WIP buggy multisample code

include/polyscope/render/engine.h

@@ -37,7 +37,7 @@ enum class FilterMode { Nearest = 0, Linear };
 enum class TextureFormat { RGB8 = 0, RGBA8, RG16F, RGB16F, RGBA16F, RGBA32F, RGB32F, R32F };
 enum class RenderBufferType { Color, ColorAlpha, Depth, Float4 };
 enum class DepthMode { Less, LEqual, LEqualReadOnly, Disable };
-enum class BlendMode { Over, OverNoWrite, Disable }; // TODO what to call these...
+enum class BlendMode { Over, OverNoWrite, Zero, Disable }; // TODO what to call these...
 
 namespace render {
 
@@ -63,6 +63,9 @@ class TextureBuffer {
   // void fillTextureData2D(std::string name, unsigned char* texData, unsigned int width, unsigned int height,
   // bool withAlpha = true, bool useMipMap = false, bool repeat = false);
 
+  // Limited support for multisampled buffers
+  bool isMultisample = false;
+
   virtual void* getNativeHandle() = 0; // used to interop with external things, e.g. ImGui
 
 protected:
@@ -116,7 +119,7 @@ class FrameBuffer {
 
   virtual void setDrawBuffers() = 0;
 
-  // Specify the viewport coordinates 
+  // Specify the viewport coordinates
   virtual void setViewport(int startX, int startY, unsigned int sizeX, unsigned int sizeY);
 
   // Resizes textures and renderbuffers if different from current size.
@@ -133,8 +136,8 @@ class FrameBuffer {
 
   // Buffers
   int nColorBuffers = 0;
-  std::vector<std::shared_ptr<RenderBuffer>> renderBuffers;
-  std::vector<std::shared_ptr<TextureBuffer>> textureBuffers;
+  std::vector<std::shared_ptr<RenderBuffer>> renderBuffersColor, renderBuffersDepth;
+  std::vector<std::shared_ptr<TextureBuffer>> textureBuffersColor, textureBuffersDepth;
 };
 
 // == Shaders
@@ -274,12 +277,15 @@ class Engine {
   virtual bool bindSceneBuffer();
   virtual void resizeSceneBuffer(int width, int height);
   virtual void setSceneBufferViewport(int xStart, int yStart, int sizeX, int sizeY);
-  virtual void lightSceneBuffer(); // tonemap and gamma correct, render to active framebuffer
-  void renderBackground();         // respects background setting
+  glm::vec4 getSceneBufferViewport();
+  virtual void lightSceneBuffer(); // tonemap and gamma correct, render to active buffer
+  virtual void blitFinalSceneToScreen() = 0;
+  void renderBackground(); // respects background setting
 
   // Manage render state
   virtual void setDepthMode(DepthMode newMode = DepthMode::Less) = 0;
   virtual void setBlendMode(BlendMode newMode = BlendMode::Over) = 0;
+  virtual void setColorMask(std::array<bool, 4> mask = {true, true, true, true}) = 0;
 
   // Helpers
   void allocateGlobalBuffersAndPrograms(); // called once during startup
@@ -326,6 +332,9 @@ class Engine {
   virtual std::shared_ptr<TextureBuffer> generateTextureBuffer(TextureFormat format, unsigned int sizeX_,
                                                                unsigned int sizeY_,
                                                                float* data) = 0; // 2d
+  virtual std::shared_ptr<TextureBuffer> generateTextureBufferMultisample(TextureFormat format, unsigned int sizeX_,
+                                                                          unsigned int sizeY_,
+                                                                          unsigned int nSamples) = 0; // 2d
 
   // create render buffers
   virtual std::shared_ptr<RenderBuffer> generateRenderBuffer(RenderBufferType type, unsigned int sizeX_,
@@ -339,11 +348,11 @@ class Engine {
                                                                DrawMode dm, unsigned int nPatchVertices = 0) = 0;
 
   // === The frame buffers used in the rendering pipeline
-  std::shared_ptr<FrameBuffer> sceneBuffer;
+  std::shared_ptr<FrameBuffer> sceneBuffer, sceneBufferFinal;
   std::shared_ptr<FrameBuffer> pickFramebuffer;
 
   // Main buffers for rendering
-  std::shared_ptr<TextureBuffer> sceneColor;
+  std::shared_ptr<TextureBuffer> sceneColor, sceneColorFinal;
   std::shared_ptr<RenderBuffer> sceneDepth, pickColorBuffer, pickDepthBuffer;
 
   // General-use programs used by the engine
@@ -353,14 +362,15 @@ class Engine {
   // Options
   BackgroundView background = BackgroundView::None;
 
-  // TODO make these persistent?
   float exposure = 0.9;
   float whiteLevel = 0.7;
   float gamma = 2.2;
 
 protected:
   // TODO Manage a cache of compiled shaders?
 
