/*************************************************************************/
/*  audio_effect_phaser.h                                                */
/*************************************************************************/
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/* Copyright (c) 2007-2022 Juan Linietsky, Ariel Manzur.                 */
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#ifndef AUDIO_EFFECT_PHASER_H
#define AUDIO_EFFECT_PHASER_H

#include "servers/audio/audio_effect.h"

class AudioEffectPhaser;

class AudioEffectPhaserInstance : public AudioEffectInstance {
	GDCLASS(AudioEffectPhaserInstance, AudioEffectInstance);
	friend class AudioEffectPhaser;
	Ref<AudioEffectPhaser> base;

	float phase;
	AudioFrame h;

	class AllpassDelay {
		float a, h;

	public:
		_ALWAYS_INLINE_ void delay(float d) {
			a = (1.f - d) / (1.f + d);
		}

		_ALWAYS_INLINE_ float update(float s) {
			float y = s * -a + h;
			h = y * a + s;
			return y;
		}

		AllpassDelay() {
			a = 0;
			h = 0;
		}
	};

	AllpassDelay allpass[2][6];

public:
	virtual void process(const AudioFrame *p_src_frames, AudioFrame *p_dst_frames, int p_frame_count) override;
};

class AudioEffectPhaser : public AudioEffect {
	GDCLASS(AudioEffectPhaser, AudioEffect);

	friend class AudioEffectPhaserInstance;
	float range_min;
	float range_max;
	float rate;
	float feedback;
	float depth;

protected:
	static void _bind_methods();

public:
	Ref<AudioEffectInstance> instantiate() override;

	void set_range_min_hz(float p_hz);
	float get_range_min_hz() const;

	void set_range_max_hz(float p_hz);
	float get_range_max_hz() const;

	void set_rate_hz(float p_hz);
	float get_rate_hz() const;

	void set_feedback(float p_fbk);
	float get_feedback() const;

	void set_depth(float p_depth);
	float get_depth() const;

	AudioEffectPhaser();
};

#endif // AUDIO_EFFECT_PHASER_H