ui/gfx/matrix3_f.h

   1 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef UI_GFX_MATRIX3_F_H_
   6 #define UI_GFX_MATRIX3_F_H_
   7
   8 #include "base/logging.h"
   9 #include "ui/gfx/vector3d_f.h"
  10
  11 namespace gfx {
  12
  13 class UI_EXPORT Matrix3F {
  14  public:
  15   ~Matrix3F();
  16
  17   static Matrix3F Zeros();
  18   static Matrix3F Ones();
  19   static Matrix3F Identity();
  20   static Matrix3F FromOuterProduct(const Vector3dF& a, const Vector3dF& bt);
  21
  22   bool IsEqual(const Matrix3F& rhs) const;
  23
  24   // Element-wise comparison with given precision.
  25   bool IsNear(const Matrix3F& rhs, float precision) const;
  26
  27   float get(int i, int j) const {
  28     return data_[MatrixToArrayCoords(i, j)];
  29   }
  30
  31   void set(int i, int j, float v) {
  32     data_[MatrixToArrayCoords(i, j)] = v;
  33   }
  34
  35   void set(float m00, float m01, float m02,
  36            float m10, float m11, float m12,
  37            float m20, float m21, float m22) {
  38     data_[0] = m00;
  39     data_[1] = m01;
  40     data_[2] = m02;
  41     data_[3] = m10;
  42     data_[4] = m11;
  43     data_[5] = m12;
  44     data_[6] = m20;
  45     data_[7] = m21;
  46     data_[8] = m22;
  47   }
  48
  49   Vector3dF get_column(int i) const {
  50     return Vector3dF(
  51       data_[MatrixToArrayCoords(0, i)],
  52       data_[MatrixToArrayCoords(1, i)],
  53       data_[MatrixToArrayCoords(2, i)]);
  54   }
  55
  56   void set_column(int i, const Vector3dF& c) {
  57     data_[MatrixToArrayCoords(0, i)] = c.x();
  58     data_[MatrixToArrayCoords(1, i)] = c.y();
  59     data_[MatrixToArrayCoords(2, i)] = c.z();
  60   }
  61
  62   // Returns an inverse of this if the matrix is non-singular, zero (== Zero())
  63   // otherwise.
  64   Matrix3F Inverse() const;
  65
  66   // Value of the determinant of the matrix.
  67   float Determinant() const;
  68
  69   // Trace (sum of diagonal elements) of the matrix.
  70   float Trace() const {
  71     return data_[MatrixToArrayCoords(0, 0)] +
  72         data_[MatrixToArrayCoords(1, 1)] +
  73         data_[MatrixToArrayCoords(2, 2)];
  74   }
  75
  76   // Compute eigenvalues and (optionally) normalized eigenvectors of
  77   // a positive defnite matrix *this. Eigenvectors are computed only if
  78   // non-null |eigenvectors| matrix is passed. If it is NULL, the routine
  79   // will not attempt to compute eigenvectors but will still return eigenvalues
  80   // if they can be computed.
  81   // If eigenvalues cannot be computed (the matrix does not meet constraints)
  82   // the 0-vector is returned. Note that to retrieve eigenvalues, the matrix
  83   // only needs to be symmetric while eigenvectors require it to be
  84   // positive-definite. Passing a non-positive definite matrix will result in
  85   // NaNs in vectors which cannot be computed.
  86   // Eigenvectors are placed as column in |eigenvectors| in order corresponding
  87   // to eigenvalues.
  88   Vector3dF SolveEigenproblem(Matrix3F* eigenvectors) const;
  89
  90  private:
  91   Matrix3F();  // Uninitialized default.
  92
  93   static int MatrixToArrayCoords(int i, int j) {
  94     DCHECK(i >= 0 && i < 3);
  95     DCHECK(j >= 0 && j < 3);
  96     return i * 3 + j;
  97   }
  98
  99   float data_[9];
 100 };
 101
 102 inline bool operator==(const Matrix3F& lhs, const Matrix3F& rhs) {
 103   return lhs.IsEqual(rhs);
 104 }
 105
 106 }  // namespace gfx
 107
 108 #endif  // UI_GFX_MATRIX3_F_H_