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

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Revision 2227 - (show annotations) (download) (as text)
Wed Aug 3 17:11:40 2011 UTC (12 years, 7 months ago) by iliev
File MIME type: text/x-c++hdr
File size: 5408 byte(s)
* sfz engine: implemented opcodes fillfo_freqccN,
  pitchlfo_freqccN, amplfo_freqccN, lfoN_freq_onccX

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_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
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
107 void setFrequency(float Frequency, unsigned int SampleRate) {
108 const unsigned int intLimit = (unsigned int) -1; // all 0xFFFF...
109 float r = Frequency / (float) SampleRate; // frequency alteration quotient
110 c = (int) (intLimit * r);
111 }
112
113 protected:
114 unsigned int uiLevel;
115 int c;
116 float c2;
117 float normalizer;
118 };
119
120 } // namespace LinuxSampler
121
122 #endif // __LS_SINELFO_H__

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