CGAL 4.12.1 - 2D Arrangements
ArrTraits::ParameterSpaceInY_2 Concept Reference

## Operations

A model of this concept must provide:

Arr_parameter_space operator() (const ArrTraits::X_monotone_curve_2 &xcv, Arr_curve_end ce)
Given an $$x$$-monotone curve xcv and an enumeration ce that specifies either the minimum or the maximum end of the curve, determines the location of the curve end along the $$y$$-dimension. More...

## ◆ operator()()

 Arr_parameter_space ArrTraits::ParameterSpaceInY_2::operator() ( const ArrTraits::X_monotone_curve_2 & xcv, Arr_curve_end ce )

Given an $$x$$-monotone curve xcv and an enumeration ce that specifies either the minimum or the maximum end of the curve, determines the location of the curve end along the $$y$$-dimension.

The variable xcv identifies the parametric curve $$C(t) = (X(t),Y(t))$$ defined over an open or half-open interval with endpoints $$0$$ and $$1$$. The enumeration ce identifies an open end $$d \in\{0,1\}$$ of $$C$$. Formally, determines whether $$\lim_{t \rightarrow d} Y(t)$$ evaluates to $$b_b$$, $$b_t$$, or a value in between, where $$b_b$$ and $$b_t$$ are the $$y$$-coordinates of the bottom and top boundaries of the parameter space, respectively. Returns ARR_BOTTOM_BOUNDARY, ARR_TOP_BOUNDARY, or ARR_INTERIOR, accordingly.

Postcondition
If ArrTraits::Bottom_side_category is not convertible to Arr_open_side_tag then the result is not ARR_BOTTOM_BOUNDARY.
If ArrTraits::Top_side_category is not convertible to Arr_open_side_tag then the result is not ARR_TOP_BOUNDARY.