int main() {
Arr_traits_2 arr_traits;
Arr_traits_2::Construct_curve_2 construct_curve
= arr_traits.construct_curve_2_object();
Arr_traits_2::Construct_x_monotone_segment_2 construct_x_monotone_segment
= arr_traits.construct_x_monotone_segment_2_object();
Arr_traits_2::Construct_point_2 construct_point
= arr_traits.construct_point_2_object();
Arr_traits_2::Make_x_monotone_2 make_x_monotone
= arr_traits.make_x_monotone_2_object();
Arrangement_2 arr(&arr_traits);
std::vector<X_monotone_curve_2> segs;
Polynomial_2 x = CGAL::shift(Polynomial_2(1),1,0);
Polynomial_2 y = CGAL::shift(Polynomial_2(1),1,1);
// Construct x^4+y^3-1
Curve_2 cv0 = construct_curve(CGAL::ipower(x,4)+CGAL::ipower(y,3)-1);
// Construct all x-monotone segments using the Make_x_mononotone functor
std::vector<CGAL::Object> pre_segs;
make_x_monotone(cv0,std::back_inserter(pre_segs));
// Cast all CGAL::Objects into X_monotone_segment_2
// (the vector might also contain Point_2 objects for isolated points,
// but not for this instance
for(size_t i = 0; i < pre_segs.size(); i++ ) {
X_monotone_curve_2 curr;
bool check = CGAL::assign(curr,pre_segs[i]);
assert(check);
segs.push_back(curr);
}
// Construct an ellipse with equation 2*x^2+5*y^2-7=0
Curve_2 cv1 = construct_curve(2*CGAL::ipower(x,2)+5*CGAL::ipower(y,2)-7);
// Construct point on the upper arc (counting of arc numbers starts with 0!
Point_2 p11 = construct_point(Algebraic_real_1(0),cv1,1);
construct_x_monotone_segment(cv1,p11,Arr_traits_2::POINT_IN_INTERIOR,
std::back_inserter(segs));
// Construct a vertical cusp x^2-y^3=0
Curve_2 cv2 = construct_curve(CGAL::ipower(x,2)-CGAL::ipower(y,3));
// Construct a segment containing the cusp point.
// This adds to X_monotone_curve_2 objects to the vector,
// because the cusp is a critical point
Point_2 p21 = construct_point(Algebraic_real_1(-2),cv2,0);
Point_2 p22 = construct_point(Algebraic_real_1(2),cv2,0);
construct_x_monotone_segment(cv2,p21,p22,std::back_inserter(segs));
// Construct an unbounded curve, starting at x=3
Point_2 p23 = construct_point(Algebraic_real_1(3),cv2,0);
construct_x_monotone_segment(cv2,p23,Arr_traits_2::MIN_ENDPOINT,
std::back_inserter(segs));
// Construct another conic: y^2-x^2+1
Curve_2 cv3 = construct_curve(CGAL::ipower(y,2)-CGAL::ipower(x,2)+1);
Point_2 p31 = construct_point(Algebraic_real_1(2),cv3,1);
construct_x_monotone_segment(cv3,p31,Arr_traits_2::MAX_ENDPOINT,
std::back_inserter(segs));
// Construct a vertical segment
Point_2 v1 = construct_point(0,0);
Point_2 v2 = construct_point(Algebraic_real_1(0),cv1,1);
construct_x_monotone_segment(v1,v2,std::back_inserter(segs));
CGAL::insert(arr,segs.begin(),segs.end());
// Add some isolated points (must be wrapped into CGAL::Object)
std::vector<CGAL::Object> isolated_points;
isolated_points.push_back
(CGAL::make_object(construct_point(Algebraic_real_1(2),cv3,0)));
isolated_points.push_back
(CGAL::make_object(construct_point(Integer(1),Integer(5))));
isolated_points.push_back
(CGAL::make_object(construct_point(Algebraic_real_1(-1),
Algebraic_real_1(5))));
CGAL::insert(arr,isolated_points.begin(), isolated_points.end());
// Print the arrangement size.
std::cout << "The arrangement size:" << std::endl
<< " V = " << arr.number_of_vertices()
<< ", E = " << arr.number_of_edges()
<< ", F = " << arr.number_of_faces() << std::endl;
return 0;
}
// read one stroke from file stream
// if successed,return the file position after reading one stroke
// else return -1
// pay attention to call this function,
// we should guarantee file position should stop at the beginning of stroke
long read_stroke (FILE * file, PtrStroke stroke)
{
int i;
PtrInkPoint point;
if (file == NULL || stroke == NULL)
{
SB_INKERRPRINTF("failed:incorrect arguments\n");
return -1;
}
if ( !read_integer(&(stroke->iPenSize), file) )
{
SB_INKPRINTF("failed getting stroke->iPenSize\n");
return -1;
}
//read rgb
if ( !read_rgb(&stroke->gdkColor,file) )
{
SB_INKERRPRINTF("failed write rgb\n");
return 0;
}
if ( !read_integer(&(stroke->nPoints), file) )
{
SB_INKERRPRINTF("failed getting stroke->nPoints\n");
return -1;
}
SB_INKPRINTF("npoints=%d,ipensize=%d\n",
stroke->nPoints,stroke->iPenSize);
if ( stroke->nPoints == 0)
{
SB_INKPRINTF("returned because of stroke->nPoints=0\n");
return ftell (file);//lPos
}
//stroke->nPoints will be changed in iteration,so we should keep it.
int nTotalPoints=stroke->nPoints;
for (i = 0; i < nTotalPoints; i++)
{
point = construct_point ();
if ( NULL==point )
{
SB_INKERRPRINTF("construct point error\n");
return -1;
}
if ( !read_integer (&(point->x), file) )
{
SB_INKERRPRINTF("failed getting (point%d->x)\n",i);
return -1;
}
if ( !read_integer (&(point->y), file) )
{
SB_INKERRPRINTF("failed getting (point%d->y)\n",i);
return -1;
}
//SB_INKPRINTF("point(%d,%d) \n", point->x, point->y);
ink_add_point(stroke, point);
}
return ftell (file);//current file pointer position
}