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

18-depth-testing/config.json

@@ -1,21 +1,25 @@
 {
   "scene": {
     "shader": {
-      "vertex_path": "shaders/17-vert.glsl",
-      "frag_path": "shaders/17-frag.glsl"
+      "vertex_path": "shaders/18-vert.glsl",
+      "frag_path": "shaders/18-frag.glsl"
     },
     "light_shader": {
-      "vertex_path": "shaders/17-vert.glsl",
-      "frag_path": "shaders/17-lightsource.frag.glsl"
+      "vertex_path": "shaders/18-vert.glsl",
+      "frag_path": "shaders/18-lightsource.frag.glsl"
+    },
+    "outline_shader": {
+      "vertex_path": "shaders/18-vert.glsl",
+      "frag_path": "shaders/18-outline.glsl"
     },
     "materials": {
-      "crate": {
+      "default": {
         "ambient": [0.5, 0.5, 0.5],
         "shininess": 32.0,
         "diffuseMap": 0,
         "specularMap": 0
       },
-      "popcorn": {
+      "shiny": {
         "ambient": [0.5, 0.25, 0.31],
         "shininess": 10000.0,
         "diffuseMap": 0,
@@ -23,29 +27,22 @@
       }
     },
     "models": {
-      "crate": {
+      "marble_cube": {
         "directory": "assets",
-        "model_path": "crate.obj"
+        "model_path": "marble_cube.glb"
       },
-      "popcorn": {
+      "metal_floor": {
         "directory": "assets",
-        "model_path": "popcorn_model_a.glb"
+        "model_path": "metal_floor.glb"
       }
     },
     "things": [
-      {"model": "crate", "position": [0.0,  0.0,  0.0], "material": "crate"},
-      {"model": "crate", "position": [2.0,  5.0, -15.0], "material": "crate"},
-      {"model": "crate", "position": [-1.5, -2.2, -2.5], "material": "crate"},
-      {"model": "popcorn", "position": [-3.8, -2.0, -12.3], "material": "popcorn"},
-      {"model": "crate", "position": [ 2.4, -0.4, -3.5], "material": "crate"},
-      {"model": "crate", "position": [-1.7,  3.0, -7.5], "material": "crate"},
-      {"model": "popcorn", "position": [ 1.3, -2.0, -2.5], "material": "popcorn"},
-      {"model": "crate", "position": [ 1.5,  2.0, -2.5], "material": "crate"},
-      {"model": "popcorn", "position": [ 1.5,  0.2, -1.5], "material": "popcorn"},
-      {"model": "crate", "position": [-1.3,  1.0, -1.5], "material": "crate"}
+      {"model": "marble_cube", "position": [-1.0,  0.0,  -1.0], "material": "default"},
+      {"model": "marble_cube", "position": [2.0,  0.0, 0.0], "material": "default"},
+      {"model": "metal_floor", "position": [0.0, 0.0, 0.0], "material": "shiny"}
     ],
     "camera": {
-      "position": [0.0, 0.0, 3.0],
+      "position": [0.0, 0.1, 3.0],
       "front": [0.0, 0.0, -1.0],
       "up": [0.0, 1.0, 0.0],
       "direction": [0.0, 0.0, 0.0],

18-depth-testing/shaders/18-frag.glsl

@@ -55,6 +55,10 @@ uniform DirLight dirLights[MAX_LIGHTS];
 uniform int spotLightCount = 0;
 uniform SpotLight spotLights[MAX_LIGHTS];
 
+
+float near = 0.1;
+float far = 100.0;
+
 vec3 CalcDirLight(DirLight light, vec3 normal, vec3 viewDir)
 {
   vec3 mat_tex = vec3(texture(material.diffuse, TexCoords));
@@ -137,6 +141,13 @@ vec3 CalcSpotLight(SpotLight light, vec3 normal, vec3 fragPos, vec3 viewDir)
   return ambient + diffuse + specular;
 }
 
+float LinearizeDepth(float depth)
+{
+  float ndc = depth * 2.0 - 1.0;
+  return (2.0 * near * far) / (far + near - ndc * (far - near));
+}
+
+
 void main()
 {
   vec3 norm = normalize(Normal);
@@ -159,4 +170,7 @@ void main()
   }
 
   FragColor = vec4(result, 1.0);
+
+  // float depth = LinearizeDepth(gl_FragCoord.z) / far;
+  // FragColor = vec4(vec3(depth), 1.0);
 }

18-depth-testing/shaders/18-outline.glsl

@@ -0,0 +1,6 @@
+#version 330 core
+out vec4 FragColor;
+
+void main() {
+  FragColor = vec4(1.0, 0.0, 0.0, 1.0);
+}

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);