Proper transparency via sorting + new test level

CMakeLists.txt

@@ -7,7 +7,7 @@ find_package(OpenGL REQUIRED)
 find_package(glfw3 REQUIRED)
 find_package(glm REQUIRED)
 
-add_executable(ecsgame Util/glad.c Util/OBJ_Loader.h Rendering/Shader.cpp Rendering/Shader.h main.cpp ECS/Components/Transform.h ECS/Components/Movement.h ECS/Events/InputEvent.h ECS/Events/MouseMoveEvent.h ECS/Systems/GravitySystem.h ECS/Systems/PositionDebugSystem.h ECS/Systems/KeyboardMovementSystem.h ECS/Components/Camera.h ECS/Systems/RenderSystem.h ECS/Components/Mesh.h ECS/Systems/MouseLookSystem.h ECS/Components/MouseLook.h ECS/Components/ObjMesh.h Util/stb_setup.cpp ECS/Components/Texture.h ECS/Components/LODObjMesh.h)
+add_executable(ecsgame Util/glad.c Util/OBJ_Loader.h Rendering/Shader.cpp Rendering/Shader.h main.cpp ECS/Components/Transform.h ECS/Components/Movement.h ECS/Events/InputEvent.h ECS/Events/MouseMoveEvent.h ECS/Systems/GravitySystem.h ECS/Systems/PositionDebugSystem.h ECS/Systems/KeyboardMovementSystem.h ECS/Components/Camera.h ECS/Systems/RenderSystem.h ECS/Components/Mesh.h ECS/Systems/MouseLookSystem.h ECS/Components/MouseLook.h ECS/Components/ObjMesh.h Util/stb_setup.cpp ECS/Components/Texture.h ECS/Components/LODObjMesh.h ECS/Components/SineAnimation.h ECS/Systems/SineAnimationSystem.h)
 
 include_directories(${OPENGL_INCLUDE_DIRS})
 

ECS/Components/ObjMesh.h

@@ -13,6 +13,8 @@ struct ObjMesh : public Mesh {
         Settings(float minDistanceForRender, float maxDistanceForRender) : minDistanceForRender(
                 minDistanceForRender), maxDistanceForRender(maxDistanceForRender) {}
 
+        Settings() = default;
+
         float minDistanceForRender = 0.0;
         float maxDistanceForRender = 1000.0;
     };

ECS/Systems/RenderSystem.h

@@ -21,7 +21,7 @@ public:
     void render(World *pWorld, Shader shader) {
 
         pWorld->each<Camera, Transform>([&](Entity *ent, ComponentHandle<Camera> camera, ComponentHandle<Transform> cameraTransform) {
-            glClearColor(0.2f, 0.3f, 0.3f, 1.0f);
+            glClearColor(0.6f, 0.9f, 0.9f, 1.0f);
             glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 
             shader.use();
@@ -30,22 +30,24 @@ public:
             shader.setMat4("view", glm::inverse(cameraTransform->matrix));
 
             std::vector<RenderObject> renderObjects;
+            std::vector<RenderObject> transparentRenderObjects;
 
             pWorld->each<Mesh, Transform>([&](Entity *ent, ComponentHandle<Mesh> mesh, ComponentHandle<Transform> transform) {
-                renderObjects.emplace_back(RenderObject(transform->matrix, 0, mesh.get()));
+                renderObjects.emplace_back(RenderObject(transform->matrix, 0, mesh.get(), 0));
             });
 
             glm::vec3 cameraPos = cameraTransform->getPosition();
 
-            // TODO: Is it possible to do get ObjMeshes in the Mesh loop above implicitly via polymorphism?
+            /*// TODO: Is it possible to do get ObjMeshes in the Mesh loop above implicitly via polymorphism?
+             * // TODO: Commented out because of double rendering - we only want to get objects that explicitly DON'T have a texture here!
             pWorld->each<ObjMesh, Transform>([&](Entity *ent, ComponentHandle<ObjMesh> mesh, ComponentHandle<Transform> transform) {
                 // Add the object to the renderObjects to draw if the distance is within the min and max distance of the mesh
                 float distance = glm::distance(cameraPos, transform->getPosition());
 
                 if (distance > mesh->minDistance && distance < mesh->maxDistance) {
-                    renderObjects.emplace_back(RenderObject(transform->matrix, 0, mesh.get()));
+                    renderObjects.emplace_back(RenderObject(transform->matrix, 0, mesh.get(), distance));
                 }
-            });
+            });*/
 
