How do I specify mouse position over DrawingCanvas?

I'm making a rgb color eyedropper tool.

The workflow is as follows:

1. Have a picture in the form of a sprite.
2. Set DrawingCanvas size and position to that of the sprite.
3. Paste picture into the DrawingCanvas.
4. Save snapshot of the DrawingCanvas.
5. When ready, on mouse click I do "snapshotRedAt(mouse.x,mouse.y)

That returns nothing when I click on the canvas, yet gives some readings when clicking outside the canvas which probably means that the coordinates for snapshotRedAt need to be relative?

How do I then provide mouse coordinates for snapshotRedAt correctly in order to read pixel at that precise spot (independently of where the canvas is located in the layout?)

thanks!

Thanks dop2000, that seems to be working.

It still however only reads pixels in a fragment of the canvas. Upon logging things to the console it seems that for some reason the snapshot has different dimensions than the DrawingCanvas?

//dimensions of sprite and canvas after pasting sprite (x and y)
Dimensions of picture:768 511
dimensions of DrawingCanvas: 768 511
//dimensions of snapshot (inside "on snapshot")
snapshot width: 339 snapshot height:226

Yeah, snapshot dimensions may be different, you need to take this into account:

construct.net/en/make-games/manuals/construct-3/plugin-reference/drawing-canvas

So I'm guessing you need (mouse.x-DrawingCanvas.BBoxLeft)/DrawingCanvas.PixelScale

or possibly multiply :)