Peter Jakobs pjako

How do you descriptor set?

Descriptor sets have vexed me at every step of development. They're new and different and they have a lot of rules which aren't all that obvious. This document will hopefully lay out everything in one convenient place that I - and also you - can refer to

First, let's talk about what we're trying to do

Use Case

Most renderers need some way for shaders to access resources like textures, buffers, etc. For the Vulkan API, this way is the almighty descriptor set. Descriptors, as I understand them, are essentially a pointer to a resource. You update your descriptor sets with your resources, then you bind the descriptor sets to your command buffer, then shaders involved in subsequent drawcalls can look at the descriptors to know what resources they should actually read from. I'm not entirely sure why there's this indirection - and in fact, on AMD GPUs descriptor sets are actually just pointers - but the indirection exists, and we all have to find a way to deal with it

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

D3D11 essentials:

create window, device, device context and swap chain (easy mode): https://github.com/floooh/sokol-samples/blob/master/d3d11/d3d11entry.c
create vertex+index buffers: https://github.com/floooh/sokol/blob/b9490494987a9738a4dda484e8dda5df0dab217c/sokol_gfx.h#L6702
create textures/render targets/samplers: https://github.com/floooh/sokol/blob/b9490494987a9738a4dda484e8dda5df0dab217c/sokol_gfx.h#L6775
create shaders: https://github.com/floooh/sokol/blob/b9490494987a9738a4dda484e8dda5df0dab217c/sokol_gfx.h#L7078
create "pipeline state" (all the render state, vertex layout (aka input layout): https://github.com/floooh/sokol/blob/b9490494987a9738a4dda484e8dda5df0dab217c/sokol_gfx.h#L7192
create "render target views": https://github.com/floooh/sokol/blob/b9490494987a9738a4dda484e8dda5df0dab217c/sokol_gfx.h#L7330
start rendering (clearing etc): https://github.com/floooh/sokol/blob/b9490494987a9738a4dda484e8dda5df0dab217c/sokol_gfx.h#L7438
MSAA resolve (when rendering to offscreen rende

	// Polymorphic hashtable API in C
	//
	// We get value semantics here for hset and hget (see comments below).
	// An extra layer of indirection is internally used so we can sort {k,v} pairs, e.g. for priority queue.
	// The main trick is the use of comma in C. Any statement in C takes on the value of the expression
	// in the final comma, not any of the prior. We can use that to "return" a value in `hget` while running
	// a few expressions beforehand. Since the user type is a pointer to a value we get polymorphism by
	// the indirection or array operator `*h` or `h[0]`.
	//
	// Original inspired from these resources by Per Vognsen and Micha Mettke

	double delta_time_filtered(double dt_nanos){
	// Warm start the filter by assuming 60 Hz.
	static double x[] = {1.6e7, 1.6e7, 1.6e7}, y[] = {1.6e7, 1.6e7, 1.6e7};
	// IIR filter coefficients. 2rd order lowpass butterworth at 1/128 the sample rate.
	static const double b[] = {6.321391700454014e-5, 0.00012642783400908025, 6.321391700454014e-5};
	static const double a[] = {1.0, -1.9681971279272976, 0.9684499835953156};

	// Apply IIR filter coefficients.
	double value = b[0]*dt_nanos;
	for(uint i = 2; i > 0; i--){

	// ref: http://www.codercorner.com/RadixSortRevisited.htm
	// http://stereopsis.com/radix.html
	// int/float: https://github.com/lshamis/FloatRadixSort
	// string: https://github.com/rantala/string-sorting/blob/master/src/msd_ce.cpp

	struct str {
	const char *str;
	const char *end;
	int len;
	};

	1. windows update
	1a. Right click on the windows icon in the task bar, select Settings, select Apps, and then click Manage optional features.
	1b. Click Add a feature
	1c. In the Optional features list, select Graphics Tools and then click Install.

	2. that doesn't work, here's the hail mary:
	* Run regedit.exe
	* Navigate to folder HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate\AU\
	* Double click on entry UseWUServer, change the value to 0, click OK
	* Reboot

	//

	struct TerminalCell
	{
	// cell index into GlyphTexture, should be two 16-bit (x,y) values packed: "x \| (y << 16)"
	uint GlyphIndex;

	// 0xAABBGGRR encoded colors, nonzero alpha for Foreground indicates to render colored-glyph
	// which means use RGB values from GlyphTexture directly as output, not as ClearType blending weights
	uint Foreground;


	#include <TinyCRT/TinyCRT.h>
	#include <TinyCRT/TinyWindows.h>

	namespace
	{
	constexpr uint64_t time100NSecsPerSec = 10000000;

	uint64_t FileTimeToU64(FILETIME ft)
	{

	void assert_func(int cond, const char *msg) {
	if (!cond) {
	fprintf(stderr, "assert failed: %s\n", msg);
	abort();
	}
	}

	#define assert_helper(x, y, ...) assert_func(x, y)
	#define assert(x, ...) assert_helper((x), ## __VA_ARGS__, #x)