devkitPro

While I know 3DS homebrew is a long ways off, this concerns DS homebrew, and a problem associated with it when running on a 3DS. Whether or not current implementations of the touch-screen in libnds is the culprit, I don't know, but I figure it wouldn't hurt to ask, so here's the situation.

With a 3DS, there are 2 display modes when running DS-mode. One keeps the "natural resolution" of 256x192 (the lower screen positioning the output centered and towards the hinge), and the other stretches it to 320x240. There is nothing wrong with the former, but there is a problem with the latter with touch screen input. It appears that in this mode, touch-screen input is still stuck in "natural resolution" mode. This can be seen when running the 'touch_test' example under 'examples/nds/input/Touch_Pad'. I have tested and seen this problem using the SCDS2 card, and another person tested this with the Acekard 2i.

Might ignore this, mainly because I dug a little deeper into the problem, and it could be just my unit and it dealing with DS homebrew (commercial games work fine though). Unless anyone else has the problem and posts at the GBATemp thread here, then I might have a faulty 3DS unit. Nonetheless, if commercial games are not affected, then perhaps there's another way to handle DS touch-screen input?

That's definitely rather odd, I can't seem to replicate it here - touch screen seems to work as expected in both native and stretched modes for both DS and DSi mode. Have you updated the 3DS firmware and calibrated the touch screen?

That's just it. For some reason after calibration, the touch-screen input (not actual display) is forced into whatever mode was used last prior to the calibration, even if the mode used next is different. I can re-creating it every time.

Start in native, recalibrate. Test native again, works fine. Test in stretched, input acts in native mode.
Start in stretched, recalibrate. Test stretched again, works fine. Test in native, input acts in stretched mode.

Firmware had been updated last week. Again, only affects DS homebrew. Commercial DS games, on legit cards or flashcards (needed to make sure it wasn't the flashcard), don't have any problems with this.