HalfEdgeDSRendering.cpp

#define RADPERDEG 0.0174533

#include "HalfEdgeDSRendering.h"

#include <GL/glut.h>
const float VDIAM = 0.10f;
const float EDIAM = 0.04f;

void renderDS(const HalfEdgeDS& heDS)
{
     for (auto const *v : heDS.getVertices()) renderV(v); // render all vertices as points
     for (auto const *e : heDS.getEdges()) renderE(e); // render all edges as lines
}

void renderE(const Edge* e, const Vec3f& color)
{
     glColor3f(color.x, color.y, color.z);
     Vec3f p1 = e->he1->startV->coordinates;
     Vec3f p2 = e->he2->startV->coordinates;
     Vec3f dir = p2 - p1;
     float length = dir.length();
     if (length < 0.00001f) return;

     GLUquadricObj *quadObj;

     glPushMatrix();

     glTranslated(p1.x, p1.y, p1.z);

     if ((dir.x != 0.) || (dir.y != 0.)) {
          glRotated(atan2(dir.y, dir.x) / RADPERDEG, 0., 0., 1.);
          glRotated(atan2(sqrt(dir.x*dir.x + dir.y*dir.y), dir.z) / RADPERDEG, 0., 1., 0.);
     }
     else if (dir.z < 0) {
          glRotated(180, 1., 0., 0.);
     }

     quadObj = gluNewQuadric();
     gluQuadricDrawStyle(quadObj, GLU_FILL);
     gluQuadricNormals(quadObj, GLU_SMOOTH);
     gluCylinder(quadObj, EDIAM*0.5f, EDIAM*0.5f, length, 16, 1);
     gluDeleteQuadric(quadObj);
     glPopMatrix();
}

void renderHE(const HalfEdge* he, const Vec3f& color, const float dim)
{
     Vec3f start = he->startV->coordinates;
     Vec3f end = he->getEdgeSibling()->startV->coordinates;
     glColor3f(color.x, color.y, color.z);
     renderArrow(start, end, dim);
}

void renderV(const Vertex* v, const Vec3f& color)
{
     glColor3f(color.x, color.y, color.z);
     Vec3f p = v->coordinates;
     GLUquadricObj *quadObj;

     glPushMatrix();
     glTranslated(p.x, p.y, p.z);

     quadObj = gluNewQuadric();
     gluQuadricDrawStyle(quadObj, GLU_FILL);
     gluQuadricNormals(quadObj, GLU_SMOOTH);
     gluSphere(quadObj, VDIAM * 0.5f, 16, 16);
     gluDeleteQuadric(quadObj);
     glPopMatrix();
}


void renderHEActive(const HalfEdge* he)
{
     if(he)
          renderHE(he, Vec3f(0.004f, 0.388f, 0.941f));
}

void renderArrow(const Vec3f& p1, const Vec3f& p2, float diameter)
{
     Vec3f dir = p2 - p1;
     float length = dir.length();
     if (length < 0.00001f) return;

     GLUquadricObj *quadObj;

     glPushMatrix ();

     glTranslated(p1.x, p1.y, p1.z);

     if((dir.x!=0.)||(dir.y!=0.)) {
          glRotated(atan2(dir.y,dir.x)/RADPERDEG,0.,0.,1.);
          glRotated(atan2(sqrt(dir.x*dir.x+dir.y*dir.y),dir.z)/RADPERDEG,0.,1.,0.);
     } else if (dir.z<0){
          glRotated(180,1.,0.,0.);
     }

     glTranslatef(0,0,length-4*diameter);

     quadObj = gluNewQuadric ();
     gluQuadricDrawStyle (quadObj, GLU_FILL);
     gluQuadricNormals (quadObj, GLU_SMOOTH);
     gluCylinder(quadObj, 2*diameter, 0.0, 4*diameter, 32, 1);
     gluDeleteQuadric(quadObj);

     quadObj = gluNewQuadric ();
     gluQuadricDrawStyle (quadObj, GLU_FILL);
     gluQuadricNormals (quadObj, GLU_SMOOTH);
     gluDisk(quadObj, 0.0, 2*diameter, 32, 1);
     gluDeleteQuadric(quadObj);

     glTranslatef(0,0,-length+4*diameter);

     quadObj = gluNewQuadric ();
     gluQuadricDrawStyle (quadObj, GLU_FILL);
     gluQuadricNormals (quadObj, GLU_SMOOTH);
     gluCylinder(quadObj, diameter, diameter, length-4*diameter, 32, 1);
     gluDeleteQuadric(quadObj);

     quadObj = gluNewQuadric ();
     gluQuadricDrawStyle (quadObj, GLU_FILL);
     gluQuadricNormals (quadObj, GLU_SMOOTH);
     gluDisk(quadObj, 0.0, diameter, 32, 1);
     gluDeleteQuadric(quadObj);

     glPopMatrix ();
}