Sprites Multiplexing is a technic often used on other achines machines with Hardware Sprite Capability.
It was often used on the [[Commodore 64|C64]].
On the Amstrad PLUS [[Plus]] range, it couldn't be used as well. But some possibilities exist.
It allows to "Multiplex " the same Sprite at different rasters lines.
The technic impose some specifications :
* The same Sprite is simply copied as it is.
* No multiplexed sprites can be at the same Line.
This can then be used for games like Shoot'emups... as the spriutes don't always need to be well animated (just moved) and as enemies waves are often pre-determined (R-Type is the typical exemple).==Limitations of Sprites Multiplexing on Amstrad Plus==
So it fit well for Vertical Waves The technic impose some limitations due to the somewhat unachieved design of enemies. Also for vertical or even diagonal special effects.the Amstrad Plus and the complex specificity of the [[ASIC]] :
* The same Sprite is simply copied/duplicated as it is.
* No multiplexed sprites can be at the same Line.
Multiplexing on the PLUS is much more difficult than on the C64. The reason is that the location for the graphics are fixed on the PLUS. e.g. Sprite 0 always looks at &4000 in the ASIC sprite RAM. This can't be changed.
Another way to multiplex sprites is to use screen rupture, because the sprite X,Y coordinate is based on the CRTC's Raster and Line Counter.
==Possible uses== This can then be used for games like Shoot'emups... as the sprites don't always need to be well animated (just moved) and as enemies waves are often pre-determined (R-Type is the typical example). So it fit well for Vertical Waves of enemies. Also for vertical or even diagonal special effects. ==Examples of Sprites Multiplexing on an Amstrad Plus ==
* maybe This Technic wasn't really exploited on the amstrad Plus, mainly because the Amstrad Plus wasn't really exploited. * [[Black Sabbath]] by [[BDC-Iron]] (first harwired sprites multiplexing demo as claimed by its author)*[[ Delirium Tremens]] preview by BDC-Iron (32 Harware sprites per line with actually only 8 sprites slots used) * [[Synergy]] synergy demo.by [[AsT/Impact]] (ndAsT : Yes this demo uses Sprites Multiplexing ! For example, the wobbler only uses 1 sprite line !!!... and have you ever count the balls displayed on the screen ?)*[[XMas 2008 Dentro]] by [[AsT/impact]] (The christmas balls are composed of 4 sprites... copied 4 times on your screen)*Probably [[It was so nice before the crash of the mir station]] In games, [[Prehistorik 2]] by [[Titus Software]] uses sprite multiplexing for the (second) big cloud/rocks that appear in the front. Did you notice that there are always 2 identical big clouds/rocks on screen at once..? Each one is drawn using all 16 hardware sprites. ==Video== *Sprite Multiplexing on C64 : http://www.youtube.com/watch?v=oyf2W239eRY*Synergy Demo on Amstrad Plus : http://www.youtube.com/watch?v=YGH5JIPWQ2I ==Other Sources and links == *[[Amstrad CPC plus sprite format]]*[[Programming:CPC Plus Hardware Sprites]]
*[http://codebase64.org/doku.php?id==Other Sources ==base:sprite_multiplexing Sprite Multiplexing Article at a C64wiki]*[http://lywenn.eu.org/projets/mtpx/mtpx.pdf Sprite Multiplexing project on Nintendo DS]
[[http://codebase64.org/doku.php?id=base:sprite_multiplexing Sprite Multiplexing Article for C64]]
[[Category:CPC Plus]][[Category:Programming]][[Category:Graphic]][[Category:Stub]]
