Files
openlayers/src/ol/geom/flat/flip.js
2018-01-26 16:33:02 +01:00

36 lines
931 B
JavaScript

/**
* @module ol/geom/flat/flip
*/
/**
* @param {Array.<number>} flatCoordinates Flat coordinates.
* @param {number} offset Offset.
* @param {number} end End.
* @param {number} stride Stride.
* @param {Array.<number>=} opt_dest Destination.
* @param {number=} opt_destOffset Destination offset.
* @return {Array.<number>} Flat coordinates.
*/
export function flipXY(flatCoordinates, offset, end, stride, opt_dest, opt_destOffset) {
let dest, destOffset;
if (opt_dest !== undefined) {
dest = opt_dest;
destOffset = opt_destOffset !== undefined ? opt_destOffset : 0;
} else {
dest = [];
destOffset = 0;
}
let j = offset;
while (j < end) {
const x = flatCoordinates[j++];
dest[destOffset++] = flatCoordinates[j++];
dest[destOffset++] = x;
for (let k = 2; k < stride; ++k) {
dest[destOffset++] = flatCoordinates[j++];
}
}
dest.length = destOffset;
return dest;
}