Converting position offset to scale relative to different things?

[acuaro]

Hello,

Currently I have a drawing feature in my game where it places a frame at the mouse position, and it works great if I’m just using offset. Problem is, I’ll need to take that drawing, and be able to render it on many different frames (same aspect ratio, different sizes). So, I was thinking that I would need to convert the positional value to scale.

I’ve tried dividing by the viewport, but the problem is, this is relative to the screen, rather than the frame (see video below).

function Signing:_offsetToScale(x, y)
	local viewport = workspace.Camera.ViewportSize
	
	return x / viewport.X, y / viewport.Y
end

---

Is it possible to make it relative to the frame, or should I take a different approach in how I use offset so I can render the drawing on different scales?

[SubtotalAnt8185]

@acuaro

I’ve tried dividing by the viewport, but the problem is, this is relative to the screen, rather than the frame

Did you try AbsoluteSize on the frame?

[acuaro]

Dividing by it? Yeah, I did but they went out of the canvas instead:

[SubtotalAnt8185]

Okay, you’re supposed to divide mouse position by viewport size, and then you parent the “ink” into the frame and use scale position.

[acuaro]

I think that’s what I am currently doing, but I don’t get what you mean

@SubtotalAnt8185

use scale position.

Use the mouse/viewport scale or something else?

function Signing:_offsetToScale(x, y, canvas)
	local viewport = canvas.AbsoluteSize
	
	return x / viewport.X, y / viewport.Y
end

function Signing:_drawAt(x, y, canvas)

	local point = Instance.new("Frame")
    --x & y come from the mouse pos

	x, y = Signing:_offsetToScale(x, y, canvas)
	
	point.Position = UDim2.fromScale(x, y)
	point.Parent = canvas

    -- code is truncated, but this is the part you are referring to 
end

[SubtotalAnt8185]

If your frame is in the exact center of the screen, you could possibly apply an offset of the mouse relative to the center of the frame as the position of the points.

[acuaro]

@SubtotalAnt8185

you could possibly apply an offset of the mouse relative to the center of the frame as the position of the points.

How would I approach doing this?

[FunAsiK]

I think you have to get the position of the mouse relative to the window position and divide by the absolute size of the window, like this:

local mouse_pos = UserInputService:GetMouseLocation() - Vector2.new(0, 36)
local rel_pos = (mouse_pos - window.AbsolutePosition) / window.AbsoluteSize

point.Position = UDim2.fromScale(rel_pos.X, rel_pos.Y)

window is the frame you’re painting on.

[acuaro]

Thanks!

I removed the - Vector2.new(0, 36) as all it did was apply an offset to the final product, but once I did, it worked great.