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Old 01 April 2013, 23:03   #2
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Join Date: May 2001
Location: Auckland / New Zealand
Posts: 3,139
Post Rink a Dink end credits

you have been watching



L E M O N - P O I N T

an OCS trackmo for the
oldschool demo competion at


29th March - 1st April 2013
Saarbrucken - Germany



Original Soundtrack

The Redux Remix

- second track -

Gone 4D
- ending track -

Code & Design

- also starring -

The Red Faced Monster
Paradroid 2.0

This Lovely Lady
Mrs Paradroid

Hi there! Paradroid here, but I don't really have time to write much as the deadline for the compo has already passed. Luckily I already prepared a run down of all the effects in this demo, giving a short explanation of the techniques and tricks used, so at least you're not now viewing an empty screen... : )

(left mouse button to pause)

Opening Logo Zoom
Same as the original RAD, but with a reverse of direction which leads into a brief mosaic effect. The zoom is a simple enough trick, with each line displaying a coarsely pre-scaled image with the smooth steps in between achieved by spamming the hardware scroll register across the screen. The hardest part was making it work with both real hardware and WinUAE as the DMA timings are slightly different and I'd often get gaps in one or the other.

Star Zoom
Not much to see here, but I spiced up the transition a little by adding a feedback effect to give the impression of particles.

The first thing I coded for the demo. The original twister used pre-calculated points that were plotted and then filled, the shading was probably the same. Not sure why I did it that way as the hardware is plenty fast enough to do it realtime, in fact after recoding it I had so much time left over that I made it solid. All was great until I ran it on a real Amiga and it was hellishly slow – turns out I wasn't running WinUAE in cycle exact mode so had to recode it. Lesson learned and luckily I had been a bit lazy and had plenty of scope for optimisation to get it back into 50Hz, phew!

Rink A Dink: Redux
Similar to first time around, although I made the logos appear in the correct order this time. The 'A' also now has a transparency effect. The intention was
to have a warping lens effect here, but I ran out of time. Most of the coding time was sunk into making the Redux logo fall into place as it required some convoluted clipping of the RAD scene.

Lemon Image
This was an abandoned effect, but I had a second to fill so used it for the transition to black. It's used again for a different transition later on...

Rewrite of the original plasma effect, but shortened to improve the pacing. The second effect is a simple variation that blends two plasmas together.

Glenz Vector
I just had to have some classic Celebrandle vectors. The object that zooms into the scene is drawn using a couple of methods as the blitter wasn't quick enough to draw and fill three overscan bitplanes at 50Hz. The front facing and inner white polygons are drawn using the blitter as normal, but the bitplane for the overall shape is achieved using the copper to select bitplane spans.

When the clipping kicks in I switch to pure blitter rendering, but this time there are four bitplanes. The rendering is copper controlled while the CPU is running flat out doing the clipping and generating the blitter information. I'd only seen this effect done properly (i.e. all 4 bitplanes clipped) in an A1200 demo, so I was very happy when I finally got it working at full speed on a vanilla A500.

Vertical Bars
I had this in mind years ago after seeing an ident sequence on TV. I found a rough version of it I'd coded up for a demo called DMA Dream and worked from that. It actually looked a little dull as an effect, so I made the light source dynamic and introduced some stippling to achieve the illusion of extra shades.

Colourful Vertical Bars
More old code revamped, but it's quick and I needed to buy some time for preparing the next sections of demo. The bars are a realtime generated HAM image and there were going to be a few more patterns, but it was a bit dull to see after the previous effect so I stuck to a single spinner and made it move on as soon as possible. Apologies for the programmer colours, I left it until too late to them properly, oops!

Star Field
Nothing special with just a couple of thousand stars, but again this is because I needed to leave over some CPU for preparing the next part. You may have missed that the final larger star balls to fly out of the screen are the same colours as the balls in the next sequence.

Big Balls
A world record? I actually found out about an OCS demo that had already done 8 after finishing this effect, so I went back and redid it to get an extra one in there. This was all done with bitplanes which is why I was able to add a translucency effect too, unlike other demos which use sprites for the balls at the back. A think I can push the number even higher, but that will be a task for another demo.

Colourful Image
What a pain in the ass this was! It may look like a simple image, but it's HAM mode and changing it's palette every line to get even more colours out of it. Having that and then also stretching it down the screen should have been easy enough, but WinUAE does some strange things when you use HAM and a none black background, so lots of messing about was needed, grrrrr!

It was getting close to the deadline for completion and there was no time for anyone to pixel a proper picture, so I opted for a photo of my kid instead. His face painted to look a little like the monster that featured in the original RAD, although you probably wouldn't have noticed until reading this : )

Similar to the original in that it can display 4096 colours, but I managed to more than double the vertical resolution and add a 50Hz offset flicker to give the impression of increased horizontal resolution too. I had some free frame time so chucked in a simple warp effect to finish it off. The tricky part of this effect was to the fade in from white at the very start of it. The original used pre-faded images for this, but I didn't have enough memory this time around, so I instead generated a small animation in the background and played that back – a bit over the top for what is only about 8 frames, but it looked better for it.

So I actually remembered to put greetings in a demo for once! There are several thousand dots being plotted behind the scroller, which isn't a record, but that's the price of having other stuff going on at the same time.

The “Heart of Melon” animation is just a little joke dating back to some of the trolling/trash talk that went on between our groups back in the day. No harm is meant by it, in fact they were one of my favourite groups and some of us were friends and remain so to this day. Maybe they should make another OCS demo too so they can send a reply – I can but dream! : )

Dot Vector
As seen before in Kefren's Desert Dream. Nothing too clever going on here, I just wanted something to transition to the next effect that wasn't just a simple fade and I had an in progress version ready to work from.

Clipping/Morphing Vectors
An effect lifted directly from Booze Design's C64 demo “Edge of Disgrace”, which explains the little message that appears at the bottom of the screen ; ) After I finished it I was well within 50Hz so added a stipple layer that allowed for much smoother lighting (when viewing on a CRT display).

Lit & Clipped Icosahedron
A continuation of the sequence from EoD, but I added some full colour (i.e. not RGB) light sources. It's based on the code for the clipped glenz, so there is nothing more to explain.

Filled Balls
These are visually the same as the balls I created for Anarchy's Deja-Vu demo, but a little bigger and with an extra ball thrown in. The balls at the front are rendered with bitplane spans, while the furthest is constructed from sprites. The trick was to animate it in such a way that the smallest ball was never over a certain size, otherwise it couldn't be represented with sprites. I could have made them even bigger, but opted to keep the preferred to keep the noisier fill pattern (see Desert Dream for what they look like without this) and avoid losing two sprites as happens when using overscan mode.

Pretty much identical to the original RAD but with a few tweaks to allow the top and bottom to animate at the same time. I did rewrite it to handle more colours in zooming logos, but needed the frame time for background tasks relating to the next effect.

The original RAD stored these on disk and just played them back. I planned to do the same with Redux but we ran out of diskspace towards the end of development and the tunnel data was the stand out candidate for culling. It took a couple of days to rewrite the effect but eventually got it quick enough, saving the second music track from being removed instead, YAY! : )

The End
Nothing much to say, it just seemed like a fitting end to a demo that has been an absolute joy to program. Most of my working day is spent making API calls to hardware that does everything for you, so to come back to a platform that lets you get so close to the metal and have some fun has been a truly wonderful experience.

Thank you for watching.

See you in the post-party AGA fixed version!

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