#52 WinGCC-Driver cant display plpoin with code=-1

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Arjen Markus
None
5
2009-11-16
2008-05-26
Stefan Menzel
No

Hi Dear Programmers,

under WinXP SP2, PlPlot 5.9.0 and Cmake 2.6 the WinGCC-Driver cant display one-pixel-points generated with plpoin and code=-1 (by the way that code No. is undocumented).With png (Gd-Device) this works.

Thanks
Stefan

Discussion

  • Arjen Markus
    Arjen Markus
    2008-05-29

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    I am not sure whether the support in the GD device is a coincidence or not.
    What happens if you use -2 or -3? The reason I ask is that some graphical
    devices have a not quite intuitive way of handling coordinates. This is
    especially an issue with very small objects.

     
  • Stefan Menzel
    Stefan Menzel
    2008-05-29

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    Code values lower than -1 and more than 127 result in an error message of plpoin.
    I dont know where the problem is with the WinGCC-Driver, drawing the One-Pixel-Thick-Axis is no problem at all.
    It would be great if someone could fix that, because I dont want switch to another library because of an elementary feature like drawing Pixels.

    BTW: drawing a line with equal start and end-points doesn't work as temporary workaround...

     
  • Arjen Markus
    Arjen Markus
    2008-05-30

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    I quickly checked the code:
    a size parameter of -1 draws a line with the same start and end points.

    There is a comment that that might not work well on some smart devices ...

    The wingcc driver has explicit support for drawing a single pixel, so the solution
    here would be to look for zero-length lines and turn them into a single pixel.
    I will look into this.

     
  • Alan W. Irwin
    Alan W. Irwin
    2009-11-16

    • assigned_to: nobody --> arjenmarkus