (c.a < 1) { discard; }// 透明
                half g = input.brightness;
                half d;
                half w;
                half zero = half2(0, 0);

                // sqrt(unity_LightAtten[0].w)でライトのrange
                if (unity_LightColor[0][0] != 0) {
                    w = ceil(sqrt(unity_LightAtten[0].w));
                    d = distance(half2(ceil(input.light_dist0.x), ceil(input.light_dist0.y)), zero);
                    g = max(d > w ? 0 : (w - d) / w, g);
                } else {
                    return c * g;
                }

                if (unity_LightColor[1][0] != 0) {
                    w = ceil(sqrt(unity_LightAtten[1].w));
                    d = distance(half2(ceil(input.light_dist1.x), ceil(input.light_dist1.y)), zero);
                    g = max(d > w ? 0 : (w - d) / w, g);
                } else {
                    return c * g;
                }

                if (unity_LightColor[2][0] != 0) {
                    w = ceil(sqrt(unity_LightAtten[2].w));
                    d = distance(half2(ceil(input.light_dist2.x), ceil(input.light_dist2.y)), zero);
                    g = max(d > w ? 0 : (w - d) / w, g);
                } else {
                    return c * g;
                }

                if (unity_LightColor[3][0] != 0) {
                    w = ceil(sqrt(unity_LightAtten[3].w));
                    d = distance(half2(ceil(input.light_dist3.x), ceil(input.light_dist3.y)), zero);
                    g = max(d > w ? 0 : (w - d) / w, g);
                } else {
                    return c * g;
                }

                if (unity_LightColor[4][0] != 0) {
                    w = ceil(sqrt(unity_LightAtten[0].w));
                    d = distance(half2(ceil(input.light_dist4.x), ceil(input.light_dist4.y)), zero);
                    g = max(d > w ? 0 : (w - d) / w, g);
                } else {
                    return c * g;
                }

                if (unity_LightColor[5][0] != 0) {
                    w = ceil(sqrt(unity_LightAtten[1].w));
                    d = distance(half2(ceil(input.light_dist5.x), ceil(input.light_dist5.y)), zero);
                    g = max(d > w ? 0 : (w - d) / w, g);
                } else {
                    return c * g;
                }

                if (unity_LightColor[6][0] != 0) {
                    w = ceil(sqrt(unity_LightAtten[2].w));
                    d = distance(half2(ceil(input.light_dist6.x), ceil(input.light_dist6.y)), zero);
                    g = max(d > w ? 0 : (w - d) / w, g);
                } else {
                    return c * g;
                }

                if (unity_LightColor[7][0] != 0) {
                    w = ceil(sqrt(unity_LightAtten[3].w));
                    d = distance(half2(ceil(input.light_dist7.x), ceil(input.light_dist7.y)), zero);
                    g = max(d > w ? 0 : (w - d) / w, g);
                } else {
                    return c * g;
                }

                return c * g;
            }

            ENDCG
        }
    }
    Fallback "Diffuse"
}