From ac19024c141448dbc5d89ad943a28875b4504f5c Mon Sep 17 00:00:00 2001

From: =?UTF-8?q?Caol=C3=A1n=20McNamara?= <caolanm@redhat.com>

Date: Fri, 25 Nov 2016 14:11:13 +0000

Subject: [PATCH] gtk3: implement opengl support for slideshow

MIME-Version: 1.0

Content-Type: text/plain; charset=UTF-8

Content-Transfer-Encoding: 8bit

all of them work, except "Fall" doesn't look right, but it has

the exact same problem under gtk2/gen to.

Change-Id: I73cb9c0fb8211f727198be78d90d4f80a4f8c7c8

Reviewed-on: https://gerrit.libreoffice.org/31214

Reviewed-by: Caolán McNamara <caolanm@redhat.com>

Tested-by: Caolán McNamara <caolanm@redhat.com>

(cherry picked from commit 8bd9db90383ee008777903c35c7a5eb2c5352e71)

---

 include/vcl/opengl/OpenGLContext.hxx               |   2 +

 slideshow/source/engine/opengl/TransitionImpl.cxx  |  73 ++++++------

 slideshow/source/engine/opengl/TransitionImpl.hxx  |   9 +-

 .../source/engine/opengl/TransitionerImpl.cxx      |   7 +-

 vcl/inc/unx/gtk/gtkinst.hxx                        |   1 +

 vcl/source/opengl/OpenGLContext.cxx                |   5 +

 vcl/unx/gtk3/gtk3gtkinst.cxx                       | 127 +++++++++++++++++++++

 7 files changed, 181 insertions(+), 43 deletions(-)

diff --git a/include/vcl/opengl/OpenGLContext.hxx b/include/vcl/opengl/OpenGLContext.hxx

index ffcd816..5796f7e 100644

--- a/include/vcl/opengl/OpenGLContext.hxx

+++ b/include/vcl/opengl/OpenGLContext.hxx

@@ -129,6 +129,8 @@ public:

     void registerAsCurrent();

     /// reset the GL context so this context is not implicit in subsequent GL calls.

     virtual void resetCurrent();

+    /// unbind the GL_FRAMEBUFFER to its default state, needed for gtk3

+    virtual void restoreDefaultFramebuffer();

     virtual void swapBuffers();

     virtual void sync();

     void show();

diff --git a/slideshow/source/engine/opengl/TransitionImpl.cxx b/slideshow/source/engine/opengl/TransitionImpl.cxx

index 115aaf2..7b9b894 100644

--- a/slideshow/source/engine/opengl/TransitionImpl.cxx

+++ b/slideshow/source/engine/opengl/TransitionImpl.cxx

@@ -29,6 +29,7 @@

 #include <glm/gtc/matrix_transform.hpp>

 #include <glm/gtc/type_ptr.hpp>

 #include <vcl/opengl/OpenGLHelper.hxx>

+#include <vcl/opengl/OpenGLContext.hxx>

 #include <algorithm>

 #include <array>

@@ -132,7 +133,7 @@ static std::vector<int> uploadPrimitives(const Primitives_t& primitives)

     return indices;

 }

-bool OGLTransitionImpl::prepare( sal_Int32 glLeavingSlideTex, sal_Int32 glEnteringSlideTex )

+bool OGLTransitionImpl::prepare( sal_Int32 glLeavingSlideTex, sal_Int32 glEnteringSlideTex, OpenGLContext *pContext )

 {

     m_nProgramObject = makeShader();

     if (!m_nProgramObject)

@@ -200,7 +201,7 @@ bool OGLTransitionImpl::prepare( sal_Int32 glLeavingSlideTex, sal_Int32 glEnteri

     glBindBuffer(GL_ARRAY_BUFFER, 0);

     CHECK_GL_ERROR();

-    prepareTransition( glLeavingSlideTex, glEnteringSlideTex );

+    prepareTransition( glLeavingSlideTex, glEnteringSlideTex, pContext );

     return true;

