Handle very high resolution imagery (#1926)

* Ensure Fusion level doesn't exceed the max

* Add unit tests

Author: tst-lsavoie

earth_enterprise/src/common/SConscript

@@ -211,5 +211,9 @@ env.test('sharedstring_unittest',
          'sharedstring_unittest.cpp',
           LIBS=['geutil', 'gtest', 'gecommon'])
 
+env.test('khTileAddr_unittest',
+         'khTileAddr_unittest.cpp',
+          LIBS=['geutil', 'gtest', 'gecommon'])
+
 env.install('common_lib', [gecommon])
 env.install('common_lib', [geutil])

earth_enterprise/src/common/khTileAddr.h

@@ -386,10 +386,10 @@ class khTilespaceFlat : public khTilespace {
   }
 
   // Return the level where this pixel size belongs. It will always "snapup"
-  // the level.
+  // the level except that it will stop at the maximum Fusion level.
   inline unsigned int LevelFromDegPixelSize(double degPixelSize) const {
     unsigned int level = 0;
-    for (; level < NumFusionLevels; ++level) {
+    for (; level < MaxFusionLevel; ++level) {
       if (degPixelSize >= DegPixelSize(level))
         break;
     }
@@ -431,10 +431,10 @@ class khTilespaceMercator : public khTilespace {
   }
 
   // Return the level where this pixel size belongs. It will always "snapup"
-  // the level.
+  // the level except that it will stop at the maximum Fusion level.
   inline unsigned int LevelFromPixelSizeInMeters(double pixelSizeInMeters) const {
     unsigned int level = 0;
-    for (; level < NumFusionLevels; ++level) {
+    for (; level < MaxFusionLevel; ++level) {
       if (pixelSizeInMeters >= AveragePixelSizeInMercatorMeters(level))
         break;
     }

earth_enterprise/src/common/khTileAddr_unittest.cpp

@@ -0,0 +1,95 @@
+// Copyright 2021 The Open GEE Contributors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include <gtest/gtest.h>
+
+#include "common/khTileAddr.h"
+
+#include "common/khGeomUtils.h"
+
+extern const khTilespaceFlat RasterProductTilespaceFlat;
+extern const khTilespaceMercator RasterProductTilespaceMercator;
+
+double MetersToDegrees(double meters) {
+  return meters / khGeomUtils::khEarthCircumferencePerDegree;
+}
+
+double MetersToDegreesMerc(double meters) {
+  return meters / khGeomUtilsMercator::khEarthCircumferencePerDegree;
+}
+
+TEST(TileAddrTest, FlatLowRes) {
+  double degrees = MetersToDegrees(400000000);
+  unsigned int level = RasterProductTilespaceFlat.LevelFromDegPixelSize(degrees);
+  ASSERT_EQ(0, level);
+}
+
+TEST(TileAddrTest, FlatMedRes) {
+  double degrees = MetersToDegrees(4000); // Same as bluemarble
+  unsigned int level = RasterProductTilespaceFlat.LevelFromDegPixelSize(degrees);
+  // The reported level will be 8 levels off from the level in the Fusion UI
+  ASSERT_EQ(6 + 8, level);
+}
+
+TEST(TileAddrTest, FlatHighRes) {
+  double degrees = MetersToDegrees(0.0187);
+  unsigned int level = RasterProductTilespaceFlat.LevelFromDegPixelSize(degrees);
+  ASSERT_EQ(31, level);
+}
+
+// Make sure the level tops out at 31
+TEST(TileAddrTest, FlatTooHighRes) {
+  double degrees = MetersToDegrees(0.00000001);
+  unsigned int level = RasterProductTilespaceFlat.LevelFromDegPixelSize(degrees);
+  ASSERT_EQ(31, level);
+}
+
+TEST(TileAddrTest, MercLowRes) {
+  unsigned int level = RasterProductTilespaceMercator.LevelFromPixelSizeInMeters(400000000);
+  ASSERT_EQ(0, level);
+}
+
+TEST(TileAddrTest, MercMedRes) {
+  // Same resolution as bluemarble
+  unsigned int level = RasterProductTilespaceMercator.LevelFromPixelSizeInMeters(4000);
+  // The reported level will be 8 levels off from the level in the Fusion UI
+  ASSERT_EQ(6 + 8, level);
+}
+
+TEST(TileAddrTest, MercHighRes) {
+  unsigned int level = RasterProductTilespaceMercator.LevelFromPixelSizeInMeters(0.0187);
+  ASSERT_EQ(31, level);
+}
+
+// Make sure the level tops out at 31
+TEST(TileAddrTest, MercTooHighRes) {
+  unsigned int level = RasterProductTilespaceMercator.LevelFromPixelSizeInMeters(0.00000001);
+  ASSERT_EQ(31, level);
+}
+
+// The purpose of this test is to demonstrate that flat and mercator behave
+// differently.
+TEST(TileAddrTest, FlatVsMercDiff) {
+  double meters = 2504689.303265145;
+  double degrees = MetersToDegrees(meters);
+  unsigned int mercLevel = RasterProductTilespaceMercator.LevelFromPixelSizeInMeters(meters);
+  unsigned int flatLevel = RasterProductTilespaceFlat.LevelFromDegPixelSize(degrees);
+  ASSERT_EQ(4, mercLevel);
+  ASSERT_EQ(5, flatLevel);
+}
+
+int main(int argc, char **argv) {
+  testing::InitGoogleTest(&argc, argv);
+  return RUN_ALL_TESTS();
+}

earth_enterprise/src/fusion/khgdal/SConscript

@@ -66,3 +66,7 @@ env.install('fusion_bin', [geinfo, gevirtualraster, gesplitkhvr,
                            getranslate, gereproject])
 env.install('tools_bin', [geupdatelut, khprepvirtrast])
 env.install('fusion_lib', [gegdal, gegdalutil])
+
+env.test('khGDALDataset_unittest',
+          'khGDALDataset_unittest.cpp',
+          LIBS=['gegdal', 'gdal', 'gecommon', 'gtest'])