1 /*
2  * Copyright (C) 2011 Google Inc. All rights reserved.
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  *
8  * 1.  Redistributions of source code must retain the above copyright
9  *     notice, this list of conditions and the following disclaimer.
10  * 2.  Redistributions in binary form must reproduce the above copyright
11  *     notice, this list of conditions and the following disclaimer in the
12  *     documentation and/or other materials provided with the distribution.
13  * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
14  *     its contributors may be used to endorse or promote products derived
15  *     from this software without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
18  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
19  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
20  * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
21  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
22  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
23  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
24  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 #ifndef ZeroPole_h
30 #define ZeroPole_h
31 
32 namespace WebCore {
33 
34 // ZeroPole is a simple filter with one zero and one pole.
35 
36 class ZeroPole {
37 public:
ZeroPole()38     ZeroPole()
39         : m_zero(0)
40         , m_pole(0)
41         , m_lastX(0)
42         , m_lastY(0)
43     {
44     }
45 
46     void process(const float *source, float *destination, int framesToProcess);
47 
48     // Reset filter state.
reset()49     void reset() { m_lastX = 0; m_lastY = 0; }
50 
setZero(float zero)51     void setZero(float zero) { m_zero = zero; }
setPole(float pole)52     void setPole(float pole) { m_pole = pole; }
53 
zero()54     float zero() const { return m_zero; }
pole()55     float pole() const { return m_pole; }
56 
57 private:
58     float m_zero;
59     float m_pole;
60     float m_lastX;
61     float m_lastY;
62 };
63 
64 } // namespace WebCore
65 
66 #endif // ZeroPole_h
67