Add 7-segment display polygon generator to basegfx.

Basegfx gets a basegfx::tools::number2PolyPolygon method that
converts a number 0-9 into a 7-segment digit display polygon.

Change-Id: I4d3326c9fe9e42d07a6248781127f19ac27d8b72

basegfx/Library_basegfx.mk

@@ -69,6 +69,7 @@ $(eval $(call gb_Library_add_exception_objects,basegfx,\
     basegfx/source/tools/canvastools \
     basegfx/source/tools/gradienttools \
     basegfx/source/tools/keystoplerp \
+    basegfx/source/tools/numbertools \
     basegfx/source/tools/tools \
     basegfx/source/tools/unopolypolygon \
     basegfx/source/tools/unotools \

basegfx/source/polygon/b2dpolypolygontools.cxx

@@ -515,6 +515,139 @@ namespace basegfx
 
             return true;
         }
+
+        B2DPolyPolygon createSevenSegmentPolyPolygon(sal_Char nNumber, bool bLitSegments)
+        {
+            // config here
+            // {
+            const double fTotalSize=1.0;
+            const double fPosMiddleSegment=0.6;
+            const double fSegmentEndChopHoriz=0.08;
+            const double fSegmentEndChopVert =0.04;
+            // }
+            // config here
+
+            const double fLeft=0.0;
+            const double fRight=fTotalSize;
+            const double fTop=0.0;
+            const double fMiddle=fPosMiddleSegment;
+            const double fBottom=fTotalSize;
+
+            // from 0 to 5: pair of segment corner coordinates
+            //
+            // segment corner indices are these:
+            //
+            //   0 - 1
+            //   |   |
+            //   2 - 3
+            //   |   |
+            //   4 - 5
+            //
+            static const double corners[] =
+            {
+                fLeft,  fTop,
+                fRight, fTop,
+                fLeft,  fMiddle,
+                fRight, fMiddle,
+                fLeft,  fBottom,
+                fRight, fBottom
+            };
+
+            // from 0 to 9: which segments are 'lit' for this number?
+            //
+            // array denotes graph edges to traverse, with -1 means
+            // stop (the vertices are the corner indices from above):
+            //     0
+            //     -
+            // 1 |   | 2
+            //     - 3
+            // 4 |   | 5
+            //     -
+            //     6
+            //
+            static const int numbers[] =
+            {
+                1, 1, 1, 0, 1, 1, 1, // 0
+                0, 0, 1, 0, 0, 1, 0, // 1
+                1, 0, 1, 1, 1, 0, 1, // 2
+                1, 0, 1, 1, 0, 1, 1, // 3
+                0, 1, 1, 1, 0, 1, 0, // 4
+                1, 1, 0, 1, 0, 1, 1, // 5
+                1, 1, 0, 1, 1, 1, 1, // 6
+                1, 0, 1, 0, 0, 1, 0, // 1
+                1, 1, 1, 1, 1, 1, 1, // 8
+                1, 1, 1, 1, 0, 1, 1, // 9
+                0, 0, 0, 1, 0, 0, 0, // '-'
+                1, 1, 0, 1, 1, 0, 1, // 'E'
+            };
+
+            // maps segment index to two corner ids:
+            static const int index2corner[] =
+            {
+                0, 2,  // 0
+                0, 4,  // 1
+                2, 6,  // 2
+                4, 6,  // 3
+                4, 8,  // 4
+                6, 10, // 5
+                8, 10, // 6
+            };
+
+            B2DPolyPolygon aRes;
+            if( nNumber == '-' )
+            {
+                nNumber = 10;
+            }
+            else if( nNumber == 'E' )
+            {
+                nNumber = 11;
+            }
+            else if( nNumber == '.' )
+            {
+                if( bLitSegments )
+                    aRes.append(createPolygonFromCircle(B2DPoint(fTotalSize/2, fTotalSize),
+                                                        fSegmentEndChopHoriz));
+                return aRes;
+            }
+            else
+            {
+                nNumber=clamp<sal_uInt32>(nNumber,'0','9') - '0';
+            }
+
+            B2DPolygon aCurrSegment;
+            const size_t sliceSize=sizeof(numbers)/sizeof(*numbers)/12;
+            const int* pCurrSegment=numbers + nNumber*sliceSize;
+            for( size_t i=0; i<sliceSize; i++, pCurrSegment++)
+            {
+                if( !(*pCurrSegment ^ bLitSegments) )
+                {
+                    const size_t j=2*i;
+                    aCurrSegment.clear();
+                    B2DPoint start(corners[index2corner[j]],
+                                   corners[index2corner[j]+1]  );
+                    B2DPoint end  (corners[index2corner[j+1]],
+                                   corners[index2corner[j+1]+1]);
+
+                    if( start.getX() == end.getX() )
+                    {
+                        start.setY(start.getY()+fSegmentEndChopVert);
+                        end.setY(end.getY()-fSegmentEndChopVert);
+                    }
+                    else
+                    {
+                        start.setX(start.getX()+fSegmentEndChopHoriz);
+                        end.setX(end.getX()-fSegmentEndChopHoriz);
+                    }
+
+                    aCurrSegment.append(start);
+                    aCurrSegment.append(end);
+                }
+                aRes.append(aCurrSegment);
+            }
+
+            return aRes;
+        }
+
     } // end of namespace tools
 } // end of namespace basegfx
 

