Merge lp:~spacedout/qtubuntu/fix_opengl_sharing into lp:qtubuntu

[David Fries]

All of OpenGL, OpenGLES, and Qt5 support sharing a context, but the ubuntu-touch Qt5 abstraction does not, this adds that support, otherwise programs can't offload tasks to another thread to execute.

All of OpenGL, OpenGLES, and Qt5 support sharing a context, but the ubuntu-touch Qt5 abstraction does not, this adds that support, otherwise programs can't offload tasks to another thread to execute.

[Francis Ginther (fginther)]

Jenkins will not perform a ci build on this until it is reviewed and top approved by a Canonical employee. Your best bet for finding a reviewer is through the #ubuntu-touch IRC channel on freenode.

If this is approved and still fails to be tested by jenkins, please ping me again.

[Francis Ginther (fginther)]

Oh, one more thing. You'll need to provide a commit message through launchpad as jenkins enforces this as part of this project's workflow. Copy-n-paste of the current Description should be suitable.

[Loïc Molinari (loic.molinari)]

The code looks good. I'll test on the device and approve if everything's fine.

[David Fries (spacedout)]

On Tue, May 21, 2013 at 05:10:37PM -0000, Loïc Molinari wrote:
> The code looks good. I'll test on the device and approve if everything's fine.

Depending on how you plan to test it I wanted to pass along a tip.

There is a related issue I'll mention that I've only worked around.
The problem is while I could create a new window for the new context,
it would be resized to the full screen, even though show() was never
called. While the hidden window was not visible (the main window
continued to be updated and displayed), all touch events were directed
to the hidden window. My hack was to turn around and deliver them in
my code to the main window object so things would continue to work.

The upcoming Qt 5.1 has an QOffscreenSurface that would be nice to
support directly, but that's independent of this.

--
David Fries <email address hidden> PGP pub CB1EE8F0
http://fries.net/~david/

[Gerry Boland (gerboland)]

Most of this seems implemented by now:
http://bazaar.launchpad.net/~phablet-team/qtubuntu/trunk/view/head:/src/platforms/base/context.cc

isSharing is not implemented in trunk though, yet these shared contexts are being used by the oxide browser. So not sure that needed either

review: Needs Fixing

Unmerged revisions

132. By David Fries on 2013-05-13

Enable sharing OpenGL contexts

Sharing OpenGL contexts are required to offload OpenGL tasks to another
thread such as uploading textues or drawing into a framebuffer to use
as a texture.

131. By David Fries on 2013-05-13

QUbuntuBaseIntegration allocate in const remove typecast

The base QPlatformIntegration doesn't have the non-const version of
createPlatformOpenGLContext and this routine doesn't require it,
so simplifying the code and removing a typecast along the way.

=== modified file 'src/platforms/base/context.cc'
--- src/platforms/base/context.cc	2013-02-14 16:31:33 +0000
+++ src/platforms/base/context.cc	2013-05-13 06:45:33 +0000
@@ -37,7 +37,10 @@
 }
 #endif
 
-QUbuntuBaseContext::QUbuntuBaseContext(QUbuntuBaseScreen* screen) {
+QUbuntuBaseContext::QUbuntuBaseContext(QUbuntuBaseScreen* screen,
+  QPlatformOpenGLContext *share) :
+  sharingContext_(false) {
+  DLOG("QUbuntuBaseContext::QUbuntuBaseContext (screen=%p, share=%p)", screen, share);
   DASSERT(screen != NULL);
   eglDisplay_ = screen->eglDisplay();
   screen_ = screen;
@@ -48,10 +51,21 @@
   attribs.append(2);
   attribs.append(EGL_NONE);
   ASSERT(eglBindAPI(EGL_OPENGL_ES_API) == EGL_TRUE);
-  ASSERT((eglContext_ = eglCreateContext(
-      eglDisplay_, screen->eglConfig(), EGL_NO_CONTEXT, attribs.constData())) != EGL_NO_CONTEXT);
+  EGLContext shareContext = EGL_NO_CONTEXT;
+  if (share) {
+    shareContext = static_cast<QUbuntuBaseContext*>(share)->eglContext();
+    sharingContext_ = true;
+  }
 
