CuriousTorvald curioustorvald

Funk Repeat and Invert Loop — `EF $x` in ProTracker 1.x

Formal specification, derived by transcription from the ProTracker 1.0C and 1.1B playroutine sources. Nothing here is derived from other articles or inferred from a third-party player; every claim is traceable to a line of 68000 assembly cited inline. Where the sources are silent or damaged, this document says so explicitly.

Audience: someone implementing EF $x — either half of it — in a software mixer.

0. Provenance

File	What it is

Funk Repeat, Demystified

Or: how one effect letter held two completely different ideas, and why the one everybody remembers is the boring one

The effect nobody uses

Every MOD effect list has the same shape at the bottom. EC cuts the note, ED delays it, EE delays the pattern, and then there is EF $x, sitting at the end of the table like the last kid picked for football, labelled Invert Loop, and hardly anyone has ever written a tune with it on purpose.

Open a modern tracker and EF $x does this: it walks through your loop one byte at a time and flips each byte upside down. Leave it running and your nice sampled bass turns into a buzzsaw. Leave it running longer and — this is the bit people miss — it comes back, because flipping a byte twice gives you the byte back. It is a slow, destructive, unmusical waveform-mangler, and its own author could not be bothered to pretend otherwise.

openSUSE Tumbleweed/Leap을 위한 두벌식 및 세벌식 한글 입력 설정

openSUSE를 영어로 설치, 레이아웃은 일단은 무조건 Qwerty

빌드에 필요한 패키지들을 설치

sudo zypper in cmake gtk2-devel gtk3-devel gtk4-devel fcitx fcitx-devel libqt5-qtbase-devel pkg-config libtool intltool

코드를 가져오기. (새로 설치한 시스템에는 git이 없기 때문에 sudo zypper in git git-lfs를 먼저 실행해주자)

git clone https://gitlab.com/3beol/libhangul.git

	daemon:
	modules:
	- Xim
	- Wayland
	- Indicator
	indicator:
	icon_color: White
	log:
	global_level: DEBUG
	engine:

	#version 330 core
	/*
	Copyright 2025 CuriousTorvald
	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 OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
	*/

	// ============================================================================
	// CRT + NTSC Composite/S-Video Signal Simulation Shader (Enhanced Version)
	// ============================================================================

	// XYB Color Space Conversion Functions
	// Based on JPEG XL XYB specification with proper sRGB linearization
	// test with:
	//// gcc -DXYB_TEST_MAIN -o test_xyb xyb_conversion.c -lm && ./test_xyb

	#include <stdio.h>
	#include <math.h>
	#include <stdint.h>
	#include <stdlib.h>

	/*
	Copyright 2024 CuriousTorvald

	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 OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
	*/

	#ifdef GL_ES
	precision mediump float;

	#!/usr/bin/env python3

	# This code is based on tutorial by slicktechies modified as needed to use oauth token from Twitch.
	# You can read more details at: https://www.junian.net/2017/01/how-to-record-twitch-streams.html
	# original code is from https://slicktechies.com/how-to-watchrecord-twitch-streams-using-livestreamer/
	# 24/7/365 NAS adaptation by CuriousTorvald (https://gist.github.com/curioustorvald/f7d1eefe1310efb8d41bee2f48a8e681)
	# Twitch Helix API integration by Krepe.Z (https://gist.github.com/krepe90/22a0a6159b024ccf8f67ee034f94c1cc)
	# Chzzk adaptation by CuriousTorvald (https://gist.github.com/curioustorvald/240e67a53f8131d7166ad5269044c719)

	# Copyright (c) 2017, 2019, 2020, 2022, 2024 Junian, CuriousTorvald and Krepe.Z

	# usage: python3 cull.py HUE
	# where HUE is a number
	#
	# Get datasets faster using multiple threads, like:
	# seq 360 \| xargs --max-procs=8 -n 1 python cull.py

	# Copyright © 2022 CuriousTorvald
	#
	# 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 furnished to do so, subject to the following conditions:
	#