tutorial: refresh some tutorial programs to use the init/release entity mechanism.

doc/tutorial/02_cube.cpp

@@ -25,23 +25,6 @@ class Cube : public WorldEntity
 {
 public:
     Cube()
-      : m_angle(0),
-        m_mesh({ /* Front vertices/colors */
-                 { vec3(-1.0, -1.0,  1.0), vec3(1.0, 0.0, 1.0) },
-                 { vec3( 1.0, -1.0,  1.0), vec3(0.0, 1.0, 0.0) },
-                 { vec3( 1.0,  1.0,  1.0), vec3(1.0, 0.5, 0.0) },
-                 { vec3(-1.0,  1.0,  1.0), vec3(1.0, 1.0, 0.0) },
-                 /* Back */
-                 { vec3(-1.0, -1.0, -1.0), vec3(1.0, 0.0, 0.0) },
-                 { vec3( 1.0, -1.0, -1.0), vec3(0.0, 0.5, 0.0) },
-                 { vec3( 1.0,  1.0, -1.0), vec3(0.0, 0.5, 1.0) },
-                 { vec3(-1.0,  1.0, -1.0), vec3(0.0, 0.0, 1.0) } }),
-        m_lines_indices({ 0, 1, 1, 2, 2, 3, 3, 0,
-                          4, 5, 5, 6, 6, 7, 7, 4,
-                          0, 4, 1, 5, 2, 6, 3, 7, }),
-        m_faces_indices({ 0, 1, 2, 2, 3, 0, 1, 5, 6, 6, 2, 1,
-                          7, 6, 5, 5, 4, 7, 4, 0, 3, 3, 7, 4,
-                          4, 5, 1, 1, 0, 4, 3, 2, 6, 6, 7, 3, })
     {
         m_camera = new Camera();
         m_camera->SetProjection(mat4::perspective(radians(30.f), 640.f, 480.f, .1f, 1000.f));
@@ -62,6 +45,34 @@ public:
 
     virtual bool init_draw() override
     {
+        array<vec3, vec3> mesh
+        {
+            // Front vertices/colors
+            { vec3(-1.0, -1.0,  1.0), vec3(1.0, 0.0, 1.0) },
+            { vec3( 1.0, -1.0,  1.0), vec3(0.0, 1.0, 0.0) },
+            { vec3( 1.0,  1.0,  1.0), vec3(1.0, 0.5, 0.0) },
+            { vec3(-1.0,  1.0,  1.0), vec3(1.0, 1.0, 0.0) },
+            // Back
+            { vec3(-1.0, -1.0, -1.0), vec3(1.0, 0.0, 0.0) },
+            { vec3( 1.0, -1.0, -1.0), vec3(0.0, 0.5, 0.0) },
+            { vec3( 1.0,  1.0, -1.0), vec3(0.0, 0.5, 1.0) },
+            { vec3(-1.0,  1.0, -1.0), vec3(0.0, 0.0, 1.0) },
+        };
+
+        array<uint16_t> lines_indices
+        {
+            0, 1, 1, 2, 2, 3, 3, 0,
+            4, 5, 5, 6, 6, 7, 7, 4,
+            0, 4, 1, 5, 2, 6, 3, 7,
+        };
+
+        array<uint16_t> faces_indices
+        {
+            0, 1, 2, 2, 3, 0, 1, 5, 6, 6, 2, 1,
+            7, 6, 5, 5, 4, 7, 4, 0, 3, 3, 7, 4,
+            4, 5, 1, 1, 0, 4, 3, 2, 6, 6, 7, 3,
+        };
+
         m_shader = Shader::Create(LOLFX_RESOURCE_NAME(02_cube));
 
         m_mvp = m_shader->GetUniformLocation("u_matrix");
@@ -72,19 +83,19 @@ public:
                                 VertexStream<vec3,vec3>(VertexUsage::Position,
                                                         VertexUsage::Color));
 
-        m_vbo = std::make_shared<VertexBuffer>(m_mesh.bytes());
-        void *mesh = m_vbo->Lock(0, 0);
-        memcpy(mesh, m_mesh.data(), m_mesh.bytes());
+        m_vbo = std::make_shared<VertexBuffer>(mesh.bytes());
+        void *data = m_vbo->Lock(0, 0);
+        memcpy(data, mesh.data(), mesh.bytes());
         m_vbo->Unlock();
 
