tdf#94006 - re-factor and fix OpenGLContext mis-use.

Squashes two related patches from master:

Don't use rtl::Reference for the global / list state, so the
ref-count reflects the number of real users.
Hold a reference during ~OpenGLContext.

Fix mis-use in:
gltf rendering, OpenGL canvas, GL transitions & GL capable (charts)
Avoid GLX operations on un-initialized contexts.

Signed-off-by: Miklos Vajna <vmiklos@collabora.co.uk>

Conflicts:
	vcl/source/opengl/OpenGLContext.cxx
	vcl/workben/vcldemo.cxx
	canvas/source/opengl/ogl_spritedevicehelper.hxx

Change-Id: I7ea29b544d53bb80b25fa6663d39f345bf8f4e64

2 files changed, 18 insertions, 17 deletions

diff --git a/canvas/source/opengl/ogl_spritedevicehelper.cxx b/canvas/source/opengl/ogl_spritedevicehelper.cxx
index 37122d8740ca..091279c27242 100644
--- a/canvas/source/opengl/ogl_spritedevicehelper.cxx
+++ b/canvas/source/opengl/ogl_spritedevicehelper.cxx
@@ -87,7 +87,8 @@ namespace oglcanvas
         mnRadialTwoColorGradientProgram(0),
         mnRadialMultiColorGradientProgram(0),
         mnRectangularTwoColorGradientProgram(0),
-        mnRectangularMultiColorGradientProgram(0)
+        mnRectangularMultiColorGradientProgram(0),
+        mxContext(OpenGLContext::Create())
     {}
 
     SpriteDeviceHelper::~SpriteDeviceHelper()
@@ -104,8 +105,8 @@ namespace oglcanvas
                 VCLUnoHelper::GetInterface(&rWindow),
                 uno::UNO_QUERY_THROW) );
 
-        maContext.requestLegacyContext();
-        maContext.init(&rWindow);
+        mxContext->requestLegacyContext();
+        mxContext->init(&rWindow);
         // init window context
         initContext();
 
@@ -127,7 +128,7 @@ namespace oglcanvas
         mnRectangularTwoColorGradientProgram =
             OpenGLHelper::LoadShaders("dummyVertexShader", "rectangularTwoColorGradientFragmentShader");
 
-        maContext.makeCurrent();
+        mxContext->makeCurrent();
 
         notifySizeUpdate(rViewArea);
         // TODO(E3): check for GL_ARB_imaging extension
@@ -140,7 +141,7 @@ namespace oglcanvas
         mpDevice = NULL;
         mpTextureCache.reset();
 
-        if( maContext.isInitialized() )
+        if( mxContext->isInitialized() )
         {
             glDeleteProgram( mnRectangularTwoColorGradientProgram );
             glDeleteProgram( mnRectangularMultiColorGradientProgram );
@@ -153,11 +154,11 @@ namespace oglcanvas
 
     geometry::RealSize2D SpriteDeviceHelper::getPhysicalResolution()
     {
-        if( !maContext.isInitialized() )
+        if( !mxContext->isInitialized() )
             return ::canvas::tools::createInfiniteSize2D(); // we're disposed
 
         // Map a one-by-one millimeter box to pixel
-        SystemChildWindow* pChildWindow = maContext.getChildWindow();
+        SystemChildWindow* pChildWindow = mxContext->getChildWindow();
         const MapMode aOldMapMode( pChildWindow->GetMapMode() );
         pChildWindow->SetMapMode( MapMode(MAP_MM) );
         const Size aPixelSize( pChildWindow->LogicToPixel(Size(1,1)) );
@@ -168,11 +169,11 @@ namespace oglcanvas
 
     geometry::RealSize2D SpriteDeviceHelper::getPhysicalSize()
     {
-        if( !maContext.isInitialized() )
+        if( !mxContext->isInitialized() )
             return ::canvas::tools::createInfiniteSize2D(); // we're disposed
 
         // Map the pixel dimensions of the output window to millimeter
-        SystemChildWindow* pChildWindow = maContext.getChildWindow();
+        SystemChildWindow* pChildWindow = mxContext->getChildWindow();
         const MapMode aOldMapMode( pChildWindow->GetMapMode() );
         pChildWindow->SetMapMode( MapMode(MAP_MM) );
         const Size aLogSize( pChildWindow->PixelToLogic(pChildWindow->GetOutputSizePixel()) );
@@ -273,13 +274,13 @@ namespace oglcanvas
     bool SpriteDeviceHelper::showBuffer( bool bIsVisible, bool /*bUpdateAll*/ )
     {
         // hidden or disposed?
-        if( !bIsVisible || !maContext.isInitialized() || !mpSpriteCanvas )
+        if( !bIsVisible || !mxContext->isInitialized() || !mpSpriteCanvas )
             return false;
 
         if( !activateWindowContext() )
             return false;
 
-        SystemChildWindow* pChildWindow = maContext.getChildWindow();
+        SystemChildWindow* pChildWindow = mxContext->getChildWindow();
         const ::Size& rOutputSize = pChildWindow->GetSizePixel();
         initTransformation(rOutputSize);
 
@@ -329,7 +330,7 @@ namespace oglcanvas
         unx::glXWaitGL();
         XSync( reinterpret_cast<unx::Display*>(mpDisplay), false );
         */
-        maContext.swapBuffers();
+        mxContext->swapBuffers();
 
         // flush texture cache, such that it does not build up
         // indefinitely.
@@ -353,7 +354,7 @@ namespace oglcanvas
 
     uno::Any SpriteDeviceHelper::getDeviceHandle() const
     {
-        const SystemChildWindow* pChildWindow = maContext.getChildWindow();
+        const SystemChildWindow* pChildWindow = mxContext->getChildWindow();
         return uno::makeAny( reinterpret_cast< sal_Int64 >(pChildWindow) );
     }
 
@@ -372,9 +373,9 @@ namespace oglcanvas
 
     void SpriteDeviceHelper::notifySizeUpdate( const awt::Rectangle& rBounds )
     {
-        if( maContext.isInitialized() )
+        if( mxContext->isInitialized() )
         {
-            SystemChildWindow* pChildWindow = maContext.getChildWindow();
+            SystemChildWindow* pChildWindow = mxContext->getChildWindow();
             pChildWindow->setPosSizePixel(
                 0,0,rBounds.Width,rBounds.Height);
         }
@@ -509,7 +510,7 @@ namespace oglcanvas
 
     bool SpriteDeviceHelper::activateWindowContext()
     {
-        maContext.makeCurrent();
+        mxContext->makeCurrent();
         return true;
     }
 
diff --git a/canvas/source/opengl/ogl_spritedevicehelper.hxx b/canvas/source/opengl/ogl_spritedevicehelper.hxx
index b1a988d51305..3d05f23b7445 100644
--- a/canvas/source/opengl/ogl_spritedevicehelper.hxx
+++ b/canvas/source/opengl/ogl_spritedevicehelper.hxx
@@ -140,7 +140,7 @@ namespace oglcanvas
         unsigned int                                       mnRectangularTwoColorGradientProgram;
         unsigned int                                       mnRectangularMultiColorGradientProgram;
 
-        OpenGLContext maContext;
+        rtl::Reference<OpenGLContext>                      mxContext;
     };
 }