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Old 20 November 2013, 14:57   #161
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Join Date: Jan 2012
Location: USA
Posts: 281
Originally Posted by Jacques View Post
I don't mean any harm and I'm grateful for AmiWolf, but it just makes me wonder why it's playable on the likes of PC AT 16 MHz, even 8 MHz ATARIs and isn't as quick as it should on 030@50MHz Amiga, even considering need for C2P conversion it should fly (DoomAttack and AmiDoom do fly considering 030@50 MHz speed)

Programming language maybe (C vs assembler)?
The ST version benefits from the the ST's unique bitplane organization. C2P on the Amiga is much slower from what I understand.

There's a chance, though, that the blitter can be setup to draw vertical strips for the walls without using C2P at all.

For long vertical strips of wall, the idea would be to load BLTADAT with 16 pixels of texture and BLTAFWM and BLTALWM with values that reveal only one pixel strip of data. Then a nearly vertical line would be drawn so that as A is slowly shifted, one of the texture pixels moves though the gap created by the masks. The greater the slope of the line, the longer the strip.

For very short strips the slope would become more horizontal and BLTCMOD and BLTDMOD would have to be one less than normal so that writes would be to the pixels immediately below the first pixel. One dot per line mode might speed things up for short vertical wall segments.
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