1 files changed, 147 insertions, 0 deletions
diff --git a/canvas/source/vcl/bitmapbackbuffer.cxx b/canvas/source/vcl/bitmapbackbuffer.cxx
new file mode 100644
index 0000000000..3766276f3b
--- /dev/null
+++ b/canvas/source/vcl/bitmapbackbuffer.cxx
@@ -0,0 +1,147 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * This file incorporates work covered by the following license notice:
+ *
+ *   Licensed to the Apache Software Foundation (ASF) under one or more
+ *   contributor license agreements. See the NOTICE file distributed
+ *   with this work for additional information regarding copyright
+ *   ownership. The ASF licenses this file to you under the Apache
+ *   License, Version 2.0 (the "License"); you may not use this file
+ *   except in compliance with the License. You may obtain a copy of
+ *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
+ */
+
+#include <sal/config.h>
+
+#include <osl/diagnose.h>
+#include <vcl/bitmapex.hxx>
+#include <vcl/svapp.hxx>
+
+#include "bitmapbackbuffer.hxx"
+#include "impltools.hxx"
+
+namespace vclcanvas
+{
+    BitmapBackBuffer::BitmapBackBuffer( const BitmapEx&         rBitmap,
+                                        const OutputDevice&     rRefDevice ) :
+        maBitmap( rBitmap ),
+        mpVDev( nullptr ),
+        mrRefDevice( rRefDevice ),
+        mbBitmapContentIsCurrent( false ),
+        mbVDevContentIsCurrent( false )
+    {
+    }
+
+    BitmapBackBuffer::~BitmapBackBuffer()
+    {
+        // make sure solar mutex is held on deletion (other methods
+        // are supposed to be called with already locked solar mutex)
+        SolarMutexGuard aGuard;
+
+        mpVDev.disposeAndClear();
+    }
+
+    OutputDevice& BitmapBackBuffer::getOutDev()
+    {
+        createVDev();
+        updateVDev();
+        return *mpVDev;
+    }
+
+    const OutputDevice& BitmapBackBuffer::getOutDev() const
+    {
+        createVDev();
+        updateVDev();
+        return *mpVDev;
+    }
+
+    void BitmapBackBuffer::clear()
+    {
+        // force current content to bitmap, make all transparent white
+        getBitmapReference().Erase(COL_TRANSPARENT);
+    }
+
+    BitmapEx& BitmapBackBuffer::getBitmapReference()
+    {
+        OSL_ENSURE( !mbBitmapContentIsCurrent || !mbVDevContentIsCurrent,
+                    "BitmapBackBuffer::getBitmapReference(): Both bitmap and VDev are valid?!" );
+
+        if( mbVDevContentIsCurrent && mpVDev )
+        {
+            // VDev content is more current than bitmap - copy contents before!
+            mpVDev->EnableMapMode( false );
+            mpVDev->SetAntialiasing( AntialiasingFlags::Enable );
+            const Point aEmptyPoint;
+            *maBitmap = mpVDev->GetBitmapEx( aEmptyPoint,
+                                             mpVDev->GetOutputSizePixel() );
+        }
+
+        // client queries bitmap, and will possibly alter content -
+        // next time, VDev needs to be updated
+        mbBitmapContentIsCurrent = true;
+        mbVDevContentIsCurrent   = false;
+
+        return *maBitmap;
+    }
+
+    Size BitmapBackBuffer::getBitmapSizePixel() const
+    {
+        Size aSize = maBitmap->GetSizePixel();
+
+        if( mbVDevContentIsCurrent && mpVDev )
+        {
+            mpVDev->EnableMapMode( false );
+            mpVDev->SetAntialiasing( AntialiasingFlags::Enable );
+            aSize = mpVDev->GetOutputSizePixel();
+        }
+
+        return aSize;
+    }
+
+    void BitmapBackBuffer::createVDev() const
+    {
+        if( mpVDev )
+            return;
+
+        // VDev not yet created, do it now. Create an alpha-VDev,
+        // if bitmap has transparency.
+        mpVDev = maBitmap->IsAlpha() ?
+            VclPtr<VirtualDevice>::Create( mrRefDevice, DeviceFormat::WITH_ALPHA ) :
+            VclPtr<VirtualDevice>::Create( mrRefDevice );
+
+        OSL_ENSURE( mpVDev,
+                    "BitmapBackBuffer::createVDev(): Unable to create VirtualDevice" );
+
+        mpVDev->SetOutputSizePixel( maBitmap->GetSizePixel() );
+
+        tools::SetDefaultDeviceAntiAliasing( mpVDev );
+    }
+
+    void BitmapBackBuffer::updateVDev() const
+    {
+        OSL_ENSURE( !mbBitmapContentIsCurrent || !mbVDevContentIsCurrent,
+                    "BitmapBackBuffer::updateVDev(): Both bitmap and VDev are valid?!" );
+
+        if( mpVDev && mbBitmapContentIsCurrent )
+        {
+            // fill with bitmap content
+            mpVDev->EnableMapMode( false );
+            mpVDev->SetAntialiasing( AntialiasingFlags::Enable );
+            const Point aEmptyPoint;
+            mpVDev->DrawBitmapEx( aEmptyPoint, *maBitmap );
+        }
+
+        // canvas queried the VDev, and will possibly paint into
+        // it. Next time, bitmap must be updated
+        mbBitmapContentIsCurrent = false;
+        mbVDevContentIsCurrent   = true;
+    }
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */