add geode::cocos::switchToScene utility

loader/include/Geode/ui/SceneManager.hpp

@@ -1,5 +1,8 @@
 #pragma once
 
+#include "../DefaultInclude.hpp"
+#include <cocos2d.h>
+
 namespace cocos2d {
     class CCArray;
     class CCNode;

loader/include/Geode/utils/cocos.hpp

@@ -123,6 +123,14 @@ namespace geode::cocos {
      */
     GEODE_DLL cocos2d::CCRect calculateChildCoverage(cocos2d::CCNode* parent);
 
+    /**
+     * Create a CCScene from a layer and switch to it with the default fade 
+     * transition
+     * @param layer Layer to create a scene from
+     * @returns Created scene (not the fade transition)
+     */
+    GEODE_DLL cocos2d::CCScene* switchToScene(cocos2d::CCLayer* layer);
+
     /**
      * Rescale node to fit inside given size
      * @param node Node to rescale

loader/src/utils/cocos.cpp

@@ -99,3 +99,12 @@ bool geode::cocos::fileExistsInSearchPaths(const char* filename) {
     auto utils = CCFileUtils::sharedFileUtils();
     return utils->isFileExist(utils->fullPathForFilename(filename, false));
 }
+
+CCScene* geode::cocos::switchToScene(CCLayer* layer) {
+    auto scene = CCScene::create();
+    scene->addChild(layer);
+    CCDirector::get()->replaceScene(CCTransitionFade::create(
+        .5f, scene
+    ));
+    return scene;
+}