kaervin

CUSTOM GAME ENGINES: A Small Study

A couple of weeks ago I played (and finished) A Plague Tale, a game by Asobo Studio. I was really captivated by the game, not only by the beautiful graphics but also by the story and the locations in the game. I decided to investigate a bit about the game tech and I was surprised to see it was developed with a custom engine by a relatively small studio. I know there are some companies using custom engines but it's very difficult to find a detailed market study with that kind of information curated and updated. So this article.

Nowadays lots of companies choose engines like Unreal or Unity for their games (or that's what lot of people think) because d

	// example how to set up D3D11 rendering on Windows in C

	#define COBJMACROS
	#define WIN32_LEAN_AND_MEAN
	#include <windows.h>
	#include <d3d11.h>
	#include <dxgi1_3.h>
	#include <d3dcompiler.h>
	#include <dxgidebug.h>

	// example how to set up OpenGL core context on Windows
	// and use basic functionality of OpenGL 4.5 version

	// important extension functionality used here:
	// (4.3) KHR_debug: https://www.khronos.org/registry/OpenGL/extensions/KHR/KHR_debug.txt
	// (4.5) ARB_direct_state_access: https://www.khronos.org/registry/OpenGL/extensions/ARB/ARB_direct_state_access.txt
	// (4.1) ARB_separate_shader_objects: https://www.khronos.org/registry/OpenGL/extensions/ARB/ARB_separate_shader_objects.txt
	// (4.2) ARB_shading_language_420pack: https://www.khronos.org/registry/OpenGL/extensions/ARB/ARB_shading_language_420pack.txt
	// (4.3) ARB_explicit_uniform_location: https://www.khronos.org/registry/OpenGL/extensions/ARB/ARB_explicit_uniform_location.txt

	#include "freeverb.h"


	#define undenormalize(n) { if (xabs(n) < 1e-37) { (n) = 0; } }


	static inline float xabs(float n) {
	return n < 0 ? -n : n;
	}

	#include <stdio.h>

	#define STR2(x) #x
	#define STR(x) STR2(x)

	#ifdef _WIN32
	#define INCBIN_SECTION ".rdata, \"dr\""
	#else
	#define INCBIN_SECTION ".rodata"
	#endif

	# Warning: this implementation doesn't check if writes or reads will happen
	# out of input/output buffer range, so that will generate IndexError exception

	def LZ4_decompress(source, osize):
	isize = len(source)

	src = bytearray(source)
	dst = bytearray(osize)

	si = 0