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Talk:R-Type

822 bytes added, 20:23, 6 January 2010
[[User:Fano|Fano]] 16:47, 21 November 2009 (UTC)
 
==Level graphics==
 
Let's continue for 2K10 !
 
Game screen is composed of 8*5 blocks of 4*4 chars (8*8 pixies)
Blocks are stored in memory in the same way as sprites.
 
Per char :
 
*1 byte : flag , #36 = skip
*8 bytes : pixels in 1bit
 
There are 16 chars so 144 bytes per block
 
Levels are composed of columns of 5 blocks.The index of the first level bloc is located at #C4B1 (byte).The first column is located at (#C4BC)
 
A column address (word) can be computed like this : (column*5) + (#C4BC)
 
Each byte of the column is a block number :
* bit 7 -> if set block if verticaly reversed
* bit 6 -> if set block if horizontaly reversed
* bits 0->5 block index
 
Using block index , it is possible to compute address (word) with this simple formula :
 
(#C4BC)-((index+1)*144)
 
[[User:Fano|Fano]] 20:23, 6 January 2010 (UTC)
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