 }

@@ -233,7 +234,7 @@ void OGLTransitionImpl::finish( double, double, double, double, double )

 {

 }

-void OGLTransitionImpl::prepareTransition( sal_Int32, sal_Int32 )

+void OGLTransitionImpl::prepareTransition( sal_Int32, sal_Int32, OpenGLContext* )

 {

 }

@@ -241,7 +242,7 @@ void OGLTransitionImpl::finishTransition()

 {

 }

-void OGLTransitionImpl::displaySlides_( double nTime, sal_Int32 glLeavingSlideTex, sal_Int32 glEnteringSlideTex, double SlideWidthScale, double SlideHeightScale )

+void OGLTransitionImpl::displaySlides_( double nTime, sal_Int32 glLeavingSlideTex, sal_Int32 glEnteringSlideTex, double SlideWidthScale, double SlideHeightScale, OpenGLContext * )

 {

     CHECK_GL_ERROR();

     applyOverallOperations( nTime, SlideWidthScale, SlideHeightScale );

@@ -257,7 +258,7 @@ void OGLTransitionImpl::displaySlides_( double nTime, sal_Int32 glLeavingSlideTe

 }

 void OGLTransitionImpl::display( double nTime, sal_Int32 glLeavingSlideTex, sal_Int32 glEnteringSlideTex,

-                                 double SlideWidth, double SlideHeight, double DispWidth, double DispHeight )

+                                 double SlideWidth, double SlideHeight, double DispWidth, double DispHeight, OpenGLContext *pContext )

 {

     const double SlideWidthScale = SlideWidth/DispWidth;

     const double SlideHeightScale = SlideHeight/DispHeight;

@@ -267,7 +268,7 @@ void OGLTransitionImpl::display( double nTime, sal_Int32 glLeavingSlideTex, sal_

     prepare( nTime, SlideWidth, SlideHeight, DispWidth, DispHeight );

     CHECK_GL_ERROR();

-    displaySlides_( nTime, glLeavingSlideTex, glEnteringSlideTex, SlideWidthScale, SlideHeightScale );

+    displaySlides_( nTime, glLeavingSlideTex, glEnteringSlideTex, SlideWidthScale, SlideHeightScale, pContext );

     CHECK_GL_ERROR();

     displayScene( nTime, SlideWidth, SlideHeight, DispWidth, DispHeight );

     CHECK_GL_ERROR();

@@ -534,9 +535,9 @@ public:

 private:

     virtual GLuint makeShader() const override;

-    virtual void displaySlides_( double nTime, sal_Int32 glLeavingSlideTex, sal_Int32 glEnteringSlideTex, double SlideWidthScale, double SlideHeightScale ) override;

+    virtual void displaySlides_( double nTime, sal_Int32 glLeavingSlideTex, sal_Int32 glEnteringSlideTex, double SlideWidthScale, double SlideHeightScale, OpenGLContext *pContext ) override;

-    virtual void prepareTransition( sal_Int32, sal_Int32 ) override {

+    virtual void prepareTransition( sal_Int32, sal_Int32, OpenGLContext* ) override {

         glDisable(GL_CULL_FACE);

     }

@@ -551,7 +552,7 @@ GLuint ReflectionTransition::makeShader() const

 }

 void ReflectionTransition::displaySlides_( double nTime, sal_Int32 glLeavingSlideTex, sal_Int32 glEnteringSlideTex,

-                                              double SlideWidthScale, double SlideHeightScale )

+                                              double SlideWidthScale, double SlideHeightScale, OpenGLContext * )

 {

     CHECK_GL_ERROR();

     applyOverallOperations( nTime, SlideWidthScale, SlideHeightScale );

@@ -598,7 +599,7 @@ public:

 private:

     virtual GLuint makeShader() const override;

-    virtual void displaySlides_( double nTime, sal_Int32 glLeavingSlideTex, sal_Int32 glEnteringSlideTex, double SlideWidthScale, double SlideHeightScale ) override;

