support single pass instanced rendering.

Assets/uDesktopDuplication/Shaders/uDD_Common.cginc

@@ -8,12 +8,14 @@ struct appdata
 {
     float4 vertex : POSITION;
     float2 uv     : TEXCOORD0;
+    UNITY_VERTEX_INPUT_INSTANCE_ID
 };
 
 struct v2f
 {
     float4 vertex : SV_POSITION;
     float2 uv     : TEXCOORD0;
+    UNITY_VERTEX_OUTPUT_STEREO
 };
 
 struct Input 

Assets/uDesktopDuplication/Shaders/uDD_Unlit.shader

@@ -28,6 +28,9 @@ CGINCLUDE
 v2f vert(appdata v)
 {
     v2f o;
+    UNITY_SETUP_INSTANCE_ID(v);
+    UNITY_INITIALIZE_OUTPUT(v2f, o);
+    UNITY_INITIALIZE_VERTEX_OUTPUT_STEREO(o);
     uddBendVertex(v.vertex.xyz, _Radius, _Width, _Thickness);
     o.vertex = UnityObjectToClipPos(v.vertex);
     o.uv = TRANSFORM_TEX(v.uv, _MainTex);

Assets/uDesktopDuplication/Shaders/uDD_Unlit_BlackMask.shader

@@ -33,6 +33,9 @@ fixed _Mask;
 v2f vert(appdata v)
 {
     v2f o;
+    UNITY_SETUP_INSTANCE_ID(v);
+    UNITY_INITIALIZE_OUTPUT(v2f, o);
+    UNITY_INITIALIZE_VERTEX_OUTPUT_STEREO(o);
     uddBendVertex(v.vertex.xyz, _Radius, _Width, _Thickness);
     o.vertex = UnityObjectToClipPos(v.vertex);
     o.uv = TRANSFORM_TEX(v.uv, _MainTex);

Assets/uDesktopDuplication/Shaders/uDD_Unlit_Transparent.shader

@@ -30,6 +30,9 @@ CGINCLUDE
 v2f vert(appdata v)
 {
     v2f o;
+    UNITY_SETUP_INSTANCE_ID(v);
+    UNITY_INITIALIZE_OUTPUT(v2f, o);
+    UNITY_INITIALIZE_VERTEX_OUTPUT_STEREO(o);
     uddBendVertex(v.vertex.xyz, _Radius, _Width, _Thickness);
     o.vertex = UnityObjectToClipPos(v.vertex);
     o.uv = TRANSFORM_TEX(v.uv, _MainTex);