Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Converting between coordinate planes

  1. Feb 11, 2007 #1
    How would you go about converting from a Cartesian coordinate plane to one where (0,0) is in the top left hand corner?
  2. jcsd
  3. Feb 11, 2007 #2
    What do you mean by the origin being in the top left hand corner?
  4. Feb 11, 2007 #3
    Like this:

    Attached Files:

  5. Feb 11, 2007 #4
    It's still pretty much the same cartesian plane, I guess it's just resized because for whatever purpose that is needed for only requires the fourth quadrant.
  6. Feb 11, 2007 #5
    Ok.. maybe I should have put my question a bit better, with a bit more info on what I need this for.

    What I have is an object, inside a screen, that is inside another screen. The object can move, and the screen inside the screen is partially-fixed onto the object. If I move the mouse to the left, the screen will follow it to the left, up until the object is on the very right side of the screen which stops it from moving further.

    The objects coordinates are based on the large screens origin, and my mouse coordinates are based on the smaller screens plane, which starts in the top left 0,0.

    What I am trying to do is to get the mouses coordinates relative to the larger screen.
  7. Feb 11, 2007 #6
    I guess you could shift the coordinate axes of the upper left coordinate point to be (0,0) and adjust all other points accordingly.
  8. Feb 11, 2007 #7


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Have you got any ideas on how you could accomplish this?
  9. Feb 11, 2007 #8
    I'm getting there. I started off by thinking that if the mouse was at say, (0,0) then it would be a whole screen distance up and to the left so I would say distance x = Screen size - 0 and distance y = Screen size - 0 up until half of the screen. I realise now that this would only work at the maximums (I think) because as you go towards the middle you would be getting half the screen size, which isn't what I want.

    I am about to go to bed, so I will give this a bit of thought while going to sleep and then continue on tommorow.

    Oh, one other thing I forgot to mention is that up is -ve and down is +ve, right is +ve and left is -ve for the objects coordinates relative to the large screen.

    After a little bit of brainstorming, maybe the distance from the middle of the screen. I'm done. Bed.
    Last edited: Feb 11, 2007
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook