/[svn]/linuxsampler/trunk/src/engines/common/SineLFO.h
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Annotation of /linuxsampler/trunk/src/engines/common/SineLFO.h

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Revision 2225 - (hide annotations) (download) (as text)
Tue Aug 2 13:44:57 2011 UTC (12 years, 7 months ago) by iliev
File MIME type: text/x-c++hdr
File size: 5092 byte(s)
* sfz engine: implemented opcodes lfoN_phase, lfoN_phase_onccX,
  lfoN_pitch, lfoN_pitch_onccX

1 iliev 2223 /***************************************************************************
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_SINELFO_H__
23     #define __LS_SINELFO_H__
24    
25     #include "LFOBase.h"
26    
27     namespace LinuxSampler {
28    
29     /** @brief sine LFO
30     */
31     template<range_type_t RANGE>
32     class SineLFO : public LFOBase<RANGE> {
33     public:
34    
35     /**
36     * Constructor
37     *
38     * @param Max - maximum value of the output levels
39     */
40     SineLFO(float Max) : LFOBase<RANGE>::LFOBase(Max) {
41     }
42    
43     /**
44     * Calculates exactly one sample point of the LFO wave.
45     *
46     * @returns next LFO level
47     */
48     inline float render() {
49     uiLevel += c;
50     if (RANGE == range_unsigned)
51     return normalizer * (sin(c2 * (float)uiLevel) + 1.0f);
52     else /* signed range */
53     return normalizer * sin(c2 * (float)uiLevel);
54     }
55    
56     /**
57     * Update LFO depth with a new external controller value.
58     *
59     * @param ExtControlValue - new external controller value
60     */
61     inline void update(const uint16_t& ExtControlValue) {
62     const unsigned int intLimit = (unsigned int) -1; // all 0xFFFF...
63     const float max = this->InternalDepth + ExtControlValue * this->ExtControlDepthCoeff;
64     if (RANGE == range_unsigned) {
65     normalizer = max / 2.0f;
66     } else { // signed range
67     normalizer = max;
68     }
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 StartLevel - not implemented
76     * @param InternalDepth - firm, internal oscillator amplitude
77     * @param ExtControlDepth - defines how strong the external MIDI
78     * controller has influence on the
79     * oscillator amplitude
80     * @param FlipPhase - not implemented
81     * @param SampleRate - current sample rate of the engines
82     * audio output signal
83     */
84     virtual void trigger(float Frequency, start_level_t StartLevel, uint16_t InternalDepth, uint16_t ExtControlDepth, bool FlipPhase, unsigned int SampleRate) {
85     this->InternalDepth = (InternalDepth / 1200.0f) * this->Max;
86     this->ExtControlDepthCoeff = (((float) ExtControlDepth / 1200.0f) / 127.0f) * this->Max;
87    
88     const unsigned int intLimit = (unsigned int) -1; // all 0xFFFF...
89     const float r = Frequency / (float) SampleRate; // frequency alteration quotient
90     c = (int) (intLimit * r);
91     c2 = (2.0f * M_PI) / (float) intLimit;
92    
93     uiLevel = 0;
94     }
95 iliev 2225
96     /**
97     * @param phase 0 to 360 degrees
98     */
99     void setPhase(float phase) {
100     if (phase < 0) phase = 0;
101     if (phase > 360) phase = 360;
102     phase /= 360.0f;
103     const unsigned int intLimit = (unsigned int) -1; // all 0xFFFF...
104     uiLevel = intLimit * phase;
105     }
106 iliev 2223
107     protected:
108     unsigned int uiLevel;
109     int c;
110     float c2;
111     float normalizer;
112     };
113    
114     } // namespace LinuxSampler
115    
116     #endif // __LS_SINELFO_H__

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