Full Moon Amiga AGA Demo End Credits Remake

[henhouseharry]

nicsure (not sure if he's on this forum) has recreated the end part of Full Moon (A1200) originally by Virtual Dreams/Fairlight:
[ Show youtube player ]
It looks great but it is a prerendered animation. I want to rewrite it using DirectX!

I tried converting this to the PC in DOS in 1996 using TurboC in DOS without extended memory, but it looked terrible because I couldn't get the original graphics. It was incredible on the A1200 but because we didn't have a hardware Action Replay and the software Action Replay 4 wasn't very good we couldn't tell if it was a real time animation, rotoscope or looped animation.

Because WinUAE does not have a debugging feature I couldn't get a clear view of the background animation so like nicsure I used Cheat Engine to space over the scrolltext.

I have so far captured the animation to an uncompressed AVI using WinUAE, saved each frame using VLC, removed the borders using imagemagick to get a nice 640x448 grab. I wrote a .NET tool to analyse the animation frame by frame so that the loop is correct etc. It seems to be a 24 frame animation but if it was 320x240 on the Amiga it would have taken 921k of memory which sounds about right.

A problem is that WinUAE doesn't have a window size consistent with the original Amiga resolution and I can't make out if the original was dithered or not. I have saved without dithering and each frame has 16 colours so I assume that the original was a 5 bit plane display with the top bit plane being used for the scroller.

I have the animation running in 640x480 and the music playing in a double buffered 256 colour full screen display using DirectX on Windows but I haven't got the fade at the start or the text scroller working yet.

It has been years since I have done any DirectX programming so I am a bit rusty. Modern screens run at 60Hz, 100Hz or more whereas in 2002 50Hz and 70Hz were the most common refresh rates. This demo was designed to run at 50Hz. My laptop runs at 60Hz and I can slow down the display update code to 30Hz which looks more acceptable. Is there a proper way to set the frame rate other than the screen device frame rate?

[hooverphonique]

This looks like the classic "blitter tornado" effect, although in 4 bpls instead of 2.
If it really is a 24 frame looping anim, I wonder how they came up with a pattern which makes it possible to loop seamlessly...

[alexh]

A thread describing this technique was re-opened last week and an example shown in Spectrum Basic (for Windows).

http://eab.abime.net/showthread.php?t=65300

Originally Posted by hooverphonique

This looks like the classic "blitter tornado" effect, although in 4 bpls instead of 2.
If it really is a 24 frame looping anim, I wonder how they came up with a pattern which makes it possible to loop seamlessly...

In the original demo it was a looping animation. It's very easy to see it is a loop vs non-looping real-time generated ones.

[ Show youtube player ]

The music in this demo is a copy of a copy of the Intro music to Thalion's game "A Prehistoric Tale" by Jochen "Mad Max" Hippel who went uncredited in the original Full Moon demo. Nice to see him credited here.

[henhouseharry]

Thanks hooverphonique and alexh.

Here is a picture of my loop testing program:
https://lynn3686.com/images/fullmoon/f23.png

The left side is frame 23, the right side is frame 0.
The red box shows a consistent data point -the little dinosaur shaped island.

Frame 23 appears to be a little to the left so maybe it does move forward and back by some sort of scrolling effect? I can't scroll through memory on a real Amiga with a graphics ripper so I guess I'll never know.

I have the animation and music playing in 640x480 at 30fps in C++ using DirectX but I'll have to wait to get more time to develop the zooming text scroller.