Michael Campagnaro sir-pinecone

A quick breakdown of lighting in the restir-meets-surfel branch of my renderer, where I revive some olde surfel experiments, and generously sprinkle ReSTIR on top.

General remarks

Please note that this is all based on work-in-progress experimental software, and represents a single snapshot in development history. Things will certainly change 😛

Due to how I'm capturing this, there's frame-to-frame variability, e.g. different rays being shot, TAA shimmering slightly. Some of the images come from a dedicated visualization pass, and are anti-aliased, and some show internal buffers which are not anti-aliased.

Final images

TLDR: if you've got a bunch of delays in series, for example all-pass filters in a reverb, put them all in a single big buffer and let them crawl over each other for a perf win!

recently I was fiddling around with my hobby reverb code, in preparation for porting it onto a smaller/slower CPU. I'd implemented a loop-of-allpass filters type reverb, just like everybody else, and indeed, I basically had the classic 'OOP'ish abstraction of an 'allpass' struct that was, say, 313 samples long, and... did an allpass. on its own little float buffer[313]. (well, short integer, not float, but thats not relevant) I'll write out the code in a moment.

but then I was browsing the internet one night, as you do, and stumbled on this old post by Sean Costello of Valhalla DSP fame - noting the sad passing of Alesis founder and general all-round DSP legend, Keith Barr. https://valhalladsp.com/2010/08/25/rip-keith-barr/

It's worth a read just for his wonderful anecdote about the birth of the midiverb - which spawned the thou

GPU Optimization for GameDev

Graphics Pipeline / GPU Architecture Overview

2011 - A trip through the Graphics Pipeline 2011
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
2020 - GPU ARCHITECTURE RESOURCES

I was told by @mmozeiko that Address Sanitizer (ASAN) works on Windows now. I'd tried it a few years ago with no luck, so this was exciting news to hear.

It was a pretty smooth experience, but with a few gotchas I wanted to document.

First, download and run the LLVM installer for Windows: https://llvm.org/builds/

Then download and install the VS extension if you're a Visual Studio 2017 user like I am.

It's now very easy to use Clang to build your existing MSVC projects since there's a cl compatible frontend:

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

What is the Strict Aliasing Rule and Why do we care?

(OR Type Punning, Undefined Behavior and Alignment, Oh My!)

What is strict aliasing? First we will describe what is aliasing and then we can learn what being strict about it means.

In C and C++ aliasing has to do with what expression types we are allowed to access stored values through. In both C and C++ the standard specifies which expression types are allowed to alias which types. The compiler and optimizer are allowed to assume we follow the aliasing rules strictly, hence the term strict aliasing rule. If we attempt to access a value using a type not allowed it is classified as undefined behavior(UB). Once we have undefined behavior all bets are off, the results of our program are no longer reliable.

Unfortunately with strict aliasing violations, we will often obtain the results we expect, leaving the possibility the a future version of a compiler with a new optimization will break code we th

	#define WIN32_LEAN_AND_MEAN
	#include <winsock2.h>
	#include <windows.h>
	#define SECURITY_WIN32
	#include <security.h>
	#include <schannel.h>
	#include <shlwapi.h>
	#include <assert.h>
	#include <stdio.h>

	// cl.exe xbox_test.c /link setupapi.lib user32.lib

	#include <windows.h>
	#include <setupapi.h>
	#include <dbt.h>
	#include <stdio.h>

	/// interface

	#define XBOX_MAX_CONTROLLERS 16

	#include <windows.h>
	#include <intrin.h>

	#define Assert(x) do { if (!(x)) __debugbreak(); } while (0)

	static struct
	{
	DWORD process_id;
	char data[4096 - sizeof(DWORD)];
	}* ods_buffer;

	/*
	The MIT License (MIT)

	Copyright (c) 2018 Eric Arnebäck

	Permission is hereby granted, free of charge, to any person obtaining a copy
	of this software and associated documentation files (the "Software"), to deal
	in the Software without restriction, including without limitation the rights
	to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	copies of the Software, and to permit persons to whom the Software is