Give mods access to imgui context

src/imgui_ui.cpp

@@ -177,6 +177,8 @@ static std::vector<MenuEntry> menuentries;
 static std::mutex menuentrieslock;
 static std::vector<std::shared_ptr<ActiveWindow>> activeWindows;
 static std::mutex activeWindowsLock;
+static std::vector<std::function<void()>> onDrawCallbacks;
+static std::mutex onDrawCallbacksLock;
 
 static void convertEntries(std::vector<MenuEntry>& menuentries, size_t length, MenuEntryABI* entries) {
     for(size_t i = 0; i < length; i++) {
@@ -280,6 +282,16 @@ void mcpelauncher_close_window(const char *title) {
     activeWindowsLock.unlock();
 }
 
+void mcpelauncher_add_draw_callback(void* user, void(*onDraw)(void* user)) {
+    onDrawCallbacksLock.lock();
+    onDrawCallbacks.push_back(std::bind(onDraw, user));
+    onDrawCallbacksLock.unlock();
+}
+
+struct ImGuiContext* mcpelauncher_get_imgui_context() {
+    return ImGui::GetCurrentContext();
+}
+
 void ImGuiUIInit(GameWindow* window) {
     if(!glGetString) {
         return;
@@ -928,6 +940,12 @@ void ImGuiUIDrawFrame(GameWindow* window) {
         activeWindowsLock.unlock();
     }
 
+    onDrawCallbacksLock.lock();
+    for(size_t i = 0; i < onDrawCallbacks.size(); i++) {
+        onDrawCallbacks[i]();
+    }
+    onDrawCallbacksLock.unlock();
+
     // Rendering
     ImGui::Render();
     ImGui_ImplOpenGL3_RenderDrawData(ImGui::GetDrawData());

src/imgui_ui.h

@@ -55,4 +55,8 @@ struct control
 };
 void mcpelauncher_show_window(const char* title, int isModal, void* user, void(*onClose)(void* user), int count, control* controls);
 
-void mcpelauncher_close_window(const char *title);
+void mcpelauncher_close_window(const char *title);
+
+void mcpelauncher_add_draw_callback(void* user, void(*onDraw)(void* user));
+
+struct ImGuiContext* mcpelauncher_get_imgui_context();

src/main.cpp

@@ -378,6 +378,8 @@ Hardware	: Qualcomm Technologies, Inc MSM8998
         { "mcpelauncher_addmenu", (void*)mcpelauncher_addmenu },
         { "mcpelauncher_show_window", (void*)mcpelauncher_show_window },
         { "mcpelauncher_close_window", (void*)mcpelauncher_close_window },
+        { "mcpelauncher_add_draw_callback", (void*)mcpelauncher_add_draw_callback },
+        { "mcpelauncher_get_imgui_context", (void*)mcpelauncher_get_imgui_context },
     });
 
     ModLoader modLoader;