commonMain.earth.worldwind.geom.TileMatrix.kt Maven / Gradle / Ivy

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The WorldWind Kotlin SDK (WWK) includes the library, examples and tutorials for building multiplatform 3D virtual globe applications for Android, Web and Java.

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package earth.worldwind.geom

import earth.worldwind.geom.Sector.Companion.fromDegrees

open class TileMatrix internal constructor(
    val sector: Sector, val ordinal: Int, val matrixWidth: Int, val matrixHeight: Int, val tileWidth: Int, val tileHeight: Int
) {
    val resolution get() = sector.deltaLatitude.div(matrixHeight * tileHeight)

    fun tileKey(row: Int, column: Int): Long {
        val lOrd = (ordinal and 0xFF).toLong() // 8 bits
        val lRow = (row and 0xFFFFFFF).toLong() // 28 bits
        val lCol = (column and 0xFFFFFFF).toLong() // 28 bits
        return lOrd.shl(56) or lRow.shl(28) or lCol
    }

    fun tileSector(row: Int, column: Int): Sector {
        val deltaLat = sector.deltaLatitude.inDegrees / matrixHeight
        val deltaLon = sector.deltaLongitude.inDegrees / matrixWidth
        val minLat = sector.maxLatitude.inDegrees - deltaLat * (row + 1)
        val minLon = sector.minLongitude.inDegrees + deltaLon * column
        return fromDegrees(minLat, minLon, deltaLat, deltaLon)
    }

    /**
     * Calculates number of tiles, which fit specified sector
     *
     * @param sector the desired sector to check tile count
     * @return Number of tiles which fit specified sector at this level
     */
    fun tilesInSector(sector: Sector) = with(this.sector) {
        val deltaLat = deltaLatitude / matrixHeight
        val deltaLon = deltaLongitude / matrixWidth
        val firstRow = computeRow(deltaLat, sector.minLatitude)
        val lastRow = computeLastRow(deltaLat, sector.maxLatitude)
        val firstCol = computeColumn(deltaLon, sector.minLongitude)
        val lastCol = computeLastColumn(deltaLon, sector.maxLongitude)
        (lastRow - firstRow + 1).toLong() * (lastCol - firstCol + 1).toLong()
    }
}