add CCNode::getChildByIndex

Author: nytelytee

loader/include/Geode/cocos/base_nodes/CCNode.h

@@ -648,7 +648,7 @@ class CC_DLL CCNode : public CCObject
     inline auto getChildrenExt() {
         // CCArrayExt is defined in geode/utils/cocos.hpp, which we cannot include due to circular includes.
         // This is an incredibly hacky way to still be able to use the type
-        
+
         using CCArrayExt = geode::CCArrayExtCheck<T, PleaseDontChangeMe>::type;
         static_assert(!std::is_void_v<CCArrayExt>, "Please include <Geode/utils/cocos.hpp> to use getChildrenExt()");
 
@@ -1182,6 +1182,23 @@ class CC_DLL CCNode : public CCObject
         return nullptr;
     }
 
+    /**
+     * Get child at index. Checks bounds. A negative
+     * index will get the child starting from the end
+     * @returns Child at index cast to the given type,
+     * or nullptr if index exceeds bounds
+     */
+    template <class T = cocos2d::CCNode>
+    T* getChildByIndex(int i) {
+        // start from end for negative index
+        if (i < 0) i = this->getChildrenCount() + i;
+        // check if backwards index is out of bounds
+        if (i < 0) return nullptr;
+        // check if forwards index is out of bounds
+        if (static_cast<int>(this->getChildrenCount()) <= i) return nullptr;
+        return static_cast<T*>(this->getChildren()->objectAtIndex(i));
+    }
+
     /// @{
     /// @name Shader Program
     /**