engines/common/LFOBase.h

/***************************************************************************
 *                                                                         *
 *   Copyright (C) 2005 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__

#ifdef HAVE_CONFIG_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
#else
# include <math.h>
# include <stdint.h>
#endif

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;
            }

            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 update(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 ExtControlDepthCoeff;
    };

} // namespace LinuxSampler

#endif // __LS_LFOBASE_H__
1	/***************************************************************************
2	* *
3	* Copyright (C) 2005 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	#ifdef HAVE_CONFIG_H
25	# include "../../common/global.h"
26	# include "../../common/RTMath.h"
27
28	// IDs of the two possible implementations
29	// we get the implementation to pick from config.h
30	// the implementation IDs should be the same like in benchmarks/triang.cpp !
31	# define INT_MATH_SOLUTION 2
32	# define DI_HARMONIC_SOLUTION 3
33	# define INT_ABS_MATH_SOLUTION 5
34	#else
35	# include <math.h>
36	# include <stdint.h>
37	#endif
38
39	namespace LinuxSampler {
40
41	// ************* types *************
42	// *
43
44	/**
45	* Whether the LFO should have positive AND negative value range
46	* (signed) or only a positive value range (unsigned).
47	*/
48	enum range_type_t {
49	range_signed, ///< LFO's level will wave between -max ... +max
50	range_unsigned ///< LFO's level will wave between 0 ... +max
51	};
52
53	/**
54	* Defines the start level of the LFO wave within the given value range.
55	*/
56	enum start_level_t {
57	start_level_max, ///< wave starts from given max. level
58	start_level_mid, ///< wave starts from the middle of the given value range
59	start_level_min ///< wave starts from given min. level
60	};
61
62	/** @brief LFO (abstract base class)
63	*
64	* Abstract base class for all Low Frequency Oscillator implementations.
65	*/
66	template<range_type_t RANGE>
67	class LFOBase {
68	public:
69
70	// ************* attributes *************
71	// *
72
73	uint8_t ExtController; ///< MIDI control change controller number if the LFO is controlled by an external controller, 0 otherwise.
74
75
76	// ************* methods *************
77	// *
78
79	/**
80	* Constructor
81	*
82	* @param Max - maximum value of the output levels
83	*/
84	LFOBase(float Max) {
85	this->ExtController = 0;
86	this->Max = Max;
87	}
88
89	virtual ~LFOBase() {
90	}
91
92	/**
93	* Calculates exactly one sample point of the LFO wave. This
94	* inline method has to be implemented by the descendant.
95	*
96	* @returns next LFO level
97	*/
98	//abstract inline float render(); //< what a pity that abstract inliners are not supported by C++98 (probably by upcoming C++0x?)
99
100	/**
101	* Update LFO depth with a new external controller value. This
102	* inline method has to be implemented by the descendant.
103	*
104	* @param ExtControlValue - new external controller value
105	*/
106	//abstract inline void update(const uint16_t& ExtControlValue); //< what a pity that abstract inliners are not supported by C++98 (probably by upcoming C++0x?)
107
108	/**
109	* Will be called by the voice when the key / voice was triggered.
110	*
111	* @param Frequency - frequency of the oscillator in Hz
112	* @param StartLevel - on which level the wave should start
113	* @param InternalDepth - firm, internal oscillator amplitude
114	* @param ExtControlDepth - defines how strong the external MIDI
115	* controller has influence on the
116	* oscillator amplitude
117	* @param FlipPhase - inverts the oscillator wave against
118	* a horizontal axis
119	* @param SampleRate - current sample rate of the engines
120	* audio output signal
121	*/
122	virtual void trigger(float Frequency, start_level_t StartLevel, uint16_t InternalDepth, uint16_t ExtControlDepth, bool FlipPhase, unsigned int SampleRate) = 0;
123
124	protected:
125	float Max;
126	float InternalDepth;
127	float ExtControlDepthCoeff;
128	};
129
130	} // namespace LinuxSampler
131
132	#endif // __LS_LFOBASE_H__