VTK
vtkgluPickMatrix.h
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1/*=========================================================================
2
3 Program: Visualization Toolkit
4 Module: vtkgluPickMatrix.h
5
6 Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
7 All rights reserved.
8 See Copyright.txt or http://www.kitware.com/Copyright.htm for details.
9
10 This software is distributed WITHOUT ANY WARRANTY; without even
11 the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
12 PURPOSE. See the above copyright notice for more information.
13
14=========================================================================*/
23#ifndef vtkgluPickMatrix_h
24#define vtkgluPickMatrix_h
25
26#include "vtkOpenGL.h" // Needed for GLfloat and GLdouble.
27
28// This function was copied from Mesa and sets up the pick matrix
29inline void vtkgluPickMatrix( GLdouble x, GLdouble y,
30 GLdouble width, GLdouble height,
31 int *origin, int *size )
32{
33 GLfloat m[16];
34 GLfloat sx, sy;
35 GLfloat tx, ty;
36
37 sx = size[0] / width;
38 sy = size[1] / height;
39 tx = (size[0] + 2.0 * (origin[0] - x)) / width;
40 ty = (size[1] + 2.0 * (origin[1] - y)) / height;
41
42#define M(row,col) m[col*4+row]
43 M(0,0) = sx; M(0,1) = 0.0; M(0,2) = 0.0; M(0,3) = tx;
44 M(1,0) = 0.0; M(1,1) = sy; M(1,2) = 0.0; M(1,3) = ty;
45 M(2,0) = 0.0; M(2,1) = 0.0; M(2,2) = 1.0; M(2,3) = 0.0;
46 M(3,0) = 0.0; M(3,1) = 0.0; M(3,2) = 0.0; M(3,3) = 1.0;
47#undef M
48
49 glMultMatrixf( m );
50}
51
52#endif
53// VTK-HeaderTest-Exclude: vtkgluPickMatrix.h
@ height
Definition: vtkX3D.h:254
@ size
Definition: vtkX3D.h:253
#define M(row, col)
void vtkgluPickMatrix(GLdouble x, GLdouble y, GLdouble width, GLdouble height, int *origin, int *size)