GameMaker: applying “with” to multiple objects

As you may know, GameMaker Language has a Pascal-like "with" structure:

with (value) { code }

but it's not exactly like the Pascal version. In GameMaker, it can take an instance:

var bullet = instance_create(x, y, obj_bullet);
with (bullet) direction = 180;

or an object type (and will apply the expression to each instance of it):

with (obj_bullet) instance_destroy();

This can be rather handy under the multiple circumstances.

However, initially the same block can not be applied to multiple values, and that's less handy.

Sometimes you can cheat by applying the expression to a shared "parent" type of objects, but that is not always the case (and can have side effects if there are more object types meeting the condition).

So let's consider your options for applying a piece of code to all instances of several types:

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On GameMaker: Studio’ game decompilation

On GameMaker: Studio' game decompilation

It seems that questions about whether (and if so, to what extent) GameMaker: Studio games can be decompiled are being asked at a constant pace, and yet there are still no resources to clear up these questions. So I've decided to make a small post on the matter.

If you are not familiar with what is this all about: older versions of GameMaker had produced executables that could be reversed into an editable file with a help of a program ("decompiler"). Such unpleasant turn of events was made possible because:

  1. Game data was more or less just appended to the end of a "runtime" executable
  2. Source code was inserted into data as text, with code structure and comments intact.

So a program would "read" the appropriate sections of the executable, extract game data, and repack it into an editable file, permitting various acitivities, most of which would violate EULA.

To mention, a lot of Lua-based game engines also suffer from this kind of problem, and it is generally solved by obfuscating source code and altering the executable structure (in GM's case, with a so-called "anti-decompiler") for the "decompiler" to not even be able to extract the obscured game data as easily.

So it's a valid thing to wonder about how much of this still applies to GameMaker: Studio...

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GameMaker: Tetris in full Drag & Drop


Click to launch the HTML5 version of the game

First, take a look at the above link. There's score, 7 tetriminos, slowly growing difficulty - standard things for a Tetris game. The catch? There isn't a single line of code. Nor a single variable. It's all done in GameMaker's "drag & drop" visual scripting.

The story of how this even happened is like so - yesterday was another day when my internet connection disappeared for half of the day without any logical reason whatsoever. As I look at the top of my now-static TweetDeck timeline, and notice this bunch of tweets from Vlambeer's Rami Ismail. While you can generally agree with points outlined, few things could have had better clarification:

  1. Difficulty depends not only on developer's coding skills, but also on the tools used.

    For example, making a "space invaders" game in most modern tools with built-in memory management, collisions, and function sets is easy enough, but should you go lower level... storing invader information in an array? Storing and moving around dynamically created player and invader bullets?? Programming trajectories and destructible defenses??? Not as much careless fun as you may have envisioned. Pong may seem suddenly simpler with base requirements of just a bunch of variables and inverting ball x/y velocity for bounces.

    Additionally, certain tools are best suited for certain task. For example, it is easy to make a turn-based puzzle game in PuzzleScript (hence the name) due to the way engine is based on "rule" definitions. Making a platformer game in PuzzleScript, however, is a much harder feat. It isn't, by no means, impossible, but requires more planning than it would take with a "platformer-centric" engine.

  2. Game development isn't just about having the right tools/resources/experience, but also actually using them creatively. As such, programming in general is often about finding an approach to the problem that isn't the most blatantly obvious or expected but produces results more efficient in terms of computer of development time.

To not make it all look like a rant or a opinion piece, the rest of this post is about creative use of tools - particularly, making the aforementioned Tetris in GameMaker without a single line of code or variable.

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GameMaker: trace/log function

Debugging GameMaker games can be fun. Or not fun. Depends on what your defintion of "fun" is.
Either way, in GameMaker: Studio, a new debugger was added, which you can (and probably should) enable via File - Preferences - "Scripts and Code" - "Use the new Debugger".
That includes a profiler, a step-by-step debugger, and a bunch of other useful things.

But, alas, sometimes, there is no time to explain, no time to write the best code of century, and certainly no time to sit down and stare at variables in watch window. You got to make games fast. And debug fast.

GameMaker: Studio noticeably spots a "console" dock, which is used to display compilation and runtime information, errors, and bunch of other things. But the important part is, that you can also send your own messages into it via show_debug_message. That's nice, since throwing a look at dock is fast. But, you know, what's not fast? Using show_debug_message to do so.

So this post is basically about what I've came up with to improve use of the thing, both for Studio and not.

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GameMaker: GM8 code editor color scheme for Studio

If you are using GameMaker: Studio and find default dark theme to be odd, you probably have already switched to lighter "GM8" theme via File - Preferences dialogue.

But, alas, switching to "GM8" theme does not change code editor color scheme, and you still get the default dark gray-orange theme in middle of your light-colored IDE.

So I thought that it would make sense to publish a GM8-esque color scheme that I've made and am using locally for a while now.

This color scheme follows GM8 style closely, with few exceptions like displaying resource names in teal instead of yellow (which grants higher contrast and generally looks better).

To import a color scheme, go to File - Preferences - Scripts and Code, click Import button, and pick the obtained file.

It is hard to make a large post about thing as small, so here's the file:

Download COL

Have fun!

GameMaker: Testing two game instances at once

If you are using GameMaker: Studio to create multi-player games (via not-so-recently added network_ functions or by utilizing existing DLLs) without separate projects for server and client, you might have stumbled upon one annoying limitation - you can't run two instances of game from IDE.

From a glance, this looks like a small issue, but it gets tedious really fast - to run a second instance, you have to either compile the game (takes time and monotonous file dialog actions), or find a compiled .win file in depth of temporary directories (or otherwise retrieve it's location via means of WinAPI), and pass it to the runner via command-line, like

...\AppData\Roaming\GameMaker-Studio\Runner.exe -game (path to *.win file)

But that's no fun, right?
At least I've found so.
So I took a bit of time and made a small GML snippet to lift this unfortunate limitation.

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GameMaker: Windows-specific functions for Studio

While working on one of recent projects, I've stumbled upon few common issues that many meet - even if you are only targeting Windows in GameMaker: Studio, you cannot access files outside the game's AppData directory (not even in program directory). Neither you can order system to open a file, meaning no external "readmes" to be easily hooked up with game, nor portable configuration files, and some other limitations.
So I took an evening and made a simplistic DLL library to bring equivalents to some functions (sleep, execute_shell, non-sandboxed I/O) back for Windows target. Function list is as following:

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Notepad++: Syntax highlighting for GameMaker Studio

npp-gml-gms

Some time ago I've introduced a Notepad++ syntax highlighting file for GameMaker 8.1 and earlier versions. At the time, making a GameMaker: Studio version seemed slightly less senseful, since dynamic scripting functions are no longer supported, and code in XML files is escaped slightly, but then... oh do wait, extensions!
Extensions in GameMaker: Studio are imported into each project locally, permitting easy modification of their files. Of course, this also implies ability to edit GML files in them. Which in turn permits editing them with external editor of choice without having to deal with XML conversions.
So I took those several minutes needed, and updated UDL (user defined language) file for GameMaker: Studio. It contains all functions, variables, and constants present as of version 1.2.1264 (released January 22, 2014). Apart of new keywords, it now sticks to editor style better as well.
Oh, and you can fold code with comments (//{, //}). Foldable sections are awesome.

Download UDL (XML)

(or grab source from PasteBin, if Dropbox is somehow inaccessible)

... and if you prefer Sublime Text, there's GameMaker plugin for that too (by Cycododge).