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added picking of visible faces

This commit is contained in:
Paolo Cignoni 2009-04-01 14:51:49 +00:00
parent dd468f9d5d
commit b22077f200
1 changed files with 37 additions and 2 deletions
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35
wrap/gl/pick.h
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@ -129,8 +129,43 @@ public:
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 PickFaceVisible(int x, int y, MESH_TYPE &m, std::vector<FacePointer> &resultZ, int width=4, int height=4, bool sorted=true)
{
// First step
double mm[16];
double mp[16];
GLint vp[4];
glGetIntegerv(GL_VIEWPORT,vp);
glGetDoublev(GL_MODELVIEW_MATRIX ,mm);
glGetDoublev(GL_PROJECTION_MATRIX ,mp);
int screenW = vp[2]-vp[0];
int screenH = vp[3]-vp[1];
GLfloat *buffer = new GLfloat[screenW*screenH];
glReadPixels(vp[0],vp[1],vp[2],vp[3],GL_DEPTH_COMPONENT,GL_FLOAT,buffer);
std::vector<FacePointer> result;
PickFace(x,y,m,result,width,height,sorted);
float LocalEpsilon = 0.001f;
for(int i =0;i<result.size();++i)
{
Point3f v=Barycenter(*(result[i]));
GLdouble tx,ty,tz;
gluProject(v.X(),v.Y(),v.Z(), mm,mp,vp, &tx,&ty,&tz);
if(tx >=0 && tx<screenW && ty >=0 && ty<screenH)
{
float bufZ = buffer[int(tx)+int(ty)*screenW];
//qDebug("face %i txyz (%f %f %f) bufz %f",i,tx,ty,tz,bufZ);
if(bufZ + LocalEpsilon >= tz)
resultZ.push_back(result[i]);
}
}
delete [] buffer;
}
};