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@h3r2tic
h3r2tic / raymarch.hlsl
Last active July 19, 2024 21:46
Depth buffer raymarching for contact shadows, SSGI, SSR, etc.
// Copyright (c) 2023 Tomasz Stachowiak
//
// This contribution is dual licensed under EITHER OF
//
// Apache License, Version 2.0, (http://www.apache.org/licenses/LICENSE-2.0)
// MIT license (http://opensource.org/licenses/MIT)
//
// at your option.
#include "/inc/frame_constants.hlsl"
@vurtun
vurtun / sort.c
Last active January 11, 2023 15:22
// 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;
};
@JarkkoPFC
JarkkoPFC / sphere_screen_extents.h
Last active June 13, 2023 21:27
Calculates view space 3D sphere extents on the screen
struct vec3f {float x, y, z;};
struct vec4f {float x, y, z, w;};
struct mat44f {vec4f x, y, z, w;};
//============================================================================
// sphere_screen_extents
//============================================================================
// Calculates the exact screen extents xyzw=[left, bottom, right, top] in
// normalized screen coordinates [-1, 1] for a sphere in view space. For
// performance, the projection matrix (v2p) is assumed to be setup so that
#include "FunctionalPropertyModifiers.h"
void fpmCallStore::CallAll(double time)
{
for (auto i : m_FunctionCallMap)
{
const fpmFunctionCalls& calls = i->value;
calls.call_all_fn(i->key, calls, time);
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <assert.h>
#include <string.h>
#include <stdarg.h>
#include <limits.h>
#define cast(t,p) ((t)(p))
#define szof(a) ((int)sizeof(a))
@douglashill
douglashill / main.m
Last active October 6, 2023 18:10
A minimal iOS 13 app that is set up in Objective-C rather than using a storyboard and UIApplicationSceneManifest
@import UIKit;
@interface SceneDelegate : UIResponder <UIWindowSceneDelegate>
@end
@implementation SceneDelegate
@synthesize window = _window;
- (void)scene:(UIScene *)scene willConnectToSession:(UISceneSession *)session options:(UISceneConnectionOptions *)connectionOptions {

Multi-dimensional array views for systems programmers

As C programmers, most of us think of pointer arithmetic for multi-dimensional arrays in a nested way:

The address for a 1-dimensional array is base + x. The address for a 2-dimensional array is base + x + y*x_size for row-major layout and base + y + x*y_size for column-major layout. The address for a 3-dimensional array is base + x + (y + z*y_size)*x_size for row-column-major layout. And so on.

from math import *
# a performant solution would store a prefix sum of line lengths to
# a sidechannel and then use that to do a bsearch; on the GPU,
# you'd do a sum tree / histopyramid as a preprocessing step
def find_point(points, d):
d = d
for i in range(1, len(points)):
x0,y0 = points[i-1]
x1,y1 = points[i]
@keebus
keebus / local_opaque_object.c
Last active March 25, 2022 21:33
Local opaque object in C
// library.h -------------------------------------------------------------------
#define opaque(Type) Type; int $sizeof_##Type(void);
#define opaque_impl(Type) int $sizeof_##Type(void) { return sizeof(Type); }
#define local(Type) ((Type *)alloca($sizeof_##Type()))
// foo.h -----------------------------------------------------------------------
@nadavrot
nadavrot / Matrix.md
Last active July 29, 2024 00:58
Efficient matrix multiplication

High-Performance Matrix Multiplication

This is a short post that explains how to write a high-performance matrix multiplication program on modern processors. In this tutorial I will use a single core of the Skylake-client CPU with AVX2, but the principles in this post also apply to other processors with different instruction sets (such as AVX512).

Intro

Matrix multiplication is a mathematical operation that defines the product of