Since the last demo reused the graphics of the previous one (with improved quality and additional effects, thanks to the extra alpha channel), the latter didn't look that good anymore, so I decided to rework it to produce a more meaningful and interesting result. I just released it, so who wants to try in on their machine can get it from https://retream.itch.io/ptdq as usual.



LAYERS

Common:
* PTDQ system
* RGBWa color model
* 320x256 visible dots
* interleaved bitplanes
* horizontal and vertical scrolling

Background:
* 336x272 dots
* maximum 256 colors

Foreground:
* 672x576 dots
* maximum 81 non-transparent colors
* 8-bit alpha per base color

NOTES

* Both the layers reside in CHIP RAM.
* The layers use 6 bitplanes in all.
* If the foreground had not used 100% transparent dots, its maximum number of colors would have been 256.
* The foreground mode is changed by writing a whole 24-bit palette to the COLORxx registers with the CPU during the vertical blanking. The required palettes are pre-calculated at startup.
* The Copper is idle most of time (but if the staggered lines are on, it performs a wait and a write for each visible rasterline). The Blitter is idle.
* The texture is 512x512 dots and gets scaled and rotated onto a triple-buffered 128x128 dots raster.
* The raster gets rendered onto the foreground while racing the beam by means of PTDQ_DoC2P_R() when, at the end of a frame, it is found to have changed (so, at most 50 times per second, even if the fps limit is off).

PERFORMANCE

On a stock Amiga 1200, the speed is about 17.5 fps.
On an Amiga 1200 equipped with a Blizzard 1230 IV mounting a 50 MHz 68030 and 60 ns FAST RAM, the speed varies between 80 and 94 fps.
The fps fluctuation depends on the fact that the fetching of the texture dots is more of less friendly to the CPU data cache according to the scale factor and the rotation angle.

I have just released yet another demo (months ago I had shown a video, but I had not released the program itself):



The terrain is rendered by means of perspective-correct, wrap-around texture mapping. The city is rendered by means of solid bitmap zooming. The UFO is rendered by means of zero-keyed bitmap zooming. The screen uses PTDS, is 319x200 dots and employs the RGBWa color model.
On a stock Amiga 1200, the speed varies between 19 and 23 fps. On an Amiga 1200 equipped with a Blizzard 1230 IV mounting a 50 MHz 68030 and 60 ns FAST RAM, the speed varies between 67 and 80 fps. The fps fluctuations depend on the fact that the size of the UFO goes from very small (thus requiring only a few RAM accesses) to very large (requiring a lot of RAM accesses).

Download: https://retream.itch.io/ptds

I made this PTDS proof-of-concept program many months ago, but I couldn't bother releasing it until today.
It produces an effect of movement over a variable terrain. The terrain is rendered by means of perspective-correct texture mapping, according to a looping sequence of textures (Texequencer = Textures + Sequencer), on a triple-buffered 319x200 PDTS screen, using the RGBW color model.
Apologies for the dull textures :p



NOTES
* On a stock Amiga 1200, the speed alternates between 26 and 27 fps.
* On an Amiga 1200 equipped with a Blizzard 1230 IV mounting a 50 MHz 68030 and 60 ns FAST RAM, the speed alternates between 89 and 90 fps.
* YouTube's encoding degraded the quality.

Download: https://retream.itch.io/ptds

I pushed the dual playfield a bit further: 256+256 colors, plus 8-bit alpha per color component value, plus 2-bit alpha channel.



LAYERS

Common:
* PTDQ system
* RGBWa color model
* 320x256 visible dots
* interleaved bitplanes
* horizontal and vertical scrolling

Background:
* 336x336 dots
* maximum 256 colors

Foreground:
* 672x576 dots
* maximum 256 colors
* 8-bit alpha per color component
* 2-bit alpha per pixel

NOTES

* Both the layers reside in CHIP RAM.
* The layers use 8 bitplanes in all.
* The foreground mode is changed by writing a whole 24-bit palette to the COLORxx registers with the CPU during the vertical blanking. The required palettes are pre-calculated at startup.
* The CPU is idle most of the time. The Copper is idle most of time (but if the staggered lines are on, it performs a wait and a write for each visible rasterline). The Blitter is idle.
* YouTube's encoding degraded the quality.

New demo available at https://retream.itch.io/ptdq as usual.

@328gts

Thanks! I don't plan to make another demo. I'm trying to conceive a new original game that makes use of PTDQ/PTDS.

New experiment with PTDQ: dual playfield with both layers scrolling freely.



As usual, available from https://retream.itch.io/ptdq.

Fun fact: the foreground layer is triple-buffered, but that's a complete waste as no graphics rendering is performed; the reason is that the initial 5% was made months ago, but I got around to make the rest only now that my right arm is immobilized due to injury: it was just too much of a chore to write more code and to create more assets using just the left hand - and I'm not even left-handed (even just typing this is driving me nuts)!


