改进ui多边形渲染组件功能。

改进渲染器基类流程。
改进多边形shader逻辑。

Runtime/Sample.unity

@@ -192,7 +192,12 @@ MonoBehaviour:
   - {x: 938.8, y: 3.85}
   - {x: 1000, y: 133}
   thickness: 20
-  center: 1
+  center: 0
+  cycleLoop: 0
+  a: 1
+  useChamfer: 0
+  chamferSegments: 4
+  innerRadius: 0
 --- !u!222 &246206084
 CanvasRenderer:
   m_ObjectHideFlags: 0
@@ -430,6 +435,7 @@ GameObject:
   - component: {fileID: 963194228}
   - component: {fileID: 963194227}
   - component: {fileID: 963194226}
+  - component: {fileID: 963194229}
   m_Layer: 0
   m_Name: Main Camera
   m_TagString: MainCamera
@@ -503,6 +509,39 @@ Transform:
   m_Father: {fileID: 0}
   m_RootOrder: 3
   m_LocalEulerAnglesHint: {x: 0, y: 0, z: 0}
+--- !u!114 &963194229
+MonoBehaviour:
+  m_ObjectHideFlags: 0
+  m_CorrespondingSourceObject: {fileID: 0}
+  m_PrefabInstance: {fileID: 0}
+  m_PrefabAsset: {fileID: 0}
+  m_GameObject: {fileID: 963194225}
+  m_Enabled: 1
+  m_EditorHideFlags: 0
+  m_Script: {fileID: 11500000, guid: a79441f348de89743a2939f4d699eac1, type: 3}
+  m_Name: 
+  m_EditorClassIdentifier: 
+  m_RenderShadows: 1
+  m_RequiresDepthTextureOption: 2
+  m_RequiresOpaqueTextureOption: 2
+  m_CameraType: 0
+  m_Cameras: []
+  m_RendererIndex: -1
+  m_VolumeLayerMask:
+    serializedVersion: 2
+    m_Bits: 1
+  m_VolumeTrigger: {fileID: 0}
+  m_VolumeFrameworkUpdateModeOption: 2
+  m_RenderPostProcessing: 0
+  m_Antialiasing: 0
+  m_AntialiasingQuality: 2
+  m_StopNaN: 0
+  m_Dithering: 0
+  m_ClearDepth: 1
+  m_AllowXRRendering: 1
+  m_RequiresDepthTexture: 0
+  m_RequiresColorTexture: 0
+  m_Version: 2
 --- !u!1 &1231462425
 GameObject:
   m_ObjectHideFlags: 0