Implemented imgui callbacks

Author: KiritoDv

src/port/api/ui.cpp

@@ -6,6 +6,27 @@
 #include "port/ui/MenuTypes.h"
 // Include any mod-specific header that holds your maps (e.g. Rando::StaticData)
 
+#include <vector>
+#include <algorithm>
+
+static std::vector<C_GuiDrawFunc> gGuiDrawCallbacks;
+
+void C_RunGuiDrawCallbacks() {
+    for (auto& cb : gGuiDrawCallbacks) {
+        cb();
+    }
+}
+
+extern "C" void C_AddGuiDraw(C_GuiDrawFunc cb) {
+    if (cb) gGuiDrawCallbacks.push_back(cb);
+}
+
+extern "C" void C_RemoveGuiDraw(C_GuiDrawFunc cb) {
+    gGuiDrawCallbacks.erase(
+        std::remove(gGuiDrawCallbacks.begin(), gGuiDrawCallbacks.end(), cb),
+        gGuiDrawCallbacks.end());
+}
+
 // Helper function to map C Enums to C++ Enums safely
 static UIWidgets::ComponentAlignments MapAlign(C_ComponentAlign align) {
     if (align == C_ALIGN_RIGHT)

src/port/api/ui.h

@@ -120,4 +120,13 @@ extern_s void C_AddSidebarEntry(const char* label, int column);
 extern_s void C_AddWidget(const char* sidebar, int column, const char* label, C_WidgetConfig* config);
 
 // void C_RemoveMenuEntry(const char* entryName);
-extern_s void C_RemoveSidebarEntry(const char* sidebarName);
+extern_s void C_RemoveSidebarEntry(const char* sidebarName);
+
+// ---------------------------------------------------------
+// 5. Per-frame ImGui draw callbacks
+//    Registered functions are called once per ImGui frame,
+//    inside NewFrame … Render, safe to call igBegin/igEnd.
+// ---------------------------------------------------------
+typedef void (*C_GuiDrawFunc)(void);
+extern_s void C_AddGuiDraw(C_GuiDrawFunc callback);
+extern_s void C_RemoveGuiDraw(C_GuiDrawFunc callback);

src/port/ui/GhostshipGui.cpp

@@ -3,6 +3,9 @@
 #include <spdlog/spdlog.h>
 #include <imgui.h>
 #include <imgui_internal.h>
+#include "port/api/ui.h"
+
+void C_RunGuiDrawCallbacks();
 
 #ifdef __APPLE__
 #include <fast/backends/gfx_metal.h>
@@ -20,6 +23,22 @@
 #include <ship/window/gui/EventDebuggerWindow.h>
 #include <libultraship/window/gui/GfxDebuggerWindow.h>
 
+// Invisible host window that fires C mod ImGui callbacks each frame.
+// Overrides Draw() so it never calls ImGui::Begin()/End() itself; the C
+// callbacks are free to open any number of their own igBegin/igEnd windows.
+class CGuiCallbackWindow : public Ship::GuiWindow {
+public:
+    using GuiWindow::GuiWindow;
+    void InitElement()   override {}
+    void UpdateElement() override {}
+    void DrawElement()   override {}
+    void Draw() override {
+        if (IsVisible()) {
+            C_RunGuiDrawCallbacks();
+        }
+    }
+};
+
 namespace GhostshipGui {
 // MARK: - Delegates
 std::shared_ptr<Ship::GuiWindow> mInputEditorWindow;
@@ -78,6 +97,10 @@ void SetupGuiElements() {
     mObjectViewer = std::make_shared<ObjectViewer>(CVAR_WINDOW("ObjectViewer"), "Object Viewer##Dev", ImVec2(820, 630));
     gui->AddGuiWindow(mObjectViewer);
 
+    auto cGuiWindow = std::make_shared<CGuiCallbackWindow>("gWindows.CGuiCallbacks", "##cguicallbacks");
+    cGuiWindow->Show();
+    gui->AddGuiWindow(cGuiWindow);
+
     mGhostshipMenu = std::make_shared<GhostshipMenu>(CVAR_WINDOW("Menu"), "Settings Menu");
     gui->SetMenu(mGhostshipMenu);