Package eu.svjatoslav.sixth.e3d.renderer.raster.slicer

Class BorderLine

java.lang.Object

eu.svjatoslav.sixth.e3d.renderer.raster.slicer.BorderLine

All Implemented Interfaces:

Comparator<BorderLine>

public class BorderLine
extends Object
implements Comparator<BorderLine>

Represents an edge (border line) of a triangle in the polygon slicing pipeline.

A BorderLine connects two Vertex endpoints and carries an identification count used by the Slicer to determine which edge of the original triangle this line corresponds to (1, 2, or 3). This identification is essential for correct recursive subdivision -- when the longest edge is split, the slicer uses the count to decide how to partition the triangle into two smaller triangles.

Implements Comparator so that an array of border lines can be sorted by edge length, allowing the Slicer to identify the longest edge for subdivision.

See Also:

• Slicer
• Vertex

Field Summary

Fields

Modifier and Type	Field	Description
final int	count	The edge identifier (1, 2, or 3) indicating which edge of the original triangle this border line represents.

Constructor Summary

Constructors

Constructor	Description
BorderLine(Vertex c1, Vertex c2, int count)	Creates a border line between two vertices with the given edge identifier.

Method Summary

Modifier and Type	Method	Description
int	compare(BorderLine o1, BorderLine o2)	Compares two border lines by their 3D edge length in ascending order.
double	getLength()	Computes the 3D Euclidean distance between the two endpoint vertices.
Vertex	getMiddlePoint()	Computes the midpoint vertex of this edge by averaging both the 3D coordinates and the 2D texture coordinates of the two endpoints.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface java.util.Comparator

equals, reversed, thenComparing, thenComparing, thenComparing, thenComparingDouble, thenComparingInt, thenComparingLong

Field Details

count

public final int count

The edge identifier (1, 2, or 3) indicating which edge of the original triangle this border line represents. Used by Slicer during recursive subdivision.

Constructor Details

BorderLine

public BorderLine(Vertex c1,
 Vertex c2,
 int count)

Creates a border line between two vertices with the given edge identifier.

Parameters:

c1 - the first vertex endpoint

c2 - the second vertex endpoint

count - the edge identifier (1, 2, or 3)

Method Details

compare

public int compare(BorderLine o1,
 BorderLine o2)

Compares two border lines by their 3D edge length in ascending order.

Specified by:

compare in interface Comparator<BorderLine>

Parameters:

o1 - the first border line

o2 - the second border line

Returns:

a negative value if o1 is shorter, positive if longer, zero if equal

getLength

public double getLength()

Computes the 3D Euclidean distance between the two endpoint vertices.

Returns:

the length of this edge in world-space units

getMiddlePoint

public Vertex getMiddlePoint()

Computes the midpoint vertex of this edge by averaging both the 3D coordinates and the 2D texture coordinates of the two endpoints.

Returns:

a new Vertex at the midpoint, with interpolated texture coordinates