-        m_lines_ibo = std::make_shared<IndexBuffer>(m_lines_indices.bytes());
-        void *indices = m_lines_ibo->Lock(0, 0);
-        memcpy(indices, m_lines_indices.data(), m_lines_indices.bytes());
+        m_lines_ibo = std::make_shared<IndexBuffer>(lines_indices.bytes());
+        data = m_lines_ibo->Lock(0, 0);
+        memcpy(data, lines_indices.data(), lines_indices.bytes());
         m_lines_ibo->Unlock();
 
-        m_faces_ibo = std::make_shared<IndexBuffer>(m_faces_indices.bytes());
-        indices = m_faces_ibo->Lock(0, 0);
-        memcpy(indices, m_faces_indices.data(), m_faces_indices.bytes());
+        m_faces_ibo = std::make_shared<IndexBuffer>(faces_indices.bytes());
+        data = m_faces_ibo->Lock(0, 0);
+        memcpy(data, faces_indices.data(), faces_indices.bytes());
         m_faces_ibo->Unlock();
 
         return true;
@@ -135,12 +146,12 @@ public:
 
         m_shader->SetUniform(m_mvp, m_matrix);
         m_lines_ibo->Bind();
-        m_vdecl->DrawIndexedElements(MeshPrimitive::Lines, m_lines_indices.count());
+        m_vdecl->DrawIndexedElements(MeshPrimitive::Lines, m_lines_ibo->GetSize() / sizeof(uint16_t));
         m_lines_ibo->Unbind();
 
         m_shader->SetUniform(m_mvp, m_matrix * mat4::scale(0.5f));
         m_faces_ibo->Bind();
-        m_vdecl->DrawIndexedElements(MeshPrimitive::Triangles, m_faces_indices.count());
+        m_vdecl->DrawIndexedElements(MeshPrimitive::Triangles, m_faces_ibo->GetSize() / sizeof(uint16_t));
         m_faces_ibo->Unbind();
 
         m_vdecl->Unbind();
@@ -158,10 +169,8 @@ public:
 
 private:
     Camera* m_camera = nullptr;
-    float m_angle;
+    float m_angle = 0.0f;
     mat4 m_matrix;
-    array<vec3,vec3> m_mesh;
-    array<uint16_t> m_lines_indices, m_faces_indices;
 
     std::shared_ptr<Shader> m_shader;
     ShaderAttrib m_coord, m_color;

doc/tutorial/04_texture.cpp

@@ -26,19 +26,19 @@ LOLFX_RESOURCE_DECLARE(04_texture);
 class TextureDemo : public WorldEntity
 {
 public:
-    TextureDemo()
+    virtual bool init_game() override
     {
+        /* Generate a new heightmap at the beginning */
         m_heightmap.resize(TEXTURE_WIDTH * 1);
+        memset(m_heightmap.data(), 255, m_heightmap.bytes());
+
+        return true;
     }
 
     virtual void tick_game(float seconds) override
     {
         WorldEntity::tick_game(seconds);
 
-        /* Generate a new heightmap at the beginning */
-        if (m_frames == 0)
-            memset(m_heightmap.data(), 255, m_heightmap.bytes());
-
         /* Scroll left */
         for (int i = 0; i < m_heightmap.count() - 1; i++)
             m_heightmap[i] = m_heightmap[i + 1];

doc/tutorial/05_easymesh.cpp

@@ -65,8 +65,6 @@ public:
         m_camera->SetView(mat4::lookat(vec3(-15.f, 5.f, 0.f),
                                        vec3(0.f, -1.f, 0.f),
                                        vec3(0.f, 1.f, 0.f)));
-        Scene& scene = Scene::GetScene();
-        scene.PushCamera(m_camera);
 
         /* Add a white directional light */
         m_light1 = new Light();
@@ -81,14 +79,10 @@ public:
         m_light2->SetColor(vec4(0.4f, 0.3f, 0.2f, 1.f));
         m_light2->SetType(LightType::Point);
         Ticker::Ref(m_light2);
-
-        m_ready = false;
     }
 
     ~EasyMeshTutorial()
     {
-        Scene& scene = Scene::GetScene();
-        scene.PopCamera(m_camera);
         Ticker::Unref(m_light1);
         Ticker::Unref(m_light2);
     }
@@ -123,34 +117,42 @@ public:
                       * mat4::rotate(m_gears[4].m3 - 80.0f, vec3(0, 1, 0));
     }
 
