Someone have this math function?

[Jayceon]

Hello dear reader!

I'm searching a math function to get the perfect angle.

I have one function, but it not whole.

function getAngle(x1, y1, x2, y2)
	while true do
		while true do
			if math.atan2(x2, y2) - math.atan2(x1, y1) <= -math.pi then
			end
		end
	end
	
	while true do
		if math.atan2(x2, y2) - math.atan2(x1, y1) + 2 * math.pi > math.pi then
		end
	end
	
	return math.atan2(x2, y2) - math.atan2(x1, y1) + 2 * math.pi - 2 * math.pi
end

 

Thanks the replies. (The findRotation and other simple functions not good for me.)

[Gordon_G]

I don't understand, why findRotation is not good ? It works perfectly.

Edited July 6, 2017 by Gordon_G

[Jayceon]

Yes.. works perfectly, but not for my code.

(Don't get all directions (left/right - like highways exit)

[IIYAMA]

If you need the right and the left, you can add 90 or subtract 90. If you add/subtract 180, you will have the back of it. (it can also be lower than 0 or higher than 360, which is acceptable for using in mta functions)

Edited July 6, 2017 by IIYAMA

[Jayceon]

We can not use findRotation, because we need left or right angles (it can be -10>n then it's a left turn, if it's 10<n then it's a right turn, if it's between -10 and 10 it is nothing)
We have a table with precalculated values (the need field is what we need), but we get different numbers (got field)

 

function getAngle(x1, y1, x2, y2)
	local angle = math.atan2(x1, y1) - math.atan2(x2, y2)
	
	if angle <= -math.pi then
		angle = angle + 2 * math.pi
		usedAlg = "hoz"
	else
		if angle + 2 * math.pi <= math.pi then
			angle = angle - 2 * math.pi
			usedAlg = "min"
		end
	end
    
    return -math.deg(angle)
end

pass 
fail || need: 13.532079523427 || got: -346.46792047657  
fail || need: 368.80375654813 || got: 8.8037565481247  
fail || need: 270 || got: -90  
fail || need: -85.150542731867 || got: -85.150542731865  
pass 
fail || need: 13.532079523427 || got: -346.46792047657  
pass 
pass
pass 
pass

but it does not work

[Syntrax#]

38 minutes ago, Jayceon said:

We can not use findRotation, because we need left or right angles (it can be -10>n then it's a left turn, if it's 10<n then it's a right turn, if it's between -10 and 10 it is nothing)
We have a table with precalculated values (the need field is what we need), but we get different numbers (got field)

 

function getAngle(x1, y1, x2, y2)
	local angle = math.atan2(x1, y1) - math.atan2(x2, y2)
	
	if angle <= -math.pi then
		angle = angle + 2 * math.pi
		usedAlg = "hoz"
	else
		if angle + 2 * math.pi <= math.pi then
			angle = angle - 2 * math.pi
			usedAlg = "min"
		end
	end
    
    return -math.deg(angle)
end

pass 
fail || need: 13.532079523427 || got: -346.46792047657  
fail || need: 368.80375654813 || got: 8.8037565481247  
fail || need: 270 || got: -90  
fail || need: -85.150542731867 || got: -85.150542731865  
pass 
fail || need: 13.532079523427 || got: -346.46792047657  
pass 
pass
pass 
pass

but it does not work

Lol basically what you currently got and what ya need is 360 - got.

If you do 360 - the value you get with findrotation you get what you need

[Jayceon]

We have some pass marks, so i can not 360-value every single time

[IIYAMA]

I am still having a hard time to figure out what you need. But you want to know the differences between the rotations right?(positive and negative)

 

If you calculate from both sides the rotation with findRotation, you can use this code to find the offset:

 

local rotZ1, rotZ2 = 90, -90

local rotationOffsetZ = (rotZ1 - rotZ2 + 360) % 360;
if (rotationOffsetZ > 180) then
	rotationOffsetZ = 360 - rotationOffsetZ
else
	rotationOffsetZ = -rotationOffsetZ
end

iprint(rotationOffsetZ)-- -180

 

Edited July 6, 2017 by IIYAMA

[Jayceon]

wtf is rotationOffset ? i have the function, with X Y, X2, Y2 points on the map. I need the angle between them, but it can be negative or positive depending on left or right.
n>10 -> right
n<-10 -> left
so it should work clockwise and counter-clockwise

