fdo#81055: Crash due to inadequate checks for GL version / capabilities

Base line is OpenGL 2.1 + extensions.

GL_ARB_framebuffer_object (part of OpenGL 3.0) for
glGenFramebuffers, glGenRenderbuffers...

GL_ARB_vertex_array_object (part of OpenGL 3.0) for
glGenVertexArrays, glBindVertexArray...

GL_ARB_sampler_objects (part of OpenGL 3.3) for
glGenSamplers, glBindSampler...

(cherry picked from commit 378b1d24a958114eb4484cb10f609f6e482772ec)
(and cherry picked some part of commit 23c876deeb357b6306712ff0586a819176151c15)

Change-Id: I3a3caeab7ef593188ee742c53e6715648bf14f50
Reviewed-on: https://gerrit.libreoffice.org/10440
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>

3 files changed, 49 insertions, 0 deletions

diff --git a/avmedia/source/opengl/oglplayer.cxx b/avmedia/source/opengl/oglplayer.cxx
index f39f84749427..b827d2fbe13d 100644
--- a/avmedia/source/opengl/oglplayer.cxx
+++ b/avmedia/source/opengl/oglplayer.cxx
@@ -246,6 +246,25 @@ awt::Size SAL_CALL OGLPlayer::getPreferredPlayerWindowSize() throw ( uno::Runtim
     return awt::Size( 480, 360 );
 }
 
+static bool lcl_CheckOpenGLRequirements()
+{
+    float fVersion = OpenGLHelper::getGLVersion();
+    if( fVersion >= 3.3 )
+    {
+        return true;
+    }
+    else if( fVersion >= 3.0 )
+    {
+        return glewIsSupported("GL_ARB_sampler_objects");
+    }
+    else if( fVersion >= 2.1 )
+    {
+        return glewIsSupported("GL_ARB_sampler_objects GL_ARB_framebuffer_object GL_ARB_vertex_array_object");
+    }
+
+    return false;
+}
+
 uno::Reference< media::XPlayerWindow > SAL_CALL OGLPlayer::createPlayerWindow( const uno::Sequence< uno::Any >& rArguments )
      throw ( uno::RuntimeException, std::exception )
 {
@@ -271,6 +290,12 @@ uno::Reference< media::XPlayerWindow > SAL_CALL OGLPlayer::createPlayerWindow( c
         return uno::Reference< media::XPlayerWindow >();
     }
 
+    if( !lcl_CheckOpenGLRequirements() )
+    {
+        SAL_WARN("avmedia.opengl", "Your platform does not have the minimal OpenGL requiremenets!");
+        return uno::Reference< media::XPlayerWindow >();
+    }
+
     Size aSize = pChildWindow->GetSizePixel();
     m_aContext.setWinSize(aSize);
     m_pHandle->viewport.x = 0;
@@ -305,6 +330,12 @@ uno::Reference< media::XFrameGrabber > SAL_CALL OGLPlayer::createFrameGrabber()
         return uno::Reference< media::XFrameGrabber >();
     }
 
+    if( !lcl_CheckOpenGLRequirements() )
+    {
+        SAL_WARN("avmedia.opengl", "Your platform does not have the minimal OpenGL requiremenets!");
+        return uno::Reference< media::XFrameGrabber >();
+    }
+
     m_pHandle->viewport.x = 0;
     m_pHandle->viewport.y = 0;
     m_pHandle->viewport.width = getPreferredPlayerWindowSize().Width;
diff --git a/include/vcl/opengl/OpenGLHelper.hxx b/include/vcl/opengl/OpenGLHelper.hxx
index 475bd720c082..58c3d15224e8 100644
--- a/include/vcl/opengl/OpenGLHelper.hxx
+++ b/include/vcl/opengl/OpenGLHelper.hxx
@@ -36,6 +36,9 @@ public:
      */
     static void createFramebuffer(long nWidth, long nHeight,
             GLuint& nFramebufferId, GLuint& nRenderbufferTextId, GLuint& nRenderbufferColorId);
+
+    // Get OpenGL version (needs a context)
+    static float getGLVersion();
 };
 
 VCLOPENGL_DLLPUBLIC std::ostream& operator<<(std::ostream& rStrm, const glm::mat4& rMatrix);
diff --git a/vcl/source/opengl/OpenGLHelper.cxx b/vcl/source/opengl/OpenGLHelper.cxx
index bace47b7bc33..8eb88b9642ac 100644
--- a/vcl/source/opengl/OpenGLHelper.cxx
+++ b/vcl/source/opengl/OpenGLHelper.cxx
@@ -299,5 +299,20 @@ void OpenGLHelper::createFramebuffer(long nWidth, long nHeight,
     glBindFramebuffer(GL_FRAMEBUFFER, 0);
 }
 
+float OpenGLHelper::getGLVersion()
+{
+    float fVersion = 1.0;
+    const GLubyte* aVersion = glGetString( GL_VERSION );
+    if( aVersion && aVersion[0] )
+    {
+        fVersion = aVersion[0] - '0';
+        if( aVersion[1] == '.' && aVersion[2] )
+        {
+            fVersion += (aVersion[2] - '0')/10.0;
+        }
+    }
+    return fVersion;
+}
+
 
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