fix rtt copy/move

src/rtt.h

@@ -3,19 +3,24 @@
 
 class RTT
 {
+    int w = 0;
+    int h = 0;
+    GLuint fboID = 0;
+    GLuint texID = 0;
+    GLuint rboID = 0;
+    GLint int_fmt = 0;
     bool bound = false;
     GLint oldRFboID = 0;
     GLint oldDFboID = 0;
-    GLuint fboID = 0;
-    GLuint rboID = 0;
-    GLuint texID = 0;
-    GLint int_fmt = 0;
-    int w = 0;
-    int h = 0;
 
 public:
+    // copy
     RTT(const RTT&) = delete;
+    RTT& operator=(const RTT&) = delete;
+    // move
     RTT(RTT&& other);
+    RTT& operator=(RTT&&);
+    // default
     RTT();
     ~RTT();