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authorAsheem Mamoowala <asheem.mamoowala@mapbox.com>2017-09-01 16:33:35 -0700
committerAsheem Mamoowala <asheem.mamoowala@mapbox.com>2017-09-08 17:38:42 -0700
commit50fd9175109e01c5286d3363df21aeba6e89087b (patch)
tree2f3dfada2896159f3eef64aa3f02ac231742d8a7
parentaa4dff1095e8f5e8ad584f5f7dcab3e61d8cf8ee (diff)
downloadqtlocation-mapboxgl-50fd9175109e01c5286d3363df21aeba6e89087b.tar.gz
Fast tileCount with help from @mapbox/sphericalmercator module
-rw-r--r--include/mbgl/storage/offline.hpp4
-rw-r--r--include/mbgl/util/projection.hpp22
-rw-r--r--platform/default/mbgl/storage/offline.cpp33
-rw-r--r--platform/default/mbgl/storage/offline_download.cpp4
-rw-r--r--src/mbgl/util/tile_cover.cpp21
-rw-r--r--src/mbgl/util/tile_cover.hpp3
-rw-r--r--test/storage/offline.test.cpp8
-rw-r--r--test/util/tile_cover.test.cpp9
8 files changed, 89 insertions, 15 deletions
diff --git a/include/mbgl/storage/offline.hpp b/include/mbgl/storage/offline.hpp
index 818cfe2ba5..afb2fa1e81 100644
--- a/include/mbgl/storage/offline.hpp
+++ b/include/mbgl/storage/offline.hpp
@@ -31,12 +31,14 @@ public:
/* Private */
std::vector<CanonicalTileID> tileCover(SourceType, uint16_t tileSize, const Range<uint8_t>& zoomRange) const;
-
+ unsigned long tileCount(SourceType, uint16_t tileSize, const Range<uint8_t>& zoomRange) const;
const std::string styleURL;
const LatLngBounds bounds;
const double minZoom;
const double maxZoom;
const float pixelRatio;
+private:
+ Range<uint8_t> coveringZoomRange(SourceType, uint16_t tileSize, const Range<uint8_t>& zoomRange) const;
};
/*
diff --git a/include/mbgl/util/projection.hpp b/include/mbgl/util/projection.hpp
index 3cc1146513..f64502c5bc 100644
--- a/include/mbgl/util/projection.hpp
+++ b/include/mbgl/util/projection.hpp
@@ -75,10 +75,7 @@ public:
}
static Point<double> project(const LatLng& latLng, double scale) {
- return Point<double> {
- util::LONGITUDE_MAX + latLng.longitude(),
- util::LONGITUDE_MAX - util::RAD2DEG * std::log(std::tan(M_PI / 4 + latLng.latitude() * M_PI / util::DEGREES_MAX))
- } * worldSize(scale) / util::DEGREES_MAX;
+ return project_(latLng, worldSize(scale));
}
static LatLng unproject(const Point<double>& p, double scale, LatLng::WrapMode wrapMode = LatLng::Unwrapped) {
@@ -89,6 +86,23 @@ public:
wrapMode
};
}
+
+ // Project lat, lon to point in a zoom-dependent world size
+ static Point<double> project(const LatLng& point, uint8_t zoom, uint16_t tileSize) {
+ const double t2z = tileSize * std::pow(2, zoom);
+ Point<double> pt = project_(point, t2z);
+ // Flip y coordinate
+ auto x = std::round(std::min(pt.x, t2z));
+ auto y = std::round(std::min(t2z - pt.y, t2z));
+ return { x, y };
+ }
+private:
+ static Point<double> project_(const LatLng& latLng, double worldSize) {
+ return Point<double> {
+ util::LONGITUDE_MAX + latLng.longitude(),
+ util::LONGITUDE_MAX - util::RAD2DEG * std::log(std::tan(M_PI / 4 + latLng.latitude() * M_PI / util::DEGREES_MAX))
+ } * worldSize / util::DEGREES_MAX;
+ }
};
} // namespace mbgl
diff --git a/platform/default/mbgl/storage/offline.cpp b/platform/default/mbgl/storage/offline.cpp
index fd2d47819b..644684c8a6 100644
--- a/platform/default/mbgl/storage/offline.cpp
+++ b/platform/default/mbgl/storage/offline.cpp
@@ -1,6 +1,7 @@
#include <mbgl/storage/offline.hpp>
