DXF: add creation option to set and DXF system variables

rouault · Dec 3, 2024 · 9dd8963 · 9dd8963
1 parent 5e173b5
commit 9dd8963
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Showing 6 changed files with 315 additions and 15 deletions.
diff --git a/autotest/ogr/ogr_dxf.py b/autotest/ogr/ogr_dxf.py
@@ -17,7 +17,7 @@
 import ogrtest
 import pytest
 
-from osgeo import gdal, ogr
+from osgeo import gdal, ogr, osr
 
 
 ###############################################################################
@@ -4020,3 +4020,103 @@ def test_ogr_dxf_read_closed_polyline_with_bulge():
     f = lyr.GetNextFeature()
     g = f.GetGeometryRef()
     assert g.GetGeometryType() == ogr.wkbPolygon
+
+
+###############################################################################
+
+
+def test_ogr_dxf_write_INSUNITS(tmp_vsimem):
+
+    filename = str(tmp_vsimem / "out.dxf")
+
+    with ogr.GetDriverByName("DXF").CreateDataSource(
+        filename, options=["INSUNITS=METERS"]
+    ) as ds:
+        pass
+    with ogr.Open(filename) as ds:
+        assert ds.GetMetadataItem("$INSUNITS", "DXF_HEADER_VARIABLES") == "6"
+
+    with ogr.GetDriverByName("DXF").CreateDataSource(
+        filename, options=["INSUNITS=21"]
+    ) as ds:
+        pass
+    with ogr.Open(filename) as ds:
+        assert ds.GetMetadataItem("$INSUNITS", "DXF_HEADER_VARIABLES") == "21"
+
+    with gdal.quiet_errors():
+        with ogr.GetDriverByName("DXF").CreateDataSource(
+            filename, options=["INSUNITS=INVALID"]
+        ) as ds:
+            pass
+    with ogr.Open(filename) as ds:
+        assert ds.GetMetadataItem("$INSUNITS", "DXF_HEADER_VARIABLES") == "     1"
+
+    with ogr.GetDriverByName("DXF").CreateDataSource(
+        filename, options=["INSUNITS=FROM_CRS"]
+    ) as ds:
+        srs = osr.SpatialReference()
+        srs.ImportFromEPSG(32631)
+        ds.CreateLayer("test", srs=srs)
+    with ogr.Open(filename) as ds:
+        assert ds.GetMetadataItem("$INSUNITS", "DXF_HEADER_VARIABLES") == "6"
+
+    # No CRS
+    with gdal.quiet_errors():
+        with ogr.GetDriverByName("DXF").CreateDataSource(
+            filename, options=["INSUNITS=FROM_CRS"]
+        ) as ds:
+            pass
+    with ogr.Open(filename) as ds:
+        assert ds.GetMetadataItem("$INSUNITS", "DXF_HEADER_VARIABLES") == "     1"
+
+    # Not a projected CRS
+    with gdal.quiet_errors():
+        with ogr.GetDriverByName("DXF").CreateDataSource(
+            filename, options=["INSUNITS=FROM_CRS"]
+        ) as ds:
+            srs = osr.SpatialReference()
+            srs.ImportFromEPSG(4326)
+            ds.CreateLayer("test", srs=srs)
+    with ogr.Open(filename) as ds:
+        assert ds.GetMetadataItem("$INSUNITS", "DXF_HEADER_VARIABLES") == "     1"
+
+    # Unknown linear units
+    with gdal.quiet_errors():
+        with ogr.GetDriverByName("DXF").CreateDataSource(
+            filename, options=["INSUNITS=FROM_CRS"]
+        ) as ds:
+            srs = osr.SpatialReference()
+            srs.ImportFromProj4("+proj=merc +to_meter=2")
+            ds.CreateLayer("test", srs=srs)
+        with ogr.Open(filename) as ds:
+            assert ds.GetMetadataItem("$INSUNITS", "DXF_HEADER_VARIABLES") == "     1"
+
+
+###############################################################################
+
+
+def test_ogr_dxf_write_MEASUREMENT(tmp_vsimem):
+
+    filename = str(tmp_vsimem / "out.dxf")
+
+    with ogr.GetDriverByName("DXF").CreateDataSource(
+        filename, options=["MEASUREMENT=METRIC"]
+    ) as ds:
+        pass
+    with ogr.Open(filename) as ds:
+        assert ds.GetMetadataItem("$MEASUREMENT", "DXF_HEADER_VARIABLES") == "1"
+
+    with ogr.GetDriverByName("DXF").CreateDataSource(
+        filename, options=["MEASUREMENT=1"]
+    ) as ds:
+        pass
+    with ogr.Open(filename) as ds:
+        assert ds.GetMetadataItem("$MEASUREMENT", "DXF_HEADER_VARIABLES") == "1"
+
+    with gdal.quiet_errors():
+        with ogr.GetDriverByName("DXF").CreateDataSource(
+            filename, options=["MEASUREMENT=INVALID"]
+        ) as ds:
+            pass
+    with ogr.Open(filename) as ds:
+        assert ds.GetMetadataItem("$MEASUREMENT", "DXF_HEADER_VARIABLES") == "     0"
diff --git a/doc/source/drivers/vector/dxf.rst b/doc/source/drivers/vector/dxf.rst
@@ -405,6 +405,32 @@ The driver supports the following dataset creation options:
       Override the trailer file used - in place
       of trailer.dxf located in the GDAL_DATA directory.
 
