How JavaScript beats GameMaker Language (GML)

Construct supports JavaScript coding in addition to its block-based approach. JavaScript is an industry-standard language used widely across browsers, servers and more, and is one of the most popular programming languages in the world. Some tools choose to go their own way and develop their own programming language used only in their tool. We think this has few upsides and major downsides. To illustrate this, here's a case study in how JavaScript compares to GameMaker Language, aka GML - the language used in GameMaker Studio 2.

Performance

First up, let's examine performance. For games, fast performance is an essential feature to ensure a smooth framerate. To compare the performance of the raw language, we built a simple number-crunching test that just counts how many prime numbers there are between 1 million and 2 million. The key function is IsPrime, and you can see how close the code is for each in the code sample below.

We ran this test in four ways:

1. In JavaScript, in a Construct 3 project - download C3 project
2. In GML, via the VM (an interpreter) - download GameMaker project
3. In GML, via the YYC (a C++ compiler), which is only available with a subscription
4. And despite not being a text-based language, also an equivalent in Construct's event blocks for comparison - download C3 project

In both GML cases we used the newer 64-bit runner/compiler, which performs better on this test. Modern browsers have all been 64-bit for some time already, so this also helps ensure a fair comparison. We tested with GameMaker Studio 2 v2.3.3 and C3 r260 in Chrome 92 on a Windows PC. All the files used in this test are linked above, so you can check them out and replicate results yourself. The results may surprise you! The time taken to calculate how many primes there are between 1 million and 2 million is summarised below (after a brief warmup period to ensure CPU caches and JITs are operating at peak performance).

JavaScript is far faster than GML on this test. The VM proves much slower - in fact, over 40x slower. Even if you pay for a GameMaker subscription and use YYC to compile to native code, it still comes out over 5x slower. Modern JavaScript JIT (just-in-time) compilers are incredibly sophisticated and have been fine-tuned by entire teams of dedicated engineers at the biggest tech companies for years. This also dispels the myth that just because something is compiled to C++ it's fast. JavaScript is not just 10% or 20% faster, but several times faster. Further, JavaScript JITs are also tuned for fast startup, so there's no need to sit around waiting for code to compile. It just starts running with an interpreter right away, compiles code in the background, and then switches over to it as soon as it's ready - all of which happens surprisingly quickly. And all this raw performance comes for free with the very browser you're reading this in!

Perhaps there are some obscure tricks or performance hacks that can improve the result somewhat for GML. However this still proves the point that JavaScript is super fast with straightforward, idiomatic code, and you don't need to resort to time-consuming experimentation and research to get an excellent result.

In fact, JavaScript is so fast that even our equivalent made in Construct's drag-and-drop event block system clocks in relatively close to the result for the YYC. In intensive benchmarks like this, the event system has quite a high performance overhead compared to text-based programming languages since it's essentially interpreted by JavaScript code; despite this, thanks to JavaScript's extreme performance it ends up surprisingly close to the C++ code compiled by YYC, and also far ahead of the VM interpreter. So Construct's event blocks are no slouch either.

Many games run intensive code for purposes like pathfinding, bullet hell games, and more, and high performance is key to maintaining a smooth framerate no matter what your player is battling through. This test result shows that if you want peak performance, choose JavaScript.

Ease of learning

One reason sometimes cited to develop a separate language is to customise it to be easy for beginners to learn. However the fundamentals of GML and JavaScript are very similar. They're both languages with a C-like syntax, a dynamic type system, and garbage collection to simplify memory management. Just take a look at the code samples for IsPrime above - the syntax is pretty close, and so it's likely both are about equally approachable for beginners.

Being such a widely-used language, JavaScript has several advantages for beginner learners though. There are free coding tutorials and learning resources for it all across the web, such as the MDN Learn JavaScript guide and The Modern JavaScript tutorial, some also with interactive samples where you can edit and run the code. Further there are schools, colleges, coding "bootcamps" and other educational institutions that include teaching JavaScript coding, providing more options to learn in the wider world.

Finally JavaScript is a highly transferrable skill, being widely used in industry both in browsers and on servers, and with plenty of jobs available around the world for a promising career. Learning a language only used by one tool throws extra hurdles in your way if you want to go further, having to learn the new aspects of an industry-standard language, and unlearn the quirks and bad habits that you may have picked up with the the previous language.

So overall JavaScript should be just as easy to learn, but offer a much better path onwards in future.

Language features

New JavaScript features go through a rigorous standardisation process, where proposals are thoroughly reviewed and consensus achieved before implementing and releasing them. In theory a single organisation could move quicker. However JavaScript still has many major features that are limited or entirely missing in GML. In this section we review some of them. The standardisation process also helps ensure features are designed well, with thorough reviews from technical experts across the industry.

While JavaScript has a great many language features, beginners can pretty much just ignore the more advanced parts, so this should not have any impact on how easy it is to learn the language basics. It's a great benefit to more experienced coders though, providing a wide range of tools to help you best express what you want to do, and ensuring you can go a long way without running in to limitations or missing features.

Modules

JavaScript Modules provide a useful way to write code in isolated modules, only importing and exporting what they need. It helps keep code clear with separated concerns, and helps make it easy to re-use code and third-party libraries across projects. The syntax is shown below.

// In utils.js:
export function add(a, b)
{
	return a + b;
}

// In main.js:
import * as Utils from "./utils.js";

console.log(Utils.add(2, 3)); // logs 5

async function LoadDataFromURL(url)
{
	const response = await fetch(url);
	const blob = await response.blob();
	return blob;
}

// Using normal function:
async function onStartup(runtime)
{
	// do startup stuff...
}

runOnStartup(onStartup);

// Using arrow function:
runOnStartup(async runtime =>
{
	// do startup stuff...
});

for (let i of myArray)
{
	console.log(i);
}

function* oddNumbersUpTo(limit)
{
	let n = 1;
	while (n < limit)
	{
		yield n;
		n += 2;
	}
}

for (let i of oddNumbersUpTo(10))
{
	console.log(i);
}

class Rectangle {
	constructor(width, height)
	{
		this.width = width;
		this.height = height;
	}
	// Class method
	setSize(width, height)
	{
		this.width = width;
		this.height = height;
	}
	// Class getter
	get area()
	{
		return this.width * this.height;
	}
	// ... and many more syntax features ...
}

function getTwoValues()
{
	return [10, 20];
}

const [firstValue, secondValue] = getTwoValues();
// now firstValue is 10 and secondValue is 20