vcglib/wrap/gl/pick.h

247 lines
8.1 KiB
C++

/****************************************************************************
* VCGLib o o *
* Visual and Computer Graphics Library o o *
* _ O _ *
* Copyright(C) 2004-2016 \/)\/ *
* Visual Computing Lab /\/| *
* ISTI - Italian National Research Council | *
* \ *
* All rights reserved. *
* *
* This program is free software; you can redistribute it and/or modify *
* it under the terms of the GNU General Public License as published by *
* the Free Software Foundation; either version 2 of the License, or *
* (at your option) any later version. *
* *
* This program 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 General Public License (http://www.gnu.org/licenses/gpl.txt) *
* for more details. *
* *
****************************************************************************/
#ifndef __PICK______H
#define __PICK______H
// Assumes OpenGL already included
#include <vector>
#include <algorithm>
#include <vcg/complex/complex.h>
namespace vcg{
template <class MESH_TYPE>
class GLPickTri
{
public:
typedef typename MESH_TYPE::ScalarType ScalarType;
typedef typename MESH_TYPE::CoordType CoordType;
typedef typename MESH_TYPE::FaceIterator FaceIterator;
typedef typename MESH_TYPE::VertexIterator VertexIterator;
typedef typename MESH_TYPE::FacePointer FacePointer;
typedef typename MESH_TYPE::VertexPointer VertexPointer;
typedef typename MESH_TYPE::VertexType VertexType;
static CoordType glProject(const Eigen::Matrix<ScalarType,4,4> &M, const ScalarType * viewport, const CoordType &p)
{
const ScalarType vx=viewport[0];
const ScalarType vy=viewport[1];
const ScalarType vw2=viewport[2]/ScalarType(2.0);
const ScalarType vh2=viewport[3]/ScalarType(2.0);
Eigen::Matrix<ScalarType,4,1> vp(p[0],p[1],p[2],ScalarType(1.0));
Eigen::Matrix<ScalarType,4,1> vpp = M*vp;
Eigen::Matrix<ScalarType,4,1> ndc = vpp/vpp[3];
CoordType sc(vw2*ndc[0] + vx+vw2,
vh2*ndc[1] + vy+vh2,
ndc[2]);
return sc;
}
static void FillProjectedVector(MESH_TYPE &m, std::vector<CoordType> &pVec, const Eigen::Matrix<ScalarType,4,4> &M, const ScalarType * viewportF)
{
pVec.resize(m.vert.size());
for(size_t i=0;i<m.vert.size();++i) if(!m.vert[i].IsD())
{
pVec[i] = GLPickTri<MESH_TYPE>::glProject(M, viewportF,CoordType::Construct(m.vert[i].P()));
}
}
static void glGetMatrixAndViewport(Eigen::Matrix<ScalarType,4,4> &M, ScalarType *viewportF)
{
Eigen::Matrix4d mp,mm;
GLint viewport[4];
glGetIntegerv(GL_VIEWPORT,viewport);
for(int i=0;i<4;++i) viewportF[i]=viewport[i];
glGetDoublev(GL_PROJECTION_MATRIX, mp.data());
glGetDoublev(GL_MODELVIEW_MATRIX, mm.data());
M = (mp*mm).cast<ScalarType>();
}
// compute a bbox in Device Coordinate (with the z without the near far normalization and ranged in -1 1)
static Box3<ScalarType> ComputeDCBox(int x, int y, int width, int height)
{
Box3<ScalarType> bb;
bb.SetNull();
bb.Add(CoordType(x-width/ScalarType(2.0),y-height/ScalarType(2.0),ScalarType(-1.0)));
bb.Add(CoordType(x+width/ScalarType(2.0),y+height/ScalarType(2.0), ScalarType(1.0)));
return bb;
}
static bool PickClosestFace(int x, int y, MESH_TYPE &m, FacePointer &fp,int width=4, int height=4)
{
Eigen::Matrix<ScalarType,4,4> M;
ScalarType viewportF[4];
glGetMatrixAndViewport(M,viewportF);
Box3<ScalarType> reg=ComputeDCBox(x,y,width,height);
ScalarType bzmin = std::numeric_limits<ScalarType>::max();
fp=0;
for(size_t i=0;i<m.face.size();++i) if(!m.face[i].IsD())
{
CoordType bary = vcg::Barycenter(m.face[i]);
CoordType bz = glProject(M, viewportF,bary);
