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

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Revision 3118 - (hide annotations) (download) (as text)
Fri Apr 21 13:33:03 2017 UTC (6 years, 11 months ago) by schoenebeck
Original Path: linuxsampler/trunk/src/engines/common/PulseLFO.h
File MIME type: text/x-c++hdr
File size: 6806 byte(s)
* NKSP: Fixed crash when using built-in script array variable "%ALL_EVENTS".
* NKSP: Added built-in function "change_amp_lfo_depth()".
* NKSP: Added built-in function "change_amp_lfo_freq()".
* NKSP: Added built-in function "change_pitch_lfo_depth()".
* NKSP: Added built-in function "change_pitch_lfo_freq()".
* Bumped version (2.0.0.svn44).

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_PULSELFO_H__
23     #define __LS_PULSELFO_H__
24    
25     #include "LFOBase.h"
26    
27     namespace LinuxSampler {
28    
29     /** @brief Pulse LFO (int math implementation)
30     *
31     * This is a pulse Low Frequency Oscillator which uses pure integer
32     * math (without branches) to synthesize the pulse wave.
33     */
34     template<range_type_t RANGE, int WIDTH /* in permilles */>
35     class PulseLFO : public LFOBase<RANGE> {
36     public:
37    
38     /**
39     * Constructor
40     *
41     * @param Max - maximum value of the output levels
42     */
43     PulseLFO(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     uiLevel += c;
53     if (RANGE == range_unsigned)
54     return uiLevel <= width ? normalizer : 0;
55     else /* signed range */
56     return uiLevel <= width ? normalizer : -normalizer;
57     }
58    
59     /**
60     * Update LFO depth with a new external controller value.
61     *
62     * @param ExtControlValue - new external controller value
63     */
64 schoenebeck 3118 inline void updateByMIDICtrlValue(const uint16_t& ExtControlValue) {
65     this->ExtControlValue = ExtControlValue;
66    
67     const float max = (this->InternalDepth + ExtControlValue * this->ExtControlDepthCoeff) * this->ScriptDepthFactor;
68 iliev 2223 normalizer = max;
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 InternalDepth - firm, internal oscillator amplitude
76     * @param ExtControlDepth - defines how strong the external MIDI
77     * controller has influence on the
78     * oscillator amplitude
79     * @param FlipPhase - inverts the oscillator wave against
80     * a horizontal axis
81     * @param SampleRate - current sample rate of the engines
82     * audio output signal
83     * @param PulseWidth - the pulse width in percents
84     */
85     void trigger(float Frequency, uint16_t InternalDepth, uint16_t ExtControlDepth, float PulseWidth, unsigned int SampleRate) {
86 schoenebeck 3118 this->Frequency = Frequency;
87 iliev 2223 this->InternalDepth = (InternalDepth / 1200.0f) * this->Max;
88     this->ExtControlDepthCoeff = (((float) ExtControlDepth / 1200.0f) / 127.0f) * this->Max;
89 schoenebeck 3118 this->ScriptFrequencyFactor = this->ScriptDepthFactor = 1.f; // reset for new voice
90 iliev 2223
91     const unsigned int intLimit = (unsigned int) -1; // all 0xFFFF...
92 schoenebeck 3118 const float freq = Frequency * this->ScriptFrequencyFactor;
93     const float r = freq / (float) SampleRate; // frequency alteration quotient
94 iliev 2223 c = (int) (intLimit * r);
95     width = (PulseWidth / 100.0) * intLimit;
96    
97     uiLevel = 0;
98     }
99    
100     virtual void trigger(float Frequency, start_level_t StartLevel, uint16_t InternalDepth, uint16_t ExtControlDepth, bool FlipPhase, unsigned int SampleRate) {
101     trigger(Frequency, InternalDepth, ExtControlDepth, WIDTH / 10.0f, SampleRate);
102     }
103 iliev 2225
104     /**
105     * Should be invoked after the LFO is triggered.
106     * @param phase From 0 to 360 degrees.
107     */
108     void setPhase(float phase) {
109     if (phase < 0) phase = 0;
110     if (phase > 360) phase = 360;
111     phase /= 360.0f;
112     const unsigned int intLimit = (unsigned int) -1; // all 0xFFFF...
113     uiLevel = intLimit * phase;
114     }
115 iliev 2227
116     void setFrequency(float Frequency, unsigned int SampleRate) {
117 schoenebeck 3118 this->Frequency = Frequency;
118     const float freq = Frequency * this->ScriptFrequencyFactor;
119 iliev 2227 const unsigned int intLimit = (unsigned int) -1; // all 0xFFFF...
120 schoenebeck 3118 float r = freq / (float) SampleRate; // frequency alteration quotient
121 iliev 2227 c = (int) (intLimit * r);
122     }
123 iliev 2223
124 schoenebeck 3118 void setScriptDepthFactor(float factor) {
125     this->ScriptDepthFactor = factor;
126     updateByMIDICtrlValue(this->ExtControlValue);
127     }
128    
129     void setScriptFrequencyFactor(float factor, unsigned int SampleRate) {
130     this->ScriptFrequencyFactor = factor;
131     setFrequency(this->Frequency, SampleRate);
132     }
133    
134 iliev 2223 protected:
135     unsigned int uiLevel;
136     unsigned int width;
137     int c;
138     float normalizer;
139     };
140    
141     template<range_type_t RANGE>
142     class SquareLFO : public PulseLFO<RANGE, 500> {
143     public:
144     SquareLFO(float Max) : PulseLFO<RANGE, 500>::PulseLFO(Max) { }
145     };
146    
147     } // namespace LinuxSampler
148    
149     #endif // __LS_PULSELFO_H__

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