Improving the reliability of games created in GM v6x.

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Improving the reliability of games created in GM v6.

The release of GM v6.0 although a quantum leap in the capabilities of GM, is not without a price and the number of people reporting problems with GM games is at an all time high, so I thought that in this article I would address a few of the problems.

GM v6 was a radical change from v5.x and requires a more powerful computer system than before, particularly the graphics card, which needs to be quite powerful to cope with the changes.

The recommended requirements are at least:

16 bit high colour
800*600 resolution
8Mb of graphics memory (Not specified with earlier versions.)
direct X 8.0 or higher (DirectX 5 previously.)

No processor speed is specified.

The most common problems with GM v6 appear to be:

The game freezing while loading.
Graphics splitting or tearing.
The sound volume altering.
Game speed very slow.

Note that this article is not concerned with different/missing commands etc, from v5.x, these are just alterations to the program, not problems, READ THE MANUAL. It is also not concerned with registered/not registered features, as a wide choice of options is available to all users.

So to tackle the problems in order:

The game freezing while loading.
This problem although not new with GM v6, has grown worse, personally I find between a third and half of all games freeze before they finish loading.

At first I believed this to be linked to the amount of ram available, but after some experimentation I found that it is linked to the amount of video memory available.

While monitoring a problem game loading, all would be well until the graphics began to load. This can be proven by creating a game and increasing the amount of backgrounds graphics until the game freezes.
I found that when graphics to the size of 7Mb (Measured as bmp files.) were added to the game, it was sufficient to cause problems, despite my computer having a 16Mb graphics card.
In similar tests using v5.3, over 30Mb could be added before problems occurred.

So what can be done to help avoid this problem?

Naturally if you are creating a game that uses a lot of backgrounds and complex sprites simultaneously, there is a limited amount that can be done and it must be accepted that only higher spec machines will be able to run your game.
But with a less complex game, be careful not to check the preload textures option when adding sprites and backgrounds, as this uses up a considerable amount of video memory.
Only use that option on graphics that will be used continuously throughout the game, this method can cause a slight flicker as a needed graphic loads, but on higher spec machines this will be hardly noticable, because of their speed, while slower machines will at least be able to view your game.

Graphics splitting or tearing.

This is where tears appear in the graphics, usually around the perimeter of the screen.
I suffer from this problem myself and after mentioning it in the bug forum, Mark says its a monitor problem, rather than a computer problem and there isn't much you can do about it.
I have spoke to quite a few people with this problem and it doesn't seem to matter how new or old your monitor is, its the luck of the draw whether you are affected.
Of the three machines I have access to only one is affected, unfortunately that one is mine.

So what can be done?

A common cry in the forum is update your drivers, but I tried this and it doesn't appear to make any difference.
The only help I have found is to avoid using small background images that are tiled across the room, stick with larger images, of at least a quarter of the room size, also do not stretch backgrounds.
Of course this will not help with games made by other people, but it will ensure the widest audience for your own games.
The other alternative is to buy a new monitor. If you have just bought a new system and have this problem, I would suggest going back to your supplier and nicely asking if you can exchange your monitor for a different make.

The sound volume altering.

This seems to be a very widespread problem, its partly caused by people converting games they have started in v5.x to v6.0.
The sound system although far more sophisticated in v6.0, does seem to need setting up with more care and each volume setting should be set to complement the other sounds used.

The sound is not as universally consistent between computers as it was in previous versions of GM and of the three computers available to me, the sound plays differently on each computer, regardless of the quality of sound card installed.
It may be wise to add an option to your game to allow the independant setting of the volume of the background music and effects, by the player, as many commercial games do.

Game speed very slow.

This is not specific to v6.0 and can have quite a few causes and I will list some below:

The most common cause I see, is using a large room size and then scaling the room down to fit the screen, rather then resetting the screen resolution.
This is fairly easy to spot, if any text is on screen, it will look odd, to cure it just reset your screen to a higher resolution while playing the game and remember when creating your own game, if you are using a game room greater than 800*600, set the resolution in the options and also set the game to fullscreen.

Another common problem is for instances not to be destroyed as they leave a room, this slowly slows the game as resources are not freed and is most commonly seen in scrolling shooters.

Giving too many instances, too many actions to do, try to improve the way the game works.

Your computer is just too slow, sometimes there is no getting around it.

Its possible to set the games priority when you create it, but don't rely on this too much, as the effect seems to vary. Some people report their machine freezes or crashes, other people, myself included, report no effect at all, I find I can still run anything I want, with GM on the highest setting.
If you wish to use this feature, is probably wise to use the middle setting for the most compatibility.

Finally I would like to give what I think are reasonable specs for running GM versions.

GM v6.0, I can run this but with limitations, so a machine of my spec should be taken as the absolute minimum.

Win98 or higher
800Mhz
128Mb ram (256mb would be better, or more if running XP.)
16Mb graphics card (I would suggest 64Mb would be ideal.)
DirectX 8.0 ( I actually run 8.1, but 8.0 is the minimum.)

GM v5.x, All the v5.x versions ran on my machine with very few problems, and graphics cards seem to be fairly unimportant, I would suggest:

Win98 or higher
300Mhz
80Mb ram ( More ram would be better, as bigger games struggle to load.)
DirectX 5.0

GM v4.3 This was the best (In my opinion.) of the v4.x's and should run on almost anything, I believe that you could use Win95 with this version. I have used it on a 166Mhz computer, with 64Mb ram.