engines/common/LFOPulse.h

/***************************************************************************
 *                                                                         *
 *   Copyright (C) 2005 Christian Schoenebeck                              *
 *   Copyright (C) 2011 Christian Schoenebeck and Grigor Iliev             *
 *                                                                         *
 *   This library is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 *   This library is distributed in the hope that it will be useful,       *
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
 *   GNU General Public License for more details.                          *
 *                                                                         *
 *   You should have received a copy of the GNU General Public License     *
 *   along with this library; if not, write to the Free Software           *
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston,                 *
 *   MA  02111-1307  USA                                                   *
 ***************************************************************************/

#ifndef __LS_PULSELFO_H__
#define __LS_PULSELFO_H__

#include "LFOBase.h"

namespace LinuxSampler {

    /** @brief Pulse LFO (int math implementation)
     *
     * This is a pulse Low Frequency Oscillator which uses pure integer
     * math (without branches) to synthesize the pulse wave.
     */
    template<LFO::range_type_t RANGE, int WIDTH /* in permilles */>
    class LFOPulse : public LFOBase<RANGE> {
        public:

            /**
             * Constructor
             *
             * @param Max - maximum value of the output levels
             */
            LFOPulse(float Max) : LFOBase<RANGE>::LFOBase(Max) {
            }

            /**
             * Calculates exactly one sample point of the LFO wave.
             *
             * @returns next LFO level
             */
            inline float render() {
                uiLevel += c;
                if (RANGE == LFO::range_unsigned)
                    return uiLevel <= width ? normalizer : 0;
                else /* signed range */
                    return uiLevel <= width ? normalizer : -normalizer;
            }

            /**
             * Update LFO depth with a new external controller value.
             *
             * @param ExtControlValue - new external controller value
             */
            inline void updateByMIDICtrlValue(const uint16_t& ExtControlValue) {
                this->ExtControlValue = ExtControlValue;

                const float max = (this->InternalDepth + ExtControlValue * this->ExtControlDepthCoeff) * this->ScriptDepthFactor;
                normalizer = max;
            }

            /**
             * Will be called by the voice when the key / voice was triggered.
             *
             * @param Frequency       - frequency of the oscillator in Hz
             * @param InternalDepth   - firm, internal oscillator amplitude
             * @param ExtControlDepth - defines how strong the external MIDI
             *                          controller has influence on the
             *                          oscillator amplitude
             * @param FlipPhase       - inverts the oscillator wave against
             *                          a horizontal axis
             * @param SampleRate      - current sample rate of the engines
             *                          audio output signal
             * @param PulseWidth      - the pulse width in percents
             */
            void trigger(float Frequency, uint16_t InternalDepth, uint16_t ExtControlDepth, float PulseWidth, unsigned int SampleRate) {
                this->Frequency            = Frequency;
                this->InternalDepth        = (InternalDepth / 1200.0f) * this->Max;
                this->ExtControlDepthCoeff = (((float) ExtControlDepth / 1200.0f) / 127.0f) * this->Max;
                this->ScriptFrequencyFactor = this->ScriptDepthFactor = 1.f; // reset for new voice
                this->pFinalDepth = NULL;
                this->pFinalFrequency = NULL;

                const unsigned int intLimit = (unsigned int) -1; // all 0xFFFF...
                const float freq = Frequency * this->ScriptFrequencyFactor;
                const float r = freq / (float) SampleRate; // frequency alteration quotient
                c = (int) (intLimit * r);
                width = (PulseWidth / 100.0) * intLimit;

                uiLevel = 0;
            }
            
            virtual void trigger(float Frequency, LFO::start_level_t StartLevel, uint16_t InternalDepth, uint16_t ExtControlDepth, bool FlipPhase, unsigned int SampleRate) {
                trigger(Frequency, InternalDepth, ExtControlDepth, WIDTH / 10.0f, SampleRate);
            }
            
