edu.cmu.cs.cs214.hw5.util

Class Utilities

java.lang.Object

edu.cmu.cs.cs214.hw5.util.Utilities

public final class Utilities
extends java.lang.Object

A suite of utility methods that may be useful for data source and view plugins.

These methods contain primitive mathematical and graphical operations. For Swing-specific helpers, see GUIUtilities.

Method Summary

Modifier and Type	Method and Description
static java.awt.Graphics2D	antialias(java.awt.Graphics2D g2d) Enable antialiasing and text antialiasing on the given graphics context.
static java.awt.Color	gradient(double t) Produce a color value at a certain point along a gradient.
static double	lerp(double a, double b, double t) Perform linear interpolation from a to b with factor t.
static java.awt.Color	withAlpha(java.awt.Color color, int alpha) Create a version of the provided color that has the provided value for the alpha channel value—i.e., opacity.
static java.awt.Color	withAlphaFloating(java.awt.Color color, double alpha) Create a version of the provided color that has the provided value opacity value.

Methods inherited from class java.lang.Object

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

Method Detail

lerp

public static double lerp(double a,
                          double b,
                          double t)

Perform linear interpolation from a to b with factor t. If t == 0, the result will be a; if t == 1, the result will be b.

For example, lerp(1.0, 5.0, 0.75) == 4.0.

Parameters:

a - some starting point

b - some ending point

t - some fraction (probably between 0 and 1, but not necessarily)

Returns:

the value t * 100 percent of the way from a to b

withAlphaFloating

public static java.awt.Color withAlphaFloating(java.awt.Color color,
                                               double alpha)

Create a version of the provided color that has the provided value opacity value. Setting alpha to 0.0 will make the color completely transparent; setting it to 1.0 will make it completely opaque.

The alpha value will be converted to an integer and then fed to withAlpha(Color, int).

Parameters:

color - the color whose red, green, and blue channels to use

alpha - the fractional alpha value for the color to be produced

Returns:

a color whose red, green, and blue channels are given by color and whose alpha channel is given by alpha

Throws:

java.lang.IllegalArgumentException - if alpha < 0.0 || alpha > 1.0

withAlpha

public static java.awt.Color withAlpha(java.awt.Color color,
                                       int alpha)

Create a version of the provided color that has the provided value for the alpha channel value—i.e., opacity. Setting alpha to 0 will make the color completely transparent; setting it to 255 (0xFF) will make it completely opaque.

Parameters:

color - the color whose red, green, and blue channels to use

alpha - the alpha value for the color to be produced

Returns:

a color whose red, green, and blue channels are given by color and whose alpha channel is given by alpha

Throws:

java.lang.IllegalArgumentException - if alpha < 0 || alpha > 0xFF

gradient

public static java.awt.Color gradient(double t)

Produce a color value at a certain point along a gradient.

Parameters:

t - the position along the gradient: 0.0 indicates the start of the gradient, and 1.0 indicates the end

Returns:

a color value at position t along a gradient

antialias

public static java.awt.Graphics2D antialias(java.awt.Graphics2D g2d)

Enable antialiasing and text antialiasing on the given graphics context.

Parameters:

g2d - the graphics context to modify

Returns:

the provided graphics context (for chaining, and to maintain an expression context)