Inconsistent $MEASUREMENT/$INSUNITS variables.

src/libs/vdxf/libdxfrw/drw_header.cpp

@@ -1368,7 +1368,11 @@ void DRW_Header::write(dxfWriter *writer, DRW::Version ver){
             writer->writeInt16(70, varInt);
         else
             writer->writeInt16(70, 1);
+        int insunits {Units::None};
+        getInt("$INSUNITS", &insunits);     // get $INSUNITS now to evaluate $MEASUREMENT
+        getInt("$MEASUREMENT", &varInt);    // just remove the variable from list
         writer->writeString(9, "$MEASUREMENT");
+        writer->writeInt16(70, measurement( insunits));
         if (getInt("$MEASUREMENT", &varInt))
             writer->writeInt16(70, varInt);
         else
@@ -1395,10 +1399,7 @@ void DRW_Header::write(dxfWriter *writer, DRW::Version ver){
             writer->writeInt16(290, 0);
         if (ver > DRW::AC1014) {
             writer->writeString(9, "$INSUNITS");
-            if (getInt("$INSUNITS", &varInt))
+            writer->writeInt16(70, insunits); // already fetched above for $MEASUREMENT
-                writer->writeInt16(70, varInt);
-            else
-                writer->writeInt16(70, 0);
         }
         writer->writeString(9, "$HYPERLINKBASE");
         if (getStr("$HYPERLINKBASE", &varStr))
@@ -1752,3 +1753,20 @@ bool DRW_Header::getCoord(const std::string &key, DRW_Coord *varCoord){
     }
     return result;
 }
+
+int DRW_Header::measurement(const int unit) {
+    switch (unit) {
+    case Units::Inch:
+    case Units::Foot:
+    case Units::Mile:
+    case Units::Microinch:
+    case Units::Mil:
+    case Units::Yard:
+        return Units::English;
+
+    default:
+        break;
+    }
+
+    return Units::Metric;
+}

src/libs/vdxf/libdxfrw/drw_header.h

@@ -39,6 +39,36 @@ public:
         clearVars();
     }
 
+    enum Units {
+        /** $ISUNITS header variable, since ACAD2000/AC1015 */
+        None = 0,               ///< No unit (unit from parent)
+        Inch = 1,               ///< 25.4 mm
+        Foot = 2,               ///< 12 Inches = 0.3048 m
+        Mile = 3,               ///< 1760 Yards = 1609 m
+        Millimeter = 4,         ///< 0.001 m
+        Centimeter = 5,         ///< 0.01 m
+        Meter = 6,
+        Kilometer = 7,          ///< 1000 m
+        Microinch = 8,          ///< 0.000001 Inch = 0.0000254 mm = 25.4 Nanometer
+        Mil = 9,                ///< 0.001 Inch = 0.0254 mm = 25.4 Micron
+        Yard = 10,              ///< 3 Feet = 0.9144 m
+        Angstrom = 11,          ///< 10^-10 m
+        Nanometer = 12,         ///< 10^-9 m
+        Micron = 13,            ///< 10^-6 m
+        Decimeter = 14,         ///< 0.1 m
+        Decameter = 15,         ///< 10 m
+        Hectometer = 16,        ///< 100 m
+        Gigameter = 17,         ///< 10^9 m
+        Astro = 18,             ///< ~149.6 x 10^9 m
+        Lightyear = 19,         ///< ~9.46 x 10^15 m
+        Parsec = 20,            ///< ~3.0857 x 10^16 m
+        UnitCount = 21,         ///< Used to iterate through units
+
+        /** $MEASUREMENT header variable, since R14/AC1014 */
+        English = 0,            ///< English/Imperial drawing */
+        Metric = 1,             ///< Metric drawing */
+    };
+
     DRW_Header(const DRW_Header& h)
         : vars(),
           comments(h.comments),
@@ -119,6 +149,8 @@ private:
     duint32 ucsCtrl;
     duint32 vportCtrl;
     duint32 vpEntHeaderCtrl;
+
+    int measurement(const int unit);
 };
 
 #endif