engines/common/LFOBase.h

/***************************************************************************
 *                                                                         *
 *   Copyright (C) 2005 - 2019 Christian Schoenebeck                       *
 *                                                                         *
 *   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_LFOBASE_H__
#define __LS_LFOBASE_H__

#include "../../common/global.h"
#include "../../common/RTMath.h"

// IDs of the two possible implementations
// we get the implementation to pick from config.h
// the implementation IDs should be the same like in benchmarks/triang.cpp !
#define INT_MATH_SOLUTION       2
#define DI_HARMONIC_SOLUTION    3
#define INT_ABS_MATH_SOLUTION   5

#include <math.h>
#include <stdint.h>

namespace LinuxSampler {

    // *************** types ***************
    // *

    /**
     * Whether the LFO should have positive AND negative value range
     * (signed) or only a positive value range (unsigned).
     */
    enum range_type_t {
        range_signed,  ///< LFO's level will wave between -max ... +max
        range_unsigned ///< LFO's level will wave between 0 ... +max
    };

    /**
     * Defines the start level of the LFO wave within the given value range.
     */
    enum start_level_t {
        start_level_max, ///< wave starts from given max. level
        start_level_mid, ///< wave starts from the middle of the given value range
        start_level_min  ///< wave starts from given min. level
    };

    /** @brief LFO (abstract base class)
     * 
     * Abstract base class for all Low Frequency Oscillator implementations.
     */
    template<range_type_t RANGE>
    class LFOBase {
        public:

            // *************** attributes ***************
            // *

            uint8_t ExtController; ///< MIDI control change controller number if the LFO is controlled by an external controller, 0 otherwise.


            // *************** methods ***************
            // *

            /**
             * Constructor
             *
             * @param Max - maximum value of the output levels
             */
            LFOBase(float Max) {
                this->ExtController = 0;
                this->Max           = Max;
                this->InternalDepth = 0;
                this->Frequency = 20.f;
                this->ExtControlValue = 0;
                this->ExtControlDepthCoeff = 0;
                this->ScriptDepthFactor = 1.f;
                this->ScriptFrequencyFactor = 1.f;
                this->pFinalDepth = NULL;
                this->pFinalFrequency = NULL;
            }

            virtual ~LFOBase() {
            }

            /**
             * Calculates exactly one sample point of the LFO wave. This
             * inline method has to be implemented by the descendant.
             *
             * @returns next LFO level
             */
            //abstract inline float render(); //< what a pity that abstract inliners are not supported by C++98 (probably by upcoming C++0x?)

            /**
             * Update LFO depth with a new external controller value. This
             * inline method has to be implemented by the descendant.
             *
             * @param ExtControlValue - new external controller value
             */
            //abstract inline void updateByMIDICtrlValue(const uint16_t& ExtControlValue); //< what a pity that abstract inliners are not supported by C++98 (probably by upcoming C++0x?)

            /**
             * Will be called by the voice when the key / voice was triggered.
             *
             * @param Frequency       - frequency of the oscillator in Hz
             * @param StartLevel      - on which level the wave should start
             * @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
             */
            virtual void trigger(float Frequency, start_level_t StartLevel, uint16_t InternalDepth, uint16_t ExtControlDepth, bool FlipPhase, unsigned int SampleRate) = 0;

        protected:
            float Max;
            float InternalDepth;
            float Frequency; ///< Internal base frequency for this LFO.
            float ExtControlValue; ///< The current external MIDI controller value (0-127).
            float ExtControlDepthCoeff; ///< A usually constant factor used to convert a new MIDI controller value from range 0-127 to the required internal implementation dependent value range.
            float ScriptDepthFactor; ///< Usually neutral (1.0), only altered by external RT instrument script functions.
            float ScriptFrequencyFactor; ///< Usually neutral (1.0), only altered by external RT instrument script functions.
            float* pFinalDepth; ///< Usually NULL; it may be set to one of above's member variables in order to process that and ignore all other sources for LFO depth.
            float* pFinalFrequency; ///< Usually NULL; it may be set to one of above's member variables in order to process that and ignore all other sources for LFO frequency.
    };

