add wireframe mode to sparse grid

Author: nmwsharp

include/polyscope/persistent_value.h

@@ -146,6 +146,7 @@ extern PersistentCache<MeshShadeStyle> persistentCache_MeshNormalType;
 extern PersistentCache<FilterMode>     persistentCache_FilterMode;
 extern PersistentCache<IsolineStyle>   persistentCache_IsolineStyle;
 extern PersistentCache<MeshSelectionMode>   persistentCache_MeshSelectionMode;
+extern PersistentCache<SparseVolumeGridRenderMode> persistentCache_SparseVolumeGridRenderMode;
 
 template<> inline PersistentCache<double>&                   getPersistentCacheRef<double>()                   { return persistentCache_double; }
 template<> inline PersistentCache<float>&                    getPersistentCacheRef<float>()                    { return persistentCache_float; }
@@ -163,6 +164,7 @@ template<> inline PersistentCache<MeshShadeStyle>&           getPersistentCacheR
 template<> inline PersistentCache<FilterMode>&               getPersistentCacheRef<FilterMode>()               { return persistentCache_FilterMode; }
 template<> inline PersistentCache<IsolineStyle>&             getPersistentCacheRef<IsolineStyle>()             { return persistentCache_IsolineStyle; }
 template<> inline PersistentCache<MeshSelectionMode>&        getPersistentCacheRef<MeshSelectionMode>()        { return persistentCache_MeshSelectionMode; }
+template<> inline PersistentCache<SparseVolumeGridRenderMode>& getPersistentCacheRef<SparseVolumeGridRenderMode>() { return persistentCache_SparseVolumeGridRenderMode; }
 }
 // clang-format on
 

include/polyscope/sparse_volume_grid.h

@@ -75,7 +75,7 @@ class SparseVolumeGrid : public Structure {
   // Corner c = dx*4 + dy*2 + dz maps cell[i] -> index in canonical node order
   render::ManagedBuffer<uint32_t> cornerNodeInds[8];
 
-  uint64_t nNodes();
+  uint64_t nNodes(); // NOTE: not populated until nodes are enabled (use ensureHaveCornerNodeIndices() to force this)
   const std::vector<glm::ivec3>& getCanonicalNodeInds();
   void ensureHaveCornerNodeIndices();
 
@@ -148,6 +148,18 @@ class SparseVolumeGrid : public Structure {
   SparseVolumeGrid* setCubeSizeFactor(double newVal);
   double getCubeSizeFactor();
 
+  // Render mode (gridcube or wireframe)
+  SparseVolumeGrid* setRenderMode(SparseVolumeGridRenderMode mode);
+  SparseVolumeGridRenderMode getRenderMode();
+
+  // Wireframe radius as a node-relative value. 1.0 is a reasonable default size.
+  SparseVolumeGrid* setWireframeRadius(double newVal);
+  double getWireframeRadius();
+
+  // Color used for wireframe rendering
+  SparseVolumeGrid* setWireframeColor(glm::vec3 val);
+  glm::vec3 getWireframeColor();
+
 private:
   // Field data
   glm::vec3 origin;
@@ -171,6 +183,9 @@ class SparseVolumeGrid : public Structure {
   PersistentValue<glm::vec3> edgeColor;
   PersistentValue<std::string> material;
   PersistentValue<float> cubeSizeFactor;
+  PersistentValue<SparseVolumeGridRenderMode> renderMode;
+  PersistentValue<float> wireframeRadius;
+  PersistentValue<glm::vec3> wireframeColor;
 
   // Compute cell positions and GPU indices from occupiedCellsData
   void computeCellPositions();
@@ -187,6 +202,13 @@ class SparseVolumeGrid : public Structure {
   std::shared_ptr<render::ShaderProgram> program;
   std::shared_ptr<render::ShaderProgram> pickProgram;
 
+  // Wireframe render mode
+  std::shared_ptr<render::ShaderProgram> wireframeNodeProgram;
+  std::shared_ptr<render::ShaderProgram> wireframeEdgeProgram;
+  void ensureWireframeProgramsPrepared();
+  void buildWireframeGeometry(std::vector<glm::vec3>& nodePositions, std::vector<glm::vec3>& edgeTailPositions,
+                              std::vector<glm::vec3>& edgeTipPositions);
+
   // === Helpers
   void checkForDuplicateCells();
   size_t findCellFlatIndex(glm::ivec3 cellInd3);

include/polyscope/types.h

@@ -164,6 +164,12 @@ POLYSCOPE_DEFINE_ENUM_NAMES(SparseVolumeGridElement,
     {SparseVolumeGridElement::NODE, "Node"}
 );
 
+enum class SparseVolumeGridRenderMode { Gridcube = 0, Wireframe };
+POLYSCOPE_DEFINE_ENUM_NAMES(SparseVolumeGridRenderMode,
+    {SparseVolumeGridRenderMode::Gridcube, "Gridcube"},
+    {SparseVolumeGridRenderMode::Wireframe, "Wireframe"}
+);
+
 enum class IsolineStyle { Stripe = 0, Contour };
 POLYSCOPE_DEFINE_ENUM_NAMES(IsolineStyle,
     {IsolineStyle::Stripe, "Stripe"},

src/persistent_value.cpp

@@ -24,6 +24,7 @@ PersistentCache<MeshShadeStyle> persistentCache_MeshNormalType;
 PersistentCache<FilterMode> persistentCache_FilterMode;
 PersistentCache<IsolineStyle> persistentCache_IsolineStyle;
 PersistentCache<MeshSelectionMode> persistentCache_MeshSelectionMode;
+PersistentCache<SparseVolumeGridRenderMode> persistentCache_SparseVolumeGridRenderMode;
 // clang-format on
 } // namespace detail
 } // namespace polyscope