             // ObjMesh with textures
             pWorld->each<ObjMesh, Transform, Texture>([&](Entity *ent, ComponentHandle<ObjMesh> mesh, ComponentHandle<Transform> transform, ComponentHandle<Texture> texture) {
@@ -53,7 +55,12 @@ public:
                 float distance = glm::distance(cameraPos, transform->getPosition());
 
                 if (distance > mesh->minDistance && distance < mesh->maxDistance) {
-                    renderObjects.emplace_back(RenderObject(transform->matrix, texture->id, mesh.get()));
+                    // Put it into the list of transparent render objects if the texture wants to be rendered transparently
+                    if (texture->render_transparent) {
+                        transparentRenderObjects.emplace_back(RenderObject(transform->matrix, texture->id, mesh.get(), distance));
+                    } else {
+                        renderObjects.emplace_back(RenderObject(transform->matrix, texture->id, mesh.get(), distance));
+                    }
                 }
             });
 
@@ -63,35 +70,52 @@ public:
 
                 for (const auto &mesh : lodMesh->meshes) {
                     if (distance > mesh.minDistance && distance < mesh.maxDistance) {
-                        renderObjects.emplace_back(RenderObject(transform->matrix, texture->id, mesh));
+                        // Put it into the list of transparent render objects if the texture wants to be rendered transparently
+                        if (texture->render_transparent) {
+                            transparentRenderObjects.emplace_back(RenderObject(transform->matrix, texture->id, mesh, distance));
+                        } else {
+                            renderObjects.emplace_back(RenderObject(transform->matrix, texture->id, mesh, distance));
+                        }
                     }
                 }
             });
 
-            // TODO: Separate lists for transparent and non-transparent RenderObjects. The non-transparent list is
-            //  rendered first, then the transparent list is sorted and rendered.
-
             for (const RenderObject &obj : renderObjects) {
-                shader.setMat4("model", obj.matrix);
-
-                // 0 can't be a valid texture name, so we use it for meshes without textures here
-                if (obj.texture_id != 0) {
-                    glBindTexture(GL_TEXTURE_2D, obj.texture_id);
+                obj.render(shader);
             }
 
-                obj.mesh.render();
+            // Sort transparent objects and render them
+            std::sort(transparentRenderObjects.begin(), transparentRenderObjects.end(), [](const RenderObject &first, const RenderObject &second) -> bool {
+                return first.distance > second.distance;
+            });
+            for (const RenderObject &obj : transparentRenderObjects) {
+                obj.render(shader);
             }
         });
     }
 
     struct RenderObject {
-        RenderObject(const glm::mat4 &matrix, unsigned int textureId, const Mesh &mesh) : matrix(matrix),
+        RenderObject(const glm::mat4 &matrix, unsigned int textureId, const Mesh &mesh, float distance)
+                                                                                        : matrix(matrix),
                                                                                           texture_id(textureId),
-                                                                                          mesh(mesh) {}
+                                                                                          mesh(mesh),
+                                                                                          distance(distance) {}
+
+        void render(Shader shader) const {
+            shader.setMat4("model", matrix);
+
+            // 0 can't be a valid texture name, so we use it for meshes without textures here
+            if (texture_id != 0) {
+                glBindTexture(GL_TEXTURE_2D, texture_id);
+            }
+
+            mesh.render();
+        }
 
         glm::mat4 matrix;
         unsigned int texture_id;
         Mesh mesh;
+        float distance;
     };
 };
 

Resources/Ground.mtl

@@ -0,0 +1,10 @@
+# Blender MTL File: 'None'
+# Material Count: 1
+
+newmtl None
+Ns 500
+Ka 0.8 0.8 0.8
+Kd 0.8 0.8 0.8
+Ks 0.8 0.8 0.8
+d 1
+illum 2