} // namespace LinuxSampler

#endif // __LS_LFOBASE_H__
1	/***************************************************************************
2	* *
3	* Copyright (C) 2005 - 2019 Christian Schoenebeck *
4	* *
5	* This library is free software; you can redistribute it and/or modify *
6	* it under the terms of the GNU General Public License as published by *
7	* the Free Software Foundation; either version 2 of the License, or *
8	* (at your option) any later version. *
9	* *
10	* This library is distributed in the hope that it will be useful, *
11	* but WITHOUT ANY WARRANTY; without even the implied warranty of *
12	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
13	* GNU General Public License for more details. *
14	* *
15	* You should have received a copy of the GNU General Public License *
16	* along with this library; if not, write to the Free Software *
17	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, *
18	* MA 02111-1307 USA *
19	***************************************************************************/
20
21	#ifndef __LS_LFOBASE_H__
22	#define __LS_LFOBASE_H__
23
24	#include "../../common/global.h"
25	#include "../../common/RTMath.h"
26
27	// IDs of the two possible implementations
28	// we get the implementation to pick from config.h
29	// the implementation IDs should be the same like in benchmarks/triang.cpp !
30	#define INT_MATH_SOLUTION 2
31	#define DI_HARMONIC_SOLUTION 3
32	#define INT_ABS_MATH_SOLUTION 5
33
34	#include <math.h>
35	#include <stdint.h>
36
37	namespace LinuxSampler {
38
39	// ************* types *************
40	// *
41
42	/**
43	* Whether the LFO should have positive AND negative value range
44	* (signed) or only a positive value range (unsigned).
45	*/
46	enum range_type_t {
47	range_signed, ///< LFO's level will wave between -max ... +max
48	range_unsigned ///< LFO's level will wave between 0 ... +max
49	};
50
51	/**
52	* Defines the start level of the LFO wave within the given value range.
53	*/
54	enum start_level_t {
55	start_level_max, ///< wave starts from given max. level
56	start_level_mid, ///< wave starts from the middle of the given value range
57	start_level_min ///< wave starts from given min. level
58	};
59
60	/** @brief LFO (abstract base class)
61	*
62	* Abstract base class for all Low Frequency Oscillator implementations.
63	*/
64	template<range_type_t RANGE>
65	class LFOBase {
66	public:
67
68	// ************* attributes *************
69	// *
70
71	uint8_t ExtController; ///< MIDI control change controller number if the LFO is controlled by an external controller, 0 otherwise.
72
73
74	// ************* methods *************
75	// *
76
77	/**
78	* Constructor
79	*
80	* @param Max - maximum value of the output levels
81	*/
82	LFOBase(float Max) {
83	this->ExtController = 0;
84	this->Max = Max;
85	this->InternalDepth = 0;
86	this->Frequency = 20.f;
87	this->ExtControlValue = 0;
88	this->ExtControlDepthCoeff = 0;
89	this->ScriptDepthFactor = 1.f;
90	this->ScriptFrequencyFactor = 1.f;
91	this->pFinalDepth = NULL;
92	this->pFinalFrequency = NULL;
93	}
94
95	virtual ~LFOBase() {
96	}
97
98	/**
99	* Calculates exactly one sample point of the LFO wave. This
100	* inline method has to be implemented by the descendant.
101	*
102	* @returns next LFO level
103	*/
104	//abstract inline float render(); //< what a pity that abstract inliners are not supported by C++98 (probably by upcoming C++0x?)
105
106	/**
107	* Update LFO depth with a new external controller value. This
108	* inline method has to be implemented by the descendant.
109	*
110	* @param ExtControlValue - new external controller value
111	*/
112	//abstract inline void updateByMIDICtrlValue(const uint16_t& ExtControlValue); //< what a pity that abstract inliners are not supported by C++98 (probably by upcoming C++0x?)
113
114	/**
115	* Will be called by the voice when the key / voice was triggered.
116	*
117	* @param Frequency - frequency of the oscillator in Hz
118	* @param StartLevel - on which level the wave should start
119	* @param InternalDepth - firm, internal oscillator amplitude
120	* @param ExtControlDepth - defines how strong the external MIDI
121	* controller has influence on the
122	* oscillator amplitude
123	* @param FlipPhase - inverts the oscillator wave against
124	* a horizontal axis
125	* @param SampleRate - current sample rate of the engines
126	* audio output signal
127	*/
128	virtual void trigger(float Frequency, start_level_t StartLevel, uint16_t InternalDepth, uint16_t ExtControlDepth, bool FlipPhase, unsigned int SampleRate) = 0;
129
130	protected:
131	float Max;
132	float InternalDepth;
133	float Frequency; ///< Internal base frequency for this LFO.
134	float ExtControlValue; ///< The current external MIDI controller value (0-127).
135	float ExtControlDepthCoeff; ///< A usually constant factor used to convert a new MIDI controller value from range 0-127 to the required internal implementation dependent value range.
136	float ScriptDepthFactor; ///< Usually neutral (1.0), only altered by external RT instrument script functions.
137	float ScriptFrequencyFactor; ///< Usually neutral (1.0), only altered by external RT instrument script functions.
138	float* pFinalDepth; ///< Usually NULL; it may be set to one of above's member variables in order to process that and ignore all other sources for LFO depth.
139	float* pFinalFrequency; ///< Usually NULL; it may be set to one of above's member variables in order to process that and ignore all other sources for LFO frequency.
140	};
141
142	} // namespace LinuxSampler
143
144	#endif // __LS_LFOBASE_H__