            /**
             * Should be invoked after the LFO is triggered.
             * @param phase From 0 to 360 degrees.
             */
            void setPhase(float phase) {
                if (phase < 0) phase = 0;
                if (phase > 360) phase = 360;
                phase /= 360.0f;
                const unsigned int intLimit = (unsigned int) -1; // all 0xFFFF...
                uiLevel = intLimit * phase;
            }
            
            void setFrequency(float Frequency, unsigned int SampleRate) {
                this->Frequency = Frequency;
                const float freq = Frequency * this->ScriptFrequencyFactor;
                const unsigned int intLimit = (unsigned int) -1; // all 0xFFFF...
                float r = freq / (float) SampleRate; // frequency alteration quotient
                c = (int) (intLimit * r);
            }

            void setScriptDepthFactor(float factor, bool isFinal) {
                this->ScriptDepthFactor = factor;
                // set or reset this script depth parameter to be the sole
                // source for the LFO depth
                if (isFinal && !this->pFinalDepth)
                    this->pFinalDepth = &this->ScriptDepthFactor;
                else if (!isFinal && this->pFinalDepth == &this->ScriptDepthFactor)
                    this->pFinalDepth = NULL;
                // recalculate upon new depth
                updateByMIDICtrlValue(this->ExtControlValue);
            }

            void setScriptFrequencyFactor(float factor, unsigned int SampleRate) {
                this->ScriptFrequencyFactor = factor;
                // in case script frequency was set as "final" value before,
                // reset it so that all sources are processed from now on
                if (this->pFinalFrequency == &this->ScriptFrequencyFactor)
                    this->pFinalFrequency = NULL;
                // recalculate upon new frequency
                setFrequency(this->Frequency, SampleRate);
            }

            void setScriptFrequencyFinal(float hz, unsigned int SampleRate) {
                this->ScriptFrequencyFactor = hz;
                // assign script's given frequency as sole source for the LFO
                // frequency, thus ignore all other sources
                if (!this->pFinalFrequency)
                    this->pFinalFrequency = &this->ScriptFrequencyFactor;
                // recalculate upon new frequency
                setFrequency(this->Frequency, SampleRate);
            }

        protected:
            unsigned int uiLevel;
            unsigned int width;
            int   c;
            float normalizer;
    };

