[gdal_rasterize] Also accept doubles for -ts (OSGeo#11830)

But warn if it has a decimal part.

Fixes OSGeo#11829

Author: elpaso

apps/gdal_rasterize_lib.cpp

@@ -263,10 +263,12 @@ GDALRasterizeOptionsGetParser(GDALRasterizeOptions *psOptions,
                 _("Set output file resolution in target georeferenced units."));
 
         // Store later
+        // Note: this is supposed to be int but for backward compatibility, we
+        //       use double
         auto &arg = group.add_argument("-ts")
                         .metavar("<width> <height>")
                         .nargs(2)
-                        .scan<'i', int>()
+                        .scan<'g', double>()
                         .help(_("Set output file size in pixels and lines."));
 
         argParser->add_hidden_alias_for(arg, "-outsize");
@@ -1424,10 +1426,20 @@ GDALRasterizeOptionsNew(char **papszArgv,
             psOptions->bCreateOutput = true;
         }
 
-        if (auto oTs = argParser->present<std::vector<int>>("-ts"))
+        if (auto oTs = argParser->present<std::vector<double>>("-ts"))
         {
-            psOptions->nXSize = oTs.value()[0];
-            psOptions->nYSize = oTs.value()[1];
+            const int nXSize = static_cast<int>(oTs.value()[0]);
+            const int nYSize = static_cast<int>(oTs.value()[1]);
+
+            // Warn the user if the conversion to int looses precision
+            if (nXSize != oTs.value()[0] || nYSize != oTs.value()[1])
+            {
+                CPLError(CE_Warning, CPLE_AppDefined,
+                         "-ts values parsed as %d %d.", nXSize, nYSize);
+            }
+
+            psOptions->nXSize = nXSize;
+            psOptions->nYSize = nYSize;
 
             if (psOptions->nXSize <= 0 || psOptions->nYSize <= 0)
             {

autotest/utilities/test_gdal_rasterize.py

@@ -123,7 +123,6 @@ def test_gdal_rasterize_2(gdal_rasterize_path, tmp_path):
     output_tif = str(tmp_path / "rast2.tif")
 
     # Create a raster to rasterize into.
-
     target_ds = gdal.GetDriverByName("GTiff").Create(
         output_tif, 12, 12, 3, gdal.GDT_Byte
     )
@@ -418,3 +417,33 @@ def test_gdal_rasterize_8(gdal_rasterize_path, tmp_path):
     assert cs == 21, "Did not rasterize line data properly"
 
     ds = None
+
+
+###############################################################################
+# Test that -ts also accepts double and warns if not integer
+
+
+@pytest.mark.require_driver("CSV")
+def test_gdal_rasterize_ts_1(tmp_path, gdal_rasterize_path):
+
+    output_tif = str(tmp_path / "rast2.tif")
+
+    # Create a raster to rasterize into.
+    target_ds = gdal.GetDriverByName("GTiff").Create(
+        output_tif, 12, 12, 3, gdal.GDT_Byte
+    )
+    target_ds.SetGeoTransform((0, 1, 0, 12, 0, -1))
+
+    # Close TIF file
+    target_ds = None
+
+    # Run the algorithm.
+    (_, err) = gdaltest.runexternal_out_and_err(
+        f"{gdal_rasterize_path} -at -burn 200 -ts 100.0 200.0 ../alg/data/cutline.csv {output_tif}"
+    )
+    assert err is None or err == "", f"got error/warning {err}"
+
+    (_, err) = gdaltest.runexternal_out_and_err(
+        f"{gdal_rasterize_path} -at -burn 200 -ts 100.4 200.6 ../alg/data/cutline.csv {output_tif}"
+    )
+    assert "-ts values parsed as 100 200" in err