-    virtual void tick_draw(float seconds, Scene &scene)
+    virtual bool init_draw() override
     {
-        WorldEntity::tick_draw(seconds, scene);
-
-        if (!m_ready)
-        {
-            scene.get_renderer()->SetClearColor(vec4(0.0f, 0.0f, 0.0f, 1.0f));
+        Scene& scene = Scene::GetScene();
+        scene.PushCamera(m_camera);
+        scene.get_renderer()->SetClearColor(vec4(0.0f, 0.0f, 0.0f, 1.0f));
 
-            /* Upload vertex data to GPU */
-            for (int i = 0; i < m_gears.count(); i++)
-                m_gears[i].m1.MeshConvert();
+        /* Upload vertex data to GPU */
+        for (int i = 0; i < m_gears.count(); i++)
+            m_gears[i].m1.MeshConvert();
 
 #if USE_CUSTOM_SHADER
-            /* Custom Shader: Init the shader */
-            auto custom_shader = Shader::Create(LOLFX_RESOURCE_NAME(easymesh_shiny));
-            // any other shader stuf here (Get uniform, mostly, and set texture)
+        /* Custom Shader: Init the shader */
+        auto custom_shader = Shader::Create(LOLFX_RESOURCE_NAME(easymesh_shiny));
+        // any other shader stuf here (Get uniform, mostly, and set texture)
 
-            for (int i = 0; i < m_gears.count(); i++)
-                m_gears[i].m1.SetMaterial(custom_shader);
+        for (int i = 0; i < m_gears.count(); i++)
+            m_gears[i].m1.SetMaterial(custom_shader);
 #endif
 
-            m_ready = true;
-        }
+        return true;
+    }
+
+    virtual void tick_draw(float seconds, Scene &scene) override
+    {
+        WorldEntity::tick_draw(seconds, scene);
 
         for (int i = 0; i < m_gears.count(); i++)
-        {
             m_gears[i].m1.Render(scene, m_mat * m_gears[i].m2);
-        }
+    }
+
+    virtual bool release_draw() override
+    {
+        Scene& scene = Scene::GetScene();
+        scene.PopCamera(m_camera);
+        m_gears.resize(0);
+        return true;
     }
 
 private:
@@ -159,8 +161,6 @@ private:
     mat4 m_mat;
     Camera *m_camera;
     Light *m_light1, *m_light2;
-
-    bool m_ready;
 };
 
 int main(int argc, char **argv)

doc/tutorial/06_sprite.cpp

@@ -27,8 +27,6 @@ public:
         m_camera = new Camera();
         m_camera->SetView(mat4(1.f));
         m_camera->SetProjection(mat4::ortho(0.f, 640.f, 0.f, 480.f, -100.f, 100.f));
-        Scene& scene = Scene::GetScene();
-        scene.PushCamera(m_camera);
         Ticker::Ref(m_camera);
 
         m_tileset = TileSet::create("06_sprite.png");
@@ -40,16 +38,11 @@ public:
             m_sprites.push(vec3((float)rand(-96, 640), (float)rand(-96, 480), 0.f),
                            rand(0.f, 1.f));
         }
-
-        m_ready = false;
     }
 
     ~SpriteTutorial()
     {
         TileSet::destroy(m_tileset);
-
-        Scene& scene = Scene::GetScene();
-        scene.PopCamera(m_camera);
         Ticker::Unref(m_camera);
     }
 
@@ -66,15 +59,17 @@ public:
         WorldEntity::tick_game(seconds);
     }
 
-    virtual void tick_draw(float seconds, Scene &scene)
+    virtual bool init_draw() override
     {
-        WorldEntity::tick_draw(seconds, scene);
+        Scene& scene = Scene::GetScene();
+        scene.PushCamera(m_camera);
+        scene.get_renderer()->SetClearColor(vec4(0.0f, 0.0f, 0.0f, 1.0f));
+        return true;
+    }
 
-        if (!m_ready)
-        {
-            scene.get_renderer()->SetClearColor(vec4(0.0f, 0.0f, 0.0f, 1.0f));
-            m_ready = true;
-        }
+    virtual void tick_draw(float seconds, Scene &scene) override
+    {
+        WorldEntity::tick_draw(seconds, scene);
 
         for (int i = 0; i < SPRITE_COUNT; ++i)
         {
@@ -85,6 +80,13 @@ public:
         }
     }
 
