I have an Android NDK application that is doing all of its rendering in software.
Now I want to use Open GL ES to do the rendering.
I've got unit tests running by calling EGL and creating a PBuffer.
Now I want to do everything in a window instead of a PBuffer.
I adapted the code from the hello-gl2 example.
I created a new java file that uses a GLSurfaceView instead of a SurfaceView.
I have created a few native functions for GLSurfaceView.
I have successfully called C from Java, and have successfully called Java from C.
Still, no pictures.
I traced through with Eclipse and got an error that says that GL calls are being made without having a current context. I am doing
setEGLContextFactory(new ContextFactory());
setEGLConfigChooser( translucent ? new ConfigChooser(8, 8, 8, 8, 0, 0) :
new ConfigChooser(5, 6, 5, 0, 0, 0) );
setRenderer(new Renderer());
However,
ConfigChooser.chooseConfig()
never gets called. Who is supposed to call this? The sample code gives no clue.
Do I also need to make some change in an XML file?
Please give me some ideas of paths to pursue. I'm only running into dead ends.
It turns out that there was a problem with threads: the GL rendering thread and the graphics database thread were deadlocking. Here is how I solved it. I reduced the number of threads by one, and managed GL myself:
derive MyGLSurfaceView from SurfaceView instead of GLSurfaceView.
When MyGLSurfaceView.surfaceCreated() is called, squirrel away the ANativeWindow (from the main thread) in a global.
initialize EGL in the database thread using the ANativeWindow to create an EGLContext.
Related
we have an issue in MFC-based application related to “current MFC state” and threads. In main thread we call VisualManager, because we want to have fancy toolbars. The call ends up in CMFCVisualManagerOffice2007::OnUpdateSystemColors function located inside afxvisualmanageroffice2007.cpp, which changes “current resource handle” by calling AfxSetResourceHandle function. This function gets “current module state” and changes “current resource handle” from MyApp.exe to mfc140u.dll. This is fine, because assets for VisualManager are located in that DLL and the change will be restored back to MyApp.exe in all cases.
However, what is not fine is that we spawn a new thread just before call to VisualManager (by using AfxBeginThread), this thread needs to load some strings from string table (by using CString class), but it sometimes fails to do so. It fails because there is race with main thread about AFX_MODULE_STATE::m_hCurrentResourceHandle variable. The thread expect it to be set to MyApp.exe, but the main thread changes it to mfc140u.dll and back, the “current resource handle” is effectively a global variable.
So, my questions are: 1) Are we doing something obviously wrong managing our MFC-based threads? Should we somehow copy or protect the “module state” so our new thread is immune to the change main thread is doing? Should aim MFC to create something like per-thread variable / state? 2) I believe Microsoft is wrong here, changing what is effectively a global variable and screwing other threads expectations, VisualManager should obtain the handle and pass it to all its functions as a parameter. Am I right?
EDIT:
Hi guys #iinspectable, #cha, I have an update, sorry it took so long. Steps to reproduce: Open Visual Studio 2015 Update 3, Create new MFC application through the wizard, make sure it has the "Project style" and "Visual style and colors" selected as "Office" and "Office 2007 (Blue theme)". Open file afxvisualmanageroffice2007.cpp from MSVS folder and put 4 break-points into CMFCVisualManagerOffice2007::OnUpdateSystemColors function where it calls AfxSetResourceHandle. Open file MFCApplication1.cpp in your newly created project folder and put this code [1] into CMFCApplication4App::InitInstance function just before CMainFrame* pMainFrame = new CMainFrame;, put break-point into this thread proc.
Now build and run this MFC application in debug mode, on each break-point hit, use freeze thread and thaw thread functions from Threads window, so you will arrange main thread in the middle of CMFCVisualManagerOffice2007::OnUpdateSystemColors function just after setting the global variable using AfxSetResourceHandle function and the worker thread before CStringT::LoadString. Now the load string will fail because it is looking for it inside mfc140ud.dll instead of using resource chain and MFCApplication1.exe.
I believe this is Microsoft's bug (changing global variable for a while), my code-base is full of innocent CString::LoadString calls which rely on carefully and correctly constructed resource chain with various plug-in DLLs and with an .exe at the end. If this is not Microsoft's bug then it is my bug relying on MFC on providing me a usable resource chain. I would need to create my own resource-chain-like functionality and use it everywhere when loading strings and other stuff from resources.
// [1]
AFX_THREADPROC thread_proc = [](LPVOID pParam){
CString str;
str.LoadString(IDS_CAPTION_TEXT);
UINT ret = 0;
return ret;
};
::AfxBeginThread(thread_proc, (LPVOID)nullptr);
// Same result with ::AfxBeginThread(CRuntimeClass*) overload.
I'm triying to use Media Foundation to play mp3 file and I have a problem getting PresentationDesctiptor using CreatePresentationDescriptor method
What am I doing:
Start MF using MFStartup
Create session using MFCreateMediaSession
Create SourceResolver using MFCreateSourceResolver
Create MediaSource using CreateObjectFromURL from SourceResolver
Create topology using MFCreateTopology
Trying to create PresentationDescriptor using CreatePresentationDescriptor from MediaSource
When I call CreatePresentationDescriptor no error/exception occurs it just stands there and does nothing. When I pause Visual Strudio it indicates that program is still waiting for method to finish. What am I doing wrong ?
