enforce+update DEMTileNeighbors type

4 files changed, 77 insertions, 55 deletions

diff --git a/src/mbgl/renderer/sources/render_raster_dem_source.cpp b/src/mbgl/renderer/sources/render_raster_dem_source.cpp
index 4672952f4e..2b9ae50924 100644
--- a/src/mbgl/renderer/sources/render_raster_dem_source.cpp
+++ b/src/mbgl/renderer/sources/render_raster_dem_source.cpp
@@ -84,8 +84,8 @@ static void fillBorder(RasterDEMTile& tile, const RasterDEMTile& borderTile, con
         tileDEM->backfillBorder(*borderDEM, dx, dy);
         // update the bitmask to indicate that this tiles have been backfilled by flipping the relevant bit
         tile.neighboringTiles = tile.neighboringTiles | mask;
-        std::cout << "backfilled: " << int(tile.id.canonical.z)<< "/" << tile.id.canonical.x << "/" << tile.id.canonical.y << "\n";
-        std::cout << "with neighbor " << int(mask) << " : " << int(borderTile.id.canonical.z)<< "/" << borderTile.id.canonical.x << "/" << borderTile.id.canonical.y << "\n";
+        // mark HillshadeBucket.prepared as false so it runs through the prepare render pass
+        // with the new texture data we just backfilled
         tileBucket->prepared = false;
     }
 }
@@ -104,34 +104,41 @@ void RenderRasterDEMSource::onTileChanged(Tile& tile){
         { DEMTileNeighbors::BottomLeft, DEMTileNeighbors::TopRight }
     };
 
-    if (tile.isRenderable() && demtile.neighboringTiles != 0b11111111) {
+    if (tile.isRenderable() && demtile.neighboringTiles != DEMTileNeighbors::Complete) {
         const CanonicalTileID canonical = tile.id.canonical;
         const uint dim = std::pow(2, canonical.z);
         const uint32_t px = (canonical.x - 1 + dim) % dim;
         const int pxw = canonical.x == 0 ? tile.id.wrap - 1 : tile.id.wrap;
         const uint32_t nx = (canonical.x + 1 + dim) % dim;
         const int nxw = (canonical.x + 1 == dim) ? tile.id.wrap + 1 : tile.id.wrap;
-        const int lowerY = (canonical.y + 1) == dim ? canonical.y : canonical.y + 1;
-        const int upperY = canonical.y == 0 ? canonical.y : canonical.y - 1;
-
-        std::vector<OverscaledTileID> neighbors = {
-            // left and right neighbor
-            OverscaledTileID(tile.id.overscaledZ, pxw, canonical.z, px, canonical.y),
-            OverscaledTileID(tile.id.overscaledZ, nxw, canonical.z, nx, canonical.y),
-            // upper neighboring tiles, if they exist
-            OverscaledTileID(tile.id.overscaledZ, pxw, canonical.z, px, upperY),
-            OverscaledTileID(tile.id.overscaledZ, tile.id.wrap, canonical.z, canonical.x, upperY),
-            OverscaledTileID(tile.id.overscaledZ, nxw, canonical.z, nx, upperY),
-            // lower neighboring tiles, if they exist
-            OverscaledTileID(tile.id.overscaledZ, pxw, canonical.z, px, lowerY),
-            OverscaledTileID(tile.id.overscaledZ, tile.id.wrap, canonical.z, canonical.x, lowerY),
-            OverscaledTileID(tile.id.overscaledZ, nxw, canonical.z, nx, lowerY)
+
+        auto getNeighbor = [&] (DEMTileNeighbors mask){
+            if (mask == DEMTileNeighbors::Left){
+                return OverscaledTileID(tile.id.overscaledZ, pxw, canonical.z, px, canonical.y);
+            } else if (mask == DEMTileNeighbors::Right){
+                return OverscaledTileID(tile.id.overscaledZ, nxw, canonical.z, nx, canonical.y);
+            } else if (mask == DEMTileNeighbors::TopLeft){
+                return OverscaledTileID(tile.id.overscaledZ, pxw, canonical.z, px, canonical.y - 1);
+            } else if (mask == DEMTileNeighbors::TopCenter){
+                return OverscaledTileID(tile.id.overscaledZ, tile.id.wrap, canonical.z, canonical.x, canonical.y - 1);
+            } else if (mask == DEMTileNeighbors::TopRight){
+                return OverscaledTileID(tile.id.overscaledZ, nxw, canonical.z, nx, canonical.y - 1);
+            } else if (mask == DEMTileNeighbors::BottomLeft){
+                return OverscaledTileID(tile.id.overscaledZ, pxw, canonical.z, px, canonical.y + 1);
+            } else if (mask == DEMTileNeighbors::BottomCenter){
+                return OverscaledTileID(tile.id.overscaledZ, tile.id.wrap, canonical.z, canonical.x, canonical.y + 1);
+            } else if (mask == DEMTileNeighbors::BottomRight){
+                return OverscaledTileID(tile.id.overscaledZ, nxw, canonical.z, nx, canonical.y + 1);
+            } else{
+                throw std::runtime_error("mask is not a valid tile neighbor");
+            }
         };
 