-  DLOG("QUbuntuBaseContext::QUbuntuBaseContext (this=%p, screen=%p)", this, screen);
+  eglContext_ = eglCreateContext(eglDisplay_, screen->eglConfig(), shareContext, attribs.constData());
+  if (eglContext_ == EGL_NO_CONTEXT && sharingContext_) {
+    // re-try without a shared context
+    sharingContext_ = false;
+    DLOG("QUbuntuBaseContext::QUbuntuBaseContext sharing context failed");
+    eglContext_ = eglCreateContext(
+        eglDisplay_, screen->eglConfig(), EGL_NO_CONTEXT, attribs.constData());
+  }
+  ASSERT(eglContext_ != EGL_NO_CONTEXT);
 }
 
 QUbuntuBaseContext::~QUbuntuBaseContext() {
 
=== modified file 'src/platforms/base/context.h'
--- src/platforms/base/context.h	2013-02-14 16:31:33 +0000
+++ src/platforms/base/context.h	2013-05-13 06:45:33 +0000
@@ -21,7 +21,7 @@
 
 class QUbuntuBaseContext : public QPlatformOpenGLContext {
  public:
-  QUbuntuBaseContext(QUbuntuBaseScreen* screen);
+  QUbuntuBaseContext(QUbuntuBaseScreen* screen, QPlatformOpenGLContext *share);
   ~QUbuntuBaseContext();
 
   // QPlatformOpenGLContext methods.
@@ -29,6 +29,7 @@
   void swapBuffers(QPlatformSurface* surface);
   bool makeCurrent(QPlatformSurface* surface);
   void doneCurrent();
+  bool isSharing() const { return sharingContext_; }
   bool isValid() const { return eglContext_ != EGL_NO_CONTEXT; }
   void (*getProcAddress(const QByteArray& procName)) ();
   EGLContext eglContext() const { return eglContext_; }
@@ -37,6 +38,7 @@
   QUbuntuBaseScreen* screen_;
   EGLContext eglContext_;
   EGLDisplay eglDisplay_;
+  bool sharingContext_;
 };
 
 #endif  //QUBUNTUBASECONTEXT_H
 
=== modified file 'src/platforms/base/integration.cc'
--- src/platforms/base/integration.cc	2013-02-14 16:31:33 +0000
+++ src/platforms/base/integration.cc	2013-05-13 06:45:33 +0000
@@ -70,13 +70,8 @@
     QOpenGLContext* context) const {
   DLOG("QUbuntuBaseIntegration::createPlatformOpenGLContext const (this=%p, context=%p)", this,
        context);
-  return const_cast<QUbuntuBaseIntegration*>(this)->createPlatformOpenGLContext(context);
-}
-
-QPlatformOpenGLContext* QUbuntuBaseIntegration::createPlatformOpenGLContext(
-    QOpenGLContext* context) {
-  DLOG("QUbuntuBaseIntegration::createPlatformOpenGLContext (this=%p, context=%p)", this, context);
-  return new QUbuntuBaseContext(static_cast<QUbuntuBaseScreen*>(context->screen()->handle()));
+  return new QUbuntuBaseContext(static_cast<QUbuntuBaseScreen*>(context->screen()->handle()),
+    context->shareHandle());
 }
 
 QStringList QUbuntuBaseIntegration::themeNames() const {
 
=== modified file 'src/platforms/base/integration.h'
--- src/platforms/base/integration.h	2013-02-14 16:31:33 +0000
+++ src/platforms/base/integration.h	2013-05-13 06:45:33 +0000
@@ -31,7 +31,6 @@
   QPlatformNativeInterface* nativeInterface() const { return nativeInterface_; }
   QPlatformBackingStore* createPlatformBackingStore(QWindow* window) const;
   QPlatformOpenGLContext* createPlatformOpenGLContext(QOpenGLContext* context) const;
-  QPlatformOpenGLContext* createPlatformOpenGLContext(QOpenGLContext* context);
   QPlatformFontDatabase* fontDatabase() const { return fontDb_; }
   QStringList themeNames() const;
   QPlatformTheme* createPlatformTheme(const QString& name) const;