123
-=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- (c) WidthPadding Industries 1987 0|693|0 -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=- -=+=-
Socoder -> Retro Coding -> Local bitmaps

Posted : Tuesday, 17 August 2021, 04:03
AndyH

Local bitmaps


Day job work has been insanely busy which has dampened all enthusiasm and energy for coding for fun but I've started to get into the groove again writing a new library for TRSE that will allow some enhanced games on the unexpanded Vic.

I've previously made a built in Library for trse called vbm or Vic bitmap mode. This uses a feature of the Vic that let's you fill the screen with double height characters and leaves just enough memory to redefine them all to make a bitmap display out of them. It works really well and allows pictures, software sprites and effects. Think ZX spectrum style, with colour clash and everything (although there is also a multi colour mode). Really flexible and allows for more modern looking 8bit games (1984+) at expense that you really need a memory expansion to allow for some game code and data.

This new library is a similar idea but instead of the whole screen, it creates smaller local bitmaps where you want to place a sprite image. Lbm or local bitmap mode. It has its limitations compared to vbm but a couple of advantages.

It only needs as much memory for the support routines and the local bitmap data you wish to use for each sprite. As such it will be possible to create a an unexpanded game.

It also does not need the double height mode, so colour resolution is per 8x8 character instead of 8x16.

So what am I going to do with this library? I have three ideas I may be able to fit in unexpanded, or go a bit bigger for more levels.

1. I have a simple llama game that might fit unexpanded Vic.

2. A game I designed for mobile called the sky is falling could also fit unexpanded. Stu did a c64 version a couple of years ago. Basically Vic 20 blitz turned upside down.

3.blockman gets 20 would be a perfect use of this library for some nice smooth movement but likely be an expanded game to allow for a number of designed levels.

That's what I'm up to right now. It's nice to feel like I can make something creative again even while the day job is hyper.

-=-=-
Andy H
8-bit games at www.hewco.uk
Cartoons at awful.ovine.net
Ovine at ovine.net
Posted : Tuesday, 17 August 2021, 04:09
Jayenkai
That sounds like an awful lot of hard work, but I'm glad it's worked out, so far.
I'm nowhere near familiar enough with the Vic to know how complicated it must've been.

Good luck getting a nice game out of it!

-=-=-
''Load, Next List!''
Posted : Tuesday, 17 August 2021, 06:55
AndyH
Not a lot of work, beyond figuring out a good approach for the coding interface of the unit and the brain melt on one evening where everything turned into gibberish until I woke the next morning and realised that.

But yes, very Vic and Turbo Rascal and interest will vary. I'm really enjoying this sort of stuff. I will move onto the cpc either later in the year or next, as that was my second home computer I have many fond memories of good mode 0 games and I'd like to scratch that itch.

Best I ever got on the cpc though was a one level basic demo of Doctor Who's tardis and Tom Baker walking around it with a bit of z80 assembler I'd put together using ADAM on tape, and a very nice supportive rejection letter from the BBC that they weren't into publishing computer games. Ha. Wish I still had that, I thought it looked great at the time but I bet that's rose tinted spectacle talk. 😊

-=-=-
Andy H
8-bit games at www.hewco.uk
Cartoons at awful.ovine.net
Ovine at ovine.net
Posted : Tuesday, 17 August 2021, 07:00
Jayenkai
Would love to have seen that!