Difference between revisions of "Math.atan2"

From GiderosMobile
m (Text replacement - "</source>" to "</syntaxhighlight>")
 
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__NOTOC__
 
__NOTOC__
'''<translate>Available since</translate>:''' Gideros 2011.6<br/>
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'''Available since:''' Gideros 2011.6<br/>
=== <translate>Description</translate> ===
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'''Class:''' [[math]]<br/>
<translate>Returns the arc tangent of v1/v2 (in radians), but uses the signs of both parameters to find the quadrant of the result. (It also handles correctly the case of v2 being zero.)</translate>
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<source lang="lua">
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=== Description ===
 +
Returns the arc tangent of v1/v2 (in radians), but uses the signs of both parameters to find the quadrant of the result (it also handles correctly the case of v2 being zero).
 +
<syntaxhighlight lang="lua">
 
(number) = math.atan2(v1,v2)
 
(number) = math.atan2(v1,v2)
</source>
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</syntaxhighlight>
=== <translate>Parameters</translate> ===
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'''v1''': (number) <translate>first value</translate> <br/>
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=== Parameters ===
'''v2''': (number) <translate>second value</translate> <br/>
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'''v1''': (number) first value<br/>
=== <translate>Return values</translate> ===
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'''v2''': (number) second value<br/>
'''<translate>Returns</translate>''' (number) <translate>result</translate><br/>
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 +
=== Return values ===
 +
'''Returns''' (number) the angle in radian<br/>
 +
 
 +
=== Example ===
 +
'''Aiming at an enemy'''
 +
<syntaxhighlight lang="lua">
 +
local playerX, playerY = player:getPosition()
 +
local nmeX, nmeY = nme:getPosition()
 +
-- here we get the nme angle relative to the player
 +
local angle = math.atan2(nmeY - playerY, nmeX - playerX) -- the Ys first!
 +
-- now we can target the nme
 +
missile:setPosition(15 * math.cos(angle), 15 * math.sin(angle))
 +
-- ...
 +
</syntaxhighlight>
 +
 
 +
(can be handy: https://math.stackexchange.com/a/2587852)
 +
 
 +
{{Math}}

Latest revision as of 15:30, 13 July 2023

Available since: Gideros 2011.6
Class: math

Description

Returns the arc tangent of v1/v2 (in radians), but uses the signs of both parameters to find the quadrant of the result (it also handles correctly the case of v2 being zero).

(number) = math.atan2(v1,v2)

Parameters

v1: (number) first value
v2: (number) second value

Return values

Returns (number) the angle in radian

Example

Aiming at an enemy

local playerX, playerY = player:getPosition()
local nmeX, nmeY = nme:getPosition()
-- here we get the nme angle relative to the player
local angle = math.atan2(nmeY - playerY, nmeX - playerX) -- the Ys first!
-- now we can target the nme
missile:setPosition(15 * math.cos(angle), 15 * math.sin(angle))
-- ...

(can be handy: https://math.stackexchange.com/a/2587852)