New tutorial on sprites

[Yragael]

Hi


For those who need some basic code to start with sprites in assembly language, I just published this article :


http://www.stashofcode.fr/afficher-s...s-sur-amiga-1/


Written in french, but if you don't read french and are looking for code, just download the archive that contains those basic samples :



spriteCPU.s for displaying a 4 colors sprite using the CPU only (ie: no DMA)

sprites.s for displaying a 4 colors sprite and moving it around

sprites16.s for displaying a 16 colors sprite and moving it around

spritesField.s for "repeating" a sprite (ie : display it at different horizontal positions at different vertical positions)

spritesCollision.s for detecting collision between two sprites, and between a sprite and one bitplane

spritesPlane.s for displaying a "bitplane" made of sprites (ie : display the same sprites several time at the same vertical position so that they cover the screen)

spritesAGA.s for displaying four 16 colors sprites that are 64 pixels wide on AGA systems (contains infos about how to enable sprite scan doubling and other AGA sprites features)


Have fun!

[ross]

Very interesting and complete tutorial (like usual )
Commendable that both horizontal and vertical multiplexes have been dealt.

[Yragael]

@ross: Thanks


A little bug corrected this morning in triplePlayfield.s : for an unknown reason, PF2P2 and PF1P2 must not be set in BPLCON0 for the triple playfield to work on A500 (would work wether those bits are set or not on A1200...).

[ross]

Originally Posted by Yragael

A little bug corrected this morning in triplePlayfield.s : for an unknown reason, PF2P2 and PF1P2 must not be set in BPLCON0 for the triple playfield to work on A500 (would work wether those bits are set or not on A1200...).

Are you referring to PFxPx in BPLCON2?
There are some combinations that produce strange effects on OCS, see "Undocumented Amiga hardware stuff" thread.

[redblade]

Seems to translate nicely with google translate. Great tutorial

[Yragael]

Originally Posted by ross

Are you referring to PFxPx in BPLCON2?
There are some combinations that produce strange effects on OCS, see "Undocumented Amiga hardware stuff" thread.

Ok. I will check the thread and update the article accordingly.

[Yragael]

Originally Posted by ross

Are you referring to PFxPx in BPLCON2?
There are some combinations that produce strange effects on OCS, see "Undocumented Amiga hardware stuff" thread.

I checked and this is what Tony Willen reported in the thread. I quote and underline. Thanks for noticing it :


Dual playfield:

Any number of planes. No 5+ requirement here.


If playfield's matching BPLCON2 PFx value is >=5 and if playfield is not transparent, it is always drawn using COLOR0. PF2PRI still work normally, only color selection becomes strange. (Used in Running man / Scoopex intro's logo). If both PF1 and PF2 is >=5: both playfields disappear, only background color (and sprites) are visible.

[roondar]

Nice work, clear examples and I like the screenshots