Math.isPointInPolygon - Revision history

Qaisjp: fix leading nelwine

2020-04-16T18:42:16Z

fix leading nelwine

← Older revision		Revision as of 18:42, 16 April 2020
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	{{Useful Function}}		{{Useful Function}} __NOTOC__
	__NOTOC__
	This function allow you to check if point is inside polygon or not.		This function allow you to check if point is inside polygon or not.

CrosRoad95 at 11:32, 25 May 2018

2018-05-25T11:32:26Z

← Older revision		Revision as of 11:32, 25 May 2018
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	==Syntax==		==Syntax==
	<syntaxhighlight lang="lua">bool math.isPointInPolygon( float x, float y, float vertex1x, float vertex1y, float vertex2x, float vertex2y, float vertex3x, float vertex3y, [...] )</syntaxhighlight>		<syntaxhighlight lang="lua">bool math.isPointInPolygon( float x, float y, float vertex1x, float vertex1y, float vertex2x, float vertex2y, float vertex3x, float vertex3y, [...])</syntaxhighlight>

	===Required Arguments===		===Required Arguments===

CrosRoad95 at 11:31, 25 May 2018

2018-05-25T11:31:38Z

← Older revision		Revision as of 11:31, 25 May 2018
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	===Required Arguments===		===Required Arguments===
	* '''number''': The number to round.

	~~===Optional Arguments===~~
	* '''x, y''': Position of point which you want to check.		* '''x, y''': Position of point which you want to check.
	* '''vertex1x, vertex1y''': First vertex, position `x` and `y`		* '''vertex1x, vertex1y''': First vertex, position `x` and `y`
	* '''vertex2x, vertex2y''': Second vertex, position `x` and `y`		* '''vertex2x, vertex2y''': Second vertex, position `x` and `y`
	* '''vertex3x, vertex3y''': Third vertex, position `x` and `y`		* '''vertex3x, vertex3y''': Third vertex, position `x` and `y`
			===Optional Arguments===
			* '''vertexNx, vertexNy''': Another vertex, any numbers of vertices.
	{{OptionalArg}}		{{OptionalArg}}
	* '''vertexNx, vertexNy''': Another vertex, any numbers of vertices.
	===Returns===		===Returns===
	Return true if point is inside polygon.		Return true if point is inside polygon.

CrosRoad95: Created page with "{{Useful Function}} NOTOC This function allow you to check if point is inside polygon or not. ==Syntax== bool math.isPointInPolygon( float x,..."

2018-05-25T11:19:21Z

Created page with "{{Useful Function}} __NOTOC__ This function allow you to check if point is inside polygon or not. ==Syntax== <syntaxhighlight lang="lua">bool math.isPointInPolygon( float x,..."

New page

{{Useful Function}}
__NOTOC__
This function allow you to check if point is inside polygon or not.

==Syntax==
<syntaxhighlight lang="lua">bool math.isPointInPolygon( float x, float y, float vertex1x, float vertex1y, float vertex2x, float vertex2y, float vertex3x, float vertex3y, [...] )</syntaxhighlight>

===Required Arguments===
* '''number''': The number to round.

===Optional Arguments===
* '''x, y''': Position of point which you want to check.
* '''vertex1x, vertex1y''': First vertex, position `x` and `y`
* '''vertex2x, vertex2y''': Second vertex, position `x` and `y`
* '''vertex3x, vertex3y''': Third vertex, position `x` and `y`
{{OptionalArg}}
* '''vertexNx, vertexNy''': Another vertex, any numbers of vertices.
===Returns===
Return true if point is inside polygon.

==Code==
<section name="Server- and/or clientside Script" class="both" show="true">
<syntaxhighlight lang="lua">
function pointInPolygon( x, y, ...)
local vertices = {...}
local points= {}

for i=1, #vertices-1, 2 do
points[#points+1] = { x=vertices[i], y=vertices[i+1] }
end
local i, j = #points, #points
local inside = false

for i=1, #points do
if ((points[i].y < y and points[j].y>=y or points[j].y< y and points[i].y>=y) and (points[i].x<=x or points[j].x<=x)) then
if (points[i].x+(y-points[i].y)/(points[j].y-points[i].y)*(points[j].x-points[i].x)<x) then
inside = not inside
end
end
j = i
end

return inside
end
</syntaxhighlight>
</section>

==Example==
<section name="Example usage" class="shared" show="true">
This example checks if point 0,0 and 0,5 is inside triangle.
<syntaxhighlight lang="lua" lang="lua">
local inside = pointInPolygon(0,0, -1,-1, 1,1, -1,1) -- true
local outside = pointInPolygon(0,5, -1,-1, 1,1, -1,1) -- false
print( inside, outside )

</syntaxhighlight>
</section>

Author: CrosRoad95, based on https://stackoverflow.com/questions/31730923/check-if-point-lies-in-polygon-lua

==See Also==
{{Useful_Functions}}

Math.isPointInPolygon - Revision history

Qaisjp: fix leading nelwine

CrosRoad95 at 11:32, 25 May 2018

CrosRoad95 at 11:31, 25 May 2018

CrosRoad95: Created page with "{{Useful Function}} __NOTOC__ This function allow you to check if point is inside polygon or not. ==Syntax== bool math.isPointInPolygon( float x,..."

CrosRoad95: Created page with "{{Useful Function}} NOTOC This function allow you to check if point is inside polygon or not. ==Syntax== bool math.isPointInPolygon( float x,..."