MITAB: take into account scale/bounds to properly round coordinates (m…

…apgears/mitab#2)

autotest/ogr/data/utm31.TAB

@@ -0,0 +1,13 @@
+!table
+!version 300
+!charset WindowsLatin1
+
+Definition Table
+  Type NATIVE Charset "WindowsLatin1"
+  Fields 1
+    id Integer ;
+begin_metadata
+"\IsReadOnly" = "FALSE"
+"\MapInfo" = ""
+"\MapInfo\TableID" = "f0bbc21d-6931-48be-b3f1-91f14480e738"
+end_metadata

autotest/ogr/ogr_mitab.py

@@ -595,6 +595,7 @@ def ogr_mitab_18():
         wkt = sr_got.ExportToWkt()
         if wkt.find('2154') < 0:
             gdaltest.post_reason('failure')
+            print(filename)
             print(sr_got)
             return 'fail'
         proj4 = sr_got.ExportToProj4()
@@ -607,6 +608,26 @@ def ogr_mitab_18():
     ogr.GetDriverByName('MapInfo File').DeleteDataSource('/vsimem/ogr_mitab_18.tab')
 
     return 'success'
+
+###############################################################################
+# Check that we correctly round coordinate to the appropriate precision
+# (https://github.com/mapgears/mitab/issues/2)
+
+def ogr_mitab_19():
+
+    if gdaltest.mapinfo_drv is None:
+        return 'skip'
+
+    ds = ogr.Open('data/utm31.TAB')
+    lyr = ds.GetLayer(0)
+    feat = lyr.GetNextFeature()
+    # Strict text comparison to check precision
+    if feat.GetGeometryRef().ExportToWkt() != 'POINT (485248.12 2261.45)':
+        feat.DumpReadable()
+        return 'fail'
+
+    return 'success'
+
 ###############################################################################
 #
 
@@ -640,6 +661,7 @@ def ogr_mitab_cleanup():
     ogr_mitab_16,
     ogr_mitab_17,
     ogr_mitab_18,
+    ogr_mitab_19,
     ogr_mitab_cleanup
     ]
 

gdal/ogr/ogrsf_frmts/mitab/GNUmakefile

@@ -21,6 +21,8 @@ default:	$(O_OBJ:.o=.$(OBJ_EXT))
 clean:
 	rm -f *.o $(O_OBJ)
 
+$(O_OBJ):       mitab.h mitab_priv.h
+
 update:
 	copymatch.sh ~/pkg/mitab *.TXT
 	copymatch.sh ~/pkg/mitab/mitab *.cpp *.h

gdal/ogr/ogrsf_frmts/mitab/mitab_mapheaderblock.cpp

@@ -138,6 +138,12 @@
 
 #include "mitab.h"
 
+#ifdef WIN32
+inline double round(double r) {
+    return (r > 0.0) ? floor(r + 0.5) : ceil(r - 0.5);
+}
+#endif
+
 /*---------------------------------------------------------------------
  * Set various constants used in generating the header block.
  *--------------------------------------------------------------------*/
@@ -178,6 +184,27 @@ static GByte  gabyObjLenArray[ HDR_OBJ_LEN_ARRAY_SIZE  ] = {
  **********************************************************************/
 TABMAPHeaderBlock::TABMAPHeaderBlock(TABAccess eAccessMode /*= TABRead*/):
     TABRawBinBlock(eAccessMode, TRUE)
+{
+    InitMembersWithDefaultValues();
+
+    /* We don't want to reset it once it is set */
+    m_bIntBoundsOverflow = FALSE;
+}
+
+/**********************************************************************
+ *                   TABMAPHeaderBlock::~TABMAPHeaderBlock()
+ *
+ * Destructor.
+ **********************************************************************/
+TABMAPHeaderBlock::~TABMAPHeaderBlock()
+{
+
+}
+
+/**********************************************************************
+ *            TABMAPHeaderBlock::InitMembersWithDefaultValues()
+ **********************************************************************/
+void TABMAPHeaderBlock::InitMembersWithDefaultValues()
 {
     int i;
 
