PieWheel.shader

// Upgrade NOTE: replaced 'mul(UNITY_MATRIX_MVP,*)' with 'UnityObjectToClipPos(*)'

Shader "UI/UI Pie Wheel"
{
	Properties
	{
		[PerRendererData] _MainTex ("Sprite Texture", 2D) = "white" {}
		_Color ("Tint", Color) = (1,1,1,1)
		_Slices("Slices", int) = 4
		_InnerRadius("Inner Radius", Range(0, 1)) = 0
		_SliceGap("Slice Gap", Range(0, 1)) = .2
		_GapSoftness("Gap Softness", float) = 400
		_HighlightSlice("Highlight Slice", int) = 0

		_StencilComp ("Stencil Comparison", Float) = 8
		_Stencil ("Stencil ID", Float) = 0
		_StencilOp ("Stencil Operation", Float) = 0
		_StencilWriteMask ("Stencil Write Mask", Float) = 255
		_StencilReadMask ("Stencil Read Mask", Float) = 255

		_ColorMask ("Color Mask", Float) = 15
	}

	SubShader
	{
		Tags
		{
			"Queue"="Transparent"
			"IgnoreProjector"="True"
			"RenderType"="Transparent"
			"PreviewType"="Plane"
			"CanUseSpriteAtlas"="True"
		}

		Stencil
		{
			Ref [_Stencil]
			Comp [_StencilComp]
			Pass [_StencilOp]
			ReadMask [_StencilReadMask]
			WriteMask [_StencilWriteMask]
		}

		Cull Off
		Lighting Off
		ZWrite Off
		ZTest [unity_GUIZTestMode]
		Blend SrcAlpha OneMinusSrcAlpha
		ColorMask [_ColorMask]

		Pass
		{
		CGPROGRAM
			#pragma vertex vert
			#pragma fragment frag
			#include "UnityCG.cginc"

			struct appdata_t
			{
				float4 vertex   : POSITION;
				float4 color    : COLOR;
				float2 texcoord : TEXCOORD0;
			};

			struct v2f
			{
				float4 vertex   : SV_POSITION;
				fixed4 color    : COLOR;
				half2 texcoord  : TEXCOORD0;
			};

			fixed4 _Color;
			int _Slices;
			float _InnerRadius;
			float _SliceGap;
			float _GapSoftness;
			float _HighlightSlice;

			v2f vert(appdata_t IN)
			{
				v2f OUT;
				OUT.vertex = UnityObjectToClipPos(IN.vertex);
				OUT.texcoord = IN.texcoord;
#ifdef UNITY_HALF_TEXEL_OFFSET
				OUT.vertex.xy += (_ScreenParams.zw-1.0)*float2(-1,1);
#endif
				OUT.color = IN.color * _Color;
				return OUT;
			}

			sampler2D _MainTex;

			fixed4 frag(v2f IN) : SV_Target
			{
				half4 color = tex2D(_MainTex, IN.texcoord) * IN.color;

				float alpha = color.a;
				float2 direction = 1 - IN.texcoord - float2(.5, .5);
				float distance = (1 - clamp(length(abs(IN.texcoord - float2(.5, .5))), 0 , 1)) - .5;

				if(distance < .01)
					color.a = min(distance * 200, 1);
				else
					color.a = ceil(distance);

				//color.a = distance > (1 - _InnerRadius) * .5 ? 0 : color.a;

				//color.a *= ((1 - _InnerRadius) * .5) / distance;

				if(distance > (1 - _InnerRadius) * .5)
					color.a = 0;

				color.a = lerp(color.a, color.a * .5, step(.02, distance));
				color.a = lerp(color.a, color.a / .25, step(.23, distance));

				if(_Slices > 1) {
					float angleSize = float(360) / float(_Slices);
					float angle = degrees(atan2(direction.x, direction.y)) + 180;// - (angleSize / 2);

					angle += (angleSize / 2);

					float nearestAngle = round(angle / angleSize) * angleSize;

					float edgeMask = 0;

					//edgeMask = nearestAngle - angle;
					edgeMask = saturate(angle - nearestAngle);
					edgeMask = edgeMask + saturate(nearestAngle - angle);

					//edgeMask = lerp(edgeMask, edgeMask*.2, step(.2, edgeMask));
					edgeMask *= .25;

					color.a += edgeMask;
					//color.a -= edgeMask * _GapSoftness;
					color.a = max(color.a, 0);
				}

				//color = sliceCircle(color, direction, distance);
				//if(false) {
				if(_Slices > 1) {
					float angleSize = float(360) / float(_Slices);
					float angle = degrees(atan2(direction.x, direction.y)) + 180;// - (angleSize / 2);
					float angleBefore = angle + (angleSize / 2);

					angle += (angleSize / 2);

					float angleModStep = fmod(angle / angleSize, 1);
					float angleStep = floor(angle / angleSize);
					float angleDistance = 1 - angleModStep;

					float edgeMask = clamp(angleModStep - (1 - _SliceGap), 0,  1);
					edgeMask = clamp(angleDistance - (1 - _SliceGap), 0, 1) + edgeMask;

					color.a -= edgeMask * _GapSoftness;
					color.a = max(color.a, 0);

					int currentSlice = (fmod(angleBefore / 360, 1) * floor(_Slices)) + 1;
					float highlightValue = (floor(_HighlightSlice) == currentSlice ? 1 : 0);

					color.r += highlightValue;
				}

				color.a = clamp(color.a, 0, 1);
				color.a *= alpha;

				clip (color.a - 0.01);

				return color;
			}

			/*half4 sliceCircle(half4 color, float2 direction, float distance) {
				if(_Slices > 1) {
					float angleSize = float(360) / float(_Slices);
					float angle = degrees(atan2(direction.x, direction.y)) + 180;// - (angleSize / 2);
					float angleBefore = angle + (angleSize / 2);

					angle += (angleSize / 2);

					float angleModStep = fmod(angle / angleSize, 1);
					float angleStep = floor(angle / angleSize);
					float angleDistance = 1 - angleModStep;

					float edgeMask = clamp(angleModStep - (1 - _SliceGap), 0,  1);
					edgeMask = clamp(angleDistance - (1 - _SliceGap), 0, 1) + edgeMask;

					color.a -= edgeMask * _GapSoftness;
					color.a = max(color.a, 0);

					int currentSlice = (fmod(angleBefore / 360, 1) * floor(_Slices)) + 1;
					float highlightValue = (floor(_HighlightSlice) == currentSlice ? 1 : 0);

					color.r += highlightValue;

				}

				return color;
			}*/
		ENDCG
		}
	}
}