Utilities Documentation

Utilities Documentation Source Code

Utilities Methods

beep8.Utilities.assert(cond, msg)

Asserts that the given condition is true, else shows a fatal error.

Parameters

cond (boolean): The condition that you fervently hope will be true.
msg (string): The error message to show if the condition is false.

Returns

(boolean): The ‘cond’ parameter.

beep8.Utilities.assertDebug(cond, msg)

Same as beep8.Utilities.assert() but only asserts if beep8.CONFIG.DEBUG is true.

Parameters

cond (boolean): The condition that you fervently hope will be true.
msg (string): The error message to show if the condition is false.

Returns

(boolean): The ‘cond’ parameter.

beep8.Utilities.assertEquals(expected, actual, what)

Asserts that two values are equal.

Parameters

expected (any): What you expect the value to be.
actual (any): What the value actually is.
what (string): A description of what the value is.

Returns

(any): The ‘actual’ parameter.

beep8.Utilities.checkArray(varName, varValue)

Checks that a variable is an array.

Parameters

varName (string): The name of the variable.
varValue (any): The value of the variable.

Returns

(Array): The ‘varValue’ parameter.

beep8.Utilities.checkBoolean(varName, varValue)

Checks that a variable is a boolean.

Parameters

varName (string): The name of the variable.
varValue (any): The value of the variable.

Returns

(boolean): The ‘varValue’ parameter.

beep8.Utilities.checkFunction(varName, varValue)

Checks that a variable is a function.

Parameters

varName (string): The name of the variable.
varValue (any): The value of the variable.

Returns

(Function): The ‘varValue’ parameter.

beep8.Utilities.checkInstanceOf(varName, varValue, expectedClass)

Checks that a variable is an instance of a given class.

Parameters

varName (string): The name of the variable.
varValue (any): The value of the variable.
expectedClass (Function): The expected class.

Returns

(any): The ‘varValue’ parameter.

beep8.Utilities.checkInt(varName, varValue)

Checks that a variable is an integer.

Parameters

varName (string): The name of the variable.
varValue (any): The value of the variable.

Returns

(number): The ‘varValue’ parameter.

beep8.Utilities.checkIsSet(varName, varValue)

Checks that a variable is set (not undefined or null).

Parameters

varName (string): The name of the variable.
varValue (any): The value of the variable.

Returns

(any): The ‘varValue’ parameter.

beep8.Utilities.checkNumber(varName, varValue [,optMin] [,optMax])

Checks that a variable is a number.

Parameters

varName (string): The name of the variable.
varValue (any): The value of the variable.
[optMin] (number): The minimum acceptable value for the variable. (default: undefined)
[optMax] (number): The maximum acceptable value for the variable. (default: undefined)

Returns

(number): The ‘varValue’ parameter.

beep8.Utilities.checkObject(varName, varValue)

Checks that a variable is an object.

Parameters

varName (string): The name of the variable.
varValue (any): The value of the variable.

Returns

(Object): The ‘varValue’ parameter.

beep8.Utilities.checkString(varName, varValue)

Checks that a variable is a string.

Parameters

varName (string): The name of the variable.
varValue (any): The value of the variable.

Returns

(string): The ‘varValue’ parameter.

beep8.Utilities.checkType(varName, varValue, varType)

Checks the type of a variable and throws an exception if it’s incorrect.

Parameters

varName (string): The name of the variable.
varValue (any): The value of the variable.
varType (string): The expected type of the variable.

Returns

(any): The ‘varValue’ parameter.

beep8.Utilities.clamp(x, lo, hi)

Clamps a number, ensuring it’s between a minimum and a maximum.

Parameters

x (number): The number to clamp.
lo (number): The minimum value.
hi (number): The maximum value.

Returns

(number): The clamped number.

beep8.Utilities.deepMerge(objects)

Performs a deep merge of objects and returns new object. Does not modify objects (immutable) and merges arrays via concatenation.

