Re: [hatari-devel] Motion demo Susie screen

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I've seen this Suzie demo with a previous version of hatari (it displays some blue and white buildings if I remember correctly).

the demo had a problem with the screen (videl emu I think).

I'll check with previous versions of Hatari if I can let it run again.

Laurent


Le 30/11/2020 à 20:22, Eero Tamminen a écrit :
Hi,

On 11/1/20 4:54 PM, Nicolas Pomarède wrote:
Le 27/10/2020 à 00:12, Eero Tamminen a écrit :
Only "Susie" doesn't work, it's now stuck
executing these instructions:
   $00016690 : btst   #0,$fffffc00.w    50.00%
   $00016696 : beq.s  $16690            50.00%

Nicolas, any ideas what could be the problem?

if you look at the code after, you can see that the btst is in fact waiting for a byte to be received from the ikbd ; which means a key was pressed (or mouse was moved). then just after, it compares the content of fffc02 with #$01, which is the scancode for the 'esc' key.

So, demo is not stuck ; press 'esc' and it will continue. In fact it exits. I don't know it's supposed to run sthg instead of exiting > someone would need to test on a real falcon. (or look at the source code
with the demo)

"Susie" screen description states following:
--------------------------------------------
Wolfestein/doom routine. Trilinear filtering
(mipmaps!) and featuring anti-aliasing of wall
edges. The DSP is used just to do the 3d
mathematics. Uses blitter in a funny way to read
one pixel and write it twice, but this causes
problems with the sound DMA. Massive pre-
calculations. All wall heights are in memory.
Features a nice roll effect. 2x2 pixels, but
proper ultra-low resolution screen might speed
it up to 50hz. Truecolor.
--------------------------------------------

Which corresponds to attached image (susie-pouet.png) from pouet.net.

But it looks like the attached susie-hatari.png instead.

Maybe the blitter stuff is one of the problems?

I have no idea how that e.g. interacts with Videl emulation...


    - Eero



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