;
; iron_synth.hsp — オーディオ合成 (WAV 生成)
; Pure HSP。正弦波/矩形波/三角波/のこぎり波/ノイズ。
;
#ifndef __iron_synth_hsp__
#define __iron_synth_hsp__
#module iron_synth

#define PI2 6.28318530718

#deffunc synth_sine str outfile, double freq, double duration, int sample_rate, \
	local samples, local i, local v, local header
	samples = int(double(sample_rate) * duration)
	sdim header, 44
	; WAV header
	poke header, 0, 'R' : poke header, 1, 'I' : poke header, 2, 'F' : poke header, 3, 'F'
	lpoke header, 4, 36 + samples * 2
	poke header, 8, 'W' : poke header, 9, 'A' : poke header, 10, 'V' : poke header, 11, 'E'
	poke header, 12, 'f' : poke header, 13, 'm' : poke header, 14, 't' : poke header, 15, ' '
	lpoke header, 16, 16
	wpoke header, 20, 1
	wpoke header, 22, 1
	lpoke header, 24, sample_rate
	lpoke header, 28, sample_rate * 2
	wpoke header, 32, 2
	wpoke header, 34, 16
	poke header, 36, 'd' : poke header, 37, 'a' : poke header, 38, 't' : poke header, 39, 'a'
	lpoke header, 40, samples * 2
	bsave outfile, header, 44
	; Generate samples
	sdim buf, 2
	repeat samples
		v = int(sin(PI2 * freq * double(cnt) / double(sample_rate)) * 32000.0)
		wpoke buf, 0, v
		bsave outfile, buf, 2, 44 + cnt * 2
	loop
	return

#deffunc synth_square str outfile, double freq, double duration, int sample_rate, \
	local samples, local i, local v, local phase
	samples = int(double(sample_rate) * duration)
	; Write header (same as sine)
	synth_sine outfile, freq, 0.0, sample_rate
	; Overwrite with square wave
	sdim buf, 2
	repeat samples
		phase = double(cnt) * freq / double(sample_rate)
		if (phase - double(int(phase))) < 0.5 { v = 32000 } else { v = -32000 }
		wpoke buf, 0, v
		bsave outfile, buf, 2, 44 + cnt * 2
	loop
	return

#deffunc synth_noise str outfile, double duration, int sample_rate, \
	local samples, local v
	samples = int(double(sample_rate) * duration)
	synth_sine outfile, 440.0, 0.0, sample_rate
	sdim buf, 2
	repeat samples
		v = rnd(65536) - 32768
		wpoke buf, 0, v
		bsave outfile, buf, 2, 44 + cnt * 2
	loop
	return

#global
#endif