MAYA-111889 point snapping to similar instances

lib/mayaUsd/render/vp2RenderDelegate/CMakeLists.txt

@@ -9,6 +9,7 @@ target_sources(${PROJECT_NAME}
         draw_item.cpp
         instancer.cpp
         material.cpp
+        mayaPrimCommon.cpp
         mesh.cpp
         meshViewportCompute.cpp
         proxyRenderDelegate.cpp

lib/mayaUsd/render/vp2RenderDelegate/draw_item.cpp

@@ -54,7 +54,8 @@ HdVP2DrawItem::~HdVP2DrawItem()
     }
 }
 
-void HdVP2DrawItem::AddRenderItem(MHWRender::MRenderItem* item, const HdGeomSubset* geomSubset)
+HdVP2DrawItem::RenderItemData&
+HdVP2DrawItem::AddRenderItem(MHWRender::MRenderItem* item, const HdGeomSubset* geomSubset)
 {
     _renderItems.emplace_back();
     RenderItemData& renderItemData = _renderItems.back();
@@ -69,6 +70,8 @@ void HdVP2DrawItem::AddRenderItem(MHWRender::MRenderItem* item, const HdGeomSubs
 
     renderItemData._indexBuffer.reset(
         new MHWRender::MIndexBuffer(MHWRender::MGeometry::kUnsignedInt32));
+
+    return renderItemData;
 }
 
 PXR_NAMESPACE_CLOSE_SCOPE

lib/mayaUsd/render/vp2RenderDelegate/draw_item.h

@@ -64,12 +64,20 @@ class HdVP2DrawItem final : public HdDrawItem
         //! Is _shader a fallback material?
         bool _shaderIsFallback { true };
 
+        //! Fallback color changed
+        bool _fallbackColorDirty { true };
+
         //! Whether or not the render item is enabled
         bool _enabled { true };
 
         //! Whether or not the render item is transparent
         bool _transparent { false };
 
+#ifdef MAYA_NEW_POINT_SNAPPING_SUPPORT
+        //! Whether or not the render item represents the shaded draw for selected instances
+        bool _shadedSelectedInstances { false };
+#endif
+
         //! Primitive type of the render item
         MHWRender::MGeometry::Primitive _primitiveType {
             MHWRender::MGeometry::kInvalidPrimitive
@@ -103,16 +111,17 @@ class HdVP2DrawItem final : public HdDrawItem
     //! can be created for multiple usages.
     enum RenderItemUsage
     {
-        kRegular = 1 << 0,           //!< Regular drawing (shaded, wireframe etc.)
-        kSelectionHighlight = 1 << 1 //!< Selection highlight.
+        kRegular = 1 << 0,                  //!< Regular drawing (shaded, wireframe etc.)
+        kSelectionHighlight = kRegular << 1 //!< Selection highlight.
     };
 
 public:
     HdVP2DrawItem(HdVP2RenderDelegate* delegate, const HdRprimSharedData* sharedData);
 
     ~HdVP2DrawItem();
 
-    void AddRenderItem(MHWRender::MRenderItem* item, const HdGeomSubset* geomSubset = nullptr);
+    RenderItemData&
+    AddRenderItem(MHWRender::MRenderItem* item, const HdGeomSubset* geomSubset = nullptr);
 
     using RenderItemDataVector = std::vector<RenderItemData>;
     const RenderItemDataVector& GetRenderItems() const { return _renderItems; }

lib/mayaUsd/render/vp2RenderDelegate/mayaPrimCommon.cpp

@@ -0,0 +1,45 @@
+//
+// Copyright 2021 Autodesk
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+#include "mayaPrimCommon.h"
+
+PXR_NAMESPACE_OPEN_SCOPE
+
+#ifdef MAYA_NEW_POINT_SNAPPING_SUPPORT
+
+namespace {
+
+MayaUsdCustomData sMayaUsdCustomData;
+
+} // namespace
+
+/* static */
+InstanceIdMap& MayaUsdCustomData::Get(const MHWRender::MRenderItem& renderItem)
+{
+    return sMayaUsdCustomData._itemData[renderItem.InternalObjectId()];
+}
+
+/* static */
+void MayaUsdCustomData::Remove(const MHWRender::MRenderItem& renderItem)
+{
+    // not thread safe, so if they are destroyed in parallel this will crash.
+    // consider concurrent_hash_map for locking version that can erase
+    sMayaUsdCustomData._itemData.unsafe_erase(renderItem.InternalObjectId());
+}
+
+#endif
+
+PXR_NAMESPACE_CLOSE_SCOPE

lib/mayaUsd/render/vp2RenderDelegate/mayaPrimCommon.h

@@ -19,8 +19,31 @@
 #include "pxr/imaging/hd/changeTracker.h"
 #include "pxr/imaging/hd/types.h"
 
+#include <maya/MHWGeometry.h>
+
+#include <tbb/concurrent_unordered_map.h>
+
+#include <vector>
+
 PXR_NAMESPACE_OPEN_SCOPE
 
+#ifdef MAYA_NEW_POINT_SNAPPING_SUPPORT
+// Each instanced render item needs to map from a Maya instance id
+// back to a usd instance id.
+using InstanceIdMap = std::vector<unsigned int>;
+
+// global singleton rather than MUserData, because consolidated world will
+// not consolidate render items with different MUserData objects.
+class MayaUsdCustomData
+{
+public:
+    tbb::concurrent_unordered_map<int, InstanceIdMap> _itemData;
+
+    static InstanceIdMap& Get(const MHWRender::MRenderItem& item);
+    static void           Remove(const MHWRender::MRenderItem& item);
+};
+#endif
+
 struct MayaPrimCommon
 {
     enum DirtyBits : HdDirtyBits