Anyone use GBARunner2 with center and mask disabled?

[GuyWithAWiiUQuestion]

I tried disabling it since it said it adds one frame of latency (as if I would notice such a minute difference). I wasn't expecting the result, since I guess the "mask" part of it flew over my head at first. It's pretty cool that it's almost like it expands the resolution or field of view of the game! Of course, there are lots of artifacts visible since those portions weren't meant to be visible, but it's still a fascinating insight into how the games were programmed visually.

I'm curious as to why centering the view and masking the edges adds a frame of delay. Is it just the centering that does, just the masking, or both or either?

 

[Xdqwerty]

I Only disable it for the GBA Port of a link to the past

 

[metroid maniac]

I'm curious as to why centering the view and masking the edges adds a frame of delay. Is it just the centering that does, just the masking, or both or either?

GBARunner2 uses one of the DS's two 2D graphics engine to render GBA graphics. It's almost the same, except that it's wider and taller to fill up the whole screen.
With Center & Mask disabled, this gets sent directly to the display. Since it's using the engine directly, there's little extra processing possible.
The DS also has a capture feature. This allows it to capture the output of one of its own graphics engines and store it in memory. With Centre & Mask enabled, one engine is used to render graphics and capture it, while the other is used to apply the centre and mask effect for the previous frame. Of course, this requires a complete frame to be captured before it can be centred & masked by the other engine, which is the cause for the 1 frame delay.

Fun fact: the capture feature is the only way to display 3D on both screens. The 3D engine is only able to render one screen at a time. If you step through a dual-screen 3D game like Etrian Odyssey's title screen frame-by-frame, you'll usually notice that each screen updates on alternating frames. This is because the 3D engine is alternating between rendering onto each screen and also capturing a copy for that screen to display while the other is being rendered.

 

[GuyWithAWiiUQuestion]

GBARunner2 uses one of the DS's two 2D graphics engine to render GBA graphics. It's almost the same, except that it's wider and taller to fill up the whole screen.
With Center & Mask disabled, this gets sent directly to the display. Since it's using the engine directly, there's little extra processing possible.
The DS also has a capture feature. This allows it to capture the output of one of its own graphics engines and store it in memory. With Centre & Mask enabled, one engine is used to render graphics and capture it, while the other is used to apply the centre and mask effect for the previous frame. Of course, this requires a complete frame to be captured before it can be centred & masked by the other engine, which is the cause for the 1 frame delay.

Thanks for the explanation, that makes sense.

Fun fact: the capture feature is the only way to display 3D on both screens. The 3D engine is only able to render one screen at a time. If you step through a dual-screen 3D game like Etrian Odyssey's title screen frame-by-frame, you'll usually notice that each screen updates on alternating frames. This is because the 3D engine is alternating between rendering onto each screen and also capturing a copy for that screen to display while the other is being rendered.

Ooh, that's interesting. And that explains why games with 3D on both are limited to 30 FPS. I thought it was just because that was all the DS's 3D capabilities could handle when rendering twice the resolution. Oh, and maybe that explains the weird synchronization issues between screens that I noticed in the Zelda DS games when displaying 3D on both!