Difference between revisions of "Math.atan2"

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(Created page with "__NOTOC__ '''Available since:''' Gideros 2011.6<br/> === Description === Returns the arc tangent of v1/v2 (in radians), but uses the signs of both parameters to find the quadr...")
 
m (Text replacement - "</source>" to "</syntaxhighlight>")
 
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__NOTOC__
 
__NOTOC__
 
'''Available since:''' Gideros 2011.6<br/>
 
'''Available since:''' Gideros 2011.6<br/>
 +
'''Class:''' [[math]]<br/>
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=== Description ===
 
=== 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.)
+
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).
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<source lang="lua">
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<syntaxhighlight lang="lua">
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(number), = math.atan2(v1v2,)
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(number) = math.atan2(v1,v2)
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</source>
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</syntaxhighlight>
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'''v1:''' (number) first value ''''''<br/>
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−
'''v2:''' (number) second value ''''''<br/>
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=== Parameters ===
−
'''Returns''' (number) result<br/>
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'''v1''': (number) first value<br/>
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'''v2''': (number) second value<br/>
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 +
=== Return values ===
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'''Returns''' (number) the angle in radian<br/>
 +
 
 +
=== Example ===
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'''Aiming at an enemy'''
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<syntaxhighlight lang="lua">
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local playerX, playerY = player:getPosition()
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local nmeX, nmeY = nme:getPosition()
 +
-- here we get the nme angle relative to the player
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local angle = math.atan2(nmeY - playerY, nmeX - playerX) -- the Ys first!
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-- now we can target the nme
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missile:setPosition(15 * math.cos(angle), 15 * math.sin(angle))
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-- ...
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</syntaxhighlight>
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 +
(can be handy: https://math.stackexchange.com/a/2587852)
 +
 
 +
{{Math}}

Latest revision as of 14:30, 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)



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