#71110 - deltree - Fri Feb 10, 2006 12:02 pm
after testing a few things, i'd like to know:
how many 64x64 sprites is it possible to display at a time ? it seems limited to 8, am I right ?
#71125 - tepples - Fri Feb 10, 2006 2:55 pm
If they all use the same picture, then you can display a lot more than that. Your main problem in that case will be the limitation of about 950 sprite pixels per scanline.
_________________
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#71143 - deltree - Fri Feb 10, 2006 4:30 pm
they all use the same picture.
Never heard of that limitation of 950 sprites/pixels, what does it mean exactly?
#71147 - jake2431 - Fri Feb 10, 2006 4:42 pm
Is a scanline just a rom of pixels?
#71150 - poslundc - Fri Feb 10, 2006 4:59 pm
| deltree wrote: |
| they all use the same picture. |
Then they can all point to the same location in VRAM, and you can use as many OAM entries as you like (up to 128 of them) to replicate it as many times as you want.
A single 64x64 image in 16-colours will consume 2K out of the 32K of VRAM you have. If they were all different, you could only fit 16 such images into VRAM (and then you'd have no room left for other sprites).
| Quote: |
| Never heard of that limitation of 950 sprites/pixels, what does it mean exactly? |
The GBA can only process so many sprite-pixels on each scanline - including for sprites that have transparent regions or are obscured by other sprites or BGs - before dropout starts to occur. This amount is generally 950-1200 pixels, so it's rarely a problem unless you are using scale/rot sprites, which consume more than normal sprites do.
http://www.work.de/nocash/gbatek.htm#lcdobjoverview for the specifics.
Dan.