Add quantity picking (#354)

* add additional skeleton methods for picking and delayed picking

* generalize picking for quantities

* add picking to render images

* minor depth in demo app

Author: nmwsharp

examples/demo-app/demo_app.cpp

@@ -821,6 +821,7 @@ void callback() {
       std::cout << "    io.MousePos.x: " << io.MousePos.x << " io.MousePos.y: " << io.MousePos.y << std::endl;
       std::cout << "    screenCoords.x: " << screenCoords.x << " screenCoords.y: " << screenCoords.y << std::endl;
       std::cout << "    bufferInd.x: " << xInd << " bufferInd.y: " << yInd << std::endl;
+      std::cout << "    depth: " << pickResult.depth << std::endl;
       std::cout << "    worldRay: ";
       polyscope::operator<<(std::cout, worldRay) << std::endl;
       std::cout << "    worldPos: ";

include/polyscope/camera_view.h

@@ -47,6 +47,7 @@ class CameraView : public QuantityStructure<CameraView> {
   virtual void draw() override;
   virtual void drawDelayed() override;
   virtual void drawPick() override;
+  virtual void drawPickDelayed() override;
   virtual void updateObjectSpaceBounds() override;
   virtual std::string typeName() override;
   virtual void refresh() override;

include/polyscope/context.h

@@ -107,6 +107,7 @@ struct Context {
   bool haveSelectionVal = false;
   uint64_t nextPickBufferInd = 1;
   std::unordered_map<Structure*, std::tuple<uint64_t, uint64_t>> structureRanges;
+  std::unordered_map<Quantity*, std::tuple<uint64_t, uint64_t>> quantityRanges;
 
   // ======================================================
   // === Internal globals from internal.h

include/polyscope/curve_network.h

@@ -59,6 +59,7 @@ class CurveNetwork : public QuantityStructure<CurveNetwork> {
   virtual void draw() override;
   virtual void drawDelayed() override;
   virtual void drawPick() override;
+  virtual void drawPickDelayed() override;
 
   virtual void updateObjectSpaceBounds() override;
   virtual std::string typeName() override;

include/polyscope/floating_quantity_structure.h

@@ -51,6 +51,7 @@ class FloatingQuantityStructure : public QuantityStructure<FloatingQuantityStruc
   virtual void draw() override;
   virtual void drawDelayed() override;
   virtual void drawPick() override;
+  virtual void drawPickDelayed() override;
   virtual bool hasExtents() override;
   virtual void updateObjectSpaceBounds() override;
   virtual std::string typeName() override;

include/polyscope/pick.h

@@ -4,6 +4,7 @@
 
 #include <cstdint>
 #include <string>
+#include <tuple>
 #include <utility>
 
 #include "polyscope/utilities.h"
@@ -13,6 +14,7 @@ namespace polyscope {
 
 // Forward decls
 class Structure;
+class Quantity;
 
 // == Main query
 
@@ -26,9 +28,11 @@ class Structure;
 struct PickResult {
   bool isHit = false;
   Structure* structure = nullptr;
+  Quantity* quantity = nullptr;
   WeakHandle<Structure> structureHandle; // same as .structure, but with lifetime tracking
   std::string structureType = "";
   std::string structureName = "";
+  std::string quantityName = "";
   glm::vec2 screenCoords;
   glm::ivec2 bufferInds;
   glm::vec3 position;
@@ -60,18 +64,21 @@ namespace pick {
 std::pair<Structure*, uint64_t> pickAtScreenCoords(glm::vec2 screenCoords); // takes screen coordinates
 std::pair<Structure*, uint64_t> pickAtBufferCoords(int xPos, int yPos);     // takes indices into the buffer
 std::pair<Structure*, uint64_t> evaluatePickQuery(int xPos, int yPos); // old, badly named. takes buffer coordinates.
+std::tuple<Structure*, Quantity*, uint64_t> evaluatePickQueryFull(int xPos,
+                                                                  int yPos); // badly named. takes buffer coordinates.
 
 
 // == Helpers
 
 // Set up picking (internal)
-// Called by a structure to figure out what data it should render to the pick buffer.
+// Called by a structure/quantity to figure out what data it should render to the pick buffer.
 // Request 'count' contiguous indices for drawing a pick buffer. The return value is the start of the range.
 uint64_t requestPickBufferRange(Structure* requestingStructure, uint64_t count);
+uint64_t requestPickBufferRange(Quantity* requestingQuantity, uint64_t count);
 
 // Convert between global pick indexing for the whole program, and local per-structure pick indexing
-std::pair<Structure*, uint64_t> globalIndexToLocal(uint64_t globalInd);
-uint64_t localIndexToGlobal(std::pair<Structure*, uint64_t> localPick);
+std::tuple<Structure*, Quantity*, uint64_t> globalIndexToLocal(uint64_t globalInd);
+uint64_t localIndexToGlobal(std::tuple<Structure*, Quantity*, uint64_t> localPick);
 
 // Convert indices to float3 color and back
 // Structures will want to use these to fill their pick buffers

include/polyscope/point_cloud.h

@@ -60,6 +60,7 @@ class PointCloud : public QuantityStructure<PointCloud> {
   virtual void draw() override;
   virtual void drawDelayed() override;
   virtual void drawPick() override;
+  virtual void drawPickDelayed() override;
   virtual void updateObjectSpaceBounds() override;
   virtual std::string typeName() override;
   virtual void refresh() override;

include/polyscope/polyscope.h

@@ -130,10 +130,6 @@ Structure* getStructure(std::string type, std::string name = "");
 // True if such a structure exists
 bool hasStructure(std::string type, std::string name);
 
-// Look up the string type and name for a structure from its pointer
-// (performs a naive search over all structures for now, use sparingly)
-std::tuple<std::string, std::string> lookUpStructure(Structure* structure);
-
 // De-register a structure, of any type. Also removes any quantities associated with the structure
 void removeStructure(Structure* structure, bool errorIfAbsent = false);
 void removeStructure(std::string type, std::string name, bool errorIfAbsent = false);

include/polyscope/quantity.h

@@ -30,6 +30,10 @@ class Quantity : public render::ManagedBufferRegistry {
   virtual void draw();
   virtual void drawDelayed(); // drawing that should happen after the main phase
 
+  // Draw pick buffers for the quantity
+  virtual void drawPick();
+  virtual void drawPickDelayed(); // drawing that should happen after the main phase
+
   // Draw the ImGUI ui elements
   virtual void buildUI();       // draws the tree node and enabled checkbox common to almost all quantities, and calls
                                 // drawCustomUI() below. Can still be overidden in case something else is wanted.

include/polyscope/render_image_quantity_base.h

@@ -26,8 +26,7 @@ class RenderImageQuantityBase : public FloatingQuantity, public FullscreenArtist
                           const std::vector<float>& depthData, const std::vector<glm::vec3>& normalData,
                           ImageOrigin imageOrigin);
 
-  // virtual void draw() override;
-  // virtual void drawDelayed() override;
+  virtual void drawPickDelayed() override;
 
   virtual void refresh() override;
 
@@ -73,9 +72,14 @@ class RenderImageQuantityBase : public FloatingQuantity, public FullscreenArtist
   PersistentValue<float> transparency;
   PersistentValue<bool> allowFullscreenCompositing;
 
+  // Picking is the same for all
+  std::shared_ptr<render::ShaderProgram> pickProgram;
+  glm::vec3 pickColor;
+
   // Helpers
   void prepareGeometryBuffers();
   void addOptionsPopupEntries();
+  void preparePick();
 };