+  int ssaaFactor = 1;
+
   // Helpers
   std::vector<glm::vec3> screenTrianglesCoords(); // two triangles which cover the screen
   std::vector<glm::vec4> distantCubeCoords();     // cube with vertices at infinity

include/polyscope/render/opengl/gl_engine.h

@@ -56,6 +56,7 @@ class GLTextureBuffer : public TextureBuffer {
   // create a 2D texture from data
   GLTextureBuffer(TextureFormat format, unsigned int sizeX_, unsigned int sizeY_, unsigned char* data = nullptr);
   GLTextureBuffer(TextureFormat format, unsigned int sizeX_, unsigned int sizeY_, float* data);
+  GLTextureBuffer(TextureFormat format, unsigned int sizeX_, unsigned int sizeY_, unsigned int nSamples);
 
   ~GLTextureBuffer() override;
 
@@ -67,10 +68,10 @@ class GLTextureBuffer : public TextureBuffer {
   void setFilterMode(FilterMode newMode) override;
   void* getNativeHandle() override;
 
-
   void bind();
   TextureBufferHandle getHandle() const { return handle; }
 
+
 protected:
   TextureBufferHandle handle;
 };
@@ -121,7 +122,6 @@ class GLFrameBuffer : public FrameBuffer {
 
 protected:
   FrameBufferHandle handle;
-
 };
 
 
@@ -251,10 +251,12 @@ class GLEngine : public Engine {
   void bindDisplay() override;
   void swapDisplayBuffers() override;
   std::vector<unsigned char> readDisplayBuffer() override;
+  void blitFinalSceneToScreen() override;
 
   // Manage render state
   void setDepthMode(DepthMode newMode = DepthMode::Less) override;
   void setBlendMode(BlendMode newMode = BlendMode::Over) override;
+  void setColorMask(std::array<bool, 4> mask = {true, true, true, true}) override;
 
   // === Windowing and framework things
   void makeContextCurrent() override;
@@ -283,6 +285,9 @@ class GLEngine : public Engine {
                                                        unsigned char* data = nullptr) override; // 2d
   std::shared_ptr<TextureBuffer> generateTextureBuffer(TextureFormat format, unsigned int sizeX_, unsigned int sizeY_,
                                                        float* data) override; // 2d
+  std::shared_ptr<TextureBuffer> generateTextureBufferMultisample(TextureFormat format, unsigned int sizeX_,
+                                                                  unsigned int sizeY_,
+                                                                  unsigned int nSamples) override; // 2d
 
   // create render buffers
   std::shared_ptr<RenderBuffer> generateRenderBuffer(RenderBufferType type, unsigned int sizeX_,
@@ -298,8 +303,6 @@ class GLEngine : public Engine {
 protected:
   // Helpers
 
-  // Internal members
-  std::vector<FrameBufferHandle> activeRenderBufferStack;
 
   // Internal windowing and engine details
   GLFWwindow* mainWindow = nullptr;

include/polyscope/view.h

@@ -84,7 +84,6 @@ glm::mat4 getCameraViewMatrix();
 glm::mat4 getCameraPerspectiveMatrix();
 glm::vec3 getCameraWorldPosition();
 void getCameraFrame(glm::vec3& lookDir, glm::vec3& upDir, glm::vec3& rightDir);
-glm::vec4 getViewport();
 
