The crash fixed by this commit could be triggered by attaching an OpenGL
context to a component, calling setBufferedToImage (true) on one of its
child components, and then detaching the OpenGL context from the parent.
Since 4ba01a80a0 we are creating images
with the current rendering context's native image type, so the above
scenario would leave an image buffer that references the detached
context.
This addresses an issue where OpenGL-backed image content could get lost
when putting and Android app into an inactive state. This happens
because the GL context gets destroyed, freeing all associated resources.
The workaround introduced here will listen for OpenGL state-change
events, and attempt to save and restore framebuffer content into main
memory, so that the content can be restored once the app is reactivated.
This also fixes a bug introduced in f7c7225f5c
where the condition guarding the definition of traitCollectionDidChange
was incorrect. This function is never required if the deployment target
is at least 17.0.
There were a few "ambiguous operator new/delete" errors that were due to
inheriting from a private base class that used the leak detector. These
errors are resolved by adding the leak detector to the derived classes.
JUCE_API was missing from a few useful types, notably the ARA hosting
types.
Previously, code such as the following (where MyGLComponent is rendering
using an OpenGLContext) could result in GL errors, as the destruction of
the inner context unbound the array buffer and element array buffer
after use, instead of setting them to the previous values set up by the
outer context.
Additionally, a VAO was only set up in the OpenGLContext, so rendering
into a GL-backed LowLevel graphics context could fail if no VAO was
bound.
void MyGLComponent::paint (juce::Graphics& g)
{
juce::Image image { juce::Image::PixelFormat::ARGB, width, height, false, juce::OpenGLImageType() };
{
juce::Graphics innerContext { image };
// draw into innerContext
}
g.drawImage (image, juce::Rectangle<float> { width, height });
}
This change fixes an issue where opening multiple OpenGLContexts on
certain versions of macOS (observed on 10.13) could cause a deadlock.
The issue can be reproduced by:
- Attaching an OpenGL context to the AudioPluginDemo editor
- Opening multiple copies of the editor simultaneously in a plugin host.
I tested with Live 10.
I also observed the issue in a standalone app that opened new windows
containing OpenGLContexts on a timer.
On Windows, the OpenGL context window sometimes receives a repaint
request after moving between screens with different scale factors.
If the screen has changed size/scale since the last paint operation,
failing to invalidate the painted area may cause the screen contents
to be drawn at the wrong scale until paint is next called.
- 4.1 and 4.3 contexts can now be requested
- The requested context version is no longer ignored on Linux
- Debugging contexts are now enabled in Debug builds with GL 4.3
- Fixes a bug where glEnable(GL_TEXTURE_2D) was called in core profiles
The Apple threading documentation [^1] says the following:
> The second argument to pthread_setschedparam is the desired policy,
which can currently be one of SCHED_FIFO (first in, first out),
SCHED_RR (round-robin), or SCHED_OTHER. The SCHED_OTHER policy is
generally used for extra policies that are specific to a given
operating system, and should thus be avoided when writing portable
code.
This appears to differ from the policy semantics on Linux and BSD, where
FIFO and RR are both explicitly real-time policies.
Therefore, on Linux/BSD we only enable the RR policy if the requested
priority is 8 or higher. Meanwhile, on macOS, we map all thread
priorities (0 - 10) onto the RR policy with an appropriate priority.
[^1]: https://developer.apple.com/library/archive/documentation/Darwin/Conceptual/KernelProgramming/scheduler/scheduler.html
