public void GetWorldCoord(int ix, int iy, double fz, ref msgVectorStruct coord)
{
double x, y, z, winX, winY, winZ;
// Fix the yPos value. MS Windows origin 0,0 is upper left
// while OpenGL windows origin 0,0 is lower left...
winX = ix;
winY = m_iViewport[3] - iy;
// Add the camera's focal length, or distance from 'LookAt' to 'Eye' position
// to the given 'z' coordinate.
fz += GetFocalLength();
// Calculate the winZ coordinate:
if (m_bPerspective)
{
// Compensate for perspective view
winZ = 0.5 + (((m_fFar + m_fNear) - (2 * m_fFar * m_fNear) / fz)) / (2 * (m_fFar - m_fNear));
}
else
{
// winZ is linearly interpolated between the Near_Far clipping plane
winZ = (fz - m_fNear) / (m_fFar - m_fNear);
}
// Unproject the point
unsafe
{
fixed(double *m_dModelViewMatrixPtr = m_dModelViewMatrix)
{
fixed(double *m_dProjectionMatrixPtr = m_dProjectionMatrix)
{
fixed(int *m_iViewportPtr = m_iViewport)
{
OpenGLControl.gluUnProject(winX, winY, winZ,
m_dModelViewMatrixPtr,
m_dProjectionMatrixPtr,
m_iViewportPtr,
&x, &y, &z);
}
}
}
}
coord.x = x;
coord.y = y;
coord.z = z;
}