+    virtual bool release_draw() override
+    {
+        Scene& scene = Scene::GetScene();
+        scene.PopCamera(m_camera);
+        return true;
+    }
+
 private:
     Camera *m_camera;
     TileSet *m_tileset;
@@ -92,8 +94,6 @@ private:
     static int const SPRITE_COUNT = 192;
     static int const FRAME_COUNT = 16;
     array<vec3, float> m_sprites;
-
-    bool m_ready;
 };
 
 int main(int argc, char **argv)

doc/tutorial/07_input.cpp

@@ -30,28 +30,6 @@ public:
         m_yaw_angle = 0;
         m_autorot = true;
 
-        /* Front vertices/colors */
-        m_mesh.push(vec3(-1.0, -1.0,  1.0), vec3(1.0, 0.0, 1.0));
-        m_mesh.push(vec3( 1.0, -1.0,  1.0), vec3(0.0, 1.0, 0.0));
-        m_mesh.push(vec3( 1.0,  1.0,  1.0), vec3(1.0, 0.5, 0.0));
-        m_mesh.push(vec3(-1.0,  1.0,  1.0), vec3(1.0, 1.0, 0.0));
-        /* Back */
-        m_mesh.push(vec3(-1.0, -1.0, -1.0), vec3(1.0, 0.0, 0.0));
-        m_mesh.push(vec3( 1.0, -1.0, -1.0), vec3(0.0, 0.5, 0.0));
-        m_mesh.push(vec3( 1.0,  1.0, -1.0), vec3(0.0, 0.5, 1.0));
-        m_mesh.push(vec3(-1.0,  1.0, -1.0), vec3(0.0, 0.0, 1.0));
-
-        m_faces_indices << 0 << 1 << 2 << 2 << 3 << 0;
-        m_faces_indices << 1 << 5 << 6 << 6 << 2 << 1;
-        m_faces_indices << 7 << 6 << 5 << 5 << 4 << 7;
-        m_faces_indices << 4 << 0 << 3 << 3 << 7 << 4;
-        m_faces_indices << 4 << 5 << 1 << 1 << 0 << 4;
-        m_faces_indices << 3 << 2 << 6 << 6 << 7 << 3;
-
-        m_lines_indices << 0 << 1 << 1 << 2 << 2 << 3 << 3 << 0;
-        m_lines_indices << 4 << 5 << 5 << 6 << 6 << 7 << 7 << 4;
-        m_lines_indices << 0 << 4 << 1 << 5 << 2 << 6 << 3 << 7;
-
         m_text = new Text("", "data/font/ascii.png");
         m_text->SetPos(vec3(5, 30, 1));
         Ticker::Ref(m_text);
@@ -124,6 +102,34 @@ public:
 
     virtual bool init_draw() override
     {
+        array<vec3, vec3> mesh
+        {
+            // Front vertices/colors
+            { vec3(-1.0, -1.0,  1.0), vec3(1.0, 0.0, 1.0) },
+            { vec3( 1.0, -1.0,  1.0), vec3(0.0, 1.0, 0.0) },
+            { vec3( 1.0,  1.0,  1.0), vec3(1.0, 0.5, 0.0) },
+            { vec3(-1.0,  1.0,  1.0), vec3(1.0, 1.0, 0.0) },
+            // Back
+            { vec3(-1.0, -1.0, -1.0), vec3(1.0, 0.0, 0.0) },
+            { vec3( 1.0, -1.0, -1.0), vec3(0.0, 0.5, 0.0) },
+            { vec3( 1.0,  1.0, -1.0), vec3(0.0, 0.5, 1.0) },
+            { vec3(-1.0,  1.0, -1.0), vec3(0.0, 0.0, 1.0) },
+        };
+
+        array<uint16_t> faces_indices
+        {
+            0, 1, 2, 2, 3, 0, 1, 5, 6, 6, 2, 1,
+            7, 6, 5, 5, 4, 7, 4, 0, 3, 3, 7, 4,
+            4, 5, 1, 1, 0, 4, 3, 2, 6, 6, 7, 3,
+        };
+
+        array<uint16_t> lines_indices
+        {
+            0, 1, 1, 2, 2, 3, 3, 0,
+            4, 5, 5, 6, 6, 7, 7, 4,
+            0, 4, 1, 5, 2, 6, 3, 7,
+        };
+
         m_shader = Shader::Create(LOLFX_RESOURCE_NAME(07_input));
 
         m_mvp = m_shader->GetUniformLocation("u_matrix");
@@ -134,19 +140,19 @@ public:
                                 VertexStream<vec3,vec3>(VertexUsage::Position,
                                                         VertexUsage::Color));
 
