Have a basic outlining thing with stencils but required a bit of hacking to make it work in Scene::render.

18-depth-testing/src/components.hpp

@@ -94,6 +94,7 @@ namespace components {
   struct Scene {
     components::Shader shader;
     components::Shader light_shader;
+    components::Shader outline_shader;
     std::map<std::string, Material> materials;
     std::map<std::string, Model> models;
     std::vector<Thing> things;
@@ -101,5 +102,5 @@ namespace components {
     Lighting light;
   };
 
-  ENROLL_COMPONENT(Scene, shader, light_shader, materials, models, things, camera, light);
+  ENROLL_COMPONENT(Scene, shader, light_shader, outline_shader, materials, models, things, camera, light);
 }

18-depth-testing/src/main.cpp

@@ -66,7 +66,7 @@ void process_input(GLFWwindow *window, Scene& scene) {
   }
 
   if(glfwGetKey(window, GLFW_KEY_M) == GLFW_PRESS) {
-    scene.spawn("popcorn", scene.camera.position);
+    scene.spawn("marble_cube", scene.camera.position);
   }
 
   if(glfwGetKey(window, GLFW_KEY_L) == GLFW_PRESS) {
@@ -84,6 +84,10 @@ void process_input(GLFWwindow *window, Scene& scene) {
 
 Scene setup() {
   glEnable(GL_DEPTH_TEST);
+  glDepthFunc(GL_LESS);
+  glEnable(GL_STENCIL_TEST);
+  glStencilFunc(GL_NOTEQUAL, 1, 0xFF);
+  glStencilOp(GL_KEEP, GL_KEEP, GL_REPLACE);
 
   components::Scene config = utils::load_scene_config("config.json");
   Scene scene(config);

18-depth-testing/src/scene.cpp

@@ -10,28 +10,22 @@ void Scene::update() {
   camera.update(deltaTime);
 }
 
-void Scene::draw_model(Model& scene_model, Material& material, glm::mat4& projection, glm::mat4& view, glm::vec3& position)
+void Scene::draw_model(Shader& with_shader, Model& scene_model, Material& material, glm::mat4& projection, glm::mat4& view, glm::vec3& position, float scale)
 {
-  shader.apply_material(material);
+  with_shader.apply_material(material);
 
-  float time = glfwGetTime();
   glm::mat4 model = glm::mat4(1.0f);
   model = glm::translate(model, position);
-  model = glm::rotate(model, glm::radians(time * 10.0f), glm::vec3(1.0f, 0.3f, 0.5f));
+  model = glm::scale(model, glm::vec3(scale, scale, scale));
 
-  shader.setMat4("model", model);
+  with_shader.setMat4("model", model);
 
-  scene_model.draw(shader);
+  scene_model.draw(with_shader);
 }
 
 void Scene::render(GLFWwindow* window) {
   glClearColor(0.1f, 0.1f, 0.1f, 1.0f);
-  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
-
-  shader.use();
-
-  // time is used for fake 3d rotation
-  float time = glfwGetTime();
+  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
 
   glm::mat4 view = camera.look_at();
   glm::mat4 projection = glm::mat4(1.0f);
@@ -42,7 +36,6 @@ void Scene::render(GLFWwindow* window) {
   shader.use();
   shader.setMat4("view", view);
   shader.setMat4("projection", projection);
-  shader.setVec3("viewPos", camera.position);
 
   // for now just detect the camera moved and do spotlight update
   if(camera.dirty) {
@@ -53,10 +46,41 @@ void Scene::render(GLFWwindow* window) {
     camera.dirty = false;
   }
 
-  // BUG: no connection between models and positions
+
+  // ultra dumb way to draw the floor without stencil, so next move is to
+  // be able to tag models with specific functionality during render.
   for(auto& thing : things) {
-    draw_model(thing.model, thing.material, projection, view, thing.position);
+    if(thing.name == "metal_floor") {
+      draw_model(shader, thing.model, thing.material, projection, view, thing.position);
+    }
   }
+
+  glStencilFunc(GL_ALWAYS, 1, 0xFF);
+  glStencilMask(0xFF);
+
+  for(auto& thing : things) {
+    if(thing.name != "metal_floor") {
+      draw_model(shader, thing.model, thing.material, projection, view, thing.position);
+    }
+  }
+
+  glStencilFunc(GL_NOTEQUAL, 1, 0xFF);
+  glStencilMask(0x00);
+  glDisable(GL_DEPTH_TEST);
+
+  outline_shader.use();
+  outline_shader.setMat4("view", view);
+  outline_shader.setMat4("projection", projection);
+
+  for(auto& thing : things) {
+    if(thing.name != "metal_floor") {
+      draw_model(outline_shader, thing.model, thing.material, projection, view, thing.position, 1.01f);
+    }
+  }
+
+  glStencilMask(0xFF);
+  glStencilFunc(GL_ALWAYS, 0, 0xFF);
+  glEnable(GL_DEPTH_TEST);
 }
 
 void Scene::cleanup() {
@@ -64,8 +88,13 @@ void Scene::cleanup() {
 }
 
 void Scene::spawn(const std::string& name, components::Position& position) {
-  things.emplace_back(
-      models.at(name),
-      position,
-      materials.at(name));
+  if(models.contains(name)) {
+    things.emplace_back(
+        name,
+        models.at(name),
+        position,
+        materials.at("default"));
+  } else {
+    dbc::log($F("No model named: {}", name));
+  }
 }

18-depth-testing/src/scene.hpp

@@ -14,6 +14,7 @@
 #include <vector>
 
 struct Thing {
+  std::string name;
   Model& model;
   components::Position position;
   Material& material;
@@ -22,6 +23,8 @@ struct Thing {
 struct Scene {
   Shader shader;
   Shader light_shader;
+  Shader outline_shader;
+
   std::map<std::string, components::Material> materials;
   Camera camera;
   components::Lighting light;
@@ -34,6 +37,7 @@ struct Scene {
   Scene(components::Scene& config):
     shader{config.shader.vertex_path, config.shader.frag_path},
     light_shader{config.light_shader.vertex_path, config.shader.frag_path},
+    outline_shader{config.outline_shader.vertex_path, config.outline_shader.frag_path},
     materials{config.materials},
     camera{
       .position=config.camera.position,
@@ -50,6 +54,7 @@ struct Scene {
 
     for(auto& thing : config.things) {
       things.emplace_back(
+          thing.model,
           models.at(thing.model),
           thing.position,
           materials.at(thing.material));
@@ -60,7 +65,7 @@ struct Scene {
   }
 
   void update();
-  void draw_model(Model& scene_model, Material& material, glm::mat4& projection, glm::mat4& view, glm::vec3& position);
+  void draw_model(Shader& with_shader, Model& scene_model, Material& material, glm::mat4& projection, glm::mat4& view, glm::vec3& position, float scale=1.0f);
   void render(GLFWwindow* window);
   void cleanup();
   void spawn(const std::string& name, components::Position& position);