engines/common/SawLFO.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_SAWLFO_H__
#define __LS_SAWLFO_H__

#include "LFOBase.h"

namespace LinuxSampler {

    /** @brief Saw LFO (int math implementation)
     *
     * This is a saw Low Frequency Oscillator which uses pure integer
     * math (without branches) to synthesize the saw wave.
     */
    template<range_type_t RANGE, bool SAWUP>
    class SawLFO : public LFOBase<RANGE> {
        public:

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

            /**
             * Calculates exactly one sample point of the LFO wave.
             *
             * @returns next LFO level
             */
            inline float render() {
                const unsigned int intLimit = (unsigned int) -1; // all 0xFFFF...
                
                uiLevel += c;
                if (RANGE == range_unsigned)
                    return normalizer * (float) (SAWUP ? uiLevel : intLimit - uiLevel);
                else /* signed range */
                    return normalizer * (float) (SAWUP ? uiLevel : intLimit - uiLevel) + offset;
            }

            /**
             * 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 unsigned int intLimit = (unsigned int) -1; // all 0xFFFF...
                const float max = (this->InternalDepth + ExtControlValue * this->ExtControlDepthCoeff) * this->ScriptDepthFactor;
                if (RANGE == range_unsigned) {
                    normalizer = max / (float) intLimit;
                } else { // signed range
                    normalizer = max / (float) intLimit * 2.0f;
                    offset     = -max;
                }
            }
            
            /**
             * Will be called by the voice when the key / voice was triggered.
             *
             * @param Frequency       - frequency of the oscillator in Hz
             * @param StartLevel      - not implemented
             * @param InternalDepth   - firm, internal oscillator amplitude
             * @param ExtControlDepth - defines how strong the external MIDI
             *                          controller has influence on the
             *                          oscillator amplitude
             * @param FlipPhase       - not implemented
             * @param SampleRate      - current sample rate of the engines
             *                          audio output signal
             */
            virtual void trigger(float Frequency, start_level_t StartLevel, uint16_t InternalDepth, uint16_t ExtControlDepth, bool FlipPhase, 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

                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);

                uiLevel = 0;
            }
            
            /**
             * 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) {
                this->ScriptDepthFactor = factor;
                updateByMIDICtrlValue(this->ExtControlValue);
            }

            void setScriptFrequencyFactor(float factor, unsigned int SampleRate) {
                this->ScriptFrequencyFactor = factor;
                setFrequency(this->Frequency, SampleRate);
            }

        protected:
            unsigned int uiLevel;
            int   c;
            float offset; ///< only needed for signed range
            float normalizer;
    };
    
    
    template<range_type_t RANGE>
    class SawUpLFO : public SawLFO<RANGE, true> {
        public:
            SawUpLFO(float Max) : SawLFO<RANGE, true>::SawLFO(Max) { }
    };
    
    template<range_type_t RANGE>
    class SawDownLFO : public SawLFO<RANGE, false> {
        public:
            SawDownLFO(float Max) : SawLFO<RANGE, false>::SawLFO(Max) { }
    };

} // namespace LinuxSampler

#endif // __LS_SAWLFO_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_SAWLFO_H__
23	#define __LS_SAWLFO_H__
24
25	#include "LFOBase.h"
26
27	namespace LinuxSampler {
28
29	/** @brief Saw LFO (int math implementation)
30	*
31	* This is a saw Low Frequency Oscillator which uses pure integer
32	* math (without branches) to synthesize the saw wave.
33	*/
34	template<range_type_t RANGE, bool SAWUP>
35	class SawLFO : public LFOBase<RANGE> {
36	public:
37
38	/**
39	* Constructor
40	*
41	* @param Max - maximum value of the output levels
42	*/
43	SawLFO(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	const unsigned int intLimit = (unsigned int) -1; // all 0xFFFF...
53
54	uiLevel += c;
55	if (RANGE == range_unsigned)
56	return normalizer * (float) (SAWUP ? uiLevel : intLimit - uiLevel);
57	else /* signed range */
58	return normalizer * (float) (SAWUP ? uiLevel : intLimit - uiLevel) + offset;
59	}
60
61	/**
62	* Update LFO depth with a new external controller value.
63	*
64	* @param ExtControlValue - new external controller value
65	*/
66	inline void updateByMIDICtrlValue(const uint16_t& ExtControlValue) {
67	this->ExtControlValue = ExtControlValue;
68
69	const unsigned int intLimit = (unsigned int) -1; // all 0xFFFF...
70	const float max = (this->InternalDepth + ExtControlValue * this->ExtControlDepthCoeff) * this->ScriptDepthFactor;
71	if (RANGE == range_unsigned) {
72	normalizer = max / (float) intLimit;
73	} else { // signed range
74	normalizer = max / (float) intLimit * 2.0f;
75	offset = -max;
76	}
77	}
78
79	/**
80	* Will be called by the voice when the key / voice was triggered.
81	*
82	* @param Frequency - frequency of the oscillator in Hz
83	* @param StartLevel - not implemented
84	* @param InternalDepth - firm, internal oscillator amplitude
85	* @param ExtControlDepth - defines how strong the external MIDI
86	* controller has influence on the
87	* oscillator amplitude
88	* @param FlipPhase - not implemented
89	* @param SampleRate - current sample rate of the engines
90	* audio output signal
91	*/
92	virtual void trigger(float Frequency, start_level_t StartLevel, uint16_t InternalDepth, uint16_t ExtControlDepth, bool FlipPhase, unsigned int SampleRate) {
93	this->Frequency = Frequency;
94	this->InternalDepth = (InternalDepth / 1200.0f) * this->Max;
95	this->ExtControlDepthCoeff = (((float) ExtControlDepth / 1200.0f) / 127.0f) * this->Max;
96	this->ScriptFrequencyFactor = this->ScriptDepthFactor = 1.f; // reset for new voice
97
98	const unsigned int intLimit = (unsigned int) -1; // all 0xFFFF...
99	const float freq = Frequency * this->ScriptFrequencyFactor;
100	const float r = freq / (float) SampleRate; // frequency alteration quotient
101	c = (int) (intLimit * r);
102
103	uiLevel = 0;
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) {
127	this->ScriptDepthFactor = factor;
128	updateByMIDICtrlValue(this->ExtControlValue);
129	}
130
131	void setScriptFrequencyFactor(float factor, unsigned int SampleRate) {
132	this->ScriptFrequencyFactor = factor;
133	setFrequency(this->Frequency, SampleRate);
134	}
135
136	protected:
137	unsigned int uiLevel;
138	int c;
139	float offset; ///< only needed for signed range
140	float normalizer;
141	};
142
143
144	template<range_type_t RANGE>
145	class SawUpLFO : public SawLFO<RANGE, true> {
146	public:
147	SawUpLFO(float Max) : SawLFO<RANGE, true>::SawLFO(Max) { }
148	};
149
150	template<range_type_t RANGE>
151	class SawDownLFO : public SawLFO<RANGE, false> {
152	public:
153	SawDownLFO(float Max) : SawLFO<RANGE, false>::SawLFO(Max) { }
154	};
155
156	} // namespace LinuxSampler
157
158	#endif // __LS_SAWLFO_H__