QGIS API Documentation  3.4.3-Madeira (2f64a3c)
Bezier3D.cpp
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1 /***************************************************************************
2  Bezier3D.cpp
3  ------------
4  copyright : (C) 2004 by Marco Hugentobler
5  email : [email protected]
6  ***************************************************************************/
7 
8 /***************************************************************************
9  * *
10  * This program is free software; you can redistribute it and/or modify *
11  * it under the terms of the GNU General Public License as published by *
12  * the Free Software Foundation; either version 2 of the License, or *
13  * (at your option) any later version. *
14  * *
15  ***************************************************************************/
16 
17 #include "Bezier3D.h"
18 #include "qgslogger.h"
19 #include "Vector3D.h"
20 #include "MathUtils.h"
21 
22 void Bezier3D::calcFirstDer( float t, Vector3D *v )
23 {
24  if ( v && mControlPoly )
25  {
26  v->setX( 0 );
27  v->setY( 0 );
28  v->setZ( 0 );
29 
30  if ( mControlPoly->count() < 2 )
31  {
32  return;
33  }
34 
35  for ( int n = 1; n <= int( mControlPoly->count() - 1 ); n++ )
36  {
37  double bernst = MathUtils::calcBernsteinPoly( mControlPoly->count() - 2, n - 1, t );
38  v->setX( v->getX() + ( ( *mControlPoly )[n]->x() - ( *mControlPoly )[n - 1]->x() )*bernst );
39  v->setY( v->getY() + ( ( *mControlPoly )[n]->y() - ( *mControlPoly )[n - 1]->y() )*bernst );
40  v->setZ( v->getZ() + ( ( *mControlPoly )[n]->z() - ( *mControlPoly )[n - 1]->z() )*bernst );
41  }
42  v->setX( v->getX() * ( mControlPoly->count() - 1 ) );
43  v->setY( v->getY() * ( mControlPoly->count() - 1 ) );
44  v->setZ( v->getZ() * ( mControlPoly->count() - 1 ) );
45  }
46 
47  else
48  {
49  QgsDebugMsg( QStringLiteral( "warning: null pointer" ) );
50  }
51 }
52 
53 void Bezier3D::calcPoint( float t, QgsPoint *p )
54 {
55 
56  if ( p && mControlPoly )
57  {
58  p->setX( 0 );
59  p->setY( 0 );
60  p->setZ( 0 );
61 
62  for ( int n = 1; n <= int( mControlPoly->count() ); n++ )
63  {
64  double bernst = MathUtils::calcBernsteinPoly( mControlPoly->count() - 1, n - 1, t );
65  p->setX( p->x() + ( *mControlPoly )[n - 1]->x()*bernst );
66  p->setY( p->y() + ( *mControlPoly )[n - 1]->y()*bernst );
67  p->setZ( p->z() + ( *mControlPoly )[n - 1]->z()*bernst );
68  }
69  }
70 
71  else
72  {
73  QgsDebugMsg( QStringLiteral( "warning: null pointer" ) );
74  }
75 }
76 
77 void Bezier3D::calcSecDer( float t, Vector3D *v )
78 {
79  if ( v && mControlPoly )
80  {
81  v->setX( 0 );
82  v->setY( 0 );
83  v->setZ( 0 );
84 
85  int nodes = mControlPoly->count();
86  if ( nodes < 3 )
87  {
88  return;
89  }
90 
91  for ( int n = 1; n <= int( nodes - 2 ); n++ )
92  {
93  double bernst = MathUtils::calcBernsteinPoly( nodes - 3, n - 1, t );
94  v->setX( v->getX() + ( ( *mControlPoly )[n + 1]->x() - 2 * ( *mControlPoly )[n]->x() + ( *mControlPoly )[n - 1]->x() )*bernst );
95  v->setY( v->getY() + ( ( *mControlPoly )[n + 1]->y() - 2 * ( *mControlPoly )[n]->y() + ( *mControlPoly )[n - 1]->y() )*bernst );
96  v->setZ( v->getZ() + ( ( *mControlPoly )[n + 1]->z() - 2 * ( *mControlPoly )[n]->z() + ( *mControlPoly )[n - 1]->z() )*bernst );
97  }
98  v->setX( v->getX()*MathUtils::faculty( nodes - 1 ) / MathUtils::faculty( nodes - 3 ) );
99  v->setY( v->getY()*MathUtils::faculty( nodes - 1 ) / MathUtils::faculty( nodes - 3 ) );
100  v->setZ( v->getZ()*MathUtils::faculty( nodes - 1 ) / MathUtils::faculty( nodes - 3 ) );
101  }
102 
103  else
104  {
105  QgsDebugMsg( QStringLiteral( "warning: null pointer" ) );
106  }
107 }
108 
109 
110 void Bezier3D::changeDirection()//does this work correctly? more testing is needed.
111 {
112  if ( mControlPoly )
113  {
114  QgsPoint **pointer = new QgsPoint*[mControlPoly->count()];//create an array to temporarily store pointer to the control points
115  for ( int i = 0; i < mControlPoly->count(); i++ )//store the points
116  {
117  pointer[i] = ( *mControlPoly )[i];
118  }
119 
120  for ( int i = 0; i < mControlPoly->count(); i++ )
121  {
122  mControlPoly->insert( i, pointer[( mControlPoly->count() - 1 ) - i] );
123  }
124  delete [] pointer;
125  }
126 
127  else
128  {
129  QgsDebugMsg( QStringLiteral( "warning: null pointer" ) );
130  }
131 }
132 
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void setX(double x)
Sets the x-component of the vector.
Definition: Vector3D.h:103
QVector< QgsPoint * > * mControlPoly
MControlPoly stores the points of the control polygon.
double y
Definition: qgspoint.h:42
void setZ(double z)
Sets the point&#39;s z-coordinate.
Definition: qgspoint.h:237
#define QgsDebugMsg(str)
Definition: qgslogger.h:38
void changeDirection() override
Changes the order of control points.
Definition: Bezier3D.cpp:110
void calcPoint(float t, QgsPoint *p) override
Calculates the point on the curve and assigns it to p.
Definition: Bezier3D.cpp:53
void calcSecDer(float t, Vector3D *v) override
Calculates the second derivative and assigns it to v.
Definition: Bezier3D.cpp:77
double getZ() const
Returns the z-component of the vector.
Definition: Vector3D.h:98
Class Vector3D represents a 3D-Vector, capable to store x-,y- and z-coordinates in double values...
Definition: Vector3D.h:33
void setZ(double z)
Sets the z-component of the vector.
Definition: Vector3D.h:113
void calcFirstDer(float t, Vector3D *v) override
Calculates the first derivative and assigns it to v.
Definition: Bezier3D.cpp:22
Point geometry type, with support for z-dimension and m-values.
Definition: qgspoint.h:37
void setX(double x)
Sets the point&#39;s x-coordinate.
Definition: qgspoint.h:213
void setY(double y)
Sets the point&#39;s y-coordinate.
Definition: qgspoint.h:224
double getY() const
Returns the y-component of the vector.
Definition: Vector3D.h:93
void setY(double y)
Sets the y-component of the vector.
Definition: Vector3D.h:108
double ANALYSIS_EXPORT calcBernsteinPoly(int n, int i, double t)
Calculates the value of a Bernstein polynomial.
Definition: MathUtils.cpp:101
double z
Definition: qgspoint.h:43
double getX() const
Returns the x-component of the vector.
Definition: Vector3D.h:88
int ANALYSIS_EXPORT faculty(int n)
Faculty function.
Definition: MathUtils.cpp:221
double x
Definition: qgspoint.h:41