1 files changed, 60 insertions, 0 deletions
diff --git a/vcl/source/bitmap/BitmapDisabledImageFilter.cxx b/vcl/source/bitmap/BitmapDisabledImageFilter.cxx
new file mode 100644
index 000000000..3bcf4cf9d
--- /dev/null
+++ b/vcl/source/bitmap/BitmapDisabledImageFilter.cxx
@@ -0,0 +1,60 @@
+/* -*- 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/.
+ *
+ */
+
+#include <bitmap/BitmapWriteAccess.hxx>
+#include <bitmap/BitmapDisabledImageFilter.hxx>
+
+BitmapEx BitmapDisabledImageFilter::execute(BitmapEx const& rBitmapEx) const
+{
+    const Size aSize(rBitmapEx.GetSizePixel());
+
+    // keep disable image at same depth as original where possible, otherwise
+    // use 8 bit
+    auto ePixelFormat = rBitmapEx.getPixelFormat();
+    if (sal_uInt16(ePixelFormat) < 8)
+        ePixelFormat = vcl::PixelFormat::N8_BPP;
+
+    const BitmapPalette* pPal
+        = vcl::isPalettePixelFormat(ePixelFormat) ? &Bitmap::GetGreyPalette(256) : nullptr;
+    Bitmap aGrey(aSize, ePixelFormat, pPal);
+    BitmapScopedWriteAccess pGrey(aGrey);
+
+    BitmapEx aReturnBitmap;
+    Bitmap aReadBitmap(rBitmapEx.GetBitmap());
+    Bitmap::ScopedReadAccess pRead(aReadBitmap);
+    if (pRead && pGrey)
+    {
+        for (sal_Int32 nY = 0; nY < sal_Int32(aSize.Height()); ++nY)
+        {
+            Scanline pGreyScan = pGrey->GetScanline(nY);
+            Scanline pReadScan = pRead->GetScanline(nY);
+
+            for (sal_Int32 nX = 0; nX < sal_Int32(aSize.Width()); ++nX)
+            {
+                // Get the luminance from RGB color and remap the value from 0-255 to 160-224
+                const BitmapColor aColor = pRead->GetPixelFromData(pReadScan, nX);
+                sal_uInt8 nLum(aColor.GetLuminance() / 4 + 160);
+                BitmapColor aGreyValue(ColorAlpha, nLum, nLum, nLum, aColor.GetAlpha());
+                pGrey->SetPixelOnData(pGreyScan, nX, aGreyValue);
+            }
+        }
+    }
+
+    if (rBitmapEx.IsAlpha())
+    {
+        aReturnBitmap = BitmapEx(aGrey, rBitmapEx.GetAlpha());
+    }
+    else
+        aReturnBitmap = BitmapEx(aGrey);
+
+    return aReturnBitmap;
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */