LibreOffice Module vcl (master)  1
Matrix3.cxx
Go to the documentation of this file.
1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
2 /*
3  * This file is part of the LibreOffice project.
4  *
5  * This Source Code Form is subject to the terms of the Mozilla Public
6  * License, v. 2.0. If a copy of the MPL was not distributed with this
7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
8  *
9  */
10 
11 #include <pdf/Matrix3.hxx>
12 #include <cmath>
13 
14 namespace vcl::pdf
15 {
17 {
18  // initialize to unity
19  f[0] = 1.0;
20  f[1] = 0.0;
21  f[2] = 0.0;
22  f[3] = 1.0;
23  f[4] = 0.0;
24  f[5] = 0.0;
25 }
26 
27 Point Matrix3::transform(const Point& rOrig) const
28 {
29  double x = static_cast<double>(rOrig.X()), y = static_cast<double>(rOrig.Y());
30  return Point(x * f[0] + y * f[2] + f[4], x * f[1] + y * f[3] + f[5]);
31 }
32 
33 void Matrix3::skew(double alpha, double beta)
34 {
35  double fn[6];
36  double tb = tan(beta);
37  fn[0] = f[0] + f[2] * tb;
38  fn[1] = f[1];
39  fn[2] = f[2] + f[3] * tb;
40  fn[3] = f[3];
41  fn[4] = f[4] + f[5] * tb;
42  fn[5] = f[5];
43  if (alpha != 0.0)
44  {
45  double ta = tan(alpha);
46  fn[1] += f[0] * ta;
47  fn[3] += f[2] * ta;
48  fn[5] += f[4] * ta;
49  }
50  set(fn);
51 }
52 
53 void Matrix3::scale(double sx, double sy)
54 {
55  double fn[6];
56  fn[0] = sx * f[0];
57  fn[1] = sy * f[1];
58  fn[2] = sx * f[2];
59  fn[3] = sy * f[3];
60  fn[4] = sx * f[4];
61  fn[5] = sy * f[5];
62  set(fn);
63 }
64 
65 void Matrix3::rotate(double angle)
66 {
67  double fn[6];
68  double fSin = sin(angle);
69  double fCos = cos(angle);
70  fn[0] = f[0] * fCos - f[1] * fSin;
71  fn[1] = f[0] * fSin + f[1] * fCos;
72  fn[2] = f[2] * fCos - f[3] * fSin;
73  fn[3] = f[2] * fSin + f[3] * fCos;
74  fn[4] = f[4] * fCos - f[5] * fSin;
75  fn[5] = f[4] * fSin + f[5] * fCos;
76  set(fn);
77 }
78 
79 void Matrix3::translate(double tx, double ty)
80 {
81  f[4] += tx;
82  f[5] += ty;
83 }
84 
86 {
87  // short circuit trivial cases
88  if (f[1] == f[2] && f[1] == 0.0 && f[0] == f[3] && f[0] == 1.0)
89  {
90  f[4] = -f[4];
91  f[5] = -f[5];
92  return;
93  }
94 
95  // check determinant
96  const double fDet = f[0] * f[3] - f[1] * f[2];
97  if (fDet == 0.0)
98  return;
99 
100  // invert the matrix
101  double fn[6];
102  fn[0] = +f[3] / fDet;
103  fn[1] = -f[1] / fDet;
104  fn[2] = -f[2] / fDet;
105  fn[3] = +f[0] / fDet;
106 
107  // apply inversion to translation
108  fn[4] = -(f[4] * fn[0] + f[5] * fn[2]);
109  fn[5] = -(f[4] * fn[1] + f[5] * fn[3]);
110 
111  set(fn);
112 }
113 
114 } // end vcl::pdf
115 
116 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */
void rotate(double angle)
Definition: Matrix3.cxx:65
void scale(double sx, double sy)
Definition: Matrix3.cxx:53
float x
void translate(double tx, double ty)
Definition: Matrix3.cxx:79
double f[6]
Definition: Matrix3.hxx:28
float y
void set(const double *pn)
Definition: Matrix3.hxx:30
void skew(double alpha, double beta)
Definition: Matrix3.cxx:33
Point transform(const Point &rPoint) const
Definition: Matrix3.cxx:27