NanoBoyAdvance icon indicating copy to clipboard operation
NanoBoyAdvance copied to clipboard

Disabling sprites test gives incorrect results

Open alyosha-tas opened this issue 1 year ago • 1 comments

I started making tests for examining the effect of disabling sprites midscanline. Currently Nanoboy Advance renders addtional scanlines of sprites even when disabled.

Here is the test: https://github.com/alyosha-tas/gba-tests/blob/master/ppu/Sprite_Disable_Midline.gba

The results should look like this:

correct_boxes

alyosha-tas avatar Feb 19 '24 20:02 alyosha-tas

This probably is related to the weird latching of DISPCNT enable bits that I never understood why the hardware even behaves the way it does. Apparently back when I researched this I decided that sprites unlike backgrounds should check only the latched DISPCNT enable bits and not AND them with the current enable bits unlike backgrounds... I'm not sure why I concluded that but it's likely why the test is breaking

fleroviux avatar Feb 19 '24 22:02 fleroviux