Doodle3D-Slicer/three.js-master/examples/js/geometries/hilbert2D.js

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2015-06-12 15:58:26 +02:00
/**
* Hilbert Curve: Generates 2D-Coordinates in a very fast way.
*
* @author Dylan Grafmyre
*
* Based on work by:
* @author Thomas Diewald
* @link http://www.openprocessing.org/sketch/15493
*
* @param center Center of Hilbert curve.
* @param size Total width of Hilbert curve.
* @param iterations Number of subdivisions.
* @param v0 Corner index -X, -Z.
* @param v1 Corner index -X, +Z.
* @param v2 Corner index +X, +Z.
* @param v3 Corner index +X, -Z.
*/
function hilbert2D (center, size, iterations, v0, v1, v2, v3) {
// Default Vars
var center = undefined !== center ? center : new THREE.Vector3(0, 0, 0),
size = undefined !== size ? size : 10,
half = size / 2,
iterations = undefined !== iterations ? iterations : 1,
v0 = undefined !== v0 ? v0 : 0,
v1 = undefined !== v1 ? v1 : 1,
v2 = undefined !== v2 ? v2 : 2,
v3 = undefined !== v3 ? v3 : 3
;
var vec_s = [
new THREE.Vector3( center.x - half, center.y, center.z - half ),
new THREE.Vector3( center.x - half, center.y, center.z + half ),
new THREE.Vector3( center.x + half, center.y, center.z + half ),
new THREE.Vector3( center.x + half, center.y, center.z - half )
];
var vec = [
vec_s[ v0 ],
vec_s[ v1 ],
vec_s[ v2 ],
vec_s[ v3 ]
];
// