jogl
  1. jogl
  2. JOGL-340

glClearColor with alpha set to 0 + glRTeadPixels = fail

    Details

    • Type: Bug Bug
    • Status: Resolved
    • Priority: Major Major
    • Resolution: Incomplete
    • Affects Version/s: current
    • Fix Version/s: milestone 1
    • Component/s: jogl
    • Labels:
      None
    • Environment:

      Operating System: Windows XP
      Platform: All

    • Issuezilla Id:
      340

      Description

      I have an app where I am trying to render an image to a pbuffer, then save that
      image to file. I call gl.glClearColor(0, 0, 0, 0) to make a black, transparent
      background. After this, I render a few shapes and try to read the rendered
      image back with gl.glReadPixels(0, 0, w, h, GL.GL_RGBA, GL.GL_UNSIGNED_BYTE, b).
      However, the read back result suffers from a complete lack of transparency.
      Even those places which I would expect to be transparent because nothing was
      drawn there. Every pixel in the populated data buffer has an alpha of 0xFF.
      This does not seem like correct behavior.

      My system is a newer workstation class machine with an nVidia Quadro FX graphics
      card, running windows XP. Test done with JSR 231 1.1.0 on java 1.6 JDK, run
      from within eclipse. If any of that info is helpful.

        Activity

        Hide
        personwholives added a comment -

        Ok, I'm stupid. Please ignore/close this issue. One of these days I'll check
        everything before leaping to the "it must be broken" conclusion.

        Show
        personwholives added a comment - Ok, I'm stupid. Please ignore/close this issue. One of these days I'll check everything before leaping to the "it must be broken" conclusion.
        Hide
        kbr added a comment -

        Closed as per submitter's comments.

        Show
        kbr added a comment - Closed as per submitter's comments.

          People

          • Assignee:
            jogl-issues
            Reporter:
            personwholives
          • Votes:
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            Dates

            • Created:
              Updated:
              Resolved: