#!/usr/bin/awk -f
function WaveFileGen(wave, file,	l, w) {
	# Generate a raw waveform file (file) of size SIZE by repeatedly
	# doubling the given wave string (wave).
	for(l = length(w = wave); l < SIZE; l *= 2)
		w = w w
	printf("%s", w) > file
	close(file)
}
BEGIN {
	# General variables...
#	LOOPS = 16	# This variable is no longer used.
#	The following two variables only used in for loops where their value is
#	set immediately before they are used.  The initial values assigned here
#	are overridden when these variables are used.
#	LOOP = 1
#	INTEGER = 32
	NOISE = "$VER freq.awk_Version_0.00.01_B.Walker_G0LCU."
	# Note that this is an awk script; not a shell script, VER is not
	# defined as an awk variable in this awk script, and even if it was
	# defined, $VER will not be expanded in an awk string constant.

	# Waveform variables...
	SIZE = 2**19	# Number of bytes to be placed in waveform files.
			# Note that since 524288 is 2**19 and WaveFileGen()
			# repeatedly doubles waveforms, the following waveforms
			# must have a length (not including the terminating null
			# byte) that is a power of 2 single-byte characters
			# long.
	SINEWAVE4 = "O~O "
	SINEWAVE16 = "Op}pN- -Op}pN- -"
	SINEWAVE64 = "Op}pN- -Op}pN- -Op}pN- -Op}pN- -Op}pN- -Op}pN- -Op}pN- -Op}pN- -"
	SQUAREWAVE4 = "~~  "
	SQUAREWAVE16 = "~~~~~~~~        "
	SQUAREWAVE64 = "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~                                "
	TRIANGLEWAVE4 = "O~O "
	TRIANGLEWAVE16 = "________--------"
	TRIANGLEWAVE64 = "________________________________--------------------------------"
	SAWTOOTHPLUS4 = " ?^~"
	SAWTOOTHPLUS16 = " &,29?EKRX^dkqw~"
	SAWTOOTHPLUS64 = " !#$&')*,-/0235689:<>?ABDEGHJKMNPQSTVWYZ\\^_abdeghjkmnpqstvwyz|}~"
	SAWTOOTHMINUS4 = "~^? "
	SAWTOOTHMINUS16 = "~wqkd^XRKE?92,& "
	SAWTOOTHMINUS64 = "~}|zywvtsqpnmkjhgedba_^\\ZYWVTSQPNMKJHGEDBA?><:9865320/-,*)'&$#! "
	PULSEPLUS4 = "~   "
	PULSEPLUS16 = "~               "
	PULSEPLUS64 = "~                                                               "
	PULSEMINUS4 = " ~~~"
	PULSEMINUS16 = " ~~~~~~~~~~~~~~~"
	PULSEMINUS64 = " ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~"
	# ARBITRARY can be any length from 2 to 1024 bytes (as long as the
	# length is a power of 2), sampling rate will be set to 96000 later...
	ARBITRARY = "Op}pN- -"

	# 4 byte waveforms, the sinewave and triangle wave are identical...
	WaveFileGen(SINEWAVE4, "/tmp/sinewave4.raw")
	WaveFileGen(SQUAREWAVE4, "/tmp/squarewave4.raw")
	WaveFileGen(TRIANGLEWAVE4, "/tmp/trianglewave4.raw")
	WaveFileGen(SAWTOOTHPLUS4, "/tmp/sawtoothplus4.raw")
	WaveFileGen(SAWTOOTHMINUS4, "/tmp/sawtoothminus4.raw")
	WaveFileGen(PULSEPLUS4, "/tmp/pulseplus4.raw")
	WaveFileGen(PULSEMINUS4, "/tmp/pulseminus4.raw")

	# 16 byte waveforms...
	WaveFileGen(SINEWAVE16, "/tmp/sinewave16.raw")
	WaveFileGen(SQUAREWAVE16, "/tmp/squarewave16.raw")
	WaveFileGen(TRIANGLEWAVE16, "/tmp/trianglewave16.raw")
	WaveFileGen(SAWTOOTHPLUS16, "/tmp/sawtoothplus16.raw")
	WaveFileGen(SAWTOOTHMINUS16, "/tmp/sawtoothminus16.raw")
	WaveFileGen(PULSEPLUS16, "/tmp/pulseplus16.raw")
	WaveFileGen(PULSEMINUS16, "/tmp/pulseminus16.raw")

	# 64 byte waveforms...
	WaveFileGen(SINEWAVE64, "/tmp/sinewave64.raw")
	WaveFileGen(SQUAREWAVE64, "/tmp/squarewave64.raw")
	WaveFileGen(TRIANGLEWAVE64, "/tmp/trianglewave64.raw")
	WaveFileGen(SAWTOOTHPLUS64, "/tmp/sawtoothplus64.raw")
	WaveFileGen(SAWTOOTHMINUS64, "/tmp/sawtoothminus64.raw")
	WaveFileGen(PULSEPLUS64, "/tmp/pulseplus64.raw")
	WaveFileGen(PULSEMINUS64, "/tmp/pulseminus64.raw")

	# Generate the noise waveform...
	srand()
	for(LOOP = 1; LOOP <= SIZE; ++LOOP)
	{
		INTEGER = 32 + rand() * 95
		printf("%c", INTEGER) > "/tmp/noise.raw"
	}
	close("/tmp/noise.raw")

	# Create a temporary ARBITRARY file...
	WaveFileGen(ARBITRARY, "/tmp/arbitrary.raw")
}