I did not metion that I use C# for this (did not think this was relevant)
The problem was that when importing com interfaces in C# you need to import all methods of interface not only those that are called. Some methods can call not imported methods and cause Access Violation that is not reported to Visual Strudio debugger and as a result it seems like method is never finished invokink.
Is it possible to print in Silverlight without blocking the UI thread?
I have to print a lot of pages, and consequently my UI freezes for a while. I would like to print on a background thread instead (and update a progress bar if possible), but can't figure out how.
I tried calling the Print() method of my PrintDocument inside the DoWork() method of a BackgroundWorker, but that gives me an UnauthorizedAccessException "Invalid cross-thread access".
It seems that even initiating a PrintDocument is not possible outside the UI thread:
PrintDocument pd = new PrintDocument(); in BackgroundWorker.DoWork() throws the same exception.
I found a lot of posts where people say that printing has to happen on the UI thread, but no documentation of this. I'm new to multithreading, so any pointers in the right direction would be appreciated.
I had this problem and came across this question which unfortunately didn't have the answer i was hoping for. But I thought that for anyone else who comes across this problem, this may at least shed some light.
I was following this article on printing in Silverlight, It works like a charm for regular printing on the UI Thread, but for actually trying to print on a separate thread I don't think it's possible. I switched out the last line of code in the example
printDocument.Print("SLPrintDemo document");
with an alternate one to see if it would work
new Thread(() => printDocument.Print("SLPrintDemo document")).Start();
To see if the print job itself would spawn in a separate thread. However though the code compiles and runs fine, the document does not print. The reason seems to be that once the Print command is fired, it then fires up the printing options dialog for choosing printer and other options etc. At this point it is no longer on the UI thread so nothing happens ( No exceptions, so i'm assuming they're swallowed somewhere)
So as far as I can tell at the moment, there is no way to print in Silverlight that is not in the UI thread.
Use Dispatcher for updating your UI. For example:
Dispatcher.BeginInvoke(() =>
{
ProgressBar.Value = 100;
});
I have an OpenSL ES function call that causes no problems in one application, but causes a problem in another application, both run on the same device.
The line is:
result = slCreateEngine(&engineObject, 0, NULL, 0, NULL, NULL);
Where result is of the type SLresult, engineObject is of the type SLObjectItf
The error I seem to get is:
05-19 11:56:27.007: ERROR/libOpenSLES(1425): slCreateEngine while another engine 0x299fa0 is active
It seems this is not logged from my code, but maybe it is caused by it? So what could cause this line to produce an error in one app, but not in the other?
As it happens to be, it was partly Android's Activity life-cycle which caused the error, but mostly my own fault. It was caused by the onCreate() and onResume() methods Android provides for an Activity. I never thought of the fact that onResume() also get's called when an Activity is started. Because of this, I never realized that I had a 2nd call to the slCreateEngine function.....
According to the docs "OpenSL ES for Android supports a single engine per application". I had a quick check of the source for OpenSL an I can see this is enforced by a global storing the current active engine.
So if you want to call slCreateEngine, you must make sure all other engines have been destroyed first. This includes the possibility of any 3rd party code you are linking in too (incase you are linking in something else that is creating an OpenSL engine object before you do).
I am developing a Windows forms application which connects to a piece of hardware, acquires a lot of data (~1 GSample/sec), processes it, and spits it out to the screen upon a button click. I am now trying to automate the process in a loop that can be started/stopped at any time so I can monitor it whilst tweaking the input to the acquisition hardware. I thinks it's clear that I need to do this on a separate thread, but I'm having a heck of a time trying to do this in c++/cli - I have found a number of good examples using MFC, which is not supported by Express.
Specifically: My task is to press a button which is handled in Form1.h, to call a function in my main file Acquisition.cpp which contains the following code (currently an infinite loop)
void Form1::realTimeUpdate()
{
// live is a boolean variable set by a button on the form
while(live)
{
displayVariance(getVar(getQuadratures(100),nbrSamples));
}
}
I wish to execute this code in a separate thread so that the main program can listen for the user request to stop the operation. Without threading, I currently have to forcefully quit the program (or set it to run a fixed number of times) to stop it.
Is there any suggestions how I might go about running this code on a separate thread?
I've (unsuccessfully) tried a few things already:
Modifying the example given in This Microsoft Example. Problem: requires /clr:oldSyntax option which is incompatible with the other 1300 lines of code in the program.
Trying to do what I'd do in Java (Declare a global thread and start/stop it from any point in the code. Problem: Compiler won't let me declare a global System::Threading.Thread
this beautiful example. Problem: Requires MFC.
Any suggestions would be greatly appreciated!
You can use a BackgroundWorker or a Thread to handle this. You'll need to make sure that the portion of your work that updates the UI is marshaled back to the UI thread, however.
Here is a tutorial on threading in C++/CLI.
For the record, upon Reed's suggestion about using a BackgroundWorker, I sifted through the code at the bottom of this page and modified my code so that:
It created a new backgroundWorker BGWorker in which BGWorker->DoWork() called my realTimeUpdate() function.
A button on the main Form calls either RunWorkerAsync() or CancelAsync() depending on whether or not the process is running (checked by a boolean flag in my main program).
The realTimeUpdate() function is now passed a BackgroundWorker - realTimeUpdate(BackgroundWorker^ worker, DoWorkEventArgs ^ e) After each calculation is complete within the internal loop, it calls worker->ReportProgress(result) function. In the BGWorker->ProgressChanged() function a separate function, upDataUI(int) draws the result on the main form.
Thanks again for the help.