Shader实现新手指引挖空圆形和矩形
Shader "UI/ImageWithHole" { Properties { [PerRendererData] _MainTex ("Sprite Texture", 2D) = "white" {} _TintColor ("Tint", Color) = (1,1,1,1) _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 [KeywordEnum(ROUND, RECTANGLE, NULL)] _MaskMode("Mask mode", Float) = 0 _Center("Center", vector) = (0, 0, 0, 0) _Radius("Radius", Range(0,1000)) = 100 // 圆半径 _RectangleSize("Rectangle Size", vector) = (0, 0, 0, 0) // 矩形边长 _TransitionRange("Transition Range", Range(0, 100)) = 10 } 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 Blend SrcAlpha OneMinusSrcAlpha ColorMask RGBA Pass { Name "Default" CGPROGRAM #pragma vertex vert #pragma fragment frag #pragma target 2.0 #include "UnityCG.cginc" #include "UnityUI.cginc" #pragma multi_compile __ UNITY_UI_CLIP_RECT #pragma multi_compile __ UNITY_UI_ALPHACLIP #pragma multi_compile _MASKMODE_ROUND _MASKMODE_RECTANGLE _MASKMODE_NULL struct appdata_t { float4 vertex : POSITION; float4 color : COLOR; float2 texcoord : TEXCOORD0; UNITY_VERTEX_INPUT_INSTANCE_ID }; struct v2f { float4 vertex : SV_POSITION; fixed4 color : COLOR; float2 texcoord : TEXCOORD0; float4 worldPosition : TEXCOORD1; UNITY_VERTEX_OUTPUT_STEREO }; fixed4 _TintColor; fixed4 _TextureSampleAdd; float4 _ClipRect; float2 _Center; half _Radius; float2 _RectangleSize; half _TransitionRange; v2f vert(appdata_t v) { v2f OUT; UNITY_SETUP_INSTANCE_ID(v); UNITY_INITIALIZE_VERTEX_OUTPUT_STEREO(OUT); OUT.worldPosition = v.vertex; OUT.vertex = UnityObjectToClipPos(OUT.worldPosition); OUT.texcoord = v.texcoord; OUT.color = v.color * _TintColor; return OUT; } sampler2D _MainTex; fixed4 frag(v2f i) : SV_Target { half4 color = (tex2D(_MainTex, i.texcoord) + _TextureSampleAdd) * i.color; #ifdef UNITY_UI_CLIP_RECT color.a *= UnityGet2DClipping(IN.worldPosition.xy, _ClipRect); #endif #ifdef UNITY_UI_ALPHACLIP clip (color.a - 0.001); #endif #ifdef _MASKMODE_ROUND // 计算片元世界坐标和目标中心位置的距离 half dis = distance(i.worldPosition.xy, _Center.xy); // 过滤掉距离小于(半径-过渡范围)的片元 clip(dis - (_Radius - _TransitionRange)); // 是否在圆里面 int inside = step(dis, _Radius); // 计算过渡范围内的alpha值 color.a *= (1 - inside) + inside * (dis - (_Radius - _TransitionRange)) / _TransitionRange; #elif _MASKMODE_RECTANGLE // 计算片元世界坐标和目标中心位置的距离 half disX = distance(i.worldPosition.x, _Center.x); half disY = distance(i.worldPosition.y, _Center.y); // x决定像素点应该去掉返回1,不去掉返回0 int clipX = step(disX, _RectangleSize.x-_TransitionRange); int clipY = step(disY, _RectangleSize.y-_TransitionRange); clip(disX - (_RectangleSize.x -_TransitionRange) * clipY); clip(disY - (_RectangleSize.y -_TransitionRange) * clipX); // x在范围内返回1,不在范围内返回0 int insideX = step(disX, _RectangleSize.x); int insideY = step(disY, _RectangleSize.y); half alphaX= (1 - insideX) + insideX * (disX - (_RectangleSize.x - _TransitionRange)) / _TransitionRange; half alphaY= (1 - insideY) + insideY * (disY - (_RectangleSize.y - _TransitionRange)) / _TransitionRange; color.a *= max(alphaX, alphaY); #endif return color; } ENDCG } } }