GameMaker: Microtester

Performance tester/comparator for GameMaker
And other reasons to avoid overusing reflection

On this fine day I have published the project that I use to compare relative performance of different approaches to algorithms. It aims to get a few things right with this:

  • Tested scripts are re-shuffled between runs to lower execution order/CPU cache bias.
  • Script call time can be excluded if you are comparing approaches rather than actual scripts.
  • Easy to use - you add scripts that you want tested to the project, specify how you want them to be called, and that's it.

The project can be found on GitHub.

GameMaker: Simplest possible instance methods

A tutorial about implementing instance methods in GameMaker.

After seeing series of increasingly strange uses of "user events" in GameMaker games for object-bound actions, it came to my attention that most people are only vaguely aware of other ways of doing things, so I decided to write a small blog post on the matter.

There are many uses for these - for example, you might want to have a "take X damage" method on your enemy objects so that it can be varied depending on requirements - some enemies might just take damage, some should retaliate on being hit, some might have a fancy damage reduction formula. Being able to comfortably define/redefine methods on per-object-type basis can help a lot.

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Variable references in GameMaker

A tutorial about variable references in GameMaker.

Sometimes you might want to pass an instance variable by reference rather than by value - to have a script modify instance variable(s) passed to it without having to return them, or have an instance save a reference to variable(s) that it should change on other instance, or doing anything else that would usually imply using pointers.

But it might seem like GameMaker does not support such things... or does it? Well, we'll make it.

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Simple intersection checking between rotated rectangles and circles/points

(click to interact)Intersection checking between rotated rectangle and point/circle
(mouseover/click to play GIF) (click and drag to adjust rectangle size/position/rotation; distance to a circle is shown)

Suppose you have a rotated rectangle and a basic shape that rotation doesn't matter for (such as a point, circle, or a line segment), and you want to check whether the two are intersecting - be that for collision handling, hit testing, or whatever else.

On a glance this might seem like a bother because things are rarely too simple with rotated rectangles, but in this case it isn't - because you can "unrotate" the rectangle.

This small post is about that.

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2d pivot points explained

(click to interact)Explaining pivot points
(mouseover/click to play GIF) (spaceship graphic by Kenney)

Nowadays, most development tools provide ways of setting pivot/center point for imagery - that is, the relative point around which the image will rotate and usually be positioned relative to.

However, ability to define multiple pivot points per image remains relatively uncommon, despite being something that you want to have projectiles fire from a correct point of a sprite, display weapons/attachements at right relative points, or do anything else that demands relative offsets.

This small post is about that.

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GameMaker: Beautifying/pretty-printing JSON

Partially related to an earlier blog post about minifying JSON (which I had just updated), but adressing a different problem - sometimes, rather than trying to make your JSON more compact (and, consequently, less readable), you may want to make it more readable - be that for your own debugging purposes, or not to scare players away from files that they are allowed to edit.

Take Nuclear Throne, for example. The save file is a big nested JSON structure, and, needless to say, you aren't getting around passing it through an external JSON beautifier if you want to be able to make sense of it:

With a bit of string processing, however, you can have it printed out nicely readable:

So this post is about that.

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Converting key code to key name and vice-versa

(click to interact)Converting key code to key name and vice-versa
(mouseover/click to play GIF) Interactive demo (if JavaScript is enabled)

This is a small post about how to convert key codes to key names and/or convert key names to key codes. Comes with sample code for GameMaker and a generic version.

Mostly published because it covers majority of common and semi-common buttons.

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GameMaker: Simplest possible custom timelines

This post is about implementing custom timelines in GameMaker.

Admittedly, timelines remain to be one of the more dated features of the software, designed for a specific purpose and kept in their original form for compatibility.

Time to time you'll see someone stopping by on forums to write a big rant about how these are a mess, do not do what they expect them to do, and should be redesigned immediately.
People will usually also argue that doing these things by yourself is too hard.

Since it is far easier than people claim, I decided to write a post about this.

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