add timelapse video generation on iOS and mac , fix history memory

PanoPainter/GameViewController.m

@@ -374,6 +374,10 @@ NSThread* lock_thread;
 
 - (void)glkView:(GLKView *)view drawInRect:(CGRect)rect
 {
+    static auto time = std::chrono::steady_clock::now();
+    auto now = std::chrono::steady_clock::now();
+    auto dt = std::chrono::duration<float>(now - time);
+
     [gl_lock lock];
     if (!(App::I.redraw || App::I.animate))
     {
@@ -384,9 +388,10 @@ NSThread* lock_thread;
     [EAGLContext setCurrentContext:self.context];
     [view bindDrawable];
     App::I.clear();
-    App::I.update(0);
+    App::I.update(dt.count());
     [self.context presentRenderbuffer:GL_FRAMEBUFFER];
     [gl_lock unlock];
+    time = now;
 }
 
 @end