igl | opengl | Fix memory leak in RenderPipelineState::activeAttributesLocations_

src/igl/opengl/RenderCommandAdapter.cpp

@@ -227,12 +227,11 @@ void RenderCommandAdapter::clearDependentResources(
     clearFragmentTexture();
   }
 
-  if (!newStateOpenGL || !curStateOpenGL->matchesVertexInputState(*newStateOpenGL)) {
-    // We do need to clear vertex attributes, when pipelinestate is modified.
-    // If we don't, subsequent draw calls might try to read from these locations
-    // and crashes might happen.
-    unbindVertexAttributes();
+  if (curStateOpenGL && newStateOpenGL){
+    newStateOpenGL->savePrePipelineStateAttributesLocations(*curStateOpenGL);
+  }
 
+  if (!newStateOpenGL || !curStateOpenGL->matchesVertexInputState(*newStateOpenGL)) {
     // Don't reuse previously set vertex buffers.
     clearVertexBuffers();
   }
@@ -346,6 +345,7 @@ void RenderCommandAdapter::willDraw() {
 
   // Vertex Buffers must be bound before pipelineState->bind()
   if (pipelineState) {
+    pipelineState->clearActiveAttributesLocations();
     for (size_t bufferIndex = 0; bufferIndex < IGL_VERTEX_BUFFER_MAX; ++bufferIndex) {
       if (IS_DIRTY(vertexBuffersDirty_, bufferIndex)) {
         auto& bufferState = vertexBuffers_[bufferIndex];
@@ -355,6 +355,7 @@ void RenderCommandAdapter::willDraw() {
         CLEAR_DIRTY(vertexBuffersDirty_, bufferIndex);
       }
     }
+    pipelineState->unbindPrePipelineVertexAttributes();
     if (isDirty(StateMask::PIPELINE)) {
       pipelineState->bind();
       clearDirty(StateMask::PIPELINE);

src/igl/opengl/RenderPipelineState.cpp

@@ -288,6 +288,10 @@ void RenderPipelineState::bindVertexAttributes(size_t bufferIndex, size_t buffer
     IGL_DEBUG_ASSERT(location < sMaxNumVertexAttribs);
     activeAttributesLocations_.push_back(location);
 
+    prePipelineStateAttributesLocations_.erase(std::remove(prePipelineStateAttributesLocations_.begin(),
+                                                           prePipelineStateAttributesLocations_.end(), location),
+                                               prePipelineStateAttributesLocations_.end());
+
     getContext().enableVertexAttribArray(location);
     const auto& attribute = attribList[i];
     getContext().vertexAttribPointer(
@@ -317,6 +321,13 @@ void RenderPipelineState::unbindVertexAttributes() {
   activeAttributesLocations_.clear();
 }
 
+void RenderPipelineState::unbindPrePipelineVertexAttributes() {
+  for (const auto& l : prePipelineStateAttributesLocations_) {
+    getContext().disableVertexAttribArray(l);
+  }
+  prePipelineStateAttributesLocations_.clear();
+}
+
 // Looks up the location the of the specified texture unit via its name,
 // bind the unit to the location, then activate the unit.
 //

src/igl/opengl/RenderPipelineState.h

@@ -75,6 +75,16 @@ class RenderPipelineState final : public WithContext, public IRenderPipelineStat
     return static_cast<ShaderStages*>(desc_.shaderStages.get());
   }
 
+  void savePrePipelineStateAttributesLocations(RenderPipelineState & prePipelineState){
+    prePipelineStateAttributesLocations_ = std::move(prePipelineState.activeAttributesLocations_);
+  }
+
+  void clearActiveAttributesLocations(){
+    activeAttributesLocations_.clear();
+  }
+
+  void unbindPrePipelineVertexAttributes();
+
  private:
   // Tracks a list of attribute locations associated with a bufferIndex
   std::vector<int> bufferAttribLocations_[IGL_VERTEX_BUFFER_MAX];
@@ -84,6 +94,7 @@ class RenderPipelineState final : public WithContext, public IRenderPipelineStat
   std::array<GLint, IGL_TEXTURE_SAMPLERS_MAX> unitSamplerLocationMap_{};
   std::unordered_map<int, size_t> uniformBlockBindingMap_;
   std::array<GLboolean, 4> colorMask_ = {GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE};
+  std::vector<int> prePipelineStateAttributesLocations_;
   std::vector<int> activeAttributesLocations_;
   BlendMode blendMode_ = {GL_FUNC_ADD, GL_FUNC_ADD, GL_ONE, GL_ZERO, GL_ONE, GL_ZERO};
   bool blendEnabled_ = false;