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

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Revision 3118 - (hide annotations) (download) (as text)
Fri Apr 21 13:33:03 2017 UTC (7 years ago) by schoenebeck
Original Path: linuxsampler/trunk/src/engines/common/SawLFO.h
File MIME type: text/x-c++hdr
File size: 7057 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_SAWLFO_H__
23     #define __LS_SAWLFO_H__
24    
25     #include "LFOBase.h"
26    
27     namespace LinuxSampler {
28    
29     /** @brief Saw LFO (int math implementation)
30     *
31     * This is a saw Low Frequency Oscillator which uses pure integer
32     * math (without branches) to synthesize the saw wave.
33     */
34     template<range_type_t RANGE, bool SAWUP>
35     class SawLFO : public LFOBase<RANGE> {
36     public:
37    
38     /**
39     * Constructor
40     *
41     * @param Max - maximum value of the output levels
42     */
43     SawLFO(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     const unsigned int intLimit = (unsigned int) -1; // all 0xFFFF...
53    
54     uiLevel += c;
55     if (RANGE == range_unsigned)
56     return normalizer * (float) (SAWUP ? uiLevel : intLimit - uiLevel);
57     else /* signed range */
58     return normalizer * (float) (SAWUP ? uiLevel : intLimit - uiLevel) + offset;
59     }
60    
61     /**
62     * Update LFO depth with a new external controller value.
63     *
64     * @param ExtControlValue - new external controller value
65     */
66 schoenebeck 3118 inline void updateByMIDICtrlValue(const uint16_t& ExtControlValue) {
67     this->ExtControlValue = ExtControlValue;
68    
69 iliev 2223 const unsigned int intLimit = (unsigned int) -1; // all 0xFFFF...
70 schoenebeck 3118 const float max = (this->InternalDepth + ExtControlValue * this->ExtControlDepthCoeff) * this->ScriptDepthFactor;
71 iliev 2223 if (RANGE == range_unsigned) {
72     normalizer = max / (float) intLimit;
73     } else { // signed range
74     normalizer = max / (float) intLimit * 2.0f;
75     offset = -max;
76     }
77     }
78    
79     /**
80     * Will be called by the voice when the key / voice was triggered.
81     *
82     * @param Frequency - frequency of the oscillator in Hz
83     * @param StartLevel - not implemented
84     * @param InternalDepth - firm, internal oscillator amplitude
85     * @param ExtControlDepth - defines how strong the external MIDI
86     * controller has influence on the
87     * oscillator amplitude
88     * @param FlipPhase - not implemented
89     * @param SampleRate - current sample rate of the engines
90     * audio output signal
91     */
92     virtual void trigger(float Frequency, start_level_t StartLevel, uint16_t InternalDepth, uint16_t ExtControlDepth, bool FlipPhase, unsigned int SampleRate) {
93 schoenebeck 3118 this->Frequency = Frequency;
94 iliev 2223 this->InternalDepth = (InternalDepth / 1200.0f) * this->Max;
95     this->ExtControlDepthCoeff = (((float) ExtControlDepth / 1200.0f) / 127.0f) * this->Max;
96 schoenebeck 3118 this->ScriptFrequencyFactor = this->ScriptDepthFactor = 1.f; // reset for new voice
97 iliev 2223
98     const unsigned int intLimit = (unsigned int) -1; // all 0xFFFF...
99 schoenebeck 3118 const float freq = Frequency * this->ScriptFrequencyFactor;
100     const float r = freq / (float) SampleRate; // frequency alteration quotient
101 iliev 2223 c = (int) (intLimit * r);
102    
103     uiLevel = 0;
104     }
105 iliev 2225
106     /**
107     * Should be invoked after the LFO is triggered.
108     * @param phase From 0 to 360 degrees.
109     */
110     void setPhase(float phase) {
111     if (phase < 0) phase = 0;
112     if (phase > 360) phase = 360;
113     phase /= 360.0f;
114     const unsigned int intLimit = (unsigned int) -1; // all 0xFFFF...
115     uiLevel = intLimit * phase;
116     }
117 iliev 2227
118     void setFrequency(float Frequency, unsigned int SampleRate) {
119 schoenebeck 3118 this->Frequency = Frequency;
120     const float freq = Frequency * this->ScriptFrequencyFactor;
121 iliev 2227 const unsigned int intLimit = (unsigned int) -1; // all 0xFFFF...
122 schoenebeck 3118 float r = freq / (float) SampleRate; // frequency alteration quotient
123 iliev 2227 c = (int) (intLimit * r);
124     }
125 iliev 2223
126 schoenebeck 3118 void setScriptDepthFactor(float factor) {
127     this->ScriptDepthFactor = factor;
128     updateByMIDICtrlValue(this->ExtControlValue);
129     }
130    
131     void setScriptFrequencyFactor(float factor, unsigned int SampleRate) {
132     this->ScriptFrequencyFactor = factor;
133     setFrequency(this->Frequency, SampleRate);
134     }
135    
136 iliev 2223 protected:
137     unsigned int uiLevel;
138     int c;
139     float offset; ///< only needed for signed range
140     float normalizer;
141     };
142    
143    
144     template<range_type_t RANGE>
145     class SawUpLFO : public SawLFO<RANGE, true> {
146     public:
147     SawUpLFO(float Max) : SawLFO<RANGE, true>::SawLFO(Max) { }
148     };
149    
150     template<range_type_t RANGE>
151     class SawDownLFO : public SawLFO<RANGE, false> {
152     public:
153     SawDownLFO(float Max) : SawLFO<RANGE, false>::SawLFO(Max) { }
154     };
155    
156     } // namespace LinuxSampler
157    
158     #endif // __LS_SAWLFO_H__

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