+    virtual void displaySlides_( double nTime, sal_Int32 glLeavingSlideTex, sal_Int32 glEnteringSlideTex, double SlideWidthScale, double SlideHeightScale, OpenGLContext *pContext ) override;

 };

 GLuint SimpleTransition::makeShader() const

@@ -607,7 +608,7 @@ GLuint SimpleTransition::makeShader() const

 }

 void SimpleTransition::displaySlides_( double nTime, sal_Int32 glLeavingSlideTex, sal_Int32 glEnteringSlideTex,

-                                              double SlideWidthScale, double SlideHeightScale )

+                                       double SlideWidthScale, double SlideHeightScale, OpenGLContext * )

 {

     CHECK_GL_ERROR();

     applyOverallOperations( nTime, SlideWidthScale, SlideHeightScale );

@@ -857,10 +858,10 @@ public:

     {}

 private:

-    virtual void displaySlides_(double nTime, sal_Int32 glLeavingSlideTex, sal_Int32 glEnteringSlideTex, double SlideWidthScale, double SlideHeightScale) override;

+    virtual void displaySlides_(double nTime, sal_Int32 glLeavingSlideTex, sal_Int32 glEnteringSlideTex, double SlideWidthScale, double SlideHeightScale, OpenGLContext *pContext) override;

 };

-void RochadeTransition::displaySlides_( double nTime, sal_Int32 glLeavingSlideTex, sal_Int32 glEnteringSlideTex, double SlideWidthScale, double SlideHeightScale )

+void RochadeTransition::displaySlides_( double nTime, sal_Int32 glLeavingSlideTex, sal_Int32 glEnteringSlideTex, double SlideWidthScale, double SlideHeightScale, OpenGLContext * )

 {

     applyOverallOperations( nTime, SlideWidthScale, SlideHeightScale );

@@ -1195,7 +1196,7 @@ public:

         {}

 private:

-    virtual void displaySlides_( double nTime, sal_Int32 glLeavingSlideTex, sal_Int32 glEnteringSlideTex, double SlideWidthScale, double SlideHeightScale ) override;

+    virtual void displaySlides_( double nTime, sal_Int32 glLeavingSlideTex, sal_Int32 glEnteringSlideTex, double SlideWidthScale, double SlideHeightScale, OpenGLContext *pContext ) override;

 };

 Primitives_t makeLeavingSlide(double nTime)

@@ -1229,7 +1230,7 @@ Primitives_t makeLeavingSlide(double nTime)

 }

 void DiamondTransition::displaySlides_( double nTime, sal_Int32 glLeavingSlideTex, sal_Int32 glEnteringSlideTex,

-                                              double SlideWidthScale, double SlideHeightScale )

+                                        double SlideWidthScale, double SlideHeightScale, OpenGLContext * )

 {

     CHECK_GL_ERROR();

     applyOverallOperations( nTime, SlideWidthScale, SlideHeightScale );

@@ -1411,7 +1412,7 @@ protected:

     {}

     virtual void finishTransition() override;

-    virtual void prepareTransition( sal_Int32 glLeavingSlideTex, sal_Int32 glEnteringSlideTex ) override;

+    virtual void prepareTransition( sal_Int32 glLeavingSlideTex, sal_Int32 glEnteringSlideTex, OpenGLContext *pContext ) override;

 private:

     /** various data */

@@ -1488,7 +1489,7 @@ void initPermTexture(GLuint *texID)

     CHECK_GL_ERROR();

 }

-void PermTextureTransition::prepareTransition( sal_Int32, sal_Int32 )

+void PermTextureTransition::prepareTransition( sal_Int32, sal_Int32, OpenGLContext* )

 {

     CHECK_GL_ERROR();

     GLint location = glGetUniformLocation( m_nProgramObject, "permTexture" );

@@ -1629,8 +1630,8 @@ public:

 private:

     virtual void finishTransition() override;

     virtual GLuint makeShader() const override;

-    virtual void prepareTransition( sal_Int32 glLeavingSlideTex, sal_Int32 glEnteringSlideTex ) override;

