Math-Helper-Functions

Some useful Math functions not built into the Javascript Math Object. Mainly useful for Web Games.

Functions

map(x, istart, istop, ostart, ostop) ⇒ Number

Map a value from a range of numbers to another range of numbers x is to istart and istop segment.

Returns: Number - The number that is in the same relation to ostart and ostop segment

| Param | Type | Description | | --- | --- | --- | | x | Number | Value we are testing | | istart | Number | Min value to test | | istop | Number | Max value to test | | ostart | Number | Min value to map to (based on x value) | | ostop | Number | Max value to map to (based on x value) |

Example

map(Math.random(), 0, 1, 10, 20); will provided a number between 10 and 20

limit(x, min, max) ⇒ Number

Limit a value between a min/max value

Returns: Number - Either x, or the nearest limit if x is out of bounds.

| Param | Type | Description | | --- | --- | --- | | x | Number | Value we need to limit | | min | Number | Min number to return | | max | Number | Max number to return |

toRad(x) ⇒ Number

Convert the angle, provided in degrees (0-360), into radians (0-2*PI)

Returns: Number - Angle in Radians

| Param | Type | Description | | --- | --- | --- | | x | Number | Angle in Degrees |

toDeg(x) ⇒ Number

Convert the angle, provided in radians (0-2*PI), into degrees (0-360)

Returns: Number - Angle in Degrees

| Param | Type | Description | | --- | --- | --- | | x | Number | Angle in Radians |

range(min, max) ⇒ Number

Get random Float value between range of numbers

Returns: Number - Return random Float value between min and max range

| Param | Type | Description | | --- | --- | --- | | min | Number | Min range value | | max | Number | Max range value |

distance(a, b) ⇒ Number

Distance between two points

Returns: Number - Distance between points

| Param | Type | Description | | --- | --- | --- | | a | Object | first point {x: 0, y: 0} | | b | Object | second point {x: 0, y: 0} |

Example

- can supply 2D or 3D point {x: 0, y: 0, z: 0}

lerp(current, target, time) ⇒ Number

Lerp between current position to target position over a period of time

Returns: Number - Value between current/target over the time

| Param | Type | Description | | --- | --- | --- | | current | Number | Current position value | | target | Number | Target position value | | time | Number | Time value |

average(a, b) ⇒ Number

Returns the average or the midpoint between two numbers

Returns: Number - - the midpoint between two numbers

| Param | Type | Description | | --- | --- | --- | | a | Number | first number | | b | Number | second number |

midpoint(v1, v2) ⇒ Object

Get the midpoint between two points

Returns: Object - - {x: x, y: y, z: z}

| Param | Type | Description | | --- | --- | --- | | v1 | Object | {x: 0, y: 0} | | v2 | Object | {x: 0, y: 0} |

Example

- Also accepts 3D point {x: 0, y: 0, z: 0}

chance(percent)

Return a true or false for a random chance of a percentage

| Param | Type | Description | | --- | --- | --- | | percent | Number | float percentage 0 -> 1 |

Example

if(chance(0.2)){ console.log('20% chance true') }