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datenwolf / xcb_shmimg.c
Created March 28, 2025 22:36
minimal example of using XCB to set up a framebuffer to draw to an X11 window
#include <stdlib.h>
#include <stdio.h>
#include <sys/ipc.h>
#include <sys/shm.h>
#include <xcb/xcb.h>
#include <xcb/shm.h>
#include <xcb/xcb_image.h>
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datenwolf / rgb_blend.c
Created March 27, 2025 19:52 — forked from mattiasgustavsson/rgb_blend.c
// color1 and color2 are R4G4B4 12bit RGB color values, alpha is 0-255
uint16_t blend_12bit( uint16_t color1, uint16_t color2, uint8_t alpha ) {
uint64_t c1 = (uint64_t) color1;
uint64_t c2 = (uint64_t) color2;
uint64_t a = (uint64_t)( alpha >> 4 );
// bit magic to alpha blend R G B with single mul
c1 = ( c1 | ( c1 << 12 ) ) & 0x0f0f0f;
c2 = ( c2 | ( c2 << 12 ) ) & 0x0f0f0f;
uint32_t o = ( ( ( ( c2 - c1 ) * a ) >> 4 ) + c1 ) & 0x0f0f0f;
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datenwolf / gist:151486f6d73c9b25ac701bdbdef373a5
Last active July 23, 2023 14:20
Online RDTSC visualisation
#include <GL/glut.h>
#include <imgui.h>
#include <imgui_impl_glut.h>
#include <imgui_impl_opengl2.h>
#include <sched.h>
#include <math.h>
#include <stdio.h>
#include <x86intrin.h>
#include <time.h>
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datenwolf / ensure_fpu.py
Created September 7, 2022 09:46 — forked from moyix/ensure_fpu.py
Some handy utils for messing with MXCSR (x86-64 SSE FPU control register)
#!/usr/bin/env python
import sys, os
import platform
import ctypes as ct
import mmap
from enum import Enum
import importlib
import functools
import errno
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datenwolf / pidfdino.c
Created December 21, 2020 12:09
Create Linux pidfds for several processes and dump their inode numbers.
#define _GNU_SOURCE
#include <sys/fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <wait.h>
#include <stdio.h>
static int pidfd_open(pid_t pid, unsigned flags)
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datenwolf / icestick_ring_oscillator.v
Last active April 13, 2020 18:06
`timescale 1ns / 1ps
// iCEstick signals
//
// clk_12MHz: on board 12MHz crystal oscillator
//
// USB <-> RS232 converter has standard RS232 signals
// DCD, DSR, DTR, CTS, RTS, RXD, TXD
//
// /----------------------------------------
// / A7 A6 A5 A4 A3 A2 A1 A0 GND +3.3V |
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datenwolf / hyperellipsoid.py
Created February 24, 2020 21:18 — forked from jix/hyperellipsoid.py
# Copyright 2020 Jannis Harder
#
# Permission to use, copy, modify, and/or distribute this software for any
# purpose with or without fee is hereby granted.
#
# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
# REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
# AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
# INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
# LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
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datenwolf / b64op.c
Created April 3, 2018 18:06
Modified base64 variant that is order preserving
/*
Sorting order preserving base64 implementation.
Based on the original implementation of
picoweb / litheweb -- a web server and application framework
for resource constraint systems.
Copyright (C) 2012 - 2018 Wolfgang Draxinger
This program is free software; you can redistribute it and/or modify
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datenwolf / dxiw.bat
Created December 24, 2016 17:34
CPU affinity setting starting batch script for DX:IW
start /affinity 1 dx2.exe
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datenwolf / shaderloader.c
Created November 10, 2016 17:34
#include "shaderloader.h"
#include <stdlib.h>
#include <stdio.h>
#if defined(_WIN32)
#include <windows.h>
#define shader_gl_proc(x) wglGetProcAddress(#x)
#elif defined(__APPLE__) && defined(__MACH__)
#define shader_gl_proc(x) ((void(*)())x)