Fix depth test and transparent background bug in FBO

source/fbo.cpp

@@ -42,15 +42,14 @@ void FBO::Init(int width, int height) {
     // Generate the Depth renderbuffer
     glGenRenderbuffers(1, &depth_rbo_id_);
     glBindRenderbuffer(GL_RENDERBUFFER, depth_rbo_id_);
-    glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT, width, height);
+    glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT32, width, height);
     glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, depth_rbo_id_);
 
+    glBindFramebuffer(GL_FRAMEBUFFER, 0);
     // Check if the framebuffer is complete
     if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE) {
         std::cerr << "Error: Framebuffer is not complete!" << std::endl;
     }
-
-    glBindFramebuffer(GL_FRAMEBUFFER, 0);
 }
 
 void FBO::Bind() {
@@ -63,6 +62,9 @@ void FBO::Unbind() {
 
 void FBO::Cleanup() {
     if (color_texture_id_ != -1) {
+        glDeleteTextures(1, &position_texture_id_);
+    }
+    if (position_texture_id_ != -1) {
         glDeleteTextures(1, &color_texture_id_);
     }
     if (depth_rbo_id_ != -1) {
@@ -75,4 +77,8 @@ void FBO::Cleanup() {
 
 GLuint FBO::GetColorTexture() const {
     return color_texture_id_;
+}
+
+GLuint FBO::GetPositionTexture() const {
+    return position_texture_id_;
 }

source/scene.cpp

@@ -56,8 +56,8 @@ Scene::Scene(int width, int height)
     angle_(-glm::pi<float>() / 2.0f), 
     scale_(1.0f), 
     aspect_(static_cast<float>(width) / static_cast<float>(height)), 
-    near_z_(0.01f), 
+    near_z_(0.1f), 
-    far_z_(100.0f), 
+    far_z_(10.0f), 
     fov_(glm::pi<float>() / 6.0f) 
 {}
 
@@ -74,7 +74,7 @@ void Scene::Init() {
 
     // GL_DEPTH_TEST causes artifacts in meshes made up of multiple triangles
     // disabling for now
-    //glEnable(GL_DEPTH_TEST);
+    glEnable(GL_DEPTH_TEST);
     glEnable(GL_CULL_FACE);
 
     fbo_.Init(window_width, window_height);
@@ -128,7 +128,7 @@ void Scene::GenerateGrid(int divisions, std::vector<Vertex>& verts, std::vector<
 
 // Currently creates a test triangle and initializes its buffers
 void Scene::InitBuffers() {
-    int divisions = 2;  // Number of divisions along one axis of the grid
+    int divisions = 1 + (tessellationFactor / 64);  // Number of divisions along one axis of the grid
     GenerateGrid(divisions, vertices, indices);
 
     // Create and bind VAO, VBO, and EBO, and pass the data to OpenGL
@@ -203,15 +203,14 @@ void Scene::ReloadShader() {
 }
 
 void Scene::Display(GLFWwindow* window) {
+    fbo_.Bind();   
     glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 
-    fbo_.Bind();
-
     glUseProgram(shader_program_);
 
     //glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
 
-    view_matrix_ = glm::lookAt(glm::vec3(1.4f, 1.4f, 1.4f), glm::vec3(0.0f, 0.0f, 0.0f), glm::vec3(0.0f, 1.0f, 0.0f));
+    view_matrix_ = glm::lookAt(glm::vec3(0.0f, 1.4f, -1.4f), glm::vec3(0.0f, 0.0f, 0.0f), glm::vec3(0.0f, 1.0f, 0.0f));
     Uniforms::SceneData.PV = projection_matrix_ * view_matrix_; // Projection-View matrix
     Uniforms::BufferSceneData();
 
@@ -236,7 +235,7 @@ void Scene::Display(GLFWwindow* window) {
     fbo_.Unbind();
 
     post_fbo_.Bind();
-    glDisable(GL_DEPTH_TEST);
+    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 
     glUseProgram(quad_shader_program_);
 
@@ -255,7 +254,6 @@ void Scene::Display(GLFWwindow* window) {
     glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
 
     post_fbo_.Unbind();
-    glEnable(GL_DEPTH_TEST);
 
     DrawGui(window);
     glfwSwapBuffers(window);