Clip coordinates in interleaved spatial queries to world boundaries.

common/coords.go

@@ -59,6 +59,23 @@ func maxComponent(a, b int16) int16 {
 	return b
 }
 
+func clipComponent(x int16) int16 {
+	if x < minValue {
+		return minValue
+	}
+	if x > maxValue {
+		return maxValue
+	}
+	return x
+}
+
+func ClipCoord(c Coord) Coord {
+	return Coord{
+		X: clipComponent(c.X),
+		Y: clipComponent(c.Y),
+		Z: clipComponent(c.Z)}
+}
+
 func MinCoord(a, b Coord) Coord {
 	return Coord{
 		X: minComponent(a.X, b.X),

leveldb.go

@@ -309,8 +309,8 @@ func (ldbs *LevelDBSession) interleavedSpatialQuery(first, second []byte, done c
 	if secondKey, err = common.DecodeStringFromBytes(second); err != nil {
 		return
 	}
-	c1 := common.PlainToCoord(firstKey)
-	c2 := common.PlainToCoord(secondKey)
+	c1 := common.ClipCoord(common.PlainToCoord(firstKey))
+	c2 := common.ClipCoord(common.PlainToCoord(secondKey))
 	c1, c2 = common.MinCoord(c1, c2), common.MaxCoord(c1, c2)
 
 	blocks = make(chan Block)
@@ -336,6 +336,7 @@ func (ldbs *LevelDBSession) interleavedSpatialQuery(first, second []byte, done c
 			encodedKey []byte
 		)
 
+		//log.Printf("seeking to: %d", zmin)
 		it.Seek(common.ToBigEndian(zmin))
 		for it.Valid() {
 			zcode := common.FromBigEndian(it.Key())
@@ -356,9 +357,13 @@ func (ldbs *LevelDBSession) interleavedSpatialQuery(first, second []byte, done c
 				}
 				it.Next()
 			} else {
-				it.Seek(common.ToBigEndian(common.BigMin(zmin, zmax, zcode)))
+				next := common.BigMin(zmin, zmax, zcode)
+				//log.Printf("seeking to: %d", next)
+				it.Seek(common.ToBigEndian(next))
+				//log.Printf("seeking done: %d", next)
 			}
 		}
+		//log.Println("iterating done")
 		if err = it.GetError(); err != nil {
 			log.Printf("error while iterating: %s", err)
 			return

sqlite.go

@@ -303,8 +303,8 @@ func (ss *SqliteSession) interleavedSpatialQuery(first, second []byte, done chan
 	if secondKey, err = common.DecodeStringFromBytes(second); err != nil {
 		return
 	}
-	c1 := common.PlainToCoord(firstKey)
-	c2 := common.PlainToCoord(secondKey)
+	c1 := common.ClipCoord(common.PlainToCoord(firstKey))
+	c2 := common.ClipCoord(common.PlainToCoord(secondKey))
 	c1, c2 = common.MinCoord(c1, c2), common.MaxCoord(c1, c2)
 
 	blocks = make(chan Block)