Mixxx

qt5: GLSL renderers draw signal at wrong scale and position

Bug #1530697 reported by RJ Skerry-Ryan
12
This bug affects 1 person
Affects Status Importance Assigned to Milestone
Mixxx
Fix Released
Medium
RJ Skerry-Ryan
Mixxx 2.2.0

Bug Description

[Impact]

With qt5 the GLSL renderer draw signal at wrong scale and position. See attachment in comment #1.

[Test Case]

 * Start Mixxx on and verify if the GLSL waveforms are are drawn correctly.

[Regression Potential]

There might be regressions with other waveforms.

[Other Info]

The Cosmic 2.1.3 build is also effected, see: https://bugs.launchpad.net/ubuntu/+source/mixxx/+bug/1804513

See original description
Tags: qt5
Revision history for this message
RJ Skerry-Ryan (rryan) wrote :
Changed in mixxx:
status: New → Confirmed
importance: Undecided → Medium
tags: added: qt5
Revision history for this message
RJ Skerry-Ryan (rryan) wrote :

OpenGL version 4.1
Qt 5.5.1

Revision history for this message
RJ Skerry-Ryan (rryan) wrote :

OSX 10.11.2

Revision history for this message
RJ Skerry-Ryan (rryan) wrote :

I haven't debugged yet, but I think this may be because of my hidpi display:

http://blog.qt.io/blog/2013/04/25/retina-display-support-for-mac-os-ios-and-x11/

"""
QGlWidget

OpenGL operates in device pixel space. For example, the width and height passed to glViewport should be in device pixels. QGLWidget::resizeGL() gives the width and height in device pixels.

However, QGLWidget::width() is really QWidget::width() which returns a value in device-independent pixels. Resolve it by multiplying with widget->windowHandle()->devicePixelRatio() if needed.
"""

Now that devicePIxelRatio is exposed by Qt we need to scale the widget width/height we pass to the shaders by it.

Revision history for this message
Be (be.ing) wrote :

https://github.com/mixxxdj/mixxx/pull/1739

Changed in mixxx:
status: Confirmed → Fix Committed
assignee: nobody → RJ Skerry-Ryan (rryan)
milestone: none → 2.2.0
Daniel Schürmann (daschuer)
Changed in mixxx:
status: Fix Committed → Fix Released
Daniel Schürmann (daschuer)
description: updated
Revision history for this message
Swiftb0y (swiftb0y) wrote :

Mixxx now uses GitHub for bug tracking. This bug has been migrated to:
https://github.com/mixxxdj/mixxx/issues/8417

lock status: Metadata changes locked and limited to project staff
To post a comment you must log in.
This report contains Public information  
Everyone can see this information.

Duplicates of this bug

Subscribing...

Other bug subscribers

Remote bug watches

Bug watches keep track of this bug in other bug trackers.