LAYERS

Common:
* PTDQ system
* RGBWa color model
* 320x256 visible dots
* interleaved bitplanes
* horizontal and vertical scrolling

Background:
* 336x336 dots
* maximum 256 colors

Foreground:
* 672x576 dots
* maximum 81 non-transparent colors
* triple buffer


NOTES

* Both the layers reside in CHIP RAM.
* The layers use 6 bitplanes in all.
* If the foreground had not used 100% transparent dots, its maximum number of colors would have been 256.
* The foreground mode is changed by writing a whole 24-bit palette to the COLORxx registers with the CPU during the vertical blanking. The required palettes are pre-calculated at startup.
* The CPU is idle most of the time. The Copper is idle most of time (but if the staggered lines are on, it performs a wait and a write for each visible rasterline). The Blitter is idle.
* The triple buffer was implemented for glitchless rendering of graphics, but eventually no rendering was added.
* YouTube's encoding degraded the quality.

@Tuvok

Quote:
Your screenshot is all wobbly: I hope it's just a matter of grabbing and not how you actually see the game.
Anyway, if you press [F1] any time a screenshot of the interal graphics will be saved to T: (for completeness, [F2] captures a screenshot of the graphics actually shown, instead; these are game features).

@328gts

Thanks for choosing another of my games for the compo!


@AmigaOldskooler

Quote:
Well, it's an obscure game that never got much exposure, so not many know it.

Quote:
Glad you like it!

A little backstory...

This game was born during the development of BOH: I thought I'd use the BOH skin system(*) and rotation routine (it's software-only) as the core of another game and somehow came up with the game concept. As a consequence, the development of BOH halted for the time needed to make KOG (2 or 3 months). Since I felt guilty and I really should have resumed the work on BOH, instead of making new music (which would have required additional time), I decided to reuse the music of MAH, so what you get to hear are snippets sampled from the original SID music.

(*)Initially KOG was 100% skinnable, but when I overhauled it in 2017, 9 years after the initial release, I dropped that.

@Tuvok

Quote:
Good luck with your next attempts!

Quote:
No worries: it was not a single case but 35, and not downloading is not a problem - in other words, it wasn't you ;)
Just for the record: they were not hacking attempts.

Congratulations to walkero and thanks to all those who participated and especially to 328gts for choosing Blastaway once again!
(Unfortunately, I just couldn't manage join the party :/)

@walkero

No problem, I did see your triple smile! I just seized the chance to let everybody know that care must be taken to not run out of keys.

@walkero

Quote:
No bug, you must have wasted a key by opening unnecessarily a door along the way ;)

@all

My pleasure!


@Maijestro

Quote:
The thanks must be shared with those behind qemu and with 328gts, who tested the games ;)

The AmigaOS 4 versions of Blastaway, BOH and KOG were a bit behind with respect to the Windows versions due to the fact that at some point my AmigaOne stopped working and I could no longer compile them. Lately I finally got around to install qemu and produce updated executables.
The games are available for pay-what-you-want (even as little as 0) download from https://www.retream.com / https://retream.itch.io as usual.
Many thanks to 328gts for testing the executables on his X1000.

Blastaway v1.6
* Avoided redundant operations when a video/pixel mode change requires a re-initialization of the screen/window.

BOH v2.5
* Fixed resuming of the sounds of tiles clusters (e.g. moving floors) after unpausing the game, which caused them to remain always active at maximum volume.
* Removed contact email address from executable.

KOG v2.10
* Avoided redundant operations when a video/pixel mode change requires a re-initialization of the screen/window.
* Removed contact email address from executable.

COUNTERNOTICE

The change was of no use, as other 5 fradulent purchases followed (they're 35 in all now). Hence, I have restored the URL https://retream.itch.io/gemdalus now.

NOTICE

Due to the continuing fraudulent purchases, I changed the URL of Gemdalus to https://retream.itch.io/gemdalusaga.
The game page is gettings hundreds of hits per day, but in the last 2 days only 2 fraudulent purchases succeeded, so itch.io must have set up a filter. If anybody tries to buy the game but can't manage to, please let me know so that I can report it to itch.io.

It's just thieves doing their job in the ways that the modern world offers them :(

@328gts

Yes, but the people scammed are no less than 28. And the objective is not the game, but retrieving the name and address of the people scammed.

@328gtsQuote:
I wish it were just nonsense! This is clearly somebody who stole the codes of multiple (28 so far) credit cards and is abusing them. For some reason, it seems that Gemdalus is the only game being exploited (no other game of mine is affected and, moreover, I've asked on itch.io, but got no response).

@khayoz

Quote:
Oh, your donation was really generous! Thanks a lot! Check out your email for the download key ;) I wish you lots of fun with the games!


@all

Please note that the method of buying another game and adding a donation for Gemdalus had to be dropped because it turned out that Gemdalus could not be downloaded even by who already had a key (see post #21).