Static Public Member Functions
static double	calculateDistancePointToStreet (Street street, int x, int y, boolean sqrt, int[] result)

static boolean	findNearestPointOnStreet (Street street, int x, int y, int[] result)

static Street	findNearestStreet (int x, int y, int maxDistance, double[] distance, int[] nearestPoint)

static Vehicle	findNearestVehicle (int x, int y, int maxDistance, long[] distance)

static Node	findNearestNode (int x, int y, int maxDistance, long[] distance)

static boolean	findSegmentIntersection (int x1, int y1, int x2, int y2, int x3, int y3, int x4, int y4, double[] result)

static int	findLineCircleIntersections (int circleX, int circleY, int circleRadius, int x1, int y1, int x2, int y2, boolean onlyOnSegment, int[] result)

static boolean	getXYParallelRight (int x1, int y1, int x2, int y2, int distance, double[] result)

static void	calculateBridges (Street bridgeStreet, Street otherStreet)

static void	calculateResizedLine (int[] startPoint, int[] endPoint, double correction, boolean correctStart, boolean correctEnd)

Detailed Description

This class holds some geometric functions needed for various calculations on the map. It's just a helper class to make the map class smaller and as this class has no variables, all functions are declared static.

Member Function Documentation

static void vanetsim.map.MapHelper.calculateBridges	(	Street	bridgeStreet,
		Street	otherStreet
	)

inlinestatic

Checks for intersections on the maps and creates bridges if necessary (only for display purposes). The bridge is added to the lowerspeedStreet. This function takes quite a long time to process if the map is large.

Parameters

bridgeStreet	the street which will be above `otherStreet` if both intersect
otherStreet	the other street

static double vanetsim.map.MapHelper.calculateDistancePointToStreet	(	Street	street,
		int	x,
		int	y,
		boolean	sqrt,
		int[]	result
	)

inlinestatic

Calculate the distance between a point and a street.

Parameters

street	the street given
x	x coordinate of the point
y	y coordinate of the point
sqrt	if set to `true`, the correct distance is returned; if set to `false` the square of the distance is returned (little bit faster as it saves a call to `Math.sqrt()`; however, use only if you can handle this!)
result	an array holding the point on the street so that it can be returned. `result[0]` holds the x coordinate, `result[1]` the y coordinate. Make sure the array has the correct size (2 elements)!

Returns: the distance as a double. If nothing was found, Double.MAX_VALUE is returned.

static void vanetsim.map.MapHelper.calculateResizedLine	(	int[]	startPoint,
		int[]	endPoint,
		double	correction,
		boolean	correctStart,
		boolean	correctEnd
	)

inlinestatic

Recalculates start and end points of a line so that the line is shorter or longer than before.

Parameters

startPoint	the start point. x coordinate is expected in `startPoint[0]`, y in `startPoint[1]`. Will be used to return the result.
endPoint	the end point. x coordinate is expected in `endPoint[0]`, y in `endPoint[1]`. Will be used to return the result.
correction	the amount of length correction. Use a positive value to makes the line shorter, a negative to make it longer. If `correctStart` and `correctEnd` are both `true`, the total correction is double of this value, if both are `false` no correction is done.
correctStart	if the `startPoint` shall be corrected.
correctEnd	if the `endPoint` shall be corrected.

static int vanetsim.map.MapHelper.findLineCircleIntersections	(	int	circleX,
		int	circleY,
		int	circleRadius,
		int	x1,
		int	y1,
		int	x2,
		int	y2,
		boolean	onlyOnSegment,
		int[]	result
	)

inlinestatic

Finds an intersection between a line and a circle. Code basically from VB Helper: Find the points where a line intersects a circle in Visual Basic .NET (link last visited: 31.10.2008).

Parameters

circleX	The x coordinate of the middle of the circle
circleY	The y coordinate of the middle of the circle
circleRadius	The radius of the circle
x1	The x coordinate of the start point of the line
y1	The y coordinate of the start point of the line
x2	The x coordinate of the end point of the line
y2	The y coordinate of the end point of the line
onlyOnSegment	If `true`, only intersection points are found which are on the line segment, else intersections on the extension of the line segment are also found!
result	An array to return the result. Should be an int[4]. The x coordinate of the first point will be in `result[0]`, the y coordinate in `result[1]`. The x coordinate of the second point will be in `result[2]`, the y coordinate in `result[3]`.

Returns: The amount of intersections found (0-2).

static Node vanetsim.map.MapHelper.findNearestNode	(	int	x,
		int	y,
		int	maxDistance,
		long[]	distance
	)

inlinestatic

Returns the nearest node to a given point. First all regions are calculated which are within maxDistance. Then, ALL nodes in these regions are checked if they are within this maxDistance and the best one is returned (if any exists).

