Shader "PeachValley/GameObject"
{
    Properties
	{
		[PerRendererData] _MainTex ("Sprite Texture", 2D) = "white" {}
		_Color ("Tint", Color) = (1,1,1,1)
        [PerRendererData] _AlphaTex ("External Alpha", 2D) = "white" {}
        [PerRendererData] _EnableExternalAlpha ("Enable External Alpha", Float) = 0

        [Space]
        [Header(Edge)]
        [Toggle] _EFFECT_EDGE ("Enable Edge", Float) = 0
        _OutLineColor ("Outline color", Color) = (0.804, 0.2, 0, 1)//描边颜色
        _PixelSize ("Pixel Size", Range(0, 10)) = 6
        _DetectAlpha ("DetectAlpha", Range(0, 0.2)) = 0.1 //四周的点算alpha平均，若大于则显示描边
        _ImageCullAlpha ("ImageCullAlpha", Range(0, 1)) = 0.2 //当前所在的点若大于改值，则无条件原图
        // _Smooth ("Smooth", Range(1, 10)) = 10
        // _SmoothAlphaBase ("SmoothAlphaBase", Range(0, 1)) = 0.8
        _HaveEdgeEffect ("HaveEdgeEffect", Range(0, 1)) = 1

        [Space]
        [Header(Highlight)]
        [Toggle] _EFFECT_HIGHLIGHT("Enable Highlight", Float) = 0
    }
    SubShader
    {
        Tags
		{ 
			"Queue"="Transparent" 
			"IgnoreProjector"="True" 
			"RenderType"="Transparent" 
			"PreviewType"="Plane"
			"CanUseSpriteAtlas"="True"
		}

		Cull Off
		Lighting Off
		ZWrite Off
		Blend One OneMinusSrcAlpha

        Pass
		{
		CGPROGRAM
			#pragma vertex vert
			#pragma fragment frag
			#pragma target 2.0
			#pragma multi_compile _ ETC1_EXTERNAL_ALPHA
            #pragma multi_compile _EFFECT_EDGE _EFFECT_EDGE_ON
            #pragma multi_compile _EFFECT_HIGHLIGHT _EFFECT_HIGHLIGHT_ON
			#include "UnityCG.cginc"
			
			struct appdata_t
			{
				float4 vertex   : POSITION;
				float4 color    : COLOR;
				float2 texcoord : TEXCOORD0;
			};

			struct v2f
			{
				float4 vertex   : SV_POSITION;
				fixed4 color    : COLOR;
				float2 texcoord  : TEXCOORD0;
			};

            fixed4 _Color;

            v2f vert(appdata_t IN)
			{
				v2f OUT;
				OUT.vertex = UnityObjectToClipPos(IN.vertex);
				OUT.texcoord = IN.texcoord;
				OUT.color = IN.color * _Color;
				#ifdef PIXELSNAP_ON
				OUT.vertex = UnityPixelSnap (OUT.vertex);
				#endif

				return OUT;
			}

            sampler2D _MainTex;
            sampler2D _AlphaTex;

            // for edge
            fixed4 _OutLineColor;
            float _PixelSize;
            float2 _MainTex_TexelSize;
            float _DetectAlpha;
            float _ImageCullAlpha;
            // float _Smooth;
            // float _SmoothAlphaBase;
            half _HaveEdgeEffect;

            void Edge(inout fixed4 outColor, half2 changedUV)
            {
                _PixelSize = _PixelSize * _MainTex_TexelSize;
                // fixed4 color = tex2D(_MainTex, fixed2(changedUV.x, changedUV.y));
                fixed color1 = tex2D(_MainTex, fixed2(changedUV.x + _PixelSize, changedUV.y + _PixelSize)).a;
                fixed color2 = tex2D(_MainTex, fixed2(changedUV.x - _PixelSize, changedUV.y - _PixelSize)).a;
                fixed color3 = tex2D(_MainTex, fixed2(changedUV.x + _PixelSize, changedUV.y - _PixelSize)).a;
                fixed color4 = tex2D(_MainTex, fixed2(changedUV.x - _PixelSize, changedUV.y + _PixelSize)).a;
                fixed a = (color1 + color2 + color3 + color4) / 4;
                int if1 = step(outColor.a, _ImageCullAlpha);
                int if2 = step(a, _DetectAlpha);
                // outColor = outColor* (1 - _HaveEdgeEffect) + _HaveEdgeEffect *(if1 * (((1 - if2) * fixed4(_OutLineColor.rgb, pow(a + _SmoothAlphaBase, _Smooth) * _OutLineColor.a))) + color * (1 - if1));
                outColor = outColor* (1 - _HaveEdgeEffect) + _HaveEdgeEffect *(if1 * (((1 - if2) * _OutLineColor)) + outColor * (1 - if1));
            }

            fixed4 SampleSpriteTexture (float2 uv)
            {
                fixed4 color = tex2D (_MainTex, uv);

            #if ETC1_EXTERNAL_ALPHA
                fixed4 alpha = tex2D (_AlphaTex, uv);
                color.a = lerp (color.a, alpha.r, _EnableExternalAlpha);
            #endif

                return color;
            }

            fixed4 frag(v2f IN) : SV_Target
			{
				fixed4 c = SampleSpriteTexture (IN.texcoord) * IN.color;
				
            #if _EFFECT_HIGHLIGHT_ON
                c.rgb *= fixed3(1.3, 1.3, 1.3);
            #endif

            #if _EFFECT_EDGE_ON
                Edge(c, IN.texcoord);
            #endif
                c.rgb *= c.a;

				return c;
			}
		
        ENDCG
        }
    }
    FallBack "Diffuse"
}