-        for (uint8_t i = 0; i < neighbors.size(); i++) {
+        for (uint8_t i = 0; i < 8; i++) {
             DEMTileNeighbors mask = DEMTileNeighbors(std::pow(2,i));
+            // only backfill if this neighbor has not been previously backfilled
             if ((demtile.neighboringTiles & mask) != mask) {
-                OverscaledTileID neighborid = neighbors[i];
+                OverscaledTileID neighborid = getNeighbor(mask);
                 Tile* renderableNeighbor = tilePyramid.getTile(neighborid);
                 if (renderableNeighbor != nullptr && renderableNeighbor->isRenderable()) {
                     RasterDEMTile& borderTile = static_cast<RasterDEMTile&>(*renderableNeighbor);
diff --git a/src/mbgl/renderer/sources/render_raster_dem_source.hpp b/src/mbgl/renderer/sources/render_raster_dem_source.hpp
index b524a83359..b32d3705cb 100644
--- a/src/mbgl/renderer/sources/render_raster_dem_source.hpp
+++ b/src/mbgl/renderer/sources/render_raster_dem_source.hpp
@@ -6,38 +6,6 @@
 
 namespace mbgl {
 
-enum class DEMTileNeighbors {
-  // 0b00000001
-  Left = 1 << 0,
-  // 0b00000010
-  Right = 1 << 1,
-  // 0b00000100
-  TopLeft = 1 << 2,
-  // 0b00001000
-  TopCenter = 1 << 3,
-  // 0b00010000
-  TopRight = 1 << 4,
-  // 0b00100000
-  BottomLeft = 1 << 5,
-  // 0b01000000
-  BottomCenter = 1 << 6,
-  // 0b10000000
-  BottomRight = 1 << 7
-};
-
-inline unsigned char operator|(unsigned char a, DEMTileNeighbors b) {
-    return static_cast<unsigned char>(a | int(b));
-};
-
-inline unsigned char operator&(unsigned char a, DEMTileNeighbors b) {
-    return static_cast<unsigned char>(a & int(b));
-}
-
-inline bool operator!=(unsigned char a, DEMTileNeighbors b) {
-    return a != static_cast<unsigned char>(b);
-}
-
-
 class RenderRasterDEMSource : public RenderSource {
 public:
     RenderRasterDEMSource(Immutable<style::RasterDEMSource::Impl>);
diff --git a/src/mbgl/tile/raster_dem_tile.cpp b/src/mbgl/tile/raster_dem_tile.cpp
index e435589941..a05f2a758c 100644
--- a/src/mbgl/tile/raster_dem_tile.cpp
+++ b/src/mbgl/tile/raster_dem_tile.cpp
@@ -23,12 +23,12 @@ RasterDEMTile::RasterDEMTile(const OverscaledTileID& id_,
 
     if ( id.canonical.y == 0 ){
         // this tile doesn't have upper neighboring tiles so marked those as backfilled
-        neighboringTiles = neighboringTiles | 0b00011100;
+        neighboringTiles = neighboringTiles | DEMTileNeighbors::NoUpper;
     }
 
     if (id.canonical.y + 1 == std::pow(2, id.canonical.z)){
         // this tile doesn't have lower neighboring tiles so marked those as backfilled
-        neighboringTiles = neighboringTiles | 0b11100000;
+        neighboringTiles = neighboringTiles | DEMTileNeighbors::NoLower;
     }
 }
 
diff --git a/src/mbgl/tile/raster_dem_tile.hpp b/src/mbgl/tile/raster_dem_tile.hpp
index 50dbcbac27..571c1ca7e9 100644
--- a/src/mbgl/tile/raster_dem_tile.hpp
+++ b/src/mbgl/tile/raster_dem_tile.hpp
@@ -11,6 +11,53 @@ class Tileset;
 class TileParameters;
 class HillshadeBucket;
 
+enum class DEMTileNeighbors : unsigned char {
+  // 0b00000000
+  Empty = 0 << 1,
+
+  // the order of the neighbors in this enum (or rather the order of their flipped bits
+  // must stay the same as
+
+  // 0b00000001
+  Left = 1 << 0,
+  // 0b00000010
+  Right = 1 << 1,
+  // 0b00000100
+  TopLeft = 1 << 2,
+  // 0b00001000
+  TopCenter = 1 << 3,
+  // 0b00010000
+  TopRight = 1 << 4,
+  // 0b00100000
+  BottomLeft = 1 << 5,
+  // 0b01000000
+  BottomCenter = 1 << 6,
+  // 0b10000000
+  BottomRight = 1 << 7,
+
+  // helper enums for tiles with no upper/lower neighbors
+  // and completely backfilled tiles
+
+  // 0b00011100
+  NoUpper = 0b00011100,
+  // 0b11100000
+  NoLower = 0b11100000,
+  // 0b11111111
+  Complete = 0b11111111
+};
+
+inline DEMTileNeighbors operator|(DEMTileNeighbors a, DEMTileNeighbors b) {
+    return static_cast<DEMTileNeighbors>(int(a) | int(b));
+};
+
+inline DEMTileNeighbors operator&(DEMTileNeighbors a, DEMTileNeighbors b) {
+    return static_cast<DEMTileNeighbors>(int(a) & int(b));
+}
+
+inline bool operator!=(DEMTileNeighbors a, DEMTileNeighbors b) {
+    return static_cast<unsigned char>(a) != static_cast<unsigned char>(b);
+}
+
 namespace style {
 class Layer;
 } // namespace style
@@ -34,7 +81,7 @@ public:
     
     // neighboringTiles is a bitmask for which neighboring tiles have been backfilled
     // there are max 8 possible neighboring tiles, so each bit represents one neighbor
-    unsigned char neighboringTiles = 0b00000000;
+    DEMTileNeighbors neighboringTiles = DEMTileNeighbors::Empty;
     
     void setMask(TileMask&&) override;