-    virtual void displaySlides_( double nTime, sal_Int32 glLeavingSlideTex, sal_Int32 glEnteringSlideTex, double SlideWidthScale, double SlideHeightScale ) override;

+    virtual void prepareTransition( sal_Int32 glLeavingSlideTex, sal_Int32 glEnteringSlideTex, OpenGLContext *pContext ) override;

+    virtual void displaySlides_( double nTime, sal_Int32 glLeavingSlideTex, sal_Int32 glEnteringSlideTex, double SlideWidthScale, double SlideHeightScale, OpenGLContext *pContext ) override;

     GLint mnSlideLocation = -1;

     GLint mnTileInfoLocation = -1;

@@ -1679,10 +1680,10 @@ glm::mat4 lookAt(const glm::vec3& eye, const glm::vec3& center, const glm::vec3&

                      -glm::dot(s, eye), -glm::dot(u, eye), glm::dot(f, eye), 1);

 }

-void VortexTransition::prepareTransition( sal_Int32 glLeavingSlideTex, sal_Int32 glEnteringSlideTex )

+void VortexTransition::prepareTransition( sal_Int32 glLeavingSlideTex, sal_Int32 glEnteringSlideTex, OpenGLContext *pContext )

 {

     CHECK_GL_ERROR();

-    PermTextureTransition::prepareTransition( glLeavingSlideTex, glEnteringSlideTex );

+    PermTextureTransition::prepareTransition( glLeavingSlideTex, glEnteringSlideTex, pContext );

     CHECK_GL_ERROR();

     mnSlideLocation = glGetUniformLocation(m_nProgramObject, "slide");

@@ -1783,7 +1784,7 @@ void VortexTransition::prepareTransition( sal_Int32 glLeavingSlideTex, sal_Int32

         }

     }

-    glBindFramebuffer(GL_FRAMEBUFFER, 0);

+    pContext->restoreDefaultFramebuffer();

     glBindTexture(GL_TEXTURE_2D, 0);

     glActiveTexture( GL_TEXTURE2 );

@@ -1793,7 +1794,7 @@ void VortexTransition::prepareTransition( sal_Int32 glLeavingSlideTex, sal_Int32

     glActiveTexture( GL_TEXTURE0 );

 }

-void VortexTransition::displaySlides_( double nTime, sal_Int32 glLeavingSlideTex, sal_Int32 glEnteringSlideTex, double SlideWidthScale, double SlideHeightScale )

+void VortexTransition::displaySlides_( double nTime, sal_Int32 glLeavingSlideTex, sal_Int32 glEnteringSlideTex, double SlideWidthScale, double SlideHeightScale, OpenGLContext * pContext )

 {

     CHECK_GL_ERROR();

     applyOverallOperations( nTime, SlideWidthScale, SlideHeightScale );

@@ -1815,7 +1816,7 @@ void VortexTransition::displaySlides_( double nTime, sal_Int32 glLeavingSlideTex

     displaySlide( nTime, glEnteringSlideTex, getScene().getEnteringSlide(), SlideWidthScale, SlideHeightScale );

     glViewport(viewport[0], viewport[1], viewport[2], viewport[3]);

-    glBindFramebuffer(GL_FRAMEBUFFER, 0);

+    pContext->restoreDefaultFramebuffer();

     glUniform1f( mnShadowLocation, 0.0 );

     glUniform1f( mnSlideLocation, 0.0 );

     displaySlide( nTime, glLeavingSlideTex, getScene().getLeavingSlide(), SlideWidthScale, SlideHeightScale );

@@ -1877,7 +1878,7 @@ public:

 private:

     virtual GLuint makeShader() const override;

-    virtual void prepareTransition( sal_Int32 glLeavingSlideTex, sal_Int32 glEnteringSlideTex ) override;

