slideshow: Remove extraneous checks for the program object.

Change-Id: Ice61bfbd75aafd4197584c34ef7fbed80c20c184
(cherry picked from commit 129b8b85)

slideshow/source/engine/OGLTrans/generic/OGLTrans_TransitionImpl.cxx

@@ -143,16 +143,15 @@ bool OGLTransitionImpl::prepare( sal_Int32 glLeavingSlideTex, sal_Int32 glEnteri
     if (!m_nProgramObject)
         return false;
 
+    CHECK_GL_ERROR();
+    glUseProgram( m_nProgramObject );
+    CHECK_GL_ERROR();
+
     const SceneObjects_t& rSceneObjects(maScene.getSceneObjects());
     for(size_t i(0); i != rSceneObjects.size(); ++i) {
         rSceneObjects[i]->prepare(m_nProgramObject);
     }
 
-    CHECK_GL_ERROR();
-    if( m_nProgramObject ) {
-        glUseProgram( m_nProgramObject );
-        CHECK_GL_ERROR();
-
     GLint location = glGetUniformLocation( m_nProgramObject, "leavingSlideTexture" );
     if( location != -1 ) {
         glUniform1i( location, 0 );  // texture unit 0
@@ -203,7 +202,6 @@ bool OGLTransitionImpl::prepare( sal_Int32 glLeavingSlideTex, sal_Int32 glEnteri
     }
 
     glBindBuffer(GL_ARRAY_BUFFER, 0);
-    }
     CHECK_GL_ERROR();
 
     prepareTransition( glLeavingSlideTex, glEnteringSlideTex );
@@ -252,12 +250,9 @@ void OGLTransitionImpl::displaySlides_( double nTime, sal_Int32 glLeavingSlideTe
     CHECK_GL_ERROR();
     applyOverallOperations( nTime, SlideWidthScale, SlideHeightScale );
 
-    if( m_nProgramObject ) {
     GLint location = glGetUniformLocation( m_nProgramObject, "time" );
-        if( location != -1 ) {
+    if( location != -1 )
         glUniform1f( location, nTime );
-        }
-    }
 
     glActiveTexture( GL_TEXTURE2 );
     glBindTexture( GL_TEXTURE_2D, glEnteringSlideTex );
@@ -1418,7 +1413,6 @@ static void initPermTexture(GLuint *texID)
 void PermTextureTransition::prepareTransition( sal_Int32, sal_Int32 )
 {
     CHECK_GL_ERROR();
-    if( m_nProgramObject ) {
     GLint location = glGetUniformLocation( m_nProgramObject, "permTexture" );
     if( location != -1 ) {
         glActiveTexture(GL_TEXTURE1);
@@ -1432,7 +1426,6 @@ void PermTextureTransition::prepareTransition( sal_Int32, sal_Int32 )
         glUniform1i( location, 1 );  // texture unit 1
         CHECK_GL_ERROR();
     }
-    }
     CHECK_GL_ERROR();
 }
 
@@ -1601,20 +1594,14 @@ void VortexTransition::prepareTransition( sal_Int32 glLeavingSlideTex, sal_Int32
     PermTextureTransition::prepareTransition( glLeavingSlideTex, glEnteringSlideTex );
     CHECK_GL_ERROR();
 
-    if (m_nProgramObject)
-    {
     mnTileInfoLocation = glGetAttribLocation(m_nProgramObject, "tileInfo");
     CHECK_GL_ERROR();
 
-        glUseProgram(m_nProgramObject);
-        CHECK_GL_ERROR();
-
     GLint nNumTilesLocation = glGetUniformLocation(m_nProgramObject, "numTiles");
     CHECK_GL_ERROR();
 
     glUniform2iv(nNumTilesLocation, 1, glm::value_ptr(maNumTiles));
     CHECK_GL_ERROR();
-    }
 
     glGenBuffers(1, &mnTileInfoBuffer);
     CHECK_GL_ERROR();
@@ -1712,17 +1699,11 @@ GLuint RippleTransition::makeShader() const
 
 void RippleTransition::prepareTransition( sal_Int32, sal_Int32 )
 {
-    if (m_nProgramObject)
-    {
-        glUseProgram(m_nProgramObject);
-        CHECK_GL_ERROR();
-
     GLint nCenterLocation = glGetUniformLocation(m_nProgramObject, "center");
     CHECK_GL_ERROR();
 
     glUniform2fv(nCenterLocation, 1, glm::value_ptr(maCenter));
     CHECK_GL_ERROR();
-    }
 }
 
 std::shared_ptr<OGLTransitionImpl>