[Syntrax#]

Just do this

if rotation > 9 then

"Right"

if rotation < -9 then

"Left"

This should check if it is let or right

Edited July 6, 2017 by Syntrax#

[Jayceon]

Example:

local angle = math.deg(getAngle(currentNode.x - previousNode.x, currentNode.y - previousNode.y, nextNode.x - currentNode.x, nextNode.y - currentNode.y))

if angle > 10 then
	print("right")
elseif angle < -10 then
	print("left")
end

 

[IIYAMA]

12 minutes ago, Jayceon said:

wtf is rotationOffset ? i have the function, with X Y, X2, Y2 points on the map. I need the angle between them, but it can be negative or positive depending on left or right.
n>10 -> right
n<-10 -> left
so it should work clockwise and counter-clockwise

That's what it does...

If you say the angle between them, it can only be positive.... (in my opinion) But if you talk about offset, it can also be negative.

And it freaking works for me. Just test it...

[Jayceon]

Please show me an example code, i shown you mine, just use it and please do an example getAngle function)

[Syntrax#]

17 minutes ago, IIYAMA said:

That's what it does...

If you say the angle between them, it can only be positive.... (in my opinion) But if you talk about offset, it can also be negative.

And it freaking works for me. Just test it...

He is true, you just have to check if it is positive or negative, and if the value is bigger than 10

[Jayceon]

I just need an example please

[IIYAMA]

It is still not clear to us what your end result will be.

 

This is what you have:

X, Y, X2, Y2 

Not a 3e position?(else there is nothing to compare against)

Where do you get your second angle from?

 

Do you want to add or subtract 10, to get the ones you want to get the new rotation from?

 

Or do you need the pitch rotation instead?

 

If you still can't explain what you need, then I recommend to you visualize it.

 

Edited July 6, 2017 by IIYAMA

[Jayceon]

 I have 4 positions. One X-Y pair for the start, one XY pair for the end of the line. I want to get the angle between the starting point and the endpoint of these.
But. I need it to be negative if left and positive if right.
 

[IIYAMA]

So 2 positions. (not 4)

Technically it can't be left or right unless you compare it with an start-point. Is 0 your start-point?

 

And what is left and right to you?

[Jayceon]

It is a GPS Navig system, using nodes. Now. There is a start and an endpoint of these. At every endpoint a new node starts. This is everything i know, i want to know if the endpoint is to the left or the right from the start point. If you don't understand I can visualize it.
 

for i, node in ipairs(gpsRoute) do
	local nextNode = gpsRoute[i + 1]
	local previousNode = gpsRoute[i - 1]
	
	if i > 1 and i < #gpsRoute then
		for k, v in pairs(node.neighbours) do
			if previousNode and nextNode and k ~= previousNode.id and k ~= nextNode.id then
				local nodeAngle = getAngle(node.x - previousNode.x, node.y - previousNode.y, nextNode.x - node.x, nextNode.y - node.y)
				
				if math.deg(nodeAngle) > 10 then
					print("right")
					break
				end
				
				if math.deg(nodeAngle) < -10 then
					print("left")
				end
				
				break
			end
		end
	end
end

 

[IIYAMA]

function findRotation( x1, y1, x2, y2 ) 
    local t = -math.deg( math.atan2( x2 - x1, y2 - y1 ) )
    return t < 0 and t + 360 or t
end

function getRightOrLeft(oldX, oldY, startX, startY, endX, endY)

	local rotZ1, rotZ2 = findRotation( oldX, oldY, startX, startY ), findRotation(startX, startY, endX, endY) 

	local rotationOffsetZ = (rotZ1 - rotZ2 + 360) % 360;
	if (rotationOffsetZ > 180) then
		rotationOffsetZ = 360 - rotationOffsetZ
	else
		rotationOffsetZ = -rotationOffsetZ
	end
	return rotationOffsetZ > 10 and "right" or rotationOffsetZ < -10 "left" or "nothing"
end

So you have 3 positions... seriously... pffffff your really making it hard to help you.

 

-- try to use this in your code
iprint(getRightOrLeft(previousNode.x, previousNode.y, node.x, node.y, nextNode.x, nextNode.y))
--

 

[Jayceon]

With a little transformation, but work. Thanks

[IIYAMA]

np.