 
 // Flight-related

src/curve_network.cpp

@@ -54,15 +54,15 @@ void CurveNetwork::setCurveNetworkNodeUniforms(render::ShaderProgram& p) {
   glm::mat4 P = view::getCameraPerspectiveMatrix();
   glm::mat4 Pinv = glm::inverse(P);
   p.setUniform("u_invProjMatrix", glm::value_ptr(Pinv));
-  p.setUniform("u_viewport", view::getViewport());
+  p.setUniform("u_viewport", render::engine->getSceneBufferViewport());
   p.setUniform("u_pointRadius", getRadius());
 }
 
 void CurveNetwork::setCurveNetworkEdgeUniforms(render::ShaderProgram& p) {
   glm::mat4 P = view::getCameraPerspectiveMatrix();
   glm::mat4 Pinv = glm::inverse(P);
   p.setUniform("u_invProjMatrix", glm::value_ptr(Pinv));
-  p.setUniform("u_viewport", view::getViewport());
+  p.setUniform("u_viewport", render::engine->getSceneBufferViewport());
   p.setUniform("u_radius", getRadius());
 }
 

src/curve_network_vector_quantity.cpp

@@ -54,7 +54,7 @@ void CurveNetworkVectorQuantity::draw() {
   glm::mat4 P = view::getCameraPerspectiveMatrix();
   glm::mat4 Pinv = glm::inverse(P);
   program->setUniform("u_invProjMatrix", glm::value_ptr(Pinv));
- 	program->setUniform("u_viewport", view::getViewport());
+ 	program->setUniform("u_viewport", render::engine->getSceneBufferViewport());
 
   program->draw();
 }

src/point_cloud.cpp

@@ -38,7 +38,7 @@ void PointCloud::setPointCloudUniforms(render::ShaderProgram& p) {
   glm::mat4 Pinv = glm::inverse(P);
   p.setUniform("u_pointRadius", pointRadius.get().asAbsolute());
   p.setUniform("u_invProjMatrix", glm::value_ptr(Pinv));
-  p.setUniform("u_viewport", view::getViewport());
+  p.setUniform("u_viewport", render::engine->getSceneBufferViewport());
 }
 
 void PointCloud::draw() {

src/point_cloud_vector_quantity.cpp

@@ -64,7 +64,7 @@ void PointCloudVectorQuantity::draw() {
   glm::mat4 P = view::getCameraPerspectiveMatrix();
   glm::mat4 Pinv = glm::inverse(P);
   program->setUniform("u_invProjMatrix", glm::value_ptr(Pinv));
- 	program->setUniform("u_viewport", view::getViewport());
+ 	program->setUniform("u_viewport", render::engine->getSceneBufferViewport());
 
   program->draw();
 }

src/polyscope.cpp

@@ -349,11 +349,13 @@ void renderScene() {
   }
 
   drawStructures();
+
+  render::engine->sceneBufferFinal->bindForRendering();
+  render::engine->lightSceneBuffer();
 }
 
 void renderSceneToScreen() {
-  render::engine->bindDisplay();
-  render::engine->lightSceneBuffer();
+  render::engine->blitFinalSceneToScreen();
 }
 
 void buildPolyscopeGui() {
@@ -532,7 +534,6 @@ void draw(bool withUI) {
 
   // Build the GUI components
   if (withUI) {
-    // ImGui::ShowDemoWindow();
 
     // The common case, rendering UI and structures
     if (contextStack.size() == 1) {

src/render/engine.cpp

@@ -49,11 +49,17 @@ void FrameBuffer::setViewport(int startX, int startY, unsigned int sizeX, unsign
 }
 
 void FrameBuffer::resizeBuffers(unsigned int newXSize, unsigned int newYSize) {
-	bind();
-  for (auto& b : renderBuffers) {
+  bind();
+  for (auto& b : renderBuffersColor) {
     b->resize(newXSize, newYSize);
   }
-  for (auto& b : textureBuffers) {
+  for (auto& b : renderBuffersDepth) {
+    b->resize(newXSize, newYSize);
+  }
+  for (auto& b : textureBuffersColor) {
+    b->resize(newXSize, newYSize);
+  }
+  for (auto& b : textureBuffersDepth) {
     b->resize(newXSize, newYSize);
   }
 }
@@ -88,9 +94,13 @@ void Engine::buildEngineGui() {
     ImGui::EndCombo();
   }
 
