destroy all textures on window destruction and restore OpenGL objects when Android resumes the app

android/src/main/cpp/main.cpp

@@ -357,6 +357,7 @@ static void engine_term_display(struct engine* engine) {
     engine->display = EGL_NO_DISPLAY;
     engine->context = EGL_NO_CONTEXT;
     engine->surface = EGL_NO_SURFACE;
+    App::I.terminate();
 }
 
 /**
@@ -528,7 +529,7 @@ static void engine_handle_cmd(struct android_app* app, int32_t cmd) {
         case APP_CMD_TERM_WINDOW:
             // The window is being hidden or closed, clean it up.
             engine_term_display(engine);
-            exit(0);
+            //exit(0);
             break;
         case APP_CMD_GAINED_FOCUS:
             // When our app gains focus, we start monitoring the accelerometer.

engine/app.cpp

@@ -499,18 +499,16 @@ void App::initLayout()
         }
     };
     LOG("initializing layout xml");
-#ifdef _WIN32
+    if (layout.m_loaded)
-    //layout.load("C:\\Users\\omar\\Desktop\\new_engine\\data\\layout.xml");
+        layout[main_id]->restore_context();
-    layout.load("data/layout.xml");
+    else
-#else
+        layout.load("data/layout.xml");
-    layout.load("data/layout.xml");
-#endif
     LOG("initializing layout completed");
 }
 
 void App::initLog()
 {
-    LogRemote::I.start();
+    //LogRemote::I.start();
 }
 void App::init()
 {
@@ -721,3 +719,8 @@ bool App::key_char(char key)
     layout[main_id]->update();
     return ret == kEventResult::Consumed;
 }
+
+void App::terminate()
+{
+    TextureManager::invalidate();
+}

engine/app.h

@@ -47,6 +47,7 @@ public:
     void initAssets();
     void initLayout();
     void create();
+    void terminate();
     void clear();
     void update(float dt);
     void resize(float w, float h);

engine/canvas.cpp

@@ -364,3 +364,13 @@ bool ui::Canvas::create(int width, int height)
     m_mesh.create();
     return true;
 }
+
+void ui::Canvas::snapshot_save()
+{
+
+}
+
+void ui::Canvas::snapshot_restore()
+{
+
+};

engine/canvas.h

@@ -16,6 +16,10 @@ public:
     bool m_locked = false;
     float m_opacity = 1.f;
     std::string m_name;
+    struct Snapshot
+    {
+        std::unique_ptr<uint8_t[]> image[6];
+    };
     bool create(int width, int height, std::string name)
     {
         for (int i = 0; i < 6; i++)
@@ -44,6 +48,16 @@ public:
         // restore clear color state
         glClearColor(cc[0], cc[1], cc[2], cc[3]);
     }
+    Snapshot snapshot()
+    {
+        Snapshot snap;
+        for (int i = 0; i < 6; i++)
+        {
+            snap.image[i] = std::make_unique<uint8_t[]>(m_rtt[i].bytes());
+            m_rtt[i].readTextureData(snap.image[i].get());
+        }
+        return snap;
+    }
 };
 
 class Canvas
@@ -79,6 +93,8 @@ public:
     glm::vec2 m_cam_rot;
     float m_cam_fov = 85;
     
+    std::vector<Layer::Snapshot> m_layers_snapshot;
+
     bool create(int width, int height);
     void resize(int width, int height);
     void layer_add(std::string name);
@@ -89,6 +105,8 @@ public:
     void stroke_end();
     void stroke_commit();
     void clear(const glm::vec4& color = { 1, 1, 1, 1 });
+    void snapshot_save();
+    void snapshot_restore();
 };
 
 

engine/layout.cpp

@@ -534,6 +534,9 @@ void Node::clone_children(Node* dest) const
 
 bool LayoutManager::load(const char* path)
 {
+    if (m_loaded)
+        return true; // already loaded
+
 #ifndef __ANDROID__
     struct stat tmp_info;
     if (stat(path, &tmp_info) != 0)
@@ -598,6 +601,7 @@ bool LayoutManager::load(const char* path)
     }
     if (on_loaded)
         on_loaded();
+    m_loaded = true;
 
     return true;
 }

engine/layout.h

@@ -92,6 +92,7 @@ class LayoutManager
     std::string m_path;
     struct stat m_file_info { 0 };
 public:
+    bool m_loaded = false;
     std::function<void()> on_loaded;
     bool load(const char* path);
     bool reload();
@@ -218,6 +219,13 @@ public:
         return o;
     }
 