+    virtual void prepareTransition( sal_Int32 glLeavingSlideTex, sal_Int32 glEnteringSlideTex, OpenGLContext *pContext ) override;

     virtual void prepare( double nTime, double SlideWidth, double SlideHeight, double DispWidth, double DispHeight ) override;

     glm::vec2 maCenter;

@@ -1889,7 +1890,7 @@ GLuint RippleTransition::makeShader() const

     return OpenGLHelper::LoadShaders( "basicVertexShader", "rippleFragmentShader" );

 }

-void RippleTransition::prepareTransition( sal_Int32, sal_Int32 )

+void RippleTransition::prepareTransition( sal_Int32, sal_Int32, OpenGLContext* )

 {

     GLint nCenterLocation = glGetUniformLocation(m_nProgramObject, "center");

     CHECK_GL_ERROR();

@@ -1974,7 +1975,7 @@ public:

 private:

     virtual GLuint makeShader() const override;

-    virtual void prepareTransition( sal_Int32 glLeavingSlideTex, sal_Int32 glEnteringSlideTex ) override;

+    virtual void prepareTransition( sal_Int32 glLeavingSlideTex, sal_Int32 glEnteringSlideTex, OpenGLContext *pContext ) override;

     virtual void finish( double nTime, double SlideWidth, double SlideHeight, double DispWidth, double DispHeight ) override;

     GLuint maBuffer = 0;

@@ -1990,10 +1991,10 @@ struct ThreeFloats

     GLfloat x, y, z;

 };

-void GlitterTransition::prepareTransition( sal_Int32 glLeavingSlideTex, sal_Int32 glEnteringSlideTex )

+void GlitterTransition::prepareTransition( sal_Int32 glLeavingSlideTex, sal_Int32 glEnteringSlideTex, OpenGLContext *pContext )

 {

     CHECK_GL_ERROR();

-    PermTextureTransition::prepareTransition( glLeavingSlideTex, glEnteringSlideTex );

+    PermTextureTransition::prepareTransition( glLeavingSlideTex, glEnteringSlideTex, pContext );

     CHECK_GL_ERROR();

     GLint nNumTilesLocation = glGetUniformLocation(m_nProgramObject, "numTiles");

@@ -2078,8 +2079,8 @@ public:

 private:

     virtual void finishTransition() override;

     virtual GLuint makeShader() const override;

-    virtual void prepareTransition( sal_Int32 glLeavingSlideTex, sal_Int32 glEnteringSlideTex ) override;

-    virtual void displaySlides_( double nTime, sal_Int32 glLeavingSlideTex, sal_Int32 glEnteringSlideTex, double SlideWidthScale, double SlideHeightScale ) override;

+    virtual void prepareTransition( sal_Int32 glLeavingSlideTex, sal_Int32 glEnteringSlideTex, OpenGLContext *pContext ) override;

+    virtual void displaySlides_( double nTime, sal_Int32 glLeavingSlideTex, sal_Int32 glEnteringSlideTex, double SlideWidthScale, double SlideHeightScale, OpenGLContext *pContext ) override;

     GLint maHexagonSizeLocation = -1;

     GLint maSelectedTextureLocation = -1;

@@ -2112,10 +2113,10 @@ GLuint HoneycombTransition::makeShader() const

     return OpenGLHelper::LoadShaders( "honeycombVertexShader", "honeycombFragmentShader", "honeycombGeometryShader" );

 }

-void HoneycombTransition::prepareTransition( sal_Int32 glLeavingSlideTex, sal_Int32 glEnteringSlideTex )

+void HoneycombTransition::prepareTransition( sal_Int32 glLeavingSlideTex, sal_Int32 glEnteringSlideTex, OpenGLContext *pContext )

 {

     CHECK_GL_ERROR();

-    PermTextureTransition::prepareTransition( glLeavingSlideTex, glEnteringSlideTex );

+    PermTextureTransition::prepareTransition( glLeavingSlideTex, glEnteringSlideTex, pContext );

     CHECK_GL_ERROR();

     maHexagonSizeLocation = glGetUniformLocation(m_nProgramObject, "hexagonSize");