#include <mbgl/util/tile_cover.hpp>
#include <mbgl/util/tileset.hpp>
+#include <mbgl/util/projection.hpp>
#include <rapidjson/document.h>
#include <rapidjson/stringbuffer.h>
@@ -24,17 +25,11 @@ OfflineTilePyramidRegionDefinition::OfflineTilePyramidRegionDefinition(
}
std::vector<CanonicalTileID> OfflineTilePyramidRegionDefinition::tileCover(SourceType type, uint16_t tileSize, const Range<uint8_t>& zoomRange) const {
- double minZ = std::max<double>(util::coveringZoomLevel(minZoom, type, tileSize), zoomRange.min);
- double maxZ = std::min<double>(util::coveringZoomLevel(maxZoom, type, tileSize), zoomRange.max);
-
- assert(minZ >= 0);
- assert(maxZ >= 0);
- assert(minZ < std::numeric_limits<uint8_t>::max());
- assert(maxZ < std::numeric_limits<uint8_t>::max());
+ const Range<uint8_t> clampedZoomRange = coveringZoomRange(type, tileSize, zoomRange);
std::vector<CanonicalTileID> result;
- for (uint8_t z = minZ; z <= maxZ; z++) {
+ for (uint8_t z = clampedZoomRange.min; z <= clampedZoomRange.max; z++) {
for (const auto& tile : util::tileCover(bounds, z)) {
result.emplace_back(tile.canonical);
}
@@ -43,6 +38,28 @@ std::vector<CanonicalTileID> OfflineTilePyramidRegionDefinition::tileCover(Sourc
return result;
}
+unsigned long OfflineTilePyramidRegionDefinition::tileCount(SourceType type, uint16_t tileSize, const Range<uint8_t>& zoomRange) const {
+
+ const Range<uint8_t> clampedZoomRange = coveringZoomRange(type, tileSize, zoomRange);
+ unsigned long result = 0;;
+ for (uint8_t z = clampedZoomRange.min; z <= clampedZoomRange.max; z++) {
+ result += util::tileCount(bounds, z, tileSize);
+ }
+
+ return result;
+}
+
+Range<uint8_t> OfflineTilePyramidRegionDefinition::coveringZoomRange(SourceType type, uint16_t tileSize, const Range<uint8_t>& zoomRange) const {
+ double minZ = std::max<double>(util::coveringZoomLevel(minZoom, type, tileSize), zoomRange.min);
+ double maxZ = std::min<double>(util::coveringZoomLevel(maxZoom, type, tileSize), zoomRange.max);
+
+ assert(minZ >= 0);
+ assert(maxZ >= 0);
+ assert(minZ < std::numeric_limits<uint8_t>::max());
+ assert(maxZ < std::numeric_limits<uint8_t>::max());
+ return { static_cast<uint8_t>(minZ), static_cast<uint8_t>(maxZ) };
+}
+
OfflineRegionDefinition decodeOfflineRegionDefinition(const std::string& region) {
rapidjson::GenericDocument<rapidjson::UTF8<>, rapidjson::CrtAllocator> doc;
doc.Parse<0>(region.c_str());
diff --git a/platform/default/mbgl/storage/offline_download.cpp b/platform/default/mbgl/storage/offline_download.cpp
index 7f0001f64b..ff61114888 100644
--- a/platform/default/mbgl/storage/offline_download.cpp
+++ b/platform/default/mbgl/storage/offline_download.cpp
@@ -80,7 +80,7 @@ OfflineRegionStatus OfflineDownload::getStatus() const {
auto handleTiledSource = [&] (const variant<std::string, Tileset>& urlOrTileset, const uint16_t tileSize) {
if (urlOrTileset.is<Tileset>()) {
result.requiredResourceCount +=
- definition.tileCover(type, tileSize, urlOrTileset.get<Tileset>().zoomRange).size();
+ definition.tileCount(type, tileSize, urlOrTileset.get<Tileset>().zoomRange);
} else {
result.requiredResourceCount += 1;
const auto& url = urlOrTileset.get<std::string>();
@@ -90,7 +90,7 @@ OfflineRegionStatus OfflineDownload::getStatus() const {
optional<Tileset> tileset = style::conversion::convertJSON<Tileset>(*sourceResponse->data, error);
if (tileset) {
