Get tile hash by ZXY

tile_hash.go

func getTileHash(z, x, y int) int64 {
	positions := make(map[int][2]int)

	for currentZoom := 1; currentZoom <= z; currentZoom++ {
		tileSize := int(math.Pow(2, float64(z-currentZoom)))

		centerX, centerY := tileSize-1, tileSize-1
		if currentZoom > 1 {
			n := int(math.Pow(2, float64(currentZoom-1)))
			centerX += positions[currentZoom-1][0] * n
			centerY += positions[currentZoom-1][1] * n
		}

		positionX, positionY := 0, 0
		if x > centerX {
			positionX = 1
		}
		if y > centerY {
			positionY = 1
		}

		positions[currentZoom] = [2]int{positionX, positionY}
	}

	var hash int64
	for currentZoom, p := range positions {
		hash += int64(int(math.Pow10(z-currentZoom)) * (2*p[1] + p[0] + 1))
	}

	return hash
}