-  ImGui::SliderFloat("exposure", &exposure, 0.1, 5.0, "%.3f", 2.);
-  ImGui::SliderFloat("white level", &whiteLevel, 0.0, 5.0, "%.3f", 2.);
-  ImGui::SliderFloat("gamma", &gamma, 0.1, 5.0, "%.3f", 2.);
+  ImGui::Text("Tone mapping");
+  ImGui::SliderFloat("exposure", &exposure, 0.1, 2.0, "%.3f", 2.);
+  ImGui::SliderFloat("white level", &whiteLevel, 0.0, 2.0, "%.3f", 2.);
+  ImGui::SliderFloat("gamma", &gamma, 0.5, 3.0, "%.3f", 2.);
+
+  ImGui::Text("Anti-aliasing");
+  if (ImGui::InputInt("SSAA", &ssaaFactor, 1)) resizeSceneBuffer(view::bufferWidth, view::bufferHeight);
 
   groundPlane.buildGui();
 }
@@ -103,14 +113,20 @@ void Engine::setBackgroundAlpha(float newAlpha) {
   // TODO
 }
 
-// bool Engine::bindSceneBuffer() { return sceneBuffer->bindForRendering(); }
 
-void Engine::clearSceneBuffer() { sceneBuffer->clear(); }
+void Engine::clearSceneBuffer() {
+  sceneBuffer->clear();
+  sceneBufferFinal->clear();
+}
 
-void Engine::resizeSceneBuffer(int width, int height) { sceneBuffer->resizeBuffers(width, height); }
+void Engine::resizeSceneBuffer(int width, int height) {
+  sceneBuffer->resizeBuffers(ssaaFactor * width, ssaaFactor * height);
+  sceneBufferFinal->resizeBuffers(ssaaFactor * width, ssaaFactor * height);
+}
 
 void Engine::setSceneBufferViewport(int xStart, int yStart, int sizeX, int sizeY) {
-  sceneBuffer->setViewport(xStart, yStart, sizeX, sizeY);
+  sceneBuffer->setViewport(ssaaFactor * xStart, ssaaFactor * yStart, ssaaFactor * sizeX, ssaaFactor * sizeY);
+  sceneBufferFinal->setViewport(ssaaFactor * xStart, ssaaFactor * yStart, ssaaFactor * sizeX, ssaaFactor * sizeY);
 }
 
 bool Engine::bindSceneBuffer() { return sceneBuffer->bindForRendering(); }
@@ -155,7 +171,7 @@ void Engine::allocateGlobalBuffersAndPrograms() {
   { // Scene buffer
 
     // Note that this is basically duplicated in ground_plane.cpp, changes here should probably be reflected there
-    sceneColor = generateTextureBuffer(TextureFormat::RGBA16F, view::bufferWidth, view::bufferHeight);
+    sceneColor = generateTextureBufferMultisample(TextureFormat::RGBA16F, view::bufferWidth, view::bufferHeight, 1);
     sceneDepth = generateRenderBuffer(RenderBufferType::Depth, view::bufferWidth, view::bufferHeight);
 
     sceneBuffer = generateFrameBuffer();
@@ -167,6 +183,17 @@ void Engine::allocateGlobalBuffersAndPrograms() {
     sceneBuffer->clearAlpha = 0.0;
   }
 
+  { // "Final" scene buffer (after lighting)
+    sceneColorFinal = generateTextureBuffer(TextureFormat::RGBA16F, view::bufferWidth, view::bufferHeight);
+
+    sceneBufferFinal = generateFrameBuffer();
+    sceneBufferFinal->addColorBuffer(sceneColorFinal);
+    sceneBufferFinal->setDrawBuffers();
+
+    sceneBufferFinal->clearColor = glm::vec3{1., 1., 1.};
+    sceneBufferFinal->clearAlpha = 0.0;
+  }
+
   { // Pick buffer
     pickColorBuffer = generateRenderBuffer(RenderBufferType::Float4, view::bufferWidth, view::bufferHeight);
     pickDepthBuffer = generateRenderBuffer(RenderBufferType::Depth, view::bufferWidth, view::bufferHeight);
@@ -201,6 +228,10 @@ void Engine::allocateGlobalBuffersAndPrograms() {
   }
 }
 
+glm::vec4 Engine::getSceneBufferViewport() {
+  return glm::vec4{0., 0., ssaaFactor * view::bufferWidth, ssaaFactor * view::bufferHeight};
+}
+
 std::vector<glm::vec3> Engine::screenTrianglesCoords() {
   std::vector<glm::vec3> coords = {{-1.0f, -1.0f, 0.0f}, {1.0f, -1.0f, 0.0f}, {-1.0f, 1.0f, 0.0f},
                                    {-1.0f, 1.0f, 0.0f},  {1.0f, -1.0f, 0.0f}, {1.0f, 1.0f, 0.0f}};