basegfx/source/tools/numbertools.cxx

+/* -*- 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 <basegfx/tools/tools.hxx>
+#include <basegfx/matrix/b2dhommatrix.hxx>
+#include <basegfx/polygon/b2dpolypolygon.hxx>
+#include <basegfx/polygon/b2dpolypolygontools.hxx>
+
+#include <rtl/ustrbuf.hxx>
+#include <rtl/math.hxx>
+
+#include <utility>
+
+namespace basegfx { namespace tools
+{
+    B2DPolyPolygon number2PolyPolygon(double fValue, sal_Int32 nTotalDigits, sal_Int32 nDecPlaces, bool bLitSegments)
+    {
+        // config here
+        // {
+        const double fSpace=0.2;
+        // }
+        // config here
+
+        rtl::OUStringBuffer aNum;
+        rtl::math::doubleToUStringBuffer(aNum,
+                                         fValue,
+                                         rtl_math_StringFormat_F,
+                                         nDecPlaces, '.',
+                                         0, ',');
+
+        B2DPolyPolygon aRes;
+        B2DHomMatrix aMat;
+        double fCurrX=std::max(nTotalDigits-aNum.getLength(),
+                               sal_Int32(0)) * (1.0+fSpace);
+        for( sal_Int32 i=0; i<aNum.getLength(); ++i )
+        {
+            B2DPolyPolygon aCurr;
+            aCurr=createSevenSegmentPolyPolygon(aNum[i],
+                                                bLitSegments);
+
+            aMat.identity();
+            aMat.translate(fCurrX,0.0);
+            aCurr.transform(aMat);
+
+            fCurrX += 1.0+fSpace;
+
+            aRes.append(aCurr);
+        }
+
+        return aRes;
+    }
+
+} }
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */

include/basegfx/polygon/b2dpolypolygontools.hxx

@@ -220,6 +220,26 @@ namespace basegfx
         // #i76891# Try to remove existing curve segments if they are simply edges
         BASEGFX_DLLPUBLIC B2DPolyPolygon simplifyCurveSegments(const B2DPolyPolygon& rCandidate);
 
+        /** Creates polypolygon for seven-segment display number
+
+            This function takes an integer number between 0 and 9 and
+            convert it into the well-known seven-segment display
+            number (like most digital clocks show their numbers). The
+            digit will exactly fit the unit rectangle. The polypolygon
+            will be a line polygon, i.e. if you need the segment parts
+            to have width, use createAreaGeometry() on the result.
+
+            @param cNumber
+            Number from '0' to '9' as ASCII char, or '-', 'E' and '.'
+            to convert to 7 segment code
+
+            @param bLitSegments
+            When true, return a polygon containing the segments that
+            are 'lit' for the given number. Return un-lit segments
+            otherwise.
+         */
+        B2DPolyPolygon createSevenSegmentPolyPolygon(sal_Char cNumber, bool bLitSegments=true);
+
         /** snap some polygon coordinates to discrete coordinates
 
             This method allows to snap some polygon points to discrete (integer) values

include/basegfx/tools/tools.hxx

@@ -27,6 +27,7 @@ namespace basegfx
 {
     class B2DPoint;
     class B2DRange;
+    class B2DPolyPolygon;
 
     namespace tools
     {
@@ -94,6 +95,30 @@ namespace basegfx
                                             ::basegfx::B2DPoint&        io_rRightBottom,
                                             const ::basegfx::B2DRange&  rFitTarget  );
 
+        /** Creates polypolygon with the given number as seven-segment
+            digits
+
+            @param fVal
+            Value to convert
+
+            @param nTotalDigits
+            Total number of digits to display. If less is needed for
+            given number, fill space with blanks.
+
+            @param nDecPlaces
+            Decimal places to show. When 0, display as integer. When
+            negative, fill given number of before-the-decimal point
+            with zero.
+
+            @param bLitSegments
+            When true, return a polygon containing the segments that
+            are 'lit' for the given number. Return un-lit segments
+            otherwise.
+         */
+        BASEGFX_DLLPUBLIC B2DPolyPolygon number2PolyPolygon(double    fVal,
+                                                            sal_Int32 nTotalDigits,
+                                                            sal_Int32 nDecPlaces,
+                                                            bool      bLitSegments=true);
     }
 }