Resources/Ground.obj

@@ -0,0 +1,16 @@
+# Blender v2.80 (sub 75) OBJ File: ''
+# www.blender.org
+mtllib Ground.mtl
+o Plane_Plane.001
+v -100.000000 0.000000 100.000000
+v 100.000000 0.000000 100.000000
+v -100.000000 0.000000 -100.000000
+v 100.000000 0.000000 -100.000000
+vt -49.500000 -49.500000
+vt 50.500000 -49.500000
+vt 50.500000 50.500000
+vt -49.500000 50.500000
+vn 0.0000 1.0000 0.0000
+usemtl None
+s off
+f 1/1/1 2/2/1 4/3/1 3/4/1

Resources/Wall.mtl

@@ -0,0 +1,10 @@
+# Blender MTL File: 'None'
+# Material Count: 1
+
+newmtl None
+Ns 500
+Ka 0.8 0.8 0.8
+Kd 0.8 0.8 0.8
+Ks 0.8 0.8 0.8
+d 1
+illum 2

Resources/Wall.obj

@@ -0,0 +1,16 @@
+# Blender v2.80 (sub 75) OBJ File: ''
+# www.blender.org
+mtllib Wall.mtl
+o Plane
+v -4.000000 0.000000 -0.000000
+v 4.000000 0.000000 -0.000000
+v -4.000000 8.000000 0.000000
+v 4.000000 8.000000 0.000000
+vt 0.000000 0.000000
+vt 1.000000 0.000000
+vt 1.000000 1.000000
+vt 0.000000 1.000000
+vn 0.0000 -0.0000 1.0000
+usemtl None
+s off
+f 1/1/1 2/2/1 4/3/1 3/4/1

main.cpp

@@ -84,12 +84,31 @@ int main() {
     player->assign<Movement>(glm::vec3(2.f, 2.f, 2.f));
     player->assign<Camera>(70.0f, 640, 480, 0.1f, 100.0f);
     player->assign<MouseLook>(0.1);
+    player->get<Transform>()->translate(glm::vec3(0.0f, 1.0f, 2.0f));
 
-    Entity *box2 = world->create();
-    box2->assign<Transform>();
-    box2->assign<LODObjMesh>(std::vector{ObjMesh("Resources/Monkey.obj", ObjMesh::Settings(0.0, 8.0)), ObjMesh("Resources/MonkeySimple.obj", ObjMesh::Settings(8.0, 100.0))});
-    box2->assign<Texture>("Resources/tex.png", Texture::Settings(true, true));
-    box2->get<Transform>()->translate(glm::vec3(0.0f, 0.0f, -5.0f));
+    Entity *monkey = world->create();
+    monkey->assign<Transform>();
+    monkey->assign<LODObjMesh>(std::vector{ObjMesh("Resources/Monkey.obj", ObjMesh::Settings(0.0, 8.0)), ObjMesh("Resources/MonkeySimple.obj", ObjMesh::Settings(8.0, 100.0))});
+    monkey->assign<Texture>("Resources/Marble.jpg", Texture::Settings(true, false));
+    monkey->get<Transform>()->translate(glm::vec3(0.0f, 2.0f, -6.0f));
+
+    Entity *wall1 = world->create();
+    wall1->assign<Transform>();
+    wall1->assign<ObjMesh>(ObjMesh("Resources/Wall.obj", ObjMesh::Settings()));
+    wall1->assign<Texture>("Resources/Glass.png", Texture::Settings(true, true));
+    wall1->get<Transform>()->translate(glm::vec3(0.0f, 0.0f, -2.0f));
+
+    Entity *wall2 = world->create();
+    wall2->assign<Transform>();
+    wall2->assign<ObjMesh>(ObjMesh("Resources/Wall.obj", ObjMesh::Settings()));
+    wall2->assign<Texture>("Resources/Glass.png", Texture::Settings(true, true));
+    wall2->get<Transform>()->translate(glm::vec3(0.0f, 0.0f, -10.0f));
+
+    Entity *ground = world->create();
+    ground->assign<Transform>();
+    ground->assign<ObjMesh>(ObjMesh("Resources/Ground.obj", ObjMesh::Settings()));
+    ground->assign<Texture>("Resources/Grass.jpg", Texture::Settings(true, false));
+    ground->get<Transform>()->translate(glm::vec3(0.0f, 0.0f, 0.0f));
 
     Shader defaultShader("Shaders/default-vertex.vs", "Shaders/default-fragment.fs");