@@ -2189,11 +2190,11 @@ void HoneycombTransition::prepareTransition( sal_Int32 glLeavingSlideTex, sal_In

         return;

     }

-    glBindFramebuffer(GL_FRAMEBUFFER, 0);

+    pContext->restoreDefaultFramebuffer();

 }

 void HoneycombTransition::displaySlides_( double nTime, sal_Int32 glLeavingSlideTex, sal_Int32 glEnteringSlideTex,

-                                              double SlideWidthScale, double SlideHeightScale )

+                                          double SlideWidthScale, double SlideHeightScale, OpenGLContext *pContext )

 {

     CHECK_GL_ERROR();

     applyOverallOperations(nTime, SlideWidthScale, SlideHeightScale);

@@ -2217,7 +2218,7 @@ void HoneycombTransition::displaySlides_( double nTime, sal_Int32 glLeavingSlide

     // The back (entering) slide needs to be drawn before the front (leaving) one in order for blending to work.

     glViewport(viewport[0], viewport[1], viewport[2], viewport[3]);

-    glBindFramebuffer(GL_FRAMEBUFFER, 0);

+    pContext->restoreDefaultFramebuffer();

     glUniform1f(mnShadowLocation, 0.0);

     glUniform1f(maSelectedTextureLocation, 0.0);

     glUniform1f(maHexagonSizeLocation, 1.0f - borderSize);

diff --git a/slideshow/source/engine/opengl/TransitionImpl.hxx b/slideshow/source/engine/opengl/TransitionImpl.hxx

index b739c0c..54b7ba0 100644

--- a/slideshow/source/engine/opengl/TransitionImpl.hxx

+++ b/slideshow/source/engine/opengl/TransitionImpl.hxx

@@ -36,6 +36,7 @@

 #include <vector>

 class Primitive;

+class OpenGLContext;

 class Operation;

 class SceneObject;

 class TransitionData;

@@ -136,10 +137,10 @@ public:

     /** Prepare transition.

       */

-    bool prepare( sal_Int32 glLeavingSlideTex, sal_Int32 glEnteringSlideTex );

+    bool prepare( sal_Int32 glLeavingSlideTex, sal_Int32 glEnteringSlideTex, OpenGLContext *pContext );

     /** Display a step of the transition.

       */

-    void display( double nTime, sal_Int32 glLeavingSlideTex, sal_Int32 glEnteringSlideTex, double SlideWidth, double SlideHeight, double DispWidth, double DispHeight );

+    void display( double nTime, sal_Int32 glLeavingSlideTex, sal_Int32 glEnteringSlideTex, double SlideWidth, double SlideHeight, double DispWidth, double DispHeight, OpenGLContext *pContext );

     /** Clean up after transition.

       */

     void finish();

@@ -182,7 +183,7 @@ private:

       *

       * Default implementation does nothing.

       */

-    virtual void prepareTransition( sal_Int32 glLeavingSlideTex, sal_Int32 glEnteringSlideTex );

+    virtual void prepareTransition( sal_Int32 glLeavingSlideTex, sal_Int32 glEnteringSlideTex, OpenGLContext *pContext );

     /** This function is called when the transition needs to clear after itself, like delete own textures etc.

       *

@@ -195,7 +196,7 @@ private:

       * Default implementation applies overall operations and then

       * displays both slides.

       */

-    virtual void displaySlides_( double nTime, sal_Int32 glLeavingSlideTex, sal_Int32 glEnteringSlideTex, double SlideWidthScale, double SlideHeightScale );

+    virtual void displaySlides_( double nTime, sal_Int32 glLeavingSlideTex, sal_Int32 glEnteringSlideTex, double SlideWidthScale, double SlideHeightScale, OpenGLContext *pContext );

     /** This function is called in prepare method to create the GL program.