+-  .. dsco:: FIRST_ENTITY
+      :choices: <integer>
+
+      Identifier of first entity
+
+-  .. dsco:: INSUNITS
+      :choices: HEADER_VALUE, FROM_CRS, UNITLESS, INCHES, FEET, MILLIMETERS, CENTIMETERS, METERS, US_SURVEY_FEET
+      :default: HEADER_VALUE
+      :since: 3.11
+
+      Drawing units for the model space
+      (`$INSUNITS <https://knowledge.autodesk.com/support/autocad/learn-explore/caas/CloudHelp/cloudhelp/2018/ENU/AutoCAD-Core/files/GUID-A58A87BB-482B-4042-A00A-EEF55A2B4FD8-htm.html>`__ system variable).
+      Defaults to the value of the header template, which is ``INCHES``.
+      The special value ``FROM_CRS`` means that the linear units of the CRS of
+      the layer, when it is a projected CRS, are used to set ``$INSUNITS``.
+
+-  .. dsco:: MEASUREMENT
+      :choices: HEADER_VALUE, IMPERIAL, METRIC
+      :default: HEADER_VALUE
+      :since: 3.11
+
+      Whether the current drawing uses imperial or metric hatch pattern and linetype
+      (`$MEASUREMENT <https://knowledge.autodesk.com/support/autocad/learn-explore/caas/CloudHelp/cloudhelp/2018/ENU/AutoCAD-Core/files/GUID-1D074C55-0B63-482E-8A37-A52AC0C7C8FE-htm.html>`__ system variable).
+      Defaults to the value of the header template, which is ``IMPERIAL``.
+
+
 The header and trailer templates can be
 complete DXF files. The driver will scan them and only extract the
 needed portions (portion before or after the ENTITIES section).
@@ -474,16 +500,6 @@ It is assumed that patterns are using "g" (georeferenced) units for
 defining the line pattern. If not, the scaling of the DXF patterns is
 likely to be wrong - potentially very wrong.
 
-Units
-~~~~~
-
-GDAL writes DXF files with measurement units set to "Imperial - Inches".
-If you need to change the units, edit the
-`$MEASUREMENT <https://knowledge.autodesk.com/support/autocad/learn-explore/caas/CloudHelp/cloudhelp/2018/ENU/AutoCAD-Core/files/GUID-1D074C55-0B63-482E-8A37-A52AC0C7C8FE-htm.html>`__
-and
-`$INSUNITS <https://knowledge.autodesk.com/support/autocad/learn-explore/caas/CloudHelp/cloudhelp/2018/ENU/AutoCAD-Core/files/GUID-A58A87BB-482B-4042-A00A-EEF55A2B4FD8-htm.html>`__
-variables in the header template.
-
 --------------
 
 

diff --git a/ogr/ogrsf_frmts/dxf/ogr_dxf.h b/ogr/ogrsf_frmts/dxf/ogr_dxf.h
@@ -957,6 +957,9 @@ class OGRDXFWriterDS final : public GDALDataset
 
     bool m_bHeaderFileIsTemp = false;
     bool m_bTrailerFileIsTemp = false;
+    OGRSpatialReference m_oSRS{};
+    std::string m_osINSUNITS = "HEADER_VALUE";
+    std::string m_osMEASUREMENT = "HEADER_VALUE";
 
   public:
     OGRDXFWriterDS();

diff --git a/ogr/ogrsf_frmts/dxf/ogrdxfdatasource.cpp b/ogr/ogrsf_frmts/dxf/ogrdxfdatasource.cpp
@@ -821,6 +821,8 @@ bool OGRDXFDataSource::ReadHeaderSection()
         }
 
         oHeaderVariables[l_osName] = szLineBuf;
+        GDALDataset::SetMetadataItem(l_osName.c_str(), szLineBuf,
+                                     "DXF_HEADER_VARIABLES");
     }
     if (nCode < 0)
     {
@@ -857,6 +859,8 @@ bool OGRDXFDataSource::ReadHeaderSection()
             }
 
             oHeaderVariables[l_osName] = szLineBuf;
+            GDALDataset::SetMetadataItem(l_osName.c_str(), szLineBuf,
+                                         "DXF_HEADER_VARIABLES");
         }
         if (nCode < 0)
         {

diff --git a/ogr/ogrsf_frmts/dxf/ogrdxfdriver.cpp b/ogr/ogrsf_frmts/dxf/ogrdxfdriver.cpp
@@ -129,6 +129,28 @@ void RegisterOGRDXF()
         "file' default='trailer.dxf'/>"
         "  <Option name='FIRST_ENTITY' type='int' description='Identifier of "
         "first entity'/>"
+        "  <Option name='INSUNITS' type='string-select' "
+        "description='Drawing units for the model space ($INSUNITS system "
+        "variable)' default='HEADER_VALUE'>"
+        "    <Value>HEADER_VALUE</Value>"
+        "    <Value>FROM_CRS</Value>"
+        "    <Value alias='0'>UNITLESS</Value>"
+        "    <Value alias='1'>INCHES</Value>"
+        "    <Value alias='2'>FEET</Value>"
+        "    <Value alias='4'>MILLIMETERS</Value>"
+        "    <Value alias='5'>CENTIMETERS</Value>"
+        "    <Value alias='6'>METERS</Value>"
+        "    <Value alias='21'>US_SURVEY_FEET</Value>"
+        "  </Option>"
+        "  <Option name='MEASUREMENT' type='string-select' "
+        "description='Whether the current drawing uses imperial or metric "
+        "hatch "
+        "pattern and linetype ($MEASUREMENT system variable)' "
+        "default='HEADER_VALUE'>"
+        "    <Value>HEADER_VALUE</Value>"
+        "    <Value alias='0'>IMPERIAL</Value>"
+        "    <Value alias='1'>METRIC</Value>"
+        "  </Option>"
         "</CreationOptionList>");
 
     poDriver->SetMetadataItem(