1 // Copyright 2013 Emilie Gillet.
2 //
3 // Author: Emilie Gillet (emilie.o.gillet@gmail.com)
4 //
5 // Permission is hereby granted, free of charge, to any person obtaining a copy
6 // of this software and associated documentation files (the "Software"), to deal
7 // in the Software without restriction, including without limitation the rights
8 // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
9 // copies of the Software, and to permit persons to whom the Software is
10 // furnished to do so, subject to the following conditions:
11 //
12 // The above copyright notice and this permission notice shall be included in
13 // all copies or substantial portions of the Software.
14 //
15 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
18 // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
20 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
21 // THE SOFTWARE.
22 //
23 // See http://creativecommons.org/licenses/MIT/ for more information.
24 //
25 // -----------------------------------------------------------------------------
26 //
27 // Bouncing ball.
28 
29 #ifndef PEAKS_MODULATIONS_BOUNCING_BALL_H_
30 #define PEAKS_MODULATIONS_BOUNCING_BALL_H_
31 
32 #include "stmlib/stmlib.h"
33 
34 #include <algorithm>
35 
36 #include "stmlib/utils/dsp.h"
37 #include "peaks/resources.h"
38 
39 #include "peaks/gate_processor.h"
40 
41 namespace peaks {
42 
43 class BouncingBall {
44  public:
BouncingBall()45   BouncingBall() { }
~BouncingBall()46   ~BouncingBall() { }
47 
Init()48   void Init() {
49     initial_amplitude_ = 65535L << 14;
50     gravity_ = 40;
51     bounce_loss_ = 4095;
52     initial_velocity_ = 0;
53   }
54 
Configure(uint16_t * parameter,ControlMode control_mode)55   void Configure(uint16_t* parameter, ControlMode control_mode) {
56     if (control_mode == CONTROL_MODE_HALF) {
57       set_initial_amplitude(65535);
58       set_initial_velocity(0);
59       set_gravity(parameter[0]);
60       set_bounce_loss(parameter[1]);
61     } else {
62       set_gravity(parameter[0]);
63       set_bounce_loss(parameter[1]);
64       set_initial_amplitude(parameter[2]);
65       set_initial_velocity(parameter[3] - 32768);
66     }
67   }
68 
Process(const GateFlags * gate_flags,int16_t * out,size_t size)69   void Process(const GateFlags* gate_flags, int16_t* out, size_t size) {
70     while (size--) {
71       GateFlags gate_flag = *gate_flags++;
72       if (gate_flag & GATE_FLAG_RISING) {
73         velocity_ = initial_velocity_;
74         position_ = initial_amplitude_;
75       }
76       velocity_ -= gravity_;
77       position_ += velocity_;
78       if (position_ < 0) {
79         position_ = 0;
80         velocity_ = -(velocity_ >> 12) * bounce_loss_;
81       }
82       if (position_ > (32767L << 15)) {
83         position_ = 32767L << 15;
84         velocity_ = -(velocity_ >> 12) * bounce_loss_;
85       }
86       *out++ = position_ >> 15;
87     }
88   }
89 
set_gravity(uint16_t gravity)90   inline void set_gravity(uint16_t gravity) {
91     gravity_ = stmlib::Interpolate88(lut_gravity, gravity);
92   }
93 
set_bounce_loss(uint16_t bounce_loss)94   inline void set_bounce_loss(uint16_t bounce_loss) {
95     uint32_t b = 65535 - bounce_loss;
96     b = b * b >> 16;
97     bounce_loss_ = 4095 - (b >> 4);
98   }
99 
set_initial_amplitude(uint16_t initial_amplitude)100   inline void set_initial_amplitude(uint16_t initial_amplitude) {
101     initial_amplitude_ = static_cast<int32_t>(initial_amplitude) << 14;
102   }
103 
set_initial_velocity(int16_t initial_velocity)104   inline void set_initial_velocity(int16_t initial_velocity) {
105     initial_velocity_ = static_cast<int32_t>(initial_velocity) << 4;
106   }
107 
FillBuffer()108   inline bool FillBuffer() const {
109     return true;
110   }
111 
112  private:
113   int32_t gravity_;
114   int32_t bounce_loss_;
115   int32_t initial_amplitude_;
116   int32_t initial_velocity_;
117 
118   int32_t velocity_;
119   int32_t position_;
120 
121   DISALLOW_COPY_AND_ASSIGN(BouncingBall);
122 };
123 
124 }  // namespace peaks
125 
126 #endif  // PEAKS_MODULATIONS_BOUNCING_BALL_H_
127