void DrawPolygon(clipper::Polygons &pgs)
{
glColor4f(0.0f, 0.0f, 0.0f, 0.4f);
GLUtesselator* tess = gluNewTess();
gluTessCallback(tess, GLU_TESS_BEGIN, (void (CALLBACK*)())&BeginCallback);
gluTessCallback(tess, GLU_TESS_VERTEX, (void (CALLBACK*)())&VertexCallback);
gluTessCallback(tess, GLU_TESS_END, (void (CALLBACK*)())&EndCallback);
gluTessCallback(tess, GLU_TESS_COMBINE, (void (CALLBACK*)())&CombineCallback);
gluTessCallback(tess, GLU_TESS_ERROR, (void (CALLBACK*)())&ErrorCallback);
gluTessProperty(tess, GLU_TESS_WINDING_RULE, GLU_TESS_WINDING_NONZERO);
gluTessProperty(tess, GLU_TESS_BOUNDARY_ONLY, GL_FALSE);
gluTessBeginPolygon(tess, NULL);
for (clipper::Polygons::size_type i = 0; i < pgs.size(); ++i)
{
gluTessBeginContour(tess);
for (clipper::Polygon::size_type j = 0; j < pgs[i].size(); ++j)
{
GLdouble *vert = new GLdouble[3];
vert[0] = (GLdouble)pgs[i][j].X;
vert[1] = (GLdouble)pgs[i][j].Y;
vert[2] = 0;
AddToCleanup(vert);
gluTessVertex(tess, vert, vert);
}
gluTessEndContour(tess);
}
gluTessEndPolygon(tess);
DoCleanup();
glColor4f(0.0f, 0.0f, 0.0f, 0.4f);
glLineWidth(1.2f);
gluTessProperty(tess, GLU_TESS_BOUNDARY_ONLY, GL_TRUE); //GL_FALSE
gluTessBeginPolygon(tess, NULL);
for (clipper::Polygons::size_type i = 0; i < pgs.size(); ++i)
{
gluTessBeginContour(tess);
for (clipper::Polygon::size_type j = 0; j < pgs[i].size(); ++j)
{
GLdouble *vert = new GLdouble[3];
vert[0] = (GLdouble)pgs[i][j].X;
vert[1] = (GLdouble)pgs[i][j].Y;
vert[2] = 0;
AddToCleanup(vert);
gluTessVertex(tess, vert, vert);
}
gluTessEndContour(tess);
}
gluTessEndPolygon(tess);
//final cleanup ...
gluDeleteTess(tess);
DoCleanup();
}
void tesselate(const std::vector<std::vector<Point2f> >& pgs, bool evenodd = true)
{
GLUtesselator* tess = internal_gluNewTess();
internal_gluTessCallback(tess, GLU_TESS_BEGIN_DATA, (void (*)())&BeginCallback_s);
internal_gluTessCallback(tess, GLU_TESS_VERTEX_DATA, (void (*)())&VertexCallback_s);
internal_gluTessCallback(tess, GLU_TESS_END_DATA, (void (*)())&EndCallback_s);
internal_gluTessCallback(tess, GLU_TESS_COMBINE_DATA, (void (*)())&CombineCallback_s);
internal_gluTessCallback(tess, GLU_TESS_ERROR_DATA, (void (*)())&ErrorCallback_s);
internal_gluTessCallback(tess, GLU_TESS_EDGE_FLAG_DATA, (void (*)())&EdgeCallback_s);
if (evenodd)
internal_gluTessProperty(tess, GLU_TESS_WINDING_RULE, GLU_TESS_WINDING_ODD); else
internal_gluTessProperty(tess, GLU_TESS_WINDING_RULE, GLU_TESS_WINDING_NONZERO);
internal_gluTessProperty(tess, GLU_TESS_BOUNDARY_ONLY, 0); //GL_FALSE
internal_gluTessBeginPolygon(tess, this);
for (std::size_t i = 0; i < pgs.size(); ++i)
{
internal_gluTessBeginContour(tess);
for (std::size_t j = 0; j < pgs[i].size(); ++j)
{
GLdouble *vert = new GLdouble[3];
vert[0] = (GLdouble)pgs[i][j].x;
vert[1] = (GLdouble)pgs[i][j].y;
vert[2] = 0;
AddToCleanup(vert);
internal_gluTessVertex(tess, vert, vert);
}
internal_gluTessEndContour(tess);
}
internal_gluTessEndPolygon(tess);
DoCleanup();
internal_gluDeleteTess(tess);
}
void CombineCallback(GLdouble coords[3], GLdouble *data[4], GLfloat weight[4], GLdouble **dataOut)
{
GLdouble *vert = new GLdouble[3];
vert[0] = coords[0];
vert[1] = coords[1];
vert[2] = coords[2];
*dataOut = vert;
AddToCleanup(vert);
}