} // namespace LinuxSampler

#endif // __LS_PULSELFO_H__
1	/***************************************************************************
2	* *
3	* Copyright (C) 2005 Christian Schoenebeck *
4	* Copyright (C) 2011 Christian Schoenebeck and Grigor Iliev *
5	* *
6	* This library is free software; you can redistribute it and/or modify *
7	* it under the terms of the GNU General Public License as published by *
8	* the Free Software Foundation; either version 2 of the License, or *
9	* (at your option) any later version. *
10	* *
11	* This library is distributed in the hope that it will be useful, *
12	* but WITHOUT ANY WARRANTY; without even the implied warranty of *
13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
14	* GNU General Public License for more details. *
15	* *
16	* You should have received a copy of the GNU General Public License *
17	* along with this library; if not, write to the Free Software *
18	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, *
19	* MA 02111-1307 USA *
20	***************************************************************************/
21
22	#ifndef __LS_PULSELFO_H__
23	#define __LS_PULSELFO_H__
24
25	#include "LFOBase.h"
26
27	namespace LinuxSampler {
28
29	/** @brief Pulse LFO (int math implementation)
30	*
31	* This is a pulse Low Frequency Oscillator which uses pure integer
32	* math (without branches) to synthesize the pulse wave.
33	*/
34	template<LFO::range_type_t RANGE, int WIDTH /* in permilles */>
35	class LFOPulse : public LFOBase<RANGE> {
36	public:
37
38	/**
39	* Constructor
40	*
41	* @param Max - maximum value of the output levels
42	*/
43	LFOPulse(float Max) : LFOBase<RANGE>::LFOBase(Max) {
44	}
45
46	/**
47	* Calculates exactly one sample point of the LFO wave.
48	*
49	* @returns next LFO level
50	*/
51	inline float render() {
52	uiLevel += c;
53	if (RANGE == LFO::range_unsigned)
54	return uiLevel <= width ? normalizer : 0;
55	else /* signed range */
56	return uiLevel <= width ? normalizer : -normalizer;
57	}
58
59	/**
60	* Update LFO depth with a new external controller value.
61	*
62	* @param ExtControlValue - new external controller value
63	*/
64	inline void updateByMIDICtrlValue(const uint16_t& ExtControlValue) {
65	this->ExtControlValue = ExtControlValue;
66
67	const float max = (this->InternalDepth + ExtControlValue * this->ExtControlDepthCoeff) * this->ScriptDepthFactor;
68	normalizer = max;
69	}
70
71	/**
72	* Will be called by the voice when the key / voice was triggered.
73	*
74	* @param Frequency - frequency of the oscillator in Hz
75	* @param InternalDepth - firm, internal oscillator amplitude
76	* @param ExtControlDepth - defines how strong the external MIDI
77	* controller has influence on the
78	* oscillator amplitude
79	* @param FlipPhase - inverts the oscillator wave against
80	* a horizontal axis
81	* @param SampleRate - current sample rate of the engines
82	* audio output signal
83	* @param PulseWidth - the pulse width in percents
84	*/
85	void trigger(float Frequency, uint16_t InternalDepth, uint16_t ExtControlDepth, float PulseWidth, unsigned int SampleRate) {
86	this->Frequency = Frequency;
87	this->InternalDepth = (InternalDepth / 1200.0f) * this->Max;
88	this->ExtControlDepthCoeff = (((float) ExtControlDepth / 1200.0f) / 127.0f) * this->Max;
89	this->ScriptFrequencyFactor = this->ScriptDepthFactor = 1.f; // reset for new voice
90	this->pFinalDepth = NULL;
91	this->pFinalFrequency = NULL;
92
93	const unsigned int intLimit = (unsigned int) -1; // all 0xFFFF...
94	const float freq = Frequency * this->ScriptFrequencyFactor;
95	const float r = freq / (float) SampleRate; // frequency alteration quotient
96	c = (int) (intLimit * r);
97	width = (PulseWidth / 100.0) * intLimit;
98
99	uiLevel = 0;
100	}
101
102	virtual void trigger(float Frequency, LFO::start_level_t StartLevel, uint16_t InternalDepth, uint16_t ExtControlDepth, bool FlipPhase, unsigned int SampleRate) {
103	trigger(Frequency, InternalDepth, ExtControlDepth, WIDTH / 10.0f, SampleRate);
104	}
105
106	/**
107	* Should be invoked after the LFO is triggered.
108	* @param phase From 0 to 360 degrees.
109	*/
110	void setPhase(float phase) {
111	if (phase < 0) phase = 0;
112	if (phase > 360) phase = 360;
113	phase /= 360.0f;
114	const unsigned int intLimit = (unsigned int) -1; // all 0xFFFF...
115	uiLevel = intLimit * phase;
116	}
117
118	void setFrequency(float Frequency, unsigned int SampleRate) {
119	this->Frequency = Frequency;
120	const float freq = Frequency * this->ScriptFrequencyFactor;
121	const unsigned int intLimit = (unsigned int) -1; // all 0xFFFF...
122	float r = freq / (float) SampleRate; // frequency alteration quotient
123	c = (int) (intLimit * r);
124	}
125
126	void setScriptDepthFactor(float factor, bool isFinal) {
127	this->ScriptDepthFactor = factor;
128	// set or reset this script depth parameter to be the sole
129	// source for the LFO depth
130	if (isFinal && !this->pFinalDepth)
131	this->pFinalDepth = &this->ScriptDepthFactor;
132	else if (!isFinal && this->pFinalDepth == &this->ScriptDepthFactor)
133	this->pFinalDepth = NULL;
134	// recalculate upon new depth
135	updateByMIDICtrlValue(this->ExtControlValue);
136	}
137
138	void setScriptFrequencyFactor(float factor, unsigned int SampleRate) {
139	this->ScriptFrequencyFactor = factor;
140	// in case script frequency was set as "final" value before,
141	// reset it so that all sources are processed from now on
142	if (this->pFinalFrequency == &this->ScriptFrequencyFactor)
143	this->pFinalFrequency = NULL;
144	// recalculate upon new frequency
145	setFrequency(this->Frequency, SampleRate);
146	}
147
148	void setScriptFrequencyFinal(float hz, unsigned int SampleRate) {
149	this->ScriptFrequencyFactor = hz;
150	// assign script's given frequency as sole source for the LFO
151	// frequency, thus ignore all other sources
152	if (!this->pFinalFrequency)
153	this->pFinalFrequency = &this->ScriptFrequencyFactor;
154	// recalculate upon new frequency
155	setFrequency(this->Frequency, SampleRate);
156	}
157
158	protected:
159	unsigned int uiLevel;
160	unsigned int width;
161	int c;
162	float normalizer;
163	};
164
165	} // namespace LinuxSampler
166
167	#endif // __LS_PULSELFO_H__