kevinmoran

Gilbert–Johnson–Keerthi (GJK) 3D distance algorithm

The Gilbert–Johnson–Keerthi (GJK) distance algorithm is a method of determining the minimum distance between two convex sets. The algorithm's stability, speed which operates in near-constant time, and small storage footprint make it popular for realtime collision detection.

Unlike many other distance algorithms, it has no requirments on geometry data to be stored in any specific format, but instead relies solely on a support function to iteratively generate closer simplices to the correct answer using the Minkowski sum (CSO) of two convex shapes.

Minimal D3D11

Minimal D3D11 reference implementation: An uncluttered Direct3D 11 setup + basic rendering primer and API familiarizer. Complete, runnable Windows application contained in a single function and laid out in a linear, step-by-step fashion that should be easy to follow from the code alone. ~200 LOC. No modern C++ / OOP or (other) obscuring cruft. View on YouTube

Other gists in this series:

Minimal D3D11 part 2: instancing

GPU Optimization for GameDev

Graphics Pipeline / GPU Architecture Overview

2011 - A trip through the Graphics Pipeline 2011
2013 - Performance Optimization Guidelines and the GPU Architecture behind them
2015 - Life of a triangle - NVIDIA's logical pipeline
2015 - Render Hell 2.0
2016 - How bad are small triangles on GPU and why?
2017 - GPU Performance for Game Artists
2019 - Understanding the anatomy of GPUs using Pokémon


	/* compile with:
	on linux: gcc -g stack_traces.c
	on OS X: gcc -g -fno-pie stack_traces.c
	on windows: gcc -g stack_traces.c -limagehlp
	*/

	#include <signal.h>
	#include <stdio.h>
	#include <assert.h>

	#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

	Shader "CustomPBRShader"
	{
	Properties
	{
	[NoScaleOffset] _Albedo("Albedo", Color) = (1.0, 1.0, 1.0, 1.0)
	[NoScaleOffset] _Metalness("Conductivity", Range(0.0, 1.0)) = 0.0
	[NoScaleOffset] _Roughness("Roughness", Range(0.0, 1.0)) = 0.0
	[NoScaleOffset][HDR] _RadianceMap("RadianceMap", CUBE) = "" {}
	[NoScaleOffset][HDR] _IrradianceMap("IrradianceMap", CUBE) = "" {}
	}

	// NOTE Compile without fast math flags.

	/*
	This is free and unencumbered software released into the public domain.

	Anyone is free to copy, modify, publish, use, compile, sell, or
	distribute this software, either in source code form or as a compiled
	binary, for any purpose, commercial or non-commercial, and by any
	means.

	#pragma once

	namespace YourNamespace
	{
	struct Routine
	{
	// Current "waiting time" before we run the next block
	float wait_for = 0;

	// Used during `rt_for`, which repeats the given block for X time

	#define COBJMACROS
	#define NOMINMAX
	#define WIN32_LEAN_AND_MEAN
	#include <windows.h>
	#include <d3d11.h>

	#include <stdint.h>
	#include <string.h>
	#include <intrin.h>

	// 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>