PMTiles CreateCopy(): use 'gdal raster tile' when possible

Author: rouault

apps/gdalalg_raster_tile.cpp

@@ -213,6 +213,13 @@ GDALRasterTileAlgorithm::GDALRasterTileAlgorithm(bool standaloneStep)
 
     AddArg("min-zoom", 0, _("Minimum zoom level"), &m_minZoomLevel)
         .SetMinValueIncluded(0);
+
+    // Only used by PMTiles driver for now
+    AddArg("min-zoom-single-tile", 0,
+           _("Determine minimum zoom level to produce a single tile"),
+           &m_minZoomLevelSingleTile)
+        .SetHidden();
+
     AddArg("max-zoom", 0, _("Maximum zoom level"), &m_maxZoomLevel)
         .SetMinValueIncluded(0);
 
@@ -4824,8 +4831,6 @@ bool GDALRasterTileAlgorithm::RunStep(GDALPipelineStepRunContext &ctxt)
                 m_maxZoomLevel--;
         }
     }
-    if (m_minZoomLevel < 0)
-        m_minZoomLevel = m_maxZoomLevel;
 
     auto tileMatrix = tileMatrixList[m_maxZoomLevel];
     int nMinTileX = 0;
@@ -4927,6 +4932,17 @@ bool GDALRasterTileAlgorithm::RunStep(GDALPipelineStepRunContext &ctxt)
     dstGT[4] = 0;
     dstGT[5] = -tileMatrix.mResY;
 
+    if (m_minZoomLevelSingleTile)
+    {
+        const int nMaxDim = std::max(nXSize, nYSize);
+        const int nOvrCount = static_cast<int>(
+            std::ceil(std::max(0.0, std::log2(static_cast<double>(nMaxDim) /
+                                              tileMatrix.mTileWidth))));
+        m_minZoomLevel = std::max(0, m_maxZoomLevel - nOvrCount);
+    }
+    else if (m_minZoomLevel < 0)
+        m_minZoomLevel = m_maxZoomLevel;
+
     /* -------------------------------------------------------------------- */
     /*      Setup warp options.                                             */
     /* -------------------------------------------------------------------- */

apps/gdalalg_raster_tile.h

@@ -67,6 +67,7 @@ class GDALRasterTileAlgorithm /* non final */
     std::string m_overviewResampling{};
     int m_minZoomLevel = -1;
     int m_maxZoomLevel = -1;
+    bool m_minZoomLevelSingleTile = false;
     bool m_noIntersectionIsOK = false;
     int m_minTileX = -1;
     int m_minTileY = -1;

autotest/gdrivers/pmtiles.py

@@ -206,7 +206,10 @@ def test_pmtiles_convert_from_pmtiles(tmp_path, tile_format):
 
 @pytest.mark.require_driver("MBTILES")
 @pytest.mark.parametrize("tile_format", ["PNG", "JPEG", "WEBP"])
-def test_pmtiles_convert_from_non_pmtiles(tmp_vsimem, tile_format):
+@pytest.mark.parametrize("use_gdal_raster_tile", [True, False])
+def test_pmtiles_convert_from_non_pmtiles(
+    tmp_vsimem, tile_format, use_gdal_raster_tile
+):
 
     if gdal.GetDriverByName(tile_format) is None:
         pytest.skip(f"Driver {tile_format} is not available")
@@ -228,10 +231,13 @@ def test_pmtiles_convert_from_non_pmtiles(tmp_vsimem, tile_format):
     src_ds.GetRasterBand(1).Fill(255)
     src_ds.GetRasterBand(2).Fill(255)
     src_ds.GetRasterBand(3).Fill(255)
+    options = {"TILE_FORMAT": tile_format}
+    if not use_gdal_raster_tile:
+        options["ZOOM_LEVEL_STRATEGY"] = "LOWER"
     gdal.alg.raster.convert(
         input=src_ds,
         output=tmp_vsimem / "out.pmtiles",
-        creation_option={"TILE_FORMAT": tile_format},
+        creation_option=options,
     )
 
     ds = gdal.Open(tmp_vsimem / "out.pmtiles")
@@ -253,11 +259,12 @@ def test_pmtiles_convert_from_non_pmtiles(tmp_vsimem, tile_format):
 