+    virtual void restore_context()
+    {
+        for (auto& c : m_children)
+        {
+            c->restore_context();
+        }
+    };
     void update(float width, float height, float zoom);
     void update();
     void update_internal(const glm::vec2& origin, const glm::mat4& proj);
@@ -275,39 +283,6 @@ public:
     void mouse_release() { root()->current_mouse_capture = nullptr;  m_mouse_captured = false; }
     void key_capture() { root()->current_key_capture = this; m_key_captured = true; }
     void key_release() { root()->current_key_capture = nullptr;  m_key_captured = false; }
-
-//     class iterator
-//     {
-//         std::stack<Node*> m_nodes;
-//         Node* m_current;
-//     public:
-//         iterator(Node* root)
-//         {
-//             m_current = root;
-//             if (root)
-//                 m_nodes.push(root);
-//         }
-//         iterator& operator++() 
-//         { 
-//             m_nodes.pop();
-//             for (auto& c : m_current->m_children)
-//                 m_nodes.push(c.get());
-//             m_current = m_nodes.size() ? m_nodes.top() : nullptr;
-//             return *this;
-//         }
-//         Node& operator*() { return *m_current; }
-//         Node* operator->() { return m_current; }
-//         bool operator==(const iterator& rhs) { return m_current == rhs.m_current; }
-//         bool operator!=(const iterator& rhs) { return m_current != rhs.m_current; }
-//     };
-//     iterator begin()
-//     {
-//         return this;
-//     }
-//     iterator end()
-//     {
-//         return nullptr;
-//     }
 };
 
 class NodeBorder : public Node
@@ -421,6 +396,11 @@ public:
         m_text_mesh.update(font_id, m_text.c_str());
         SetSize(m_text_mesh.bb);
     }
+    virtual void restore_context() override
+    {
+        Node::restore_context();
+        create();
+    }
     virtual void parse_attributes(kAttribute ka, const tinyxml2::XMLAttribute* attr) override
     {
         Node::parse_attributes(ka, attr);
@@ -507,6 +487,11 @@ public:
             m_sz = (m_region.zw - m_region.xy) / tex_sz;
         }
     }
+    virtual void restore_context() override
+    {
+        Node::restore_context();
+        create();
+    }
     virtual void parse_attributes(kAttribute ka, const tinyxml2::XMLAttribute* attr) override
     {
         Node::parse_attributes(ka, attr);
@@ -1711,6 +1696,12 @@ public:
         TextureManager::load("data/Icons/Round-Hard.png");
         m_brush.m_tex_id = const_hash("data/Icons/Round-Hard.png");
     }
+    virtual void restore_context() override
+    {
+        NodeBorder::restore_context();
+        init_controls();
+        m_rtt.create(m_rtt.getWidth(), m_rtt.getHeight());
+    }
     void draw_stroke()
     {
         m_rtt.bindFramebuffer();
@@ -1880,6 +1871,13 @@ public:
         m_sampler.create();
         m_face_plane.create<1>(2, 2);
     }
+    virtual void restore_context() override
+    {
+        Node::restore_context();
+        m_canvas->create(512, 512);
+        m_sampler.create();
+        m_face_plane.create<1>(2, 2);
+    }
     virtual void draw() override
     {
         using namespace ui;

engine/log.cpp

@@ -12,6 +12,9 @@ static size_t data_handler(void *contents, size_t size, size_t nmemb, void *user
 
 void LogRemote::start()
 {
+    if (m_running)
+        return; // already running
+
     m_running = true;
     m_thread = std::thread([&] {
         net_init();

engine/rtt.cpp

@@ -144,7 +144,7 @@ void RTT::readTextureData(uint8_t* buffer)
 
 uint8_t* RTT::createBuffer()
 {
-    return new uint8_t[w * h * 3];
+    return new uint8_t[w * h * 4];
 }
 
 void RTT::bindTexture()

engine/rtt.h

@@ -26,5 +26,6 @@ public:
     GLuint getTextureID() { return texID; }
     int getWidth() { return w; }
     int getHeight() { return h; }
+    int bytes() { return w * h * 4; }
     GLuint getFBO() { return fboID; }
 };

engine/texture.cpp

@@ -25,6 +25,11 @@ Texture2D& TextureManager::get(uint16_t id)
     return m_textures[id];
 }
 
+void TextureManager::invalidate()
+{
+    m_textures.clear();
+}
+
 bool Texture2D::create(int width, int height, GLint internal_format, GLint format, const uint8_t* data)
 {
     m_width = width;

engine/texture.h

@@ -40,4 +40,5 @@ public:
     static bool load(const char* path);
     static void assign(uint16_t id, GLuint tex, int w = -1, int h = -1, GLuint internal_format = GL_RGBA8, GLuint format = GL_RGBA);
     static Texture2D& get(uint16_t id);
+    static void invalidate();
 };