Madis at 20:14, 24 January 2010

2010-01-24T20:14:33Z

← Older revision		Revision as of 20:14, 24 January 2010
Line 50:		Line 50:

	==Example==		==Example==
	<section name="~~Server~~" class="client" show="true">		<section name="Client" class="client" show="true">
	This code draws a red line, enables mouse cursor and tells client how far from the line was clicked.		This code draws a red line, enables mouse cursor and tells client how far from the line was clicked.
	<syntaxhighlight lang="lua">		<syntaxhighlight lang="lua">

Dakilla: /* Example */

2010-01-24T13:47:49Z

Example

← Older revision		Revision as of 13:47, 24 January 2010
Line 56:		Line 56:
	addEventHandler("onClientRender", getRootElement(),		addEventHandler("onClientRender", getRootElement(),
	function()		function()
	dxDrawLine(20, 20, 200, 100, tocolor(255, 0, 0)		dxDrawLine(20, 20, 200, 100, tocolor(255, 0, 0))
	end		end
	)		)

Madis at 03:21, 24 January 2010

2010-01-24T03:21:46Z

← Older revision		Revision as of 03:21, 24 January 2010
Line 71:		Line 71:

	-- Calculate the distance		-- Calculate the distance
	local distance = ~~distanceBetweenPointAndSegment~~(clickedX, clickedY, 20, 20, 200, 100)		local distance = getDistanceBetweenPointAndSegment2D(clickedX, clickedY, 20, 20, 200, 100)

	-- Tell user the distance		-- Tell user the distance

Madis: Created page with '{{Useful Function}} NOTOC Takes point coordinates and line (a segment) starting and ending coordinates. It returns the shortest distance bet…'

2010-01-24T03:15:41Z

Created page with '{{Useful Function}} <lowercasetitle></lowercasetitle> __NOTOC__ Takes point coordinates and line (a segment) starting and ending coordinates. It returns the shortest distance bet…'

New page

{{Useful Function}}
<lowercasetitle></lowercasetitle>
__NOTOC__
Takes point coordinates and line (a segment) starting and ending coordinates. It returns the shortest distance between the point and the line.

==Syntax==
<syntaxhighlight lang="lua">float getDistanceBetweenPointAndSegment2D(float pointX, float pointY, float x1, float y1, float x2, float y2)</syntaxhighlight>

===Required Arguments===
* '''pointX''': The X coordinate of the point.
* '''pointY''': The Y coordinate of the point.
* '''x1''': The X coordinate of the starting point of the line.
* '''y1''': The Y coordinate of the starting point of the line.
* '''x2''': The X coordinate of the ending point of the line.
* '''y2''': The Y coordinate of the ending point of the line.

==Code==
<section name="Function source" class="both" show="true">
<syntaxhighlight lang="lua">
function getDistanceBetweenPointAndSegment2D(pointX, pointY, x1, y1, x2, y2)
local A = pointX - x1
local B = pointY - y1
local C = x2 - x1
local D = y2 - y1

local point = A * C + B * D
local lenSquare = C * C + D * D
local parameter = point / lenSquare

local shortestX
local shortestY

if parameter < 0 then
shortestX = x1
shortestY = y1
elseif parameter > 1 then
shortestX = x2
shortestY = y2
else
shortestX = x1 + parameter * C
shortestY = y1 + parameter * D
end

local distance = getDistanceBetweenPoints2D(pointX, pointY, shortestX, shortestY)

return distance
end
</syntaxhighlight>
</section>

==Example==
<section name="Server" class="client" show="true">
This code draws a red line, enables mouse cursor and tells client how far from the line was clicked.
<syntaxhighlight lang="lua">
-- Draw a red line
addEventHandler("onClientRender", getRootElement(),
function()
dxDrawLine(20, 20, 200, 100, tocolor(255, 0, 0)
end
)

-- Show cursor
showCursor(true)

-- Fires when left mouse button is clicked
function cursorPositionFromTheRedLine(button, state, clickedX, clickedY)
-- Allow function to continue only if left button was pressed and button was pressed down
if button ~= "left" or state == "up" then
return
end

-- Calculate the distance
local distance = distanceBetweenPointAndSegment(clickedX, clickedY, 20, 20, 200, 100)

-- Tell user the distance
outputChatBox("You clicked "..distance.." away from the Red Line!")
end

-- Read mouse clicks
addEventHandler("onClientClick", root, cursorPositionFromTheRedLine)
</syntaxhighlight>
</section>

Code from: http://www.allegro.cc/forums/thread/589720

==See Also==
{{Useful_Functions}}

GetDistanceBetweenPointAndSegment2D - Revision history

Madis at 20:14, 24 January 2010

Dakilla: /* Example */

Madis at 03:21, 24 January 2010

Madis: Created page with '{{Useful Function}} __NOTOC__ Takes point coordinates and line (a segment) starting and ending coordinates. It returns the shortest distance bet…'

Madis: Created page with '{{Useful Function}} NOTOC Takes point coordinates and line (a segment) starting and ending coordinates. It returns the shortest distance bet…'