if(bz[2]<bzmin && reg.IsIn(bz))
{
bzmin=bz[2];
fp = &m.face[i];
}
}
return fp!=0;
}
static bool PickClosestVert(int x, int y, MESH_TYPE &m, VertexPointer &vp,int width=4, int height=4)
{
Eigen::Matrix<ScalarType,4,4> M;
ScalarType viewportF[4];
glGetMatrixAndViewport(M,viewportF);
ScalarType bzmin = std::numeric_limits<ScalarType>::max();
vp=0;
Box3<ScalarType> reg=ComputeDCBox(x,y,width,height);
for(size_t i=0;i<m.vert.size();++i) if(!m.vert[i].IsD())
{
CoordType bz = glProject(M, viewportF,m.vert[i].P());
if(bz[2]<bzmin && reg.IsIn(bz))
{
bzmin=bz[2];
vp = &m.vert[i];
}
}
return vp!=0;
}
static int PickVert(int x, int y, MESH_TYPE &m, std::vector<VertexPointer> &result, int width=4, int height=4)
{
result.clear();
static Eigen::Matrix<ScalarType,4,4> lastM;
static MESH_TYPE *lastm=0;
static std::vector<CoordType> pVec;
Eigen::Matrix<ScalarType,4,4> M;
ScalarType viewportF[4];
glGetMatrixAndViewport(M,viewportF);
Box3<ScalarType> reg =ComputeDCBox(x,y,width,height);
if ((M != lastM) || (&m != lastm) || (pVec.size() != m.VN()))
{
FillProjectedVector(m,pVec,M,viewportF);
lastM = M;
lastm = &m;
}
for(size_t i=0;i<m.vert.size();++i) if(!m.vert[i].IsD())
{
if(reg.IsIn(pVec[i]))
result.push_back(&m.vert[i]);
}
return result.size();
}
static int PickFace(int x, int y, MESH_TYPE &m, std::vector<FacePointer> &result, int width = 4, int height = 4)
{
static Eigen::Matrix<ScalarType, 4, 4> lastM;
static MESH_TYPE *lastm = 0;
static std::vector<CoordType> pVec;
ScalarType viewportF[4];
Eigen::Matrix<ScalarType, 4, 4> M;
glGetMatrixAndViewport(M, viewportF);
result.clear();
Box3<ScalarType> reg;
reg.Add(CoordType(x - width / ScalarType(2.0), y - height / ScalarType(2.0), ScalarType(-1.0)));
reg.Add(CoordType(x + width / ScalarType(2.0), y + height / ScalarType(2.0), ScalarType(1.0)));
if ((M != lastM) || (&m != lastm) || (pVec.size() != m.VN()))
{
FillProjectedVector(m, pVec, M, viewportF);
lastM = M;
lastm = &m;
}
for (size_t i = 0; i < m.face.size(); ++i)
{
if (!m.face[i].IsD())
{
const CoordType &p0 = pVec[tri::Index(m, m.face[i].V(0))];
const CoordType &p1 = pVec[tri::Index(m, m.face[i].V(1))];
const CoordType &p2 = pVec[tri::Index(m, m.face[i].V(2))];
if (!(abs(p0[2]) > 1 || abs(p1[2]) > 1 || abs(p2[2]) > 1) && IntersectionTriangleBox(reg, p0, p1, p2))
result.push_back(&m.face[i]);
}
}
return result.size();
}
// Same of above but it also assumes that you want only visible faces.
// Visibility is computed according to the current depth buffer.
static int PickVisibleFace(int x, int y, MESH_TYPE &m, std::vector<FacePointer> &resultZ, int width=4, int height=4)
{
ScalarType vp[4];
Eigen::Matrix<ScalarType,4,4> M;
glGetMatrixAndViewport(M,vp);
int screenW = (int)(vp[2]-vp[0]);
int screenH = (int)(vp[3]-vp[1]);
GLfloat *buffer = new GLfloat[screenW*screenH];
//glReadPixels does NOT accept GL_DOUBLE
//GLenum err = glGetError();
glReadPixels(vp[0],vp[1],vp[2],vp[3],GL_DEPTH_COMPONENT,GL_FLOAT,buffer);
//err = glGetError();
std::vector<FacePointer> result;
PickFace(x,y,m,result,width,height);
ScalarType LocalEpsilon(ScalarType(0.001));
for(size_t i =0;i<result.size();++i)
{
CoordType p = glProject(M,vp,CoordType::Construct(Barycenter(*(result[i])))) ;
if(p[0] >=0 && p[0]<screenW && p[1] >=0 && p[1]<screenH)
{
ScalarType bufZ(buffer[int(p[0])+int(p[1])*screenW]);
if(bufZ + LocalEpsilon >= ScalarType(p[2]+1.0)/2.0)
resultZ.push_back(result[i]);
}
}
delete [] buffer;
return resultZ.size();
}
};
} // end namespace vcg
#endif