opengl: fix wrong clipping when drawing text

Change-Id: I41a182c5309586337032328dfe82b1c6715f0dc2

vcl/inc/openglgdiimpl.hxx

@@ -148,7 +148,7 @@ public:
     void DrawAxialGradient( const Gradient& rGradient, const Rectangle& rRect );
     void DrawRadialGradient( const Gradient& rGradient, const Rectangle& rRect );
     void DeferredTextDraw(OpenGLTexture& rTexture, const SalColor nMaskColor, const SalTwoRect& rPosAry);
-    void FlushDeferredDrawing(bool bInDraw = false);
+    void FlushDeferredDrawing();
 
 public:
     // get the width of the device
@@ -166,6 +166,9 @@ public:
     /// Oddly not all operations obey the XOR option.
     enum XOROption { IGNORE_XOR, IMPLEMENT_XOR };
 
+    // initialize pre-draw state
+    void InitializePreDrawState(XOROption eOpt = IGNORE_XOR);
+
     // operations to do before painting
     void PreDraw(XOROption eOpt = IGNORE_XOR);
 

vcl/opengl/gdiimpl.cxx

@@ -186,6 +186,13 @@ void OpenGLSalGraphicsImpl::DeInit()
 }
 
 void OpenGLSalGraphicsImpl::PreDraw(XOROption eOpt)
+{
+    FlushDeferredDrawing();
+
+    InitializePreDrawState(eOpt);
+}
+
+void OpenGLSalGraphicsImpl::InitializePreDrawState(XOROption eOpt)
 {
     OpenGLZone::enter();
 
@@ -206,8 +213,6 @@ void OpenGLSalGraphicsImpl::PreDraw(XOROption eOpt)
     glViewport( 0, 0, GetWidth(), GetHeight() );
     CHECK_GL_ERROR();
 
-    FlushDeferredDrawing(true);
-
     ImplInitClipRegion();
     CHECK_GL_ERROR();
 
@@ -268,6 +273,7 @@ void OpenGLSalGraphicsImpl::freeResources()
     {
         VCL_GL_INFO( "freeResources" );
         mpContext->makeCurrent();
+        FlushDeferredDrawing();
         mpContext->ReleaseFramebuffer( maOffscreenTex );
     }
     ReleaseContext();
@@ -357,12 +363,16 @@ const vcl::Region& OpenGLSalGraphicsImpl::getClipRegion() const
 
 bool OpenGLSalGraphicsImpl::setClipRegion( const vcl::Region& rClip )
 {
-    VCL_GL_INFO( "::setClipRegion " << rClip );
     if (maClipRegion == rClip)
-        return true;
+    {
+         VCL_GL_INFO("::setClipRegion (no change) " << rClip);
+         return true;
+    }
 
     FlushDeferredDrawing();
 
+    VCL_GL_INFO("::setClipRegion " << rClip);
+
     maClipRegion = rClip;
 
     mbUseStencil = false;
@@ -378,12 +388,16 @@ bool OpenGLSalGraphicsImpl::setClipRegion( const vcl::Region& rClip )
 // set the clip region to empty
 void OpenGLSalGraphicsImpl::ResetClipRegion()
 {
-    VCL_GL_INFO( "::ResetClipRegion" );
     if (maClipRegion.IsEmpty())
+    {
+        VCL_GL_INFO("::ResetClipRegion (no change) ");
         return;
+    }
 
     FlushDeferredDrawing();
 
+    VCL_GL_INFO("::ResetClipRegion");
+
     maClipRegion.SetEmpty();
     mbUseScissor = false;
     mbUseStencil = false;
@@ -1674,13 +1688,12 @@ void OpenGLSalGraphicsImpl::DeferredTextDraw(OpenGLTexture& rTexture, SalColor a
     mpAccumulatedTextures->insert(rTexture, aMaskColor, rPosAry);
 }
 
-void OpenGLSalGraphicsImpl::FlushDeferredDrawing(bool bIsInDraw)
+void OpenGLSalGraphicsImpl::FlushDeferredDrawing()
 {
     if (mpAccumulatedTextures->empty())
         return;
 
-    if (!bIsInDraw)
-        PreDraw();
+    InitializePreDrawState();
 
     VCL_GL_INFO("FlushDeferredDrawing");
 
@@ -1725,7 +1738,9 @@ void OpenGLSalGraphicsImpl::FlushDeferredDrawing(bool bIsInDraw)
 
     if( !UseProgram( "textureVertexShader", "maskFragmentShader" ) )
         return;
+
     mpProgram->SetBlendMode(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+
     for (auto& rPair : mpAccumulatedTextures->getAccumulatedTexturesMap())
     {
         OpenGLTexture& rTexture = rPair.second->maTexture;
@@ -1742,8 +1757,8 @@ void OpenGLSalGraphicsImpl::FlushDeferredDrawing(bool bIsInDraw)
     }
     mpProgram->Clean();
     mpAccumulatedTextures->clear();
-    if (!bIsInDraw)
-        PostDraw();
+
+    PostDraw();
 }
 
 void OpenGLSalGraphicsImpl::DrawLinearGradient( const Gradient& rGradient, const Rectangle& rRect )