Hey guys,

I'm working on an Allegro 5 game and have some huge memory problems. The game is a Roguelike Shmup where every visual asset is made from ASCII characters, this means that every visual element has originated from a .ttf font file and a series of chars or strings.

So from the GIF above, it all looks good. The game also has a level generator and the ability for a player to move around and collide with the walls, and there's even enemies and items to interact with. The problem lies when I saw it running in the Windows Task Manager:

{"name":"CG-p5POXIAAe_Wz.png","src":"\/\/djungxnpq2nug.cloudfront.net\/image\/cache\/8\/f\/8f49b86905ebb7e1bd1be336944d60ed.png","w":596,"h":87,"tn":"\/\/djungxnpq2nug.cloudfront.net\/image\/cache\/8\/f\/8f49b86905ebb7e1bd1be336944d60ed"}

I decided to let it run through Visual Studio's Memory Usage Profiler to see where this 1.8GB RAM usage is coming from, and this is what I find:

{"name":"CG-xjUiW0AAe1Xa.png","src":"\/\/djungxnpq2nug.cloudfront.net\/image\/cache\/4\/8\/48a35912ce2facca0c5ba77e7a151b06.png","w":596,"h":77,"tn":"\/\/djungxnpq2nug.cloudfront.net\/image\/cache\/4\/8\/48a35912ce2facca0c5ba77e7a151b06"}

So it appears a lot of memory is being used in allocating and destroying data within the allegro library.

My best theory so far as to why I've got this huge memory load is because of the way I'm creating the visual assets. In order to make it possible to create more visually interesting assets and reduce the amount of text rendering calls, I instead create and render bitmaps. The string of characters are then drawn onto the bitmaps in a process like this:

This way each object, including a Particle System, will use a bitmap each. instead of one to many text draw calls.

So this will probably be obvious, but considering you know the framework more than I do, I was wondering if you have any advice for what could be causing the issue based on the above evidence, and any way I can do it better so it won't require at least 2GB of memory to run.

Do you have a memory leak? Are temporary assets not getting freed?

Are you doing anything sketchy, like storing thousands of individual bitmaps for every variation of your fonts when you could just modify them as you draw? (ala a complete font stored for the color red, instead of the normal white font that gets colored red as it is drawn.)

It's also possible you've got a huge bitmap overhead by storing tons of tiny bitmaps (each with their own header data), when you could be storing them all on a few textures and using sub-bitmaps to draw them. (Someone who knows A5's allocation strategy chime in. It certainly doesn't automatically group small sprites onto single textures, does it?)

Ala this would be a single texture/bitmap in memory:

{"name":"ASCII-vga.gif","src":"\/\/djungxnpq2nug.cloudfront.net\/image\/cache\/f\/3\/f37148e48cd3c467e6b72630ecda2e87.gif","w":290,"h":160,"tn":"\/\/djungxnpq2nug.cloudfront.net\/image\/cache\/f\/3\/f37148e48cd3c467e6b72630ecda2e87"}

And you would only draw the specific coordinates, or use sub-bitmaps to draw it.

Do you clean up your bitmaps after use with al_destroy_bitmap taking care not to leak any?

Also , in Allegro 5 you can get scaling for free using transformations. You don't need a buffer bitmap, just set a scaling transform and then draw to the screen directly.

Solved the issue, and god this is embarrassing.

Turns out I completely missed the draw function of the TitleState scene, which had this line:

ALLEGRO_BITMAP* UILayer = al_create_bitmap(1280, 720);

It was not being used at all, and was being called around 120 per second. -_-

So now the game runs at a more reasonable 33MB of memory.

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