From e6279c5edc9a2610719b246f7d3034f225940991 Mon Sep 17 00:00:00 2001
From: Guilhem Moulin <guilhem@fripost.org>
Date: Thu, 28 Sep 2023 20:58:28 +0200
Subject: Merge topographic tiles if possible.
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QGIS struggles (eps. memory-wise) when a projects has many small layers.
Merging all ‘Topografi 10’ tiles of interest yields a much smoother
experience.
---
 gis-observation-map | 73 +++++++++++++++++++++++++++++++++++++++--------------
 1 file changed, 54 insertions(+), 19 deletions(-)

(limited to 'gis-observation-map')

diff --git a/gis-observation-map b/gis-observation-map
index 96eacfa..11f4473 100755
--- a/gis-observation-map
+++ b/gis-observation-map
@@ -819,26 +819,55 @@ if args.topo_basedir is not None and projectInstance is not None:
     idxContains = {}
     for topo in topo_maps:
         qlr_paths = []
+        qlr_merged = None
         d = args.topo_basedir.joinpath(topo)
         if not d.is_dir():
             continue
 
-        if args.project_home is not None:
-            l = args.project_home.joinpath(topo)
-            l.symlink_to(d, target_is_directory=True)
-            d = l
-
         idx = d.joinpath('index.geojson')
         if idx.is_file():
             tiles, idxContains[topo] = idx_intersects(idx.as_posix(), geometries)
-            for tile in tiles:
-                t = d.joinpath(tile)
-                qlr_path = find_qlr(t)
+            if len(tiles) == 0:
+                continue
+
+            if args.project_home is None:
+                for tile in tiles:
+                    t = d.joinpath(tile)
+                    qlr_path = find_qlr(t)
+                    if qlr_path is None:
+                        continue
+                    qlr_paths.append(qlr_path)
+            else:
+                t0 = d.joinpath(tiles[0])
+                qlr_path = find_qlr(d)
                 if qlr_path is None:
                     continue
-                qlr_paths.append(qlr_path)
+
+                d2 = args.project_home.joinpath(topo)
+                d2.mkdir(mode=0o755, exist_ok=True)
+                d2.joinpath(qlr_path.name).symlink_to(qlr_path, target_is_directory=False)
+                qlr_merged = d2.joinpath(qlr_path.name)
+
+                gpkgs = set()
+                for tile in tiles:
+                    for gpkg in d.joinpath(tile).glob('*.gpkg'):
+                        gpkgs.add(gpkg.name)
+
+                for gpkg in gpkgs:
+                    dst = d2.joinpath(gpkg)
+                    if dst.exists():
+                        raise Exception(f'{dst}: file exists')
+                    for tile in tiles:
+                        src = d.joinpath(tile).joinpath(gpkg)
+                        if src.is_file():
+                            gdal.VectorTranslate(dst.as_posix(), src.as_posix(), format='GPKG', accessMode='upsert')
 
         else:
+            if args.project_home is not None:
+                l = args.project_home.joinpath(topo)
+                l.symlink_to(d, target_is_directory=True)
+                d = l
+
             for t in sorted(d.glob('*')):
                 qlr_path = find_qlr(t)
                 if qlr_path is None:
@@ -855,15 +884,22 @@ if args.topo_basedir is not None and projectInstance is not None:
 
                 qlr_paths.append(qlr_path)
 
-        if projectInstance is not None and len(qlr_paths) > 0:
-            rootGroup = layerTreeRoot.addGroup(topo)
-            for qlr_path in qlr_paths:
-                QgsLayerDefinition.loadLayerDefinition(qlr_path.as_posix(), projectInstance, rootGroup)
-            lyrSubTree = rootGroup.children()
-            if len(lyrSubTree) == len(qlr_paths):
-                for i, lt in enumerate(lyrSubTree):
-                    name = qlr_paths[i].parent.stem
-                    lt.setName(name)
+        if projectInstance is not None:
+            if qlr_merged is not None:
+                QgsLayerDefinition.loadLayerDefinition(qlr_merged.as_posix(), projectInstance, layerTreeRoot)
+                lt = layerTreeRoot.children()[-1]
+                lt.setName(topo)
+                lyrSubTree = [lt]
+            elif len(qlr_paths) > 0:
+                rootGroup = layerTreeRoot.addGroup(topo)
+                for qlr_path in qlr_paths:
+                    QgsLayerDefinition.loadLayerDefinition(qlr_path.as_posix(), projectInstance, rootGroup)
+                lyrSubTree = rootGroup.children()
+                rootGroup.setExpanded(False)
+                if len(lyrSubTree) == len(qlr_paths):
+                    for i, lt in enumerate(lyrSubTree):
+                        name = qlr_paths[i].parent.stem
+                        lt.setName(name)
             for lt in lyrSubTree:
                 lt.setExpanded(False)
                 lt.setItemVisibilityChecked(True)
@@ -872,7 +908,6 @@ if args.topo_basedir is not None and projectInstance is not None:
                     lyr = lyr.layer()
                     lyr.setReadOnly(True)
                     lyr.setFlags(QgsMapLayer.Removable)
-            rootGroup.setExpanded(False)
 
     if projectInstance is not None:
         maxScale = 1
-- 
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