Files
create/src/Base/ViewProj.cpp
2018-11-20 19:21:15 +01:00

138 lines
4.2 KiB
C++

/***************************************************************************
* Copyright (c) 2005 Imetric 3D GmbH *
* *
* This file is part of the FreeCAD CAx development system. *
* *
* This library is free software; you can redistribute it and/or *
* modify it under the terms of the GNU Library General Public *
* License as published by the Free Software Foundation; either *
* version 2 of the License, or (at your option) any later version. *
* *
* This library is distributed in the hope that it will be useful, *
* but WITHOUT ANY WARRANTY; without even the implied warranty of *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
* GNU Library General Public License for more details. *
* *
* You should have received a copy of the GNU Library General Public *
* License along with this library; see the file COPYING.LIB. If not, *
* write to the Free Software Foundation, Inc., 59 Temple Place, *
* Suite 330, Boston, MA 02111-1307, USA *
* *
***************************************************************************/
#include "PreCompiled.h"
#include "ViewProj.h"
using namespace Base;
ViewProjMatrix::ViewProjMatrix (const Matrix4D &rclMtx)
: _clMtx(rclMtx)
{
double m30 = _clMtx[3][0];
double m31 = _clMtx[3][1];
double m32 = _clMtx[3][2];
double m33 = _clMtx[3][3];
isOrthographic = (m30 == 0 && m31 == 0 && m32 == 0 && m33 == 1);
// Only for orthographic projection mode we can compute a single
// matrix performing all steps.
// For perspective projection the scaling and translation must
// be done afterwards because it depends on the input point.
if (isOrthographic) {
// Scale from [-1,1] to [0,1]
// As done in OpenInventor sources (see SbDPViewVolume::projectToScreen)
_clMtx.scale(0.5, 0.5, 0.5);
_clMtx.move(0.5, 0.5, 0.5);
}
_clMtxInv = _clMtx;
_clMtxInv.inverseGauss();
}
ViewProjMatrix::~ViewProjMatrix()
{
}
Matrix4D ViewProjMatrix::getProjectionMatrix (void) const
{
// Return the same matrix as passed to the constructor
Matrix4D mat(_clMtx);
if (isOrthographic) {
mat.move(-0.5, -0.5, -0.5);
mat.scale(2.0, 2.0, 2.0);
}
return mat;
}
template<typename Vec>
void perspectiveTransform(const Base::Matrix4D& mat, Vec& pnt)
{
double m30 = mat[3][0];
double m31 = mat[3][1];
double m32 = mat[3][2];
double m33 = mat[3][3];
double w = (pnt.x * m30 + pnt.y * m31 + pnt.z * m32 + m33);
mat.multVec(pnt, pnt);
pnt /= w;
}
Vector3f ViewProjMatrix::operator()(const Vector3f& src) const
{
Vector3f dst;
if (!isOrthographic) {
dst = src;
perspectiveTransform<Vector3f>(_clMtx, dst);
dst.Set(0.5*dst.x+0.5, 0.5*dst.y+0.5, 0.5*dst.z+0.5);
}
else {
_clMtx.multVec(src, dst);
}
return dst;
}
Vector3d ViewProjMatrix::operator()(const Vector3d& src) const
{
Vector3d dst;
if (!isOrthographic) {
dst = src;
perspectiveTransform<Vector3d>(_clMtx, dst);
dst.Set(0.5*dst.x+0.5, 0.5*dst.y+0.5, 0.5*dst.z+0.5);
}
else {
_clMtx.multVec(src, dst);
}
return dst;
}
Vector3f ViewProjMatrix::inverse (const Vector3f& src) const
{
Vector3f dst;
if (!isOrthographic) {
dst.Set(2.0*src.x-1.0, 2.0*src.y-1.0, 2.0*src.z-1.0);
perspectiveTransform<Vector3f>(_clMtxInv, dst);
}
else {
_clMtxInv.multVec(src, dst);
}
return dst;
}
Vector3d ViewProjMatrix::inverse (const Vector3d& src) const
{
Vector3d dst;
if (!isOrthographic) {
dst.Set(2.0*src.x-1.0, 2.0*src.y-1.0, 2.0*src.z-1.0);
perspectiveTransform<Vector3d>(_clMtxInv, dst);
}
else {
_clMtxInv.multVec(src, dst);
}
return dst;
}