feat(tools): add toggleable debug camera plugin

engine/CMakeLists.txt

@@ -28,6 +28,7 @@ set(CUBOS_ENGINE_SOURCE
     "src/cubos/engine/tools/world_inspector/plugin.cpp"
     "src/cubos/engine/tools/entity_inspector/plugin.cpp"
     "src/cubos/engine/tools/scene_editor/plugin.cpp"
+    "src/cubos/engine/tools/debug_camera/plugin.cpp"
 
     "src/cubos/engine/transform/plugin.cpp"
     "src/cubos/engine/transform/local_to_world.cpp"

engine/include/cubos/engine/tools/debug_camera/plugin.hpp

@@ -0,0 +1,18 @@
+/// @dir
+/// @brief @ref debug-camera-plugin plugin directory.
+
+/// @file
+/// @brief Plugin entry point.
+/// @ingroup debug-camera-plugin
+
+#pragma once
+
+#include <cubos/engine/cubos.hpp>
+
+namespace cubos::engine::tools
+{
+    /// @brief Plugin entry function.
+    /// @param cubos @b CUBOS. main class
+    /// @ingroup debug-camera-plugin
+    void debugCameraPlugin(Cubos& cubos);
+} // namespace cubos::engine::tools

engine/src/cubos/engine/tools/debug_camera/plugin.cpp

@@ -0,0 +1,63 @@
+#include <imgui.h>
+
+#include <cubos/engine/imgui/plugin.hpp>
+#include <cubos/engine/renderer/environment.hpp>
+#include <cubos/engine/renderer/plugin.hpp>
+#include <cubos/engine/renderer/point_light.hpp>
+#include <cubos/engine/tools/debug_camera/plugin.hpp>
+#include <cubos/engine/transform/plugin.hpp>
+
+using cubos::core::ecs::Commands;
+using cubos::core::ecs::Entity;
+using cubos::core::ecs::Read;
+using cubos::core::ecs::Write;
+
+using namespace cubos::engine;
+
+struct DebugCameraInfo
+{
+    Entity copy[4]; // copy old camera entities to re-apply them in the next camera change
+    Entity ent;     // debug camera entity
+};
+
+static void createDebugCameraSystem(Commands commands, Write<DebugCameraInfo> debugCamera)
+{
+    debugCamera->ent = commands.create().add(Camera{}).add(Position{{}}).entity();
+}
+
+static void changeToDebugCameraSystem(Write<ActiveCameras> camera, Write<DebugCameraInfo> debugCamera)
+{
+    ImGui::Begin("Debug Camera");
+
+    ImGui::Text("Current camera: %s", debugCamera->ent == camera->entities[0] ? "Debug" : "Game");
+    ImGui::Text("Key to change: F12");
+
+    if (ImGui::Button("Change camera") || ImGui::IsKeyPressed(ImGuiKey_F12))
+    {
+        CUBOS_DEBUG("Changed camera ...");
+        if (debugCamera->ent == camera->entities[0])
+        {
+            std::copy(std::begin(debugCamera->copy), std::end(debugCamera->copy), camera->entities);
+        }
+        else
+        {
+            std::copy(std::begin(camera->entities), std::end(camera->entities), debugCamera->copy);
+            camera->entities[0] = debugCamera->ent;
+            camera->entities[1] = Entity();
+            camera->entities[2] = Entity();
+            camera->entities[3] = Entity();
+        }
+    }
+
+    ImGui::End();
+}
+
+void cubos::engine::tools::debugCameraPlugin(Cubos& cubos)
+{
+    cubos.addPlugin(imguiPlugin);
+
+    cubos.startupSystem(createDebugCameraSystem);
+    cubos.system(changeToDebugCameraSystem).tagged("cubos.imgui");
+
+    cubos.addResource<DebugCameraInfo>();
+}

tools/tesseratos/src/main.cpp

@@ -1,6 +1,7 @@
 #include <cubos/engine/renderer/plugin.hpp>
 #include <cubos/engine/settings/settings.hpp>
 #include <cubos/engine/tools/asset_explorer/plugin.hpp>
+#include <cubos/engine/tools/debug_camera/plugin.hpp>
 #include <cubos/engine/tools/entity_inspector/plugin.hpp>
 #include <cubos/engine/tools/scene_editor/plugin.hpp>
 #include <cubos/engine/tools/settings_inspector/plugin.hpp>
@@ -35,6 +36,7 @@ int main(int argc, char** argv)
     cubos.addPlugin(tools::entityInspectorPlugin);
     cubos.addPlugin(tools::worldInspectorPlugin);
     cubos.addPlugin(tools::assetExplorerPlugin);
+    cubos.addPlugin(tools::debugCameraPlugin);
 
     cubos.startupSystem(mockCamera).tagged("setup");
     cubos.startupSystem(mockSettings).tagged("setup");