@@ -207,7 +234,7 @@ TABMAPHeaderBlock::TABMAPHeaderBlock(TABAccess eAccessMode /*= TABRead*/):
     m_nDistUnitsCode = 7;       // Meters
     m_nMaxSpIndexDepth = 0;
     m_nCoordPrecision = 3;      // ??? 3 Digits of precision
-    m_nCoordOriginQuadrant = HDR_DEF_ORG_QUADRANT; // ???
+    m_nCoordOriginQuadrant = HDR_DEF_ORG_QUADRANT; // ??? N-E quadrant
     m_nReflectXAxisCoord = HDR_DEF_REFLECTXAXIS;
     m_nMaxObjLenArrayId = HDR_OBJ_LEN_ARRAY_SIZE-1;  // See gabyObjLenArray[]
     m_numPenDefs = 0;
@@ -219,10 +246,13 @@ TABMAPHeaderBlock::TABMAPHeaderBlock(TABAccess eAccessMode /*= TABRead*/):
     m_sProj.nProjId  = 0;
     m_sProj.nEllipsoidId = 0;
     m_sProj.nUnitsId = 7;
+    m_sProj.nDatumId = 0;
     m_XScale = 1000.0;  // Default coord range (before SetCoordSysBounds()) 
     m_YScale = 1000.0;  // will be [-1000000.000 .. 1000000.000]
     m_XDispl = 0.0;
     m_YDispl = 0.0;
+    m_XPrecision = 0.0;  // not specified
+    m_YPrecision = 0.0;  // not specified
 
     for(i=0; i<6; i++)
         m_sProj.adProjParams[i] = 0.0;
@@ -243,16 +273,6 @@ TABMAPHeaderBlock::TABMAPHeaderBlock(TABAccess eAccessMode /*= TABRead*/):
     m_sProj.dAffineParamF = 0.0;
 }
 
-/**********************************************************************
- *                   TABMAPHeaderBlock::~TABMAPHeaderBlock()
- *
- * Destructor.
- **********************************************************************/
-TABMAPHeaderBlock::~TABMAPHeaderBlock()
-{
-
-}
-
 
 /**********************************************************************
  *                   TABMAPHeaderBlock::InitBlockFromData()
@@ -405,6 +425,8 @@ int     TABMAPHeaderBlock::InitBlockFromData(GByte *pabyBuf,
         }
     }
 
+    UpdatePrecision();
+
     return 0;
 }
 
@@ -444,6 +466,12 @@ int TABMAPHeaderBlock::Int2Coordsys(GInt32 nX, GInt32 nY,
     else
         dY = (nY - m_YDispl) / m_YScale;
 
+    // Round coordinates to the desired precision
+    if (m_XPrecision > 0 && m_YPrecision > 0)
+    {
+        dX = round(dX*m_XPrecision)/m_XPrecision;
+        dY = round(dY*m_YPrecision)/m_YPrecision;
+    }
 //printf("Int2Coordsys: (%d, %d) -> (%.10g, %.10g)\n", nX, nY, dX, dY);
 
     return 0;
@@ -664,6 +692,8 @@ int TABMAPHeaderBlock::SetCoordsysBounds(double dXMin, double dYMin,
     m_nXMax = 1000000000;
     m_nYMax = 1000000000;
 