       *

diff --git a/slideshow/source/engine/opengl/TransitionerImpl.cxx b/slideshow/source/engine/opengl/TransitionerImpl.cxx

index 01cd3e5..f2f0b3f 100644

--- a/slideshow/source/engine/opengl/TransitionerImpl.cxx

+++ b/slideshow/source/engine/opengl/TransitionerImpl.cxx

@@ -407,7 +407,7 @@ void OGLTransitionerImpl::impl_prepareSlides()

 bool OGLTransitionerImpl::impl_prepareTransition()

 {

     if( mpTransition && mpTransition->getSettings().mnRequiredGLVersion <= mnGLVersion )

-        return mpTransition->prepare( maLeavingSlideGL, maEnteringSlideGL );

+        return mpTransition->prepare( maLeavingSlideGL, maEnteringSlideGL, mpContext.get() );

     return false;

 }

@@ -1046,10 +1046,11 @@ void SAL_CALL OGLTransitionerImpl::update( double nTime ) throw (uno::RuntimeExc

     CHECK_GL_ERROR();

     const GLWindow& rGLWindow(mpContext->getOpenGLWindow());

-    mpTransition->display( nTime, maLeavingSlideGL, maEnteringSlideGL,

+    mpTransition->display(nTime, maLeavingSlideGL, maEnteringSlideGL,

                           maSlideSize.Width, maSlideSize.Height,

                           static_cast<double>(rGLWindow.Width),

-                          static_cast<double>(rGLWindow.Height) );

+                          static_cast<double>(rGLWindow.Height),

+                          mpContext.get());

     mpContext->swapBuffers();

diff --git a/vcl/inc/unx/gtk/gtkinst.hxx b/vcl/inc/unx/gtk/gtkinst.hxx

index 514b13f..e20ca9d 100644

--- a/vcl/inc/unx/gtk/gtkinst.hxx

+++ b/vcl/inc/unx/gtk/gtkinst.hxx

@@ -239,6 +239,7 @@ public:

     virtual css::uno::Reference< css::uno::XInterface > CreateClipboard( const css::uno::Sequence< css::uno::Any >& i_rArguments ) override;

     virtual css::uno::Reference< css::uno::XInterface > CreateDragSource() override;

     virtual css::uno::Reference< css::uno::XInterface > CreateDropTarget() override;

+    virtual OpenGLContext* CreateOpenGLContext() override;

 #endif

     virtual const cairo_font_options_t* GetCairoFontOptions() override;

diff --git a/vcl/source/opengl/OpenGLContext.cxx b/vcl/source/opengl/OpenGLContext.cxx

index 1b2893b..d7d7841 100644

--- a/vcl/source/opengl/OpenGLContext.cxx

+++ b/vcl/source/opengl/OpenGLContext.cxx

@@ -330,6 +330,11 @@ void OpenGLContext::InitGLDebugging()

 #endif

 }

+void OpenGLContext::restoreDefaultFramebuffer()

+{

+    glBindFramebuffer(GL_FRAMEBUFFER, 0);

+}

+

 void OpenGLContext::setWinPosAndSize(const Point &rPos, const Size& rSize)

 {

     if(m_xWindow)

diff --git a/vcl/unx/gtk3/gtk3gtkinst.cxx b/vcl/unx/gtk3/gtk3gtkinst.cxx

index 7148882..947bcc9 100644

--- a/vcl/unx/gtk3/gtk3gtkinst.cxx

+++ b/vcl/unx/gtk3/gtk3gtkinst.cxx

@@ -916,4 +916,131 @@ Reference< XInterface > GtkInstance::CreateDragSource()

     return Reference< XInterface >( static_cast<cppu::OWeakObject *>(new GtkDragSource()) );

 }

+class GtkOpenGLContext : public OpenGLContext

+{

+    GLWindow m_aGLWin;

+    GtkWidget *m_pGLArea;

+

+public:

+    GtkOpenGLContext()

+        : OpenGLContext()

+        , m_pGLArea(nullptr)

+    {

+    }

+

+    virtual bool initWindow() override

+    {

+        if( !m_pChildWindow )

+        {

+            SystemWindowData winData = generateWinData(mpWindow, mbRequestLegacyContext);

