stanford.androidlib.graphics

Class GMath

java.lang.Object

stanford.androidlib.graphics.GMath

public class GMath
extends Object

This class defines a variety of static mathematical methods that are useful for the acm.graphics package.

Method Summary

Modifier and Type	Method and Description
static float	angle(float x, float y) Returns the angle in degrees from the origin to the point (x, y).
static float	angle(float x0, float y0, float x1, float y1) Computes the angle in degrees formed by a line segment from the point (x0, y0) and (x1, y1).
static float	cosDegrees(float angle) Returns the trigonometric cosine of its argument where angle is expressed in degrees.
static float	distance(float x, float y) Computes the distance between the origin and the point (x, y).
static float	distance(float x0, float y0, float x1, float y1) Computes the distance between the points (x0, y0) and (x1, y1).
static int	round(float x) Rounds a float value to the nearest int.
static float	sinDegrees(float angle) Returns the trigonometric sine of its argument where angle is expressed in degrees.
static float	tanDegrees(float angle) Returns the trigonometric tangent of its argument where angle is expressed in degrees.
static float	toDegrees(float radians) Converts an angle from radians to degrees.
static float	toRadians(float degrees) Converts an angle from degrees to radians.

Methods inherited from class java.lang.Object

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

Method Detail

round

public static int round(float x)

Rounds a float value to the nearest int.

Parameters:

x - A float value

Returns:

The nearest int value

Usage:

int n = round(x);

sinDegrees

public static float sinDegrees(float angle)

Returns the trigonometric sine of its argument where angle is expressed in degrees.

Parameters:

angle - An angle measured in degrees

Returns:

The trigonometric sine of the angle

Usage:

float s = sinDegrees(angle);

cosDegrees

public static float cosDegrees(float angle)

Returns the trigonometric cosine of its argument where angle is expressed in degrees.

Parameters:

angle - An angle measured in degrees

Returns:

The trigonometric cosine of the angle

Usage:

float c = cosDegrees(angle);

tanDegrees

public static float tanDegrees(float angle)

Returns the trigonometric tangent of its argument where angle is expressed in degrees.

Parameters:

angle - An angle measured in degrees

Returns:

The trigonometric tangent of the angle

Usage:

float t = tanDegrees(angle);

toDegrees

public static float toDegrees(float radians)

Converts an angle from radians to degrees. This method is defined in the Math class, but was added only in JDK1.2, which is not supported in all browsers.

Parameters:

radians - An angle measured in radians

Returns:

The equivalent angle in degrees

Usage:

float degrees = toDegrees(radians);

toRadians

public static float toRadians(float degrees)

Converts an angle from degrees to radians. This method is defined in the Math class, but was added only in JDK1.2, which is not supported in all browsers.

Parameters:

degrees - An angle measured in degrees

Returns:

The equivalent angle in radians

Usage:

float radians = toRadians(degrees);

distance

public static float distance(float x,
                             float y)

Computes the distance between the origin and the point (x, y).

Parameters:

x - The x-coordinate of the point

y - The y-coordinate of the point

Returns:

The distance from the origin to the point (x, y)

Usage:

float d = distance(x, y);

distance

public static float distance(float x0,
                             float y0,
                             float x1,
                             float y1)

Computes the distance between the points (x0, y0) and (x1, y1).

Parameters:

x0 - The x-coordinate of one point

y0 - The y-coordinate of that point

x1 - The x-coordinate of the other point

y1 - The y-coordinate of that point

Returns:

The distance between the points (x0, y0) and (x1, y1)

Usage:

float d = distance(x0, y0, x1, y1);

angle

public static float angle(float x,
                          float y)

Returns the angle in degrees from the origin to the point (x, y). This method is easier to use than atan2 because it specifies the displacements in the usual x/y order and because it takes care of the fact that the Java coordinate system is flipped. The point (0, 0) is arbitrarily defined to be at angle 0.

Parameters:

x - The x-coordinate of the point

y - The y-coordinate of the point

Returns:

The angle from the origin to the point (x, y) measured in degrees counterclockwise from the +x axis

Usage:

float theta = angle(x, y);

angle

public static float angle(float x0,
                          float y0,
                          float x1,
                          float y1)

Computes the angle in degrees formed by a line segment from the point (x0, y0) and (x1, y1).

Parameters:

x0 - The x-coordinate of one point

y0 - The y-coordinate of that point

x1 - The x-coordinate of the other point

y1 - The y-coordinate of that point

Returns:

The angle formed by the line segment from (x0, y0) to (x1, y1)

Usage:

float theta = angle(x0, y0, x1, y1);