Parameters

objects (…object): Objects to merge

Returns

(object): New object with merged key/values

beep8.Utilities.dist2d(x0, y0, x1, y1)

Calculates a 2D distance between points (x0, y0) and (x1, y1).

Parameters

x0 (number): The x-coordinate of the first point.
y0 (number): The y-coordinate of the first point.
x1 (number): The x-coordinate of the second point.
y1 (number): The y-coordinate of the second point.

Returns

(number): The distance between the two points.

beep8.Utilities.downloadFile(filename, src)

Downloads a file.

Parameters

filename (string): The name of the file.
src (string): The source URL of the file.

beep8.Utilities.error(msg)

Prints an error to the console.

Parameters

msg (string): The message to print.

beep8.Utilities.event(eventName [,detail] [,target])

Generate a new custom event.

Parameters

eventName (string): The name of the event.
[detail] (Object): The event detail. (default: {})
[target] (EventTarget): The target of the event. (default: document)

beep8.Utilities.fatal(error)

Shows a fatal error and throws an exception.

Parameters

error (string): The error to show.

beep8.Utilities.intersectIntervals(as, ae, bs, be [,result])

Calculates the intersection between two integer number intervals.

Given 2 ranges it will see if these ranges overlap and if they do it will optionally return the intersection range.

For example if the first interval is [1, 5] and the second interval is [3, 7] the intersection is [3, 5].

Parameters

as (number): The start of the first interval.
ae (number): The end of the first interval.
bs (number): The start of the second interval.
be (number): The end of the second interval.
[result] (Object): If provided, used to return the intersection. (default: null)

Returns

(boolean): True if there is an intersection, false otherwise.

beep8.Utilities.intersectRects(r1, r2 [,dx1] [,dy1] [,dx2] [,dy2] [,result])

Calculates the intersection of two rectangles.

Parameters

r1 (Object): The first rectangle.
r2 (Object): The second rectangle.
[dx1] (number): The delta X to add to the first rectangle. (default: 0)
[dy1] (number): The delta Y to add to the first rectangle. (default: 0)
[dx2] (number): The delta X to add to the second rectangle. (default: 0)
[dy2] (number): The delta Y to add to the second rectangle. (default: 0)
[result] (Object): If provided, used to return the intersection. (default: null)

Returns

(boolean): True if there is a non-empty intersection, false otherwise.

beep8.Utilities.loadFileAsync(url)

Loads a file asynchronously.

Parameters

url (string): The URL of the file.

Returns

(*Promise*): A promise that resolves to the file content.

beep8.Utilities.loadImageAsync(src) async

Loads an image asynchronously.

Parameters

src (string): The source URL of the image.

Returns

(*Promise*): A promise that resolves to the loaded image.

beep8.Utilities.log(msg)

Prints a log to the console if beep8.CONFIG.DEBUG is true.

Parameters

msg (string): The message to print.

beep8.Utilities.makeColorTransparent(img, color, range) async

Makes a color transparent in an image.

This function is asynchronous because it uses an HTMLImageElement.

Uses a range because I found that occassionally the RGB values of a saved png are not exactly as they were set in the image. Possibly due to compression.

Parameters

img (HTMLImageElement): The image to process.
color (array): The color to make transparent. By default this is pure magenta [255,0,255].
range (number): The range of RGB values to consider as the target color.

beep8.Utilities.makeUrlPretty(str)

Converts a string to a pretty URL-friendly format.

Parameters

str (string): The string to convert.

Returns

(string): The pretty string.

beep8.Utilities.padWithZeros(number, length)

Pads a number with leading zeros to the specified length.

Does not support negative numbers.

Parameters

number (number): The number to pad.
length (number): The desired length of the output string.

Returns

(string): - The padded number as a string.

beep8.Utilities.repeatArray(array, times)

Utility function to repeat an array a specified number of times.

Parameters

array (Array): The array to repeat.
times (number): The number of times to repeat the array.

Returns

(Array): The repeated array.

beep8.Utilities.warn(msg)

Prints a warning to the console.

Parameters

msg (string): The message to print.