Parameters

x	the x coordinate of the given point
y	the x coordinate of the given point
maxDistance	the maximum distance; use `Integer.MAX_VALUE` if you just want to get any nearest vehicle but note that this costs a lot of performance because ALL regions and ALL nodes are checked!
distance	an array used to return the distance between the nearest point and the point given. This should be a `long[1]` array!

Returns: the nearest node or null if none was found or an error occured

static boolean vanetsim.map.MapHelper.findNearestPointOnStreet	(	Street	street,
		int	x,
		int	y,
		int[]	result
	)

inlinestatic

Calculates the point ON a street which is nearest to a given point (for snapping or such things). This code was inspired by Paul Bourke's homepage, especially the Delphi sourcecode (link last visited on 15.08.2008). See there for the mathematical background of this calculation!

Parameters

street	the street
x	the x coordinate of the point
y	the y coordinate of the point
result	an array for the result. `result[0]` holds the x coordinate, `result[1]` the y coordinate. Make sure the array has the correct size (2 elements), otherwise you will not get a result!

Returns: true if calculation was successful, else false

static Street vanetsim.map.MapHelper.findNearestStreet	(	int	x,
		int	y,
		int	maxDistance,
		double[]	distance,
		int[]	nearestPoint
	)

inlinestatic

Returns the nearest street to a given point. First all regions are calculated which are within maxDistance. Then, ALL streets in these regions are checked if they are within this maxDistance and the best one is returned (if any exists).

Parameters

x	the x coordinate of the given point
y	the x coordinate of the given point
maxDistance	the maximum distance; use `Integer.MAX_VALUE` if you just want to get any nearest street but note that this costs a lot of performance because ALL regions and ALL streets are checked!
distance	an array used to return the distance between the nearest point and the point given. This should be a `double[1]` array!
nearestPoint	an array used to return the x-coordinate (`nearestpoint[0]`) and y-coordinate (`nearestpoint[1]`) on the street.

Returns: the nearest street or null if none was found or an error occured

static Vehicle vanetsim.map.MapHelper.findNearestVehicle	(	int	x,
		int	y,
		int	maxDistance,
		long[]	distance
	)

inlinestatic

Returns the nearest vehicle to a given point. First all regions are calculated which are within maxDistance. Then, ALL vehicles in these regions are checked if they are within this maxDistance and the best one is returned (if any exists). Note that only vehicles which are currently active will be returned!

Parameters

x	the x coordinate of the given point
y	the x coordinate of the given point
maxDistance	the maximum distance; use `Integer.MAX_VALUE` if you just want to get any nearest vehicle but note that this costs a lot of performance because ALL regions and ALL vehicles are checked!
distance	an array used to return the distance between the nearest point and the point given. This should be a `long[1]` array!

Returns: the nearest street or null if none was found or an error occured

static boolean vanetsim.map.MapHelper.findSegmentIntersection	(	int	x1,
		int	y1,
		int	x2,
		int	y2,
		int	x3,
		int	y3,
		int	x4,
		int	y4,
		double[]	result
	)

inlinestatic

Finds an intersection between two segments.
Code basically from CODE & FORM blog from Marius Watz (link last visited: 23.09.2008).

Parameters

x1	the x coordinate of the first point of the first segment
y1	the y coordinate of the first point of the first segment
x2	the x coordinate of the second point of the first segment
y2	the y coordinate of the second point of the first segment
x3	the x coordinate of the first point of the second segment
y3	the y coordinate of the first point of the second segment
x4	the x coordinate of the second point of the second segment
y4	the y coordinate of the second point of the second segment
result	an array to return the intersection point. The x coordinate will be in `result[0]`, the y coordinate in `result[1]`.

Returns: true if lines intersect, false if lines don't intersect or if you didn't supply a valid result array.

static boolean vanetsim.map.MapHelper.getXYParallelRight	(	int	x1,
		int	y1,
		int	x2,
		int	y2,
		int	distance,
		double[]	result
	)

inlinestatic

Gets the x and y coordinate difference of a parallel line on the right side (seen from first point to second point).

Parameters

x1	the x coordinate of the first point
y1	the y coordinate of the first point
x2	the x coordinate of the second point
y2	the y coordinate of the second point
distance	the distance
result	an array to return the coordinate differences of the parallel. The x coordinate difference will be in `result[0]`, the y coordinate difference in `result[1]`.

Returns: true if calculation was successful, else false

The documentation for this class was generated from the following file:

/Users/andreastomandl/Desktop/Vanet-Sim/Simulator/src/vanetsim/map/MapHelper.java

Static Public Member Functions

Detailed Description

Member Function Documentation