 @pytest.mark.require_driver("MBTILES")
 @pytest.mark.require_driver("PNG")
+@pytest.mark.parametrize("format", ["PNG", "PNG8"])
 @pytest.mark.parametrize(
     "size,expected_ovr_count", [(256, 0), (257, 1), (512, 1), (513, 2)]
 )
 def test_pmtiles_convert_from_non_pmtiles_auto_add_overviews(
-    tmp_vsimem, size, expected_ovr_count
+    tmp_path, format, size, expected_ovr_count
 ):
 
     src_ds = gdal.GetDriverByName("MEM").Create("", size, size, 3)
@@ -279,9 +286,9 @@ def test_pmtiles_convert_from_non_pmtiles_auto_add_overviews(
     src_ds.GetRasterBand(3).Fill(255)
     gdal.alg.raster.convert(
         input=src_ds,
-        output=tmp_vsimem / "out.pmtiles",
-        creation_option={"TILE_FORMAT": "PNG"},
+        output=tmp_path / "out.pmtiles",
+        creation_option={"TILE_FORMAT": format},
     )
 
-    ds = gdal.Open(tmp_vsimem / "out.pmtiles")
+    ds = gdal.Open(tmp_path / "out.pmtiles")
     assert ds.GetRasterBand(1).GetOverviewCount() == expected_ovr_count

gcore/gdalalgorithm.cpp

@@ -464,7 +464,8 @@ static bool CheckCanSetDatasetObject(const GDALAlgorithmArg *arg)
 
 bool GDALAlgorithmArg::Set(GDALDataset *ds)
 {
-    if (m_decl.GetType() != GAAT_DATASET)
+    if (m_decl.GetType() != GAAT_DATASET &&
+        m_decl.GetType() != GAAT_DATASET_LIST)
     {
         CPLError(CE_Failure, CPLE_AppDefined,
                  "Calling Set(GDALDataset*, bool) on argument '%s' of type %s "
@@ -475,8 +476,18 @@ bool GDALAlgorithmArg::Set(GDALDataset *ds)
     if (!CheckCanSetDatasetObject(this))
         return false;
     m_explicitlySet = true;
-    auto &val = *std::get<GDALArgDatasetValue *>(m_value);
-    val.Set(ds);
+    if (m_decl.GetType() == GAAT_DATASET)
+    {
+        auto &val = *std::get<GDALArgDatasetValue *>(m_value);
+        val.Set(ds);
+    }
+    else
+    {
+        CPLAssert(m_decl.GetType() == GAAT_DATASET_LIST);
+        auto &val = *std::get<std::vector<GDALArgDatasetValue> *>(m_value);
+        val.resize(1);
+        val[0].Set(ds);
+    }
     return RunAllActions();
 }
 

ogr/ogrsf_frmts/pmtiles/CMakeLists.txt

@@ -14,6 +14,11 @@ add_gdal_driver(TARGET ogr_PMTiles
 gdal_standard_includes(ogr_PMTiles)
 target_include_directories(ogr_PMTiles PRIVATE ${GDAL_VECTOR_FORMAT_SOURCE_DIR}/mvt ${GDAL_RASTER_FORMAT_SOURCE_DIR}/mbtiles)
 
+if (GDAL_ENABLE_ALGORITHMS)
+    target_compile_definitions(ogr_PMTiles PRIVATE -DGDAL_ENABLE_ALGORITHMS)
+    target_sources(ogr_PMTiles PRIVATE ogrpmtilesfromtileset.cpp)
+endif()
+
 # Needed for Create() mode
 if (GDAL_USE_GEOS)
   target_compile_definitions(ogr_PMTiles PRIVATE -DHAVE_GEOS=1)

ogr/ogrsf_frmts/pmtiles/ogr_pmtiles.h

@@ -21,6 +21,7 @@
 
 #include "include_pmtiles.h"
 
+#include <array>
 #include <limits>
 #include <set>
 #include <stack>
@@ -437,4 +438,27 @@ class OGRPMTilesWriterDataset final : public GDALDataset
 
 #endif  // HAVE_MVT_WRITE_SUPPORT
 
+/************************************************************************/
+/*                             HashArray()                              */
+/************************************************************************/
+
+// From https://codereview.stackexchange.com/questions/171999/specializing-stdhash-for-stdarray
+// We do not use std::hash<std::array<T, N>> as the name of the struct
+// because with gcc 5.4 we get the following error:
+// https://stackoverflow.com/questions/25594644/warning-specialization-of-template-in-different-namespace
+template <class T, size_t N> struct HashArray
+{
+    CPL_NOSANITIZE_UNSIGNED_INT_OVERFLOW
+    size_t operator()(const std::array<T, N> &key) const
+    {
+        std::hash<T> hasher;
+        size_t result = 0;
+        for (size_t i = 0; i < N; ++i)
+        {
+            result = result * 31 + hasher(key[i]);
+        }
+        return result;
+    }
+};
+
 #endif  // OGR_PMTILES_H_INCLUDED