tdf#89928 pptx import: implement import of BiLevel threshold

Implement import BiLevel effect's threshold value.
If threshold isn't exactly 50%, we can't map it to the doc model.

Therefore as a workaround apply the BiLevel (Black/White) effect with
specified threshold directly to the graphic.

Change-Id: Ib24d149d74b103d926560708c68bb937b02c4cfe
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/140136
Tested-by: Jenkins
Reviewed-by: Miklos Vajna <vmiklos@collabora.com>

3 files changed, 45 insertions, 0 deletions

diff --git a/oox/inc/drawingml/fillproperties.hxx b/oox/inc/drawingml/fillproperties.hxx
index 9cef3c98f2b1..828c858e12f2 100644
--- a/oox/inc/drawingml/fillproperties.hxx
+++ b/oox/inc/drawingml/fillproperties.hxx
@@ -113,6 +113,7 @@ struct BlipFillProperties
     std::optional< sal_Int32 > moColorEffect;        /// XML token for a color effect.
     std::optional< sal_Int32 > moBrightness;         /// Brightness in the range [-100000,100000].
     std::optional< sal_Int32 > moContrast;           /// Contrast in the range [-100000,100000].
+    std::optional< sal_Int32 > moBiLevelThreshold;   /// Bi-Level (Black/White) effect threshold (1/1000 percent)
     Color                 maColorChangeFrom;      /// Start color of color transformation.
     Color                 maColorChangeTo;        /// Destination color of color transformation.
     Color                 maDuotoneColors[2];     /// Duotone Colors
diff --git a/oox/source/drawingml/fillproperties.cxx b/oox/source/drawingml/fillproperties.cxx
index 1ef7579a7725..7933a79f5dba 100644
--- a/oox/source/drawingml/fillproperties.cxx
+++ b/oox/source/drawingml/fillproperties.cxx
@@ -24,6 +24,8 @@
 #include <comphelper/propertyvalue.hxx>
 #include <drawingml/graphicproperties.hxx>
 #include <vcl/graph.hxx>
+#include <vcl/BitmapFilter.hxx>
+#include <vcl/BitmapMonochromeFilter.hxx>
 
 #include <com/sun/star/beans/XPropertySet.hpp>
 #include <com/sun/star/awt/Gradient.hpp>
@@ -185,6 +187,32 @@ Reference< XGraphic > lclGreysScaleGraphic(uno::Reference<graphic::XGraphic> con
     return aReturnGraphic.GetXGraphic();
 }
 
+/// Applies the graphic Black&White (Monochrome) effect with the imported threshold
+Reference<XGraphic> lclApplyBlackWhiteEffect(const BlipFillProperties& aBlipProps,
+                                             const uno::Reference<graphic::XGraphic>& xGraphic)
+{
+    const auto& oBiLevelThreshold = aBlipProps.moBiLevelThreshold;
+    if (oBiLevelThreshold.has_value())
+    {
+        sal_uInt8 nThreshold
+            = static_cast<sal_uInt8>(oBiLevelThreshold.value() * 255 / MAX_PERCENT);
+
+        ::Graphic aGraphic(xGraphic);
+        ::Graphic aReturnGraphic;
+
+        BitmapEx aBitmapEx(aGraphic.GetBitmapEx());
+        AlphaMask aMask(aBitmapEx.GetAlpha());
+
+        BitmapEx aTmpBmpEx(aBitmapEx.GetBitmap());
+        BitmapFilter::Filter(aTmpBmpEx, BitmapMonochromeFilter{ nThreshold });
+
+        aReturnGraphic = ::Graphic(BitmapEx(aTmpBmpEx.GetBitmap(), aMask));
+        aReturnGraphic.setOriginURL(aGraphic.getOriginURL());
+        return aReturnGraphic.GetXGraphic();
+    }
+    return xGraphic;
+}
+
 Reference< XGraphic > lclCheckAndApplyChangeColorTransform(const BlipFillProperties &aBlipProps, uno::Reference<graphic::XGraphic> const & xGraphic,
                                                            const GraphicHelper& rGraphicHelper, const ::Color nPhClr)
 {
@@ -350,6 +378,7 @@ void BlipFillProperties::assignUsed( const BlipFillProperties& rSourceProps )
     assignIfUsed( moColorEffect, rSourceProps.moColorEffect );
     assignIfUsed( moBrightness, rSourceProps.moBrightness );
     assignIfUsed( moContrast, rSourceProps.moContrast );
+    assignIfUsed( moBiLevelThreshold, rSourceProps.moBiLevelThreshold );
     maColorChangeFrom.assignIfUsed( rSourceProps.maColorChangeFrom );
     maColorChangeTo.assignIfUsed( rSourceProps.maColorChangeTo );
     maDuotoneColors[0].assignIfUsed( rSourceProps.maDuotoneColors[0] );
@@ -907,6 +936,17 @@ void GraphicProperties::pushToPropMap( PropertyMap& rPropMap, const GraphicHelpe
         uno::Reference<graphic::XGraphic> xGraphic = lclCheckAndApplyChangeColorTransform(maBlipProps, maBlipProps.mxFillGraphic, rGraphicHelper, API_RGB_TRANSPARENT);
         xGraphic = lclCheckAndApplyDuotoneTransform(maBlipProps, xGraphic, rGraphicHelper, API_RGB_TRANSPARENT);
 
+        if( eColorMode == ColorMode_MONO )
+        {
+            // ColorMode_MONO is the same with MSO's biLevel with 50000 (50%) threshold,
+            // when threshold isn't 50000 bake the effect instead.
+            if( maBlipProps.moBiLevelThreshold != 50000 )
+            {
+                xGraphic = lclApplyBlackWhiteEffect(maBlipProps, xGraphic);
+                eColorMode = ColorMode_STANDARD;
+            }
+        }
+
         if (eColorMode == ColorMode_STANDARD && nBrightness == 70 && nContrast == -70)
         {
             // map MSO 'washout' to our Watermark colormode
diff --git a/oox/source/drawingml/misccontexts.cxx b/oox/source/drawingml/misccontexts.cxx
index ceeeca3d5c62..e7ec679ad318 100644
--- a/oox/source/drawingml/misccontexts.cxx
+++ b/oox/source/drawingml/misccontexts.cxx
@@ -172,6 +172,10 @@ ContextHandlerRef BlipContext::onCreateContext(
     switch( nElement )
     {
         case A_TOKEN( biLevel ):
+            mrBlipProps.moBiLevelThreshold = rAttribs.getInteger( XML_thresh );
+            mrBlipProps.moColorEffect = getBaseToken(nElement);
+            break;
+
         case A_TOKEN( grayscl ):
             mrBlipProps.moColorEffect = getBaseToken( nElement );
         break;