result.requiredResourceCount +=
- definition.tileCover(type, tileSize, (*tileset).zoomRange).size();
+ definition.tileCount(type, tileSize, (*tileset).zoomRange);
}
} else {
result.requiredResourceCountIsPrecise = false;
diff --git a/src/mbgl/util/tile_cover.cpp b/src/mbgl/util/tile_cover.cpp
index b53e91162c..c06634c9b2 100644
--- a/src/mbgl/util/tile_cover.cpp
+++ b/src/mbgl/util/tile_cover.cpp
@@ -169,5 +169,26 @@ std::vector<UnwrappedTileID> tileCover(const TransformState& state, int32_t z) {
z);
}
+// Taken from https://github.com/mapbox/sphericalmercator#xyzbbox-zoom-tms_style-srs
+// Computes the projected tiles for the lower left and uppoer right points of the bounds
+// and uses that to compute the tile cover count
+unsigned long tileCount(const LatLngBounds& bounds, uint8_t zoom, uint16_t tileSize_){
+
+ auto sw = Projection::project(bounds.southwest().wrapped(), zoom, tileSize_);
+ auto ne = Projection::project(bounds.northeast().wrapped(), zoom, tileSize_);
+
+ auto x1 = floor(sw.x/ tileSize_);
+ auto x2 = floor((ne.x - 1) / tileSize_);
+ auto y1 = floor(sw.y/ tileSize_);
+ auto y2 = floor((ne.y - 1) / tileSize_);
+
+ auto minX = std::fmax(std::min(x1, x2), 0);
+ auto maxX = std::max(x1, x2);
+ auto minY = (std::pow(2, zoom) - 1) - std::max(y1, y2);
+ auto maxY = (std::pow(2, zoom) - 1) - std::fmax(std::min(y1, y2), 0);
+
+ return (maxX - minX + 1) * (maxY - minY + 1);
+}
+
} // namespace util
} // namespace mbgl
diff --git a/src/mbgl/util/tile_cover.hpp b/src/mbgl/util/tile_cover.hpp
index 2d32d8bf41..405e6a48e6 100644
--- a/src/mbgl/util/tile_cover.hpp
+++ b/src/mbgl/util/tile_cover.hpp
@@ -18,5 +18,8 @@ int32_t coveringZoomLevel(double z, SourceType type, uint16_t tileSize);
std::vector<UnwrappedTileID> tileCover(const TransformState&, int32_t z);
std::vector<UnwrappedTileID> tileCover(const LatLngBounds&, int32_t z);
+// Compute only the count of tiles needed for tileCover
+unsigned long tileCount(const LatLngBounds&, uint8_t z, uint16_t tileSize);
+
} // namespace util
} // namespace mbgl
diff --git a/test/storage/offline.test.cpp b/test/storage/offline.test.cpp
index 0faaabc298..e7ebe5199f 100644
--- a/test/storage/offline.test.cpp
+++ b/test/storage/offline.test.cpp
@@ -52,3 +52,11 @@ TEST(OfflineTilePyramidRegionDefinition, TileCoverWrapped) {
EXPECT_EQ((std::vector<CanonicalTileID>{ { 0, 0, 0 } }),
region.tileCover(SourceType::Vector, 512, { 0, 22 }));
}
+
+TEST(OfflineTilePyramidRegionDefinition, TileCount) {
+ OfflineTilePyramidRegionDefinition region("", sanFranciscoWrapped, 0, 22, 1.0);
+
+ //These numbers match the count from tileCover().size().
+ EXPECT_EQ(38424u, region.tileCount(SourceType::Vector, 512, { 10, 18 }));
+ EXPECT_EQ(9675240u, region.tileCount(SourceType::Vector, 512, { 3, 22 }));
+}
diff --git a/test/util/tile_cover.test.cpp b/test/util/tile_cover.test.cpp
index c746e6dab5..933c18b5ea 100644
--- a/test/util/tile_cover.test.cpp
+++ b/test/util/tile_cover.test.cpp
@@ -84,3 +84,12 @@ TEST(TileCover, SanFranciscoZ0Wrapped) {
EXPECT_EQ((std::vector<UnwrappedTileID>{ { 0, 1, 0 } }),
util::tileCover(sanFranciscoWrapped, 0));
}
+
+TEST(TileCount, SanFranciscoZ10) {
+ EXPECT_EQ(4u, util::tileCount(sanFrancisco, 10, util::tileSize));
+}
+
+TEST(TileCount, SanFranciscoZ22) {
+ EXPECT_EQ(7254450u, util::tileCount(sanFrancisco, 22, util::tileSize));
+}
+