-        m_vbo = std::make_shared<VertexBuffer>(m_mesh.bytes());
-        void *mesh = m_vbo->Lock(0, 0);
-        memcpy(mesh, &m_mesh[0], m_mesh.bytes());
+        m_vbo = std::make_shared<VertexBuffer>(mesh.bytes());
+        void *data = m_vbo->Lock(0, 0);
+        memcpy(data, mesh.data(), mesh.bytes());
         m_vbo->Unlock();
 
-        m_lines_ibo = std::make_shared<IndexBuffer>(m_lines_indices.bytes());
-        void *indices = m_lines_ibo->Lock(0, 0);
-        memcpy(indices, &m_lines_indices[0], m_lines_indices.bytes());
+        m_lines_ibo = std::make_shared<IndexBuffer>(lines_indices.bytes());
+        data = m_lines_ibo->Lock(0, 0);
+        memcpy(data, lines_indices.data(), lines_indices.bytes());
         m_lines_ibo->Unlock();
 
-        m_faces_ibo = std::make_shared<IndexBuffer>(m_faces_indices.bytes());
-        indices = m_faces_ibo->Lock(0, 0);
-        memcpy(indices, &m_faces_indices[0], m_faces_indices.bytes());
+        m_faces_ibo = std::make_shared<IndexBuffer>(faces_indices.bytes());
+        data = m_faces_ibo->Lock(0, 0);
+        memcpy(data, faces_indices.data(), faces_indices.bytes());
         m_faces_ibo->Unlock();
 
         return WorldEntity::init_draw();
@@ -164,12 +170,12 @@ public:
 
         m_shader->SetUniform(m_mvp, m_matrix);
         m_lines_ibo->Bind();
-        m_vdecl->DrawIndexedElements(MeshPrimitive::Lines, m_lines_indices.count());
+        m_vdecl->DrawIndexedElements(MeshPrimitive::Lines, m_lines_ibo->GetSize() / sizeof(uint16_t));
         m_lines_ibo->Unbind();
 
         m_shader->SetUniform(m_mvp, m_matrix * mat4::scale(0.5f));
         m_faces_ibo->Bind();
-        m_vdecl->DrawIndexedElements(MeshPrimitive::Triangles, m_faces_indices.count());
+        m_vdecl->DrawIndexedElements(MeshPrimitive::Triangles, m_faces_ibo->GetSize() / sizeof(uint16_t));
         m_faces_ibo->Unbind();
 
         m_vdecl->Unbind();
@@ -190,8 +196,6 @@ private:
     float m_pitch_angle;
     float m_yaw_angle;
     mat4 m_matrix;
-    array<vec3,vec3> m_mesh;
-    array<uint16_t> m_lines_indices, m_faces_indices;
 
     std::shared_ptr<Shader> m_shader;
     ShaderAttrib m_coord, m_color;

doc/tutorial/08_fbo.cpp

@@ -69,16 +69,9 @@ public:
         m_vbo->Unlock();
 
         m_fbo = std::make_shared<Framebuffer>(Video::GetSize());
-        return true;
-    }
-
-    virtual void tick_draw(float seconds, Scene &scene) override
-    {
-        WorldEntity::tick_draw(seconds, scene);
-
-        // FIXME: this should only be done once!
         m_fbo->Bind();
         {
+            Scene& scene = Scene::GetScene();
             render_context rc(scene.get_renderer());
             rc.clear_color(vec4(0.f, 0.f, 0.f, 1.f));
             rc.clear_depth(1.f);
@@ -86,6 +79,13 @@ public:
         }
         m_fbo->Unbind();
 
+        return true;
+    }
+
+    virtual void tick_draw(float seconds, Scene &scene) override
+    {
+        WorldEntity::tick_draw(seconds, scene);
+
         /* FIXME: we should just disable depth test in the shader */
         render_context rc(scene.get_renderer());
         rc.depth_func(DepthFunc::Disabled);
@@ -140,10 +140,9 @@ int main(int argc, char **argv)
     sys::init(argc, argv);
 
