Skip to content
  • Categories
  • Recent
  • Tags
  • Popular
  • Users
  • Groups
  • Search
  • Get Qt Extensions
  • Unsolved
Collapse
Brand Logo
  1. Home
  2. Qt Development
  3. General and Desktop
  4. Line modeling
Qt 6.11 is out! See what's new in the release blog

Line modeling

Scheduled Pinned Locked Moved General and Desktop
6 Posts 4 Posters 1.6k Views 1 Watching
  • Oldest to Newest
  • Newest to Oldest
  • Most Votes
Reply
  • Reply as topic
Log in to reply
This topic has been deleted. Only users with topic management privileges can see it.
  • J Offline
    J Offline
    jcooper
    wrote on last edited by
    #1

    Hey, I want to write the line modeling application. You've got a line and you can model it in the way you want, add new points on the line, drag them, making brezier curves between them, making straight lines between them etc. I was trying with QPainterPath and functions like cubicTo etc, but there is not much information about current line (for example: y coordinate at given x coordinate on that line). I was also trying to use OpenCascade libraries, but it seems too complicated for such application and I cannot find easy examples which shows how to make 2D scene and draw on it.

    Could you give me some hints what tools may i use? Or maybe some examples with such applications?

    1 Reply Last reply
    0
    • Chris KawaC Offline
      Chris KawaC Offline
      Chris Kawa
      Lifetime Qt Champion
      wrote on last edited by
      #2

      Hi, welcome to devnet

      bq. but there is not much information about current line (for example: y coordinate at given x coordinate on that line)

      Because at any given x there might be several or no y if it's a curve. QPainterPath is not a mathematical tool to solve equations.

      You can easily get a point in a distance from one end of the line using percentAtLength() and then feed it into pointAtPercent().

      What functionality are you looking for specifically?

      1 Reply Last reply
      0
      • J Offline
        J Offline
        jcooper
        wrote on last edited by
        #3

        I should be able to add new movable points on the line and model the path between them (straight line, arc, other curve). It would be nice if i can have information about y coordinate of the line at given x. I was thinking about checking QImage for pixels to get this information if there would no other way.

        1 Reply Last reply
        0
        • S Offline
          S Offline
          Salvatello
          wrote on last edited by
          #4

          You want to create a platform to be able to draw and change what you have previously drawn. Want to create a CAD right?

          1 Reply Last reply
          0
          • J Offline
            J Offline
            jcooper
            wrote on last edited by
            #5

            Yes, something like that, but i need only line modeling functionality.

            1 Reply Last reply
            0
            • A Offline
              A Offline
              aliks-os
              wrote on last edited by
              #6

              Look at QGraphicsScene Class. -> addLine

              1 Reply Last reply
              0

              • Login

              • Login or register to search.
              • First post
                Last post
              0
              • Categories
              • Recent
              • Tags
              • Popular
              • Users
              • Groups
              • Search
              • Get Qt Extensions
              • Unsolved