Talk:Thsprite

notes on extended vram and tile boundry sizes

Some notes on this for later...

• tiles are always 8x8 pixels. 64 bytes per tile for 256 color. 32 bytes for 16 color
• videoSetMode/Sub can set either 32(default?), 64, 128, 256 byte tile boundries
• oam objects (sprites) can select tiles 0-1023..

if using 128K of extended vram for object data, if the tile boundry was 32, you would only be able to access 32*1024= 32,768 bytes of vram. setting 64 would allow you access to 64K, etc. in this way all of vram could potentially be used.

This will affect animation schemes tho. in 128 byte boundry mode, a 8x8-16color animated sprite will need to align each frame on 128 byte borders essentially wasting the other 96bytes inbetween frames.. Not that big of a deal.

so something like:

bytesperframe=(width*(height/frames)/cmode); //this would be a frame

(macro this mebbe) tiles=rounduptoboundrytile(bytesperframe,boundrysize); to this:

tiles=(bytesperframe%boundrysize)?(bytesperframe/boundrysize)+1:(bytesperframe/boundrysize);
totalframes=tiles*frames;

@_@???

Need better names for these two. So an 8x8 pixel arrangement of pixels i'll call 'tile'. first 10 bits of attribute 3 i'll call 'objtile' or mebbe just 'object'.