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General Category => Programming => Topic started by: mr_lou on 06:18, 18 June 17

Title: Idea for multicolour MODE 1 game
Post by: mr_lou on 06:18, 18 June 17
Was it "MODE 5" it was called (by some)? The MODE 1 resolution, but with more colours due to some heavy CPU demanding trickery.

I remember hearing that doing a game in this mode would be very difficult, because the changing-colour part is very CPU demanding.

But what if the game is a port of a Game & Watch game?
Like "Mario's Cement Factory?"
https://i.ytimg.com/vi/CgKdWOqT3Ls/maxresdefault.jpg

A game like that only requires a framerate of like 2-3 per second. Maybe that would be an interesting project to someone?

Idea hereby shared.
Title: Re: Idea for multicolour MODE 1 game
Post by: AMSDOS on 11:17, 18 June 17
Not sure because the Mario's Cement Factory I remember (and that was a hand-held LCD game my brother had before our folks got us an Amstrad), has Mario going up and down the screen & the cement has to be filtered down to the Cement Truck, if the Cement overloads it flies down the screen knocking out one of the guys from the Cement Truck, I think the handle you use to channel the cement down also moves. An animated sequence for the  Elevators would probably work though as it would just be a ink palette switch.


But I'm not totally sure what you had in mind. I was thinking of this Multi-coloured Modes program from AA17 Type-ins (http://cpcwiki.eu/index.php/Amstrad_Action_February_1987_Type-Ins) which works by splitting half the screen into separate colours to give it the appearance of more colours. Otherwise I would love to see a Cement Factory game on the CPC because I don't think I've seen one.
Title: Re: Idea for multicolour MODE 1 game
Post by: mr_lou on 14:32, 18 June 17
I'm not talking about adding animation. I'm talking about making a Game & Watch port. Meaning, we're only talking about 2-3 fps.
Looking at the screen of the colour version (tabletop version), it'll basically be 3 sets of colour-maps:
One with black background + white + red + orange (for Mario)
Another with black background + white + blue + light blue (for the platforms etc)
A third with black background + white + green + lime green (for the trucks - will be missing a blue though, so the frontwindow will have to be white)
These 3 colour-maps should then be applied to areas on the screen.
In the beginning of this video we can see all the "sprites" and their colour-maps:
https://www.youtube.com/watch?v=UxopKhzS_O0
Title: Re: Idea for multicolour MODE 1 game
Post by: andycadley on 17:34, 18 June 17
The game is probably simple enough that you could set aside enough frame time for colour effects. Which means it's less about the overall concept and more about how quickly you can make the necessary palette swaps. It takes a few "characters" to actually set up and change a single palette entry, so even setting aside black and white as consistent colours it might need some deep analysis of the actual display to figure out where you can change colours "ahead of time" to get the desired on screen effect without upsetting the display. There are likely moments where you'd have to at least slightly redesign/recolour graphics to give you a bit more of a chance but I wouldn't say it was impossible.
Title: Re: Idea for multicolour MODE 1 game
Post by: mr_lou on 18:09, 18 June 17
As far as I can see, the colour-palette swaps will always occur the same places. The screen will be divided into areas, and each area will always contain the same colour-palette regardless of what the state of the game currently is.
Title: Re: Idea for multicolour MODE 1 game
Post by: andycadley on 19:02, 18 June 17
The areas you want to be certain colours are in the same place, but you cannot swap two inks at the same time, so there is more subtlety than just defining square regions. You have to consider where you can start and end colour transitions without it causing visible artefacts on screen. Sometimes you might be able to transition a colour slightly earlier or later and other times you might need to tweak the graphics to get the overall result you want.
Title: Re: Idea for multicolour MODE 1 game
Post by: mr_lou on 19:28, 18 June 17
Oh, I had no idea you could only switch one colour at a time.
Title: Re: Idea for multicolour MODE 1 game
Post by: andycadley on 22:41, 18 June 17
If there was one feature I'd have killed for on the Plus machines it is a "shadow" palette you could swap in with one write. But alas we have to deal with what we have. That said, I'm still convinced it might be do-able, or at least something along those lines, because there is a reasonable amount of spacing around many of the changes. It would certainly be an interesting challenge to take on.
Title: Re: Idea for multicolour MODE 1 game
Post by: AMSDOS on 11:35, 19 June 17
Quote from: mr_lou on 14:32, 18 June 17
I'm not talking about adding animation. I'm talking about making a Game & Watch port. Meaning, we're only talking about 2-3 fps.



Neither was I, but if you're looking to use the INK palette with a program like the one I suggested above, I think you'll still run out of Ink Palette, but I don't know about that. Kong Strikes Back uses something like this I think with a Split in Screen Modes to make the Control Panel Appear in Mode 1, though there's a Colour Split around that which includes the bottom area of the screen in the Playing area, but getting back to Mario's Cement Factory with Mode 1 I cannot remember how many positions the Elevator moved until it got back to the original position on my brothers LCD game, unlike your screen shots which include colour, my brothers game was B&W with Coloured in Platforms (Red I think) & the Cement Trucks were in Colour too, Using the type-in I mentioned earlier gives you 2 colours for the top & bottom of screen, so in theory alternating INKS 1 & 2 to simulate the movement of the Elevator, that would leave INK 3 for your character, I guess to move the Cement down into the Truck some sort of trick INK animation to print the Cement running down in the right INK with the Elevator.


Unfortunately I'm unsure.  :-[
Title: Re: Idea for multicolour MODE 1 game
Post by: mr_lou on 12:59, 19 June 17
I don't want to use the inks to simulate animation.
Title: Re: Idea for multicolour MODE 1 game
Post by: arnoldemu on 13:58, 19 June 17
Quote from: mr_lou on 12:59, 19 June 17
I don't want to use the inks to simulate animation.
No need. Two ways:

1.
Turn on/off the border: Use R8 on type 0, 3 and 4 and R6 on type 1. nothing can be done on type 2. :(
Make border the same colour as pen 0, then you can disable it to hide sprites. This allows full colour mode 1 sprites. Each border on/off takes 4us or 32 mode 1 pixels. So you need a large border around them.

2. Use colour changes, but because each change requires 4us, you can only really do it monochrome (i.e. change just 1 pen). This can be done on all crtc types.

For all of these you can alter the timing per line and within the line to offset some sprites if you need to.



Title: Re: Idea for multicolour MODE 1 game
Post by: andycadley on 21:30, 19 June 17
I suspect the game is simple and slow enough that you could just XOR sprites on/off the screen as needed, without having to do anything particularly fancy. Whether you can quite get the colours as desired is the real challenge.
Title: Re: Idea for multicolour MODE 1 game
Post by: AMSDOS on 12:21, 21 June 17
Quote from: andycadley on 21:30, 19 June 17
I suspect the game is simple and slow enough that you could just XOR sprites on/off the screen as needed, without having to do anything particularly fancy. Whether you can quite get the colours as desired is the real challenge.


I would of thought so, Easi-Sprite Driver would have it spinning off it's head though it's that fast, earlier on I coded something to simulate 2 multicoloured objects alternating between each other in Mode 1, though I don't know how that could apply for this game. One of the Colours used in that though was the same, but the program was clearly alternating, I might of been using a different Ink colour between the 2 objects though I recall altering the PAPER too to give me back a Colour somehow.
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