Resolves: #i120230# Adapt hatch processing for a more pleasant visualisation

Adapt hatch processing to keep a view-dependent minimal distance for a more
pleasant visualisation

(cherry picked from commit 6a036e7ac17a1d4394d60471bd8931d9b16b7bb4)

Conflicts:
drawinglayer/inc/drawinglayer/attribute/fillhatchattribute.hxx
drawinglayer/inc/drawinglayer/primitive2d/fillhatchprimitive2d.hxx
drawinglayer/inc/drawinglayer/primitive2d/primitivetools2d.hxx
drawinglayer/source/attribute/fillhatchattribute.cxx

Change-Id: I15cd784ef7d3e47a20308f16d370c24ef46d2f22

3 files changed, 31 insertions, 1 deletions

diff --git a/include/drawinglayer/attribute/fillhatchattribute.hxx b/include/drawinglayer/attribute/fillhatchattribute.hxx
index 7e6244be090b..30e054085815 100644
--- a/include/drawinglayer/attribute/fillhatchattribute.hxx
+++ b/include/drawinglayer/attribute/fillhatchattribute.hxx
@@ -69,6 +69,7 @@ namespace drawinglayer
                 double fDistance,
                 double fAngle,
                 const basegfx::BColor& rColor,
+                sal_uInt32 nMinimalDiscreteDistance,
                 bool bFillBackground);
             FillHatchAttribute();
             FillHatchAttribute(const FillHatchAttribute& rCandidate);
@@ -86,6 +87,19 @@ namespace drawinglayer
             double getDistance() const;
             double getAngle() const;
             const basegfx::BColor& getColor() const;
+
+            // #i120230# If a minimal discrete distance is wanted (VCL used 3,
+            // this is the default for the global instance, too), set this
+            // unequal to zero. Zero means not to use it. If set bigger zero
+            // (should be at least two, one leads to a full plane filled with
+            // lines when Distance in discrete views is smaller than one) this
+            // will be used when the discrete value is less than the given one.
+            // This is used to 'emulate' old VCL behaviour which makes hatches
+            // look better by not making distances as small as needed, but
+            // keeping them on a minimal discrete value for more appealing
+            // visualisation.
+            sal_uInt32 getMinimalDiscreteDistance() const;
+
             bool isFillBackground() const;
         };
     } // end of namespace attribute
diff --git a/include/drawinglayer/primitive2d/fillhatchprimitive2d.hxx b/include/drawinglayer/primitive2d/fillhatchprimitive2d.hxx
index b0c27ba89107..f8e52c27d951 100644
--- a/include/drawinglayer/primitive2d/fillhatchprimitive2d.hxx
+++ b/include/drawinglayer/primitive2d/fillhatchprimitive2d.hxx
@@ -23,6 +23,7 @@
 #include <drawinglayer/drawinglayerdllapi.h>
 
 #include <drawinglayer/primitive2d/baseprimitive2d.hxx>
+#include <drawinglayer/primitive2d/primitivetools2d.hxx>
 #include <drawinglayer/attribute/fillhatchattribute.hxx>
 #include <basegfx/color/bcolor.hxx>
 
@@ -40,9 +41,14 @@ namespace drawinglayer
             If the background is to be filled, a flag in FillHatchAttribute is set and
             the BColor defines the background color.
 
+            #i120230# This primitive is now evtl. metric dependent due to the value
+            MinimalDiscreteDistance in the FillHatchAttribute if the value is not zero.
+            This is used for a more appealing, VCL-like visualisation by not letting the
+            distances get too small between lines.
+
             The decomposition will deliver the hatch lines.
          */
-        class DRAWINGLAYER_DLLPUBLIC FillHatchPrimitive2D : public BufferedDecompositionPrimitive2D
+        class DRAWINGLAYER_DLLPUBLIC FillHatchPrimitive2D : public DiscreteMetricDependentPrimitive2D
         {
         private:
             /// the geometric definition
@@ -76,6 +82,9 @@ namespace drawinglayer
             /// get range
             virtual basegfx::B2DRange getB2DRange(const geometry::ViewInformation2D& rViewInformation) const;
 
+            /// get local decomposition. Overloaded since this decomposition is view-dependent
+            virtual Primitive2DSequence get2DDecomposition(const geometry::ViewInformation2D& rViewInformation) const;
+
             /// provide unique ID
             DeclPrimitrive2DIDBlock()
         };
diff --git a/include/drawinglayer/primitive2d/primitivetools2d.hxx b/include/drawinglayer/primitive2d/primitivetools2d.hxx
index 6ef63f1e916b..3d208231b7ea 100644
--- a/include/drawinglayer/primitive2d/primitivetools2d.hxx
+++ b/include/drawinglayer/primitive2d/primitivetools2d.hxx
@@ -47,6 +47,13 @@ namespace drawinglayer
              */
             double                                  mfDiscreteUnit;
 
+        protected:
+            /// helper to update discrete unit
+            void updateDiscreteUnit(double fNew)
+            {
+                mfDiscreteUnit = fNew;
+            }
+
         public:
             /// constructor
             DiscreteMetricDependentPrimitive2D()