Resource centre for ZX Spectrum games
using Manic Miner and Jet Set Willy game engines
Archive of the
Manic Miner & Jet Set Willy Yahoo! Group
messages
|
|
|
|
|
Message: 468
Author: eugenebrady
Date: 02/08/2000
Subject: Re: ?tioning the mind of a genious
Manic Miner has two buffers, excluding the
screen. At the start of a level, it draws the blocks in
the first buffer. Then, on every frame, it copies
this to a second buffer, where it draws willy and the
guardians, and then copies this to the screen.
The
majority of the CPU time is spent in copying data to
buffers (using LDIR instructions), which is why fast LDIR
emulation speeds the game up so much. (You can try this in
Z80).
JSW probably does it in the same way. I'm sure that
Andy Noble's method (removing the guardians instead of
copying all of the blocks) would be faster, even on a
speccy.
Removing the background graphic would not be too
difficult, and the code used would be way smaller than 8*64
bytes. This code would only run when you enter a room,
so the speed would not be affected.
So actually
Matt Smith's techniques waste memory, and slow the
game down. The code really isn't that good IMHO,
although you really need to look at a disassembly notice
it.
|
|
|