+    UpdatePrecision();
+
     return 0;
 }
 
@@ -912,7 +942,6 @@ int     TABMAPHeaderBlock::CommitToFile()
 int     TABMAPHeaderBlock::InitNewBlock(VSILFILE *fpSrc, int nBlockSize, 
                                         int nFileOffset /* = 0*/)
 {
-    int i;
     /*-----------------------------------------------------------------
      * Start with the default initialisation
      *----------------------------------------------------------------*/
@@ -922,56 +951,7 @@ int     TABMAPHeaderBlock::InitNewBlock(VSILFILE *fpSrc, int nBlockSize,
     /*-----------------------------------------------------------------
      * Set acceptable default values for member vars.
      *----------------------------------------------------------------*/
-    m_nMAPVersionNumber = HDR_VERSION_NUMBER;
-    m_nBlockSize = HDR_DATA_BLOCK_SIZE;
-
-    m_dCoordsys2DistUnits = 1.0;
-    m_nXMin = -1000000000;
-    m_nYMin = -1000000000;
-    m_nXMax = 1000000000;
-    m_nYMax = 1000000000;
-
-    m_nFirstIndexBlock = 0;
-    m_nFirstGarbageBlock = 0;
-    m_nFirstToolBlock = 0;
-
-    m_numPointObjects = 0;
-    m_numLineObjects = 0;
-    m_numRegionObjects = 0;
-    m_numTextObjects = 0;
-    m_nMaxCoordBufSize = 0;
-
-    m_nDistUnitsCode = 7;       // Meters
-    m_nMaxSpIndexDepth = 0;
-    m_nCoordPrecision = 3;      // ??? 3 digits of precision
-    m_nCoordOriginQuadrant = HDR_DEF_ORG_QUADRANT; // ??? N-E quadrant
-    m_nReflectXAxisCoord = HDR_DEF_REFLECTXAXIS;
-    m_nMaxObjLenArrayId = HDR_OBJ_LEN_ARRAY_SIZE-1;  // See gabyObjLenArray[]
-    m_numPenDefs = 0;
-    m_numBrushDefs = 0;
-    m_numSymbolDefs = 0;
-    m_numFontDefs = 0;
-    m_numMapToolBlocks = 0;
-
-    m_sProj.nProjId  = 0;
-    m_sProj.nEllipsoidId = 0;
-    m_sProj.nUnitsId = 7;
-    m_sProj.nDatumId = 0;
-    m_XScale = 1000.0;  // Default coord range (before SetCoordSysBounds()) 
-    m_YScale = 1000.0;  // will be [-1000000.000 .. 1000000.000]
-    m_XDispl = 0.0;
-    m_YDispl = 0.0;
-
-    for(i=0; i<6; i++)
-        m_sProj.adProjParams[i] = 0.0;
-
-    m_sProj.dDatumShiftX = 0.0;
-    m_sProj.dDatumShiftY = 0.0;
-    m_sProj.dDatumShiftZ = 0.0;
-    for(i=0; i<5; i++)
-        m_sProj.adDatumParams[i] = 0.0;
-
-    m_sProj.nAffineFlag = 0;
+    InitMembersWithDefaultValues();
 
     /*-----------------------------------------------------------------
      * And Set the map object length array in the buffer...
@@ -988,6 +968,17 @@ int     TABMAPHeaderBlock::InitNewBlock(VSILFILE *fpSrc, int nBlockSize,
     return 0;
 }
 
+/**********************************************************************
+ * TABMAPHeaderBlock::UpdatePrecision()
+ *
+ * Update x and y maximum achievable precision given current scales
+ * (m_XScale and m_YScale)
+ **********************************************************************/
+void TABMAPHeaderBlock::UpdatePrecision()
+{
+    m_XPrecision = pow(10.0, round(log10(m_XScale)));
+    m_YPrecision = pow(10.0, round(log10(m_YScale)));
+}
 
 /**********************************************************************
  *                   TABMAPHeaderBlock::Dump()

gdal/ogr/ogrsf_frmts/mitab/mitab_priv.h

@@ -877,6 +877,9 @@ class TABRawBinBlock
 
 class TABMAPHeaderBlock: public TABRawBinBlock
 {
+    void        InitMembersWithDefaultValues();
+    void        UpdatePrecision();
+
   protected:
     TABProjInfo m_sProj;
 
@@ -955,7 +958,8 @@ class TABMAPHeaderBlock: public TABRawBinBlock
     double      m_YScale;
     double      m_XDispl;
     double      m_YDispl;
-
+    double      m_XPrecision; // maximum achievable precision along X axis depending on bounds extent
+    double      m_YPrecision; // maximum achievable precision along Y axis depending on bounds extent
 };
 
 /*---------------------------------------------------------------------