HD scaling for 2D effects ("Mode-7" effects)

I dont know if any DS game uses the 2D effects extensively like the GBA does.
Other emulators like mGBA/bsnes already started working on it so it
would be nice if it was possible here too.

I now remember that the Chrono Trigger DS port used it like the SNES version.
Possibly other SNES ports used it too.

[Arisotura]

I don't know of any game that uses rotscale layers for faux-3D, since the DS has an actual 3D engine

regardless, this will be a low priority

Here is just a proof that Chrono Trigger DS use the 2D engine and not the 3D one for "Mode-7" :
With multi sampling and texture scaling :

Without :

But I can understand why its low priority.

[Arisotura]

mostly the thing is that this kind of graphical improvement would require more code than 3D upscaling

namely, mode7-style faux-3D is done by changing the BG scaling parameters per scanline, which would be annoying to work with

That's cool.
I talked to the GBE+ developer and she/he would likely implement it in his emulator.
I do wonder which other games used "Mode-7" on the DS .
I think only CT DS used this feature in the most extensive way (ending + bike racing).

[poudink]

should be fixed by #2553

[Arisotura]

I don't yet know how mode7 perspective looks, because it relies on changing the rotscale params per-scanline, and that is still inherently low-res. it might require some interpolation for it to look good...

[poudink]

Alright, I tested the race. Here's what it looks like at 6x:

And at 1x:

So yeah it makes a difference but it still doesn't look great. Probably too early to close this, then.