     Application app("Tutorial 08: Framebuffer Object", ivec2(512, 512), 60.0f);
-
     new FBO();
-
     app.Run();
+
     return EXIT_SUCCESS;
 }
 

doc/tutorial/09_sound.cpp

@@ -1,7 +1,7 @@
 //
 //  Lol Engine — Sound tutorial
 //
-//  Copyright © 2011—2016 Sam Hocevar <sam@hocevar.net>
+//  Copyright © 2011—2019 Sam Hocevar <sam@hocevar.net>
 //
 //  Lol Engine is free software. It comes without any warranty, to
 //  the extent permitted by applicable law. You can redistribute it
@@ -47,7 +47,7 @@ public:
             switch (mode)
             {
             case 0: // sine wave
-                stream[i] = 400 * lol::sin(12 * i * F_TAU / bytes);
+                stream[i] = 400 * lol::sin(8 * i * F_TAU / bytes);
                 break;
             case 1: // white noise
                 stream[i] = lol::rand(-120, 120);
@@ -56,7 +56,7 @@ public:
         }
     }
 
-    virtual void tick_game(float seconds)
+    virtual void tick_game(float seconds) override
     {
         WorldEntity::tick_game(seconds);
 
@@ -85,7 +85,7 @@ public:
         }
     }
 
-    virtual void tick_draw(float seconds, Scene &scene)
+    virtual void tick_draw(float seconds, Scene &scene) override
     {
         WorldEntity::tick_draw(seconds, scene);
     }

doc/tutorial/11_fractal.cpp

@@ -31,7 +31,6 @@ class Fractal : public WorldEntity
 {
 public:
     Fractal(ivec2 const &size)
-      : m_julia(false)
     {
         /* Ensure texture size is a multiple of 16 for better aligned
          * data access. Store the dimensions of a texel for our shader,
@@ -54,8 +53,6 @@ public:
         m_oldmouse = ivec2(0, 0);
 
         m_pixels.resize(m_size.x * m_size.y);
-        m_frame = -1;
-        m_slices = 4;
         for (int i = 0; i < 4; i++)
         {
             m_deltashift[i] = real("0");
@@ -66,8 +63,6 @@ public:
         m_zoom_speed = 0.0;
         m_view.translate = rcmplx(0.0, 0.0);
         m_view.radius = 5.0;
-        m_ready = false;
-        m_drag = false;
 
         for (int i = 0; i < (MAX_ITERATIONS + 1) * PALETTE_STEP; i++)
         {
@@ -337,7 +332,7 @@ public:
         int jmax = jmin + MAX_LINES * 2;
         if (jmax > m_size.y)
             jmax = m_size.y;
-        u8vec4 *pixelstart = &m_pixels[0]
+        u8vec4 *pixelstart = m_pixels.data()
                            + m_size.x * (m_size.y / 4 * m_frame + line / 4);
 
 #if USE_REAL
@@ -429,11 +424,9 @@ public:
         }
     }
 
-    virtual void tick_draw(float seconds, Scene &scene)
+    virtual bool init_draw() override
     {
-        WorldEntity::tick_draw(seconds, scene);
-
-        static float const vertices[] =
+        float const vertices[] =
         {
              1.0f,  1.0f,
             -1.0f,  1.0f,
@@ -443,7 +436,7 @@ public:
              1.0f,  1.0f,
         };
 
-        static float const texcoords[] =
+        float const texcoords[] =
         {
              1.0f,  1.0f,
              0.0f,  1.0f,
@@ -453,43 +446,44 @@ public:
              1.0f,  1.0f,
         };
 
