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PeteCotton

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Joined: 13/08/2020
Location: Canada
Posts: 527

Posted: 12:09am 31 Mar 2025

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I know it's been a while since I've given an update on this project - but that doesn't mean I haven't been busy with it. Quite the opposite, there are some huge changes coming down the pipeline (that I'm quite excited about). But in the meantime, we had a discussion on a separate thread about using a data structure type variable within MMBASIC.

Original thread here: https://www.thebackshed.com/forum/ViewTopic.php?TID=17794&P=3

Up until now I've been using arrays to store game data, and using Constants to make them a bit more readable.

For example:

DIM FLOAT Ships(100,18)
CONST SHIP_TYPE = 1
CONST SHIP_X = 2
CONST SHIP_Y = 3
CONST SHIP_ANGLE = 4
CONST SHIP_SHIELDN = 5
CONST SHIP_SHIELDE = 6
CONST SHIP_SHIELDS = 7
CONST SHIP_SHIELDW = 8
CONST SHIP_SHIELD_MAX = 9
CONST SHIP_HULL = 10
CONST SHIP_ENGINES = 11
CONST SHIP_WEAPONS = 12
CONST SHIP_SENSORS = 13
CONST SHIP_LOGIC = 14 ' 0=None, 1=Attacking, 2=Fleeing
CONST SHIP_LOGIC2 = 15 ' Used as part of the logic
CONST SHIP_POWER = 16
CONST SHIP_DX = 17
CONST SHIP_DY = 18

So to reference the Angle of Ship 15 you would use

Ships(15,SHIP_ANGLE)

The realisation that we can use dots ('.') in variable names in MMBasic allows me to use a much neater solution where I define multiple arrays that look very similar to structures in other languages.

DIM FLOAT Ship.Type(100)
DIM FLOAT Ship.X(100)
DIM FLOAT Ship.Y(100)
DIM FLOAT Ship.Angle(100)
DIM FLOAT Ship.ShieldN(100)
DIM FLOAT Ship.ShieldE(100)
DIM FLOAT Ship.ShieldS(100)
DIM FLOAT Ship.ShieldW(100)
DIM FLOAT Ship.ShieldMax(100)
DIM FLOAT Ship.Hull(100)
DIM FLOAT Ship.Engines(100)
DIM FLOAT Ship.Weapons(100)
DIM FLOAT Ship.Sensors(100)
DIM FLOAT Ship.Logic(100)
DIM FLOAT Ship.Logic2(100)
DIM FLOAT Ship.Power(100)
DIM FLOAT Ship.DX(100)
DIM FLOAT Ship.DY(100)

This makes for much neater code, as shown below:

SHIPS(id%,SHIP_ANGLE) = SHIPS(id%,SHIP_ANGLE) + 5
IF SHIPS(id%,SHIP_ANGLE) >= 360 THEN SHIPS(id%,SHIP_ANGLE) = SHIPS(id%,SHIP_ANGLE) - 360

becomes

Ship.Angle(id%) = Ship.Angle(id%) + 5
IF Ship.Angle(id%) >= 360 THEN Ship.Angle(id%) = Ship.Angle(id%) - 360

So I've now gone through the code and changed it over to this method of variable, and it is a lot more readable.

Mixtel90

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Joined: 05/10/2019
Location: United Kingdom
Posts: 7499

Posted: 08:45am 31 Mar 2025

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That certainly looks a lot better. I think you've not been wasting time. :)

Mick

Zilog Inside! nascom.info for Nascom & Gemini
Preliminary MMBasic docs & my PCB designs

Volhout
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Joined: 05/03/2018
Location: Netherlands
Posts: 4854

Posted: 10:46am 31 Mar 2025

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Hi Vegipete,

What about

Ship.Angle(id%) = (Ship.Angle(id%) + 5) Mod 360

Volhout

PicomiteVGA PETSCII ROBOTS

PeteCotton

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Joined: 13/08/2020
Location: Canada
Posts: 527

Posted: 03:51pm 31 Mar 2025

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Mixtel90 said That certainly looks a lot better. I think you've not been wasting time. :)

Thanks!

Volhout said Hi Vegipete,

What about

Ship.Angle(id%) = (Ship.Angle(id%) + 5) Mod 360

Volhout

Wrong Pete

Non-vegie model of Pete here.

But yes, thank you - that is a very nice efficiency. I will apply it.

Volhout
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Joined: 05/03/2018
Location: Netherlands
Posts: 4854

Posted: 04:51pm 31 Mar 2025

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Oops…. Shame..

Sorry Pete

P.s. Is It really Needed to limit to 360? Maybe any angel can be use, and with 64bit floats you Will not easilly run into numerical limits within a normal game time of 1 million years..

…hours I mean.
Edited 2025-04-01 02:57 by Volhout

PicomiteVGA PETSCII ROBOTS

PeteCotton

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Joined: 13/08/2020
Location: Canada
Posts: 527

Posted: 05:43pm 31 Mar 2025

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Volhout said Oops…. Shame..
Sorry Pete

No need to be - Being mistaken for a user of such high esteem as VegiPete is a compliment!

Volhout said P.s. Is It really Needed to limit to 360? Maybe any angel can be use, and with 64bit floats you Will not easilly run into numerical limits within a normal game time of 1 million years..

…hours I mean.

Good point, however although it might not matter to the computer, limiting it to 360 makes it easier for my feeble brain to debug. There's quite a lot of relative angle work. e.g. your ship might be facing 270 degrees (West) and another ship might be South West of you, but it's facing 180 (South), so their aft and port shields are the ones that will get hit by your shot. That sort of thing. Not overly complex, but enough that I don't want to make things harder for myself

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