Graphics Reference
In-Depth Information
return
cell;
}
@end
When we scroll quickly, we get significant stuttering (see the FPS counter in Figure 12.7).
Figure 12.7
The frame rate falls to 15 FPS when scrolling in our app.
Instinctively, we might assume that the bottleneck is image loading. We're loading images
from the flash drive in real time and not caching them, so that's probably why it's slow,
right? We can fix that with some awesome code that will speculatively load our images
asynchronously using GCD and then cache them using….
Stop. Wait.
Before we start writing code, let's test our hypothesis. We'll profile the app using our three
Instruments tools to identify the problem. We suspect that the issue might be related to
image loading, so let's start with the Time Profiler tool (see Figure 12.8).
