Math

Functions
local function	abs (value)
	std.math.abs
local function	clamp (value, value_min, value_max)
	std.math.clamp
local function	clamp2 (value, value_min, value_max)
	std.math.clamp2
local function	cycle (passed, duration)
	std.math.cycle
local function	dir (value, alpha)
	std.math.dir
local function	dis (x1, y1, x2, y2)
	std.math.dis
local function	dis2 (x1, y1, x2, y2)
	std.math.dis2
local function	lerp (a, b, alpha)
	std.math.lerp
local function	map (value, in_min, in_max, out_min, out_max)
	std.math.map
local function	max (...)
	std.math.max
local function	min (...)
	std.math.min
local function	saw (value)
	std.math.saw

Detailed Description

Function Documentation

abs()

local function abs

(

value

)

module

Equation

Parameters

[in]

value

Return values

value

as positive number

clamp()

local function clamp	(	value	,
		value_min	,
		value_max	)

Parameters

[in]	value	The value to clamp
[in]	value_min	The minimum value that value can be clamped to.
[in]	value_max	The maximum value that value can be clamped to.

Return values

value	if value_min <= value <= value_max
value_min	if value < value_min
value_max	if value > value_max

clamp2()

local function clamp2	(	value	,
		value_min	,
		value_max	)

Note

similar to std.math.clamp but cyclical.

Equation

Parameters

[in]	value	The value to clamp
[in]	value_min	The minimum value that value can be clamped to.
[in]	value_max	The maximum value that value can be clamped to.

cycle()

local function cycle	(	passed	,
		duration	)

periodic cycle

Equation

Deprecated

simplify, rename, move or even remove cycle

Parameters

[in]	passed
[in]	duration

Return values

0	start of period
0.5	middle of period
1	end of period

Example

local anim = std.math.cycle(game.millis, 1000) * 5
std.draw.text(x, y + anim, 'hello!')

dir()

local function dir	(	value	,
		alpha	)

direction

Parameters

[in]	value
[in]	alpha	default=0

Return values

-1	less than alpha if value < -alpha
1	greater than alpha if value > alpha
0	when is in alpha if abs(alpha) <= aplha

Example

local sprites = {
  [-1] = game.spr_player_left,
  [1] = game.spr_player_right,
  [0] = game.player_sprite
}
game.player_sprite = sprites[std.math.dir(game.player_speed_x)]

dis()

local function dis	(	x1	,
		y1	,
		x2	,
		y2	)

euclidean distance

Equation

Parameters

[in]	x1	The x coordinate of the first point.
[in]	y1	The y coordinate of the first point.
[in]	x2	The x coordinate of the second point.
[in]	y2	The y coordinate of the second point.

Returns

distance between the two points (x1, y1) and (x2, y2).

dis2()

local function dis2	(	x1	,
		y1	,
		x2	,
		y2	)

quadratic distance

Note

this is an optimization of std.math.dist but it cannot be used to calculate collisions.

Equation

Parameters

[in]	x1	The x coordinate of the first point.
[in]	y1	The y coordinate of the first point.
[in]	x2	The x coordinate of the second point.
[in]	y2	The y coordinate of the second point.

Returns

distance between the two points (x1, y1) and (x2, y2).

lerp()

local function lerp	(	a	,
		b	,
		alpha	)

linear interpolation

Equation

Parameters

[in]	a	The starting value
[in]	b	The ending value
[in]	alpha	The interpolation parameter, typically in the range [0, 1].

Returns

The interpolated value between 'a' and 'b' based on 'alpha'.

map()

local function map	(	value	,
		in_min	,
		in_max	,
		out_min	,
		out_max	)

re-maps

• https://www.arduino.cc/reference/en/language/functions/math/map

Equation

Parameters

[in]	value	The value to be mapped from the input range to the output range.
[in]	in_min	The minimum value of the input range.
[in]	in_max	The maximum value of the input range.
[in]	out_min	The minimum value of the output range.
[in]	out_max	The maximum value of the output range.

Returns

The mapped value in the output range corresponding to 'value' in the input range.

max()

local function max

(

...

)

biggest number

Example

local one = std.math.max(0, 1)
local two = std.math.max({0, 1, 2})

min()

local function min

(

...

)

smallest number

Example

local one = std.math.max(1, 2, 3)
local two = std.math.max({2, 3, 4})

saw()

local function saw

(

value

)

sawtooth

Deprecated

simplify, rename, move or even remove saw