Namespace: Utilities

LittleJS Utility Classes and Functions
- General purpose math library
- Vector2 - fast, simple, easy 2D vector class
- Color - holds a rgba color with some math functions
- Timer - tracks time automatically

Source: engineUtilities.js, line 1

Members

(static, constant) PI :Number

A shortcut to get Math.PI

Type:

Number

Default Value: Math.PI
Source: engineUtilities.js, line 16

Methods

(static) abs(value) → {Number}

Returns absoulte value of value passed in

Parameters:

Name	Type	Description
`value`	Number

Source: engineUtilities.js, line 22

Returns:

Type:: Number

(static) clamp(value, minopt, maxopt) → {Number}

Clamps the value beween max and min

Parameters:

Name	Type	Attributes	Default
`value`	Number
`min`	Number	<optional>	0
`max`	Number	<optional>	1

Source: engineUtilities.js, line 57

Returns:

Type:: Number

(static) formatTime(t) → {String}

Formats seconds to mm:ss style for display purposes

Parameters:

Name	Type	Description
`t`	Number	time in seconds

Source: engineUtilities.js, line 108

Returns:

Type:: String

(static) hsl(hopt, sopt, lopt, aopt) → {Color}

Create a color object with HSLA values

Parameters:

Name	Type	Attributes	Default
`h`	Number	<optional>	0
`s`	Number	<optional>	0
`l`	Number	<optional>	1
`a`	Number	<optional>	1

Source: engineUtilities.js, line 362

Returns:

Type:: Color

(static) isOverlapping(pointA, sizeA, pointB, sizeBopt) → {Boolean}

Returns true if two axis aligned bounding boxes are overlapping

Parameters:

Name	Type	Attributes	Description
`pointA`	Vector2		Center of box A
`sizeA`	Vector2		Size of box A
`pointB`	Vector2		Center of box B
`sizeB`	Vector2	<optional>	Size of box B

Source: engineUtilities.js, line 94

Returns:

True if overlapping

Type:: Boolean

(static) isVector2(vector) → {Boolean}

Check if object is a valid Vector2

Parameters:

Name	Type	Description
`vector`	Vector2

Source: engineUtilities.js, line 200

Returns:

Type:: Boolean

(static) lerp(percent, minopt, maxopt) → {Number}

Linearly interpolates the percent value between max and min

Parameters:

Name	Type	Attributes	Default
`percent`	Number
`min`	Number	<optional>	0
`max`	Number	<optional>	1

Source: engineUtilities.js, line 73

Returns:

Type:: Number

(static) max(valueA, valueB) → {Number}

Returns highest of two values passed in

Parameters:

Name	Type	Description
`valueA`	Number
`valueB`	Number

Source: engineUtilities.js, line 36

Returns:

Type:: Number

(static) min(valueA, valueB) → {Number}

Returns lowest of two values passed in

Parameters:

Name	Type	Description
`valueA`	Number
`valueB`	Number

Source: engineUtilities.js, line 29

Returns:

Type:: Number

(static) mod(dividend, divisoropt) → {Number}

Returns first parm modulo the second param, but adjusted so negative numbers work as expected

Parameters:

Name	Type	Attributes	Default	Description
`dividend`	Number
`divisor`	Number	<optional>	1

Source: engineUtilities.js, line 49

Returns:

Type:: Number

(static) nearestPowerOfTwo(value) → {Number}

Returns the nearest power of two not less then the value

Parameters:

Name	Type	Description
`value`	Number

Source: engineUtilities.js, line 85

Returns:

Type:: Number

(static) percent(value, minopt, maxopt) → {Number}

Returns what percentage the value is between max and min

Parameters:

Name	Type	Attributes	Default
`value`	Number
`min`	Number	<optional>	0
`max`	Number	<optional>	1

Source: engineUtilities.js, line 65

Returns:

Type:: Number

(static) rgb(ropt, gopt, bopt, aopt) → {Color}

Create a color object with RGBA values

Parameters:

Name	Type	Attributes	Default
`r`	Number	<optional>	1
`g`	Number	<optional>	1
`b`	Number	<optional>	1
`a`	Number	<optional>	1

Source: engineUtilities.js, line 351

Returns:

Type:: Color

(static) sign(value) → {Number}

Returns the sign of value passed in (also returns 1 if 0)

Parameters:

Name	Type	Description
`value`	Number

Source: engineUtilities.js, line 42

Returns:

Type:: Number

(static) smoothStep(value) → {Number}

Applies smoothstep function to the percentage value

Parameters:

Name	Type	Description
`value`	Number

Source: engineUtilities.js, line 79

Returns:

Type:: Number

(static) vec2(xopt, yopt) → {Vector2}

Create a 2d vector, can take another Vector2 to copy, 2 scalars, or 1 scalar

Parameters:

Name	Type	Attributes	Default	Description
`x`	Number	<optional>	0
`y`	Number	<optional>	0

Source: engineUtilities.js, line 192

Returns:

Type:: Vector2

Example

let a = vec2(0, 1); // vector with coordinates (0, 1)
let b = vec2(a);    // copy a into b
a = vec2(5);        // set a to (5, 5)
b = vec2();         // set b to (0, 0)

(static) wave(frequencyopt, amplitudeopt, topt) → {Number}

Returns an oscillating wave between 0 and amplitude with frequency of 1 Hz by default

Parameters:

Name	Type	Attributes	Default	Description
`frequency`	Number	<optional>	1	Frequency of the wave in Hz
`amplitude`	Number	<optional>	1	Amplitude (max height) of the wave
`t`	Number	<optional>	time	Value to use for time of the wave

Source: engineUtilities.js, line 102

Returns:

Value waving between 0 and amplitude

Type:: Number