com.graphhopper.storage.index

Class BresenhamLine

java.lang.Object

com.graphhopper.storage.index.BresenhamLine

public class BresenhamLine
extends Object

We need the supercover line. The best algorithm is a 'voxel grid traversal algorithm' and described in "A Fast Voxel Traversal Algorithm for Ray Tracing" by John Amanatides and Andrew Woo (1987): http://www.cse.yorku.ca/~amana/research/grid.pdf

Other methods we used are Bresenham (only integer start and end values) and Xiaolin Wu (anti aliasing). See some discussion here: http://stackoverflow.com/a/3234074/194609 and here http://stackoverflow.com/q/24679963/194609

Author:

Peter Karich

Constructor Summary

Constructors

Constructor and Description
BresenhamLine()

Method Summary

Modifier and Type	Method and Description
static void	bresenham(int y1, int x1, int y2, int x2, PointEmitter emitter)
static void	calcPoints(double lat1, double lon1, double lat2, double lon2, PointEmitter emitter, double offsetLat, double offsetLon, double deltaLat, double deltaLon) Calls the Bresenham algorithm but make it working for double values
static void	calcPoints(int y1, int x1, int y2, int x2, PointEmitter emitter)

Methods inherited from class java.lang.Object

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

Constructor Detail

BresenhamLine

public BresenhamLine()

Method Detail

calcPoints

public static void calcPoints(int y1,
                              int x1,
                              int y2,
                              int x2,
                              PointEmitter emitter)

bresenham

public static void bresenham(int y1,
                             int x1,
                             int y2,
                             int x2,
                             PointEmitter emitter)

calcPoints

public static void calcPoints(double lat1,
                              double lon1,
                              double lat2,
                              double lon2,
                              PointEmitter emitter,
                              double offsetLat,
                              double offsetLon,
                              double deltaLat,
                              double deltaLon)

Calls the Bresenham algorithm but make it working for double values