3 ms·
You'd like to know how fast they're scrolling and in which direction so you can decide which resources to cache given finite disk and memory bandwidth as well a
by jsolson 17y ago
You'd like to know how fast they're scrolling and in which direction so you can decide which resources to cache given finite disk and memory bandwidth as well as finite texture memory.
Apple's implementation doesn't bother loading the cover if the album in question is going to be past the edge of the screen before the load would complete. Instead it loads covers further down the line and renders a placeholder image.
Deciding which covers to load without knowing what the user is going to do next (stop the flow, go backwards, speed up) is a classic example of an online scheduling problem.
- Groxx 17y agoDid you actually watch the video? They're stepping through covers individually ~3 times (not watching it again) and getting only a few frames of transition each time. Caching the next and previous covers that are currently off-screen isn't just easy, it's highly likely that it'll be a frequent operation, and should be optimized. If they had scrolled a few dozen in either direction a bit of lag would be expected, but not when iterating. To make matters worse, this is in an advertisement, and can be expected to perform worse IRL because everyone optimizes for their ads.