+            m_pChildWindow = VclPtr<SystemChildWindow>::Create(mpWindow, 0, &winData, false);

+        }

+

+        if (m_pChildWindow)

+        {

+            InitChildWindow(m_pChildWindow.get());

+        }

+

+        return true;

+    }

+

+private:

+    virtual const GLWindow& getOpenGLWindow() const override { return m_aGLWin; }

+    virtual GLWindow& getModifiableOpenGLWindow() override { return m_aGLWin; }

+

+    static void signalDestroy(GtkWidget*, gpointer context)

+    {

+        GtkOpenGLContext* pThis = static_cast<GtkOpenGLContext*>(context);

+        pThis->m_pGLArea = nullptr;

+    }

+

+    virtual bool ImplInit() override

+    {

+#if GTK_CHECK_VERSION(3,16,0)

+        const SystemEnvData* pEnvData = m_pChildWindow->GetSystemData();

+        GtkWidget *pParent = static_cast<GtkWidget*>(pEnvData->pWidget);

+        m_pGLArea = gtk_gl_area_new();

+        g_signal_connect(G_OBJECT(m_pGLArea), "destroy", G_CALLBACK(signalDestroy), this);

+        gtk_gl_area_set_has_depth_buffer(GTK_GL_AREA(m_pGLArea), true);

+        gtk_gl_area_set_auto_render(GTK_GL_AREA(m_pGLArea), false);

+        gtk_widget_set_hexpand(m_pGLArea, true);

+        gtk_widget_set_vexpand(m_pGLArea, true);

+        gtk_container_add(GTK_CONTAINER(pParent), m_pGLArea);

+        gtk_widget_show_all(pParent);

+        gtk_gl_area_make_current(GTK_GL_AREA(m_pGLArea));

+        gtk_gl_area_attach_buffers(GTK_GL_AREA(m_pGLArea));

+#endif

+        bool bRet = InitGL();

+        InitGLDebugging();

+        return bRet;

+    }

+

+    virtual void restoreDefaultFramebuffer() override

+    {

+        OpenGLContext::restoreDefaultFramebuffer();

+#if GTK_CHECK_VERSION(3,16,0)

+        gtk_gl_area_attach_buffers(GTK_GL_AREA(m_pGLArea));

+#endif

+    }

+

+    virtual void makeCurrent() override

+    {

+        if (isCurrent())

+            return;

+

+        clearCurrent();

+

+#if GTK_CHECK_VERSION(3,16,0)

+        if (m_pGLArea)

+            gtk_gl_area_make_current(GTK_GL_AREA(m_pGLArea));

+#endif

+

+        registerAsCurrent();

+    }

+

+    virtual void destroyCurrentContext() override

+    {

+#if GTK_CHECK_VERSION(3,16,0)

+        gdk_gl_context_clear_current();

+#endif

+    }

+

+    virtual bool isCurrent() override

+    {

+#if GTK_CHECK_VERSION(3,16,0)

+        return m_pGLArea && gdk_gl_context_get_current() == gtk_gl_area_get_context(GTK_GL_AREA(m_pGLArea));

+#else

+        return false;

+#endif

+    }

+

+    virtual void sync() override

+    {

+#if GTK_CHECK_VERSION(3,16,0)

+        gtk_gl_area_queue_render(GTK_GL_AREA(m_pGLArea));

+#endif

+    }

+

+    virtual void resetCurrent() override

+    {

+        clearCurrent();

+#if GTK_CHECK_VERSION(3,16,0)

+        gdk_gl_context_clear_current();

+#endif

+    }

+

+    virtual void swapBuffers() override

+    {

+#if GTK_CHECK_VERSION(3,16,0)

+        gtk_gl_area_queue_render(GTK_GL_AREA(m_pGLArea));

+#endif

+        BuffersSwapped();

+    }

+};

+

+OpenGLContext* GtkInstance::CreateOpenGLContext()

+{

+    return new GtkOpenGLContext;

+}

+

 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */

-- 

2.9.3