-        if (!m_ready)
-        {
-            /* Create a texture of half the width and twice the height
-             * so that we can upload four different subimages each frame. */
-            m_texture = std::make_shared<Texture>(ivec2(m_size.x / 2, m_size.y * 2),
-                                                  PixelFormat::RGBA_8);
-
-            /* Ensure the texture data is complete at least once, otherwise
-             * uploading subimages will not work. */
-            m_texture->SetData(&m_pixels[0]);
-
-            m_shader = Shader::Create(LOLFX_RESOURCE_NAME(11_fractal));
-
-            m_vertexattrib = m_shader->GetAttribLocation(VertexUsage::Position, 0);
-            m_texattrib = m_shader->GetAttribLocation(VertexUsage::TexCoord, 0);
-            m_texuni = m_shader->GetUniformLocation("u_texture");
-            m_texeluni = m_shader->GetUniformLocation("u_texel_size");
-            m_screenuni = m_shader->GetUniformLocation("u_screen_size");
-            m_zoomuni = m_shader->GetUniformLocation("u_zoom_settings");
-
-            m_vdecl = std::make_shared<VertexDeclaration>(
-                                    VertexStream<vec2>(VertexUsage::Position),
-                                    VertexStream<vec2>(VertexUsage::TexCoord));
-            m_vbo = std::make_shared<VertexBuffer>(sizeof(vertices));
-            m_tbo = std::make_shared<VertexBuffer>(sizeof(texcoords));
-
-            void *tmp = m_vbo->Lock(0, 0);
-            memcpy(tmp, vertices, sizeof(vertices));
-            m_vbo->Unlock();
-
-            tmp = m_tbo->Lock(0, 0);
-            memcpy(tmp, texcoords, sizeof(texcoords));
-            m_tbo->Unlock();
-
-            /* FIXME: this object never cleans up */
-            m_ready = true;
-        }
+        /* Create a texture of half the width and twice the height
+         * so that we can upload four different subimages each frame. */
+        m_texture = std::make_shared<Texture>(ivec2(m_size.x / 2, m_size.y * 2),
+                                              PixelFormat::RGBA_8);
+
+        /* Ensure the texture data is complete at least once, otherwise
+         * uploading subimages will not work. */
+        m_texture->SetData(m_pixels.data());
+
+        m_shader = Shader::Create(LOLFX_RESOURCE_NAME(11_fractal));
+
+        m_vertexattrib = m_shader->GetAttribLocation(VertexUsage::Position, 0);
+        m_texattrib = m_shader->GetAttribLocation(VertexUsage::TexCoord, 0);
+        m_texuni = m_shader->GetUniformLocation("u_texture");
+        m_texeluni = m_shader->GetUniformLocation("u_texel_size");
+        m_screenuni = m_shader->GetUniformLocation("u_screen_size");
+        m_zoomuni = m_shader->GetUniformLocation("u_zoom_settings");
+
+        m_vdecl = std::make_shared<VertexDeclaration>(
+                                VertexStream<vec2>(VertexUsage::Position),
+                                VertexStream<vec2>(VertexUsage::TexCoord));
+        m_vbo = std::make_shared<VertexBuffer>(sizeof(vertices));
+        m_tbo = std::make_shared<VertexBuffer>(sizeof(texcoords));
+
+        void *data = m_vbo->Lock(0, 0);
+        memcpy(data, vertices, sizeof(vertices));
+        m_vbo->Unlock();
+
+        data = m_tbo->Lock(0, 0);
+        memcpy(data, texcoords, sizeof(texcoords));
+        m_tbo->Unlock();
+
+        return true;
+    }
+
+    virtual void tick_draw(float seconds, Scene &scene) override
+    {
+        WorldEntity::tick_draw(seconds, scene);
 
         m_texture->Bind();
 
@@ -520,6 +514,16 @@ public:
         m_vdecl->Unbind();
     }
 
+    virtual bool release_draw() override
+    {
+        m_shader.reset();
+        m_vdecl.reset();
+        m_vbo.reset();
+        m_tbo.reset();
+        m_texture.reset();
+        return true;
+    }
+
 private:
     static int const MAX_ITERATIONS = 400;
     static int const PALETTE_STEP = 32;
@@ -542,8 +546,8 @@ private:
     std::shared_ptr<VertexBuffer> m_vbo, m_tbo;
     std::shared_ptr<Texture> m_texture;
 
-    int m_frame, m_slices, m_dirty[4];
-    bool m_ready, m_drag;
+    int m_frame = -1, m_slices = 4, m_dirty[4];
+    bool m_drag = false;
 
     struct view_settings
     {
@@ -556,7 +560,7 @@ private:
     rcmplx m_deltashift[4];
     real m_deltascale[4];
     double m_zoom_speed;
-    bool m_julia;
+    bool m_julia = false;
 
     vec4 m_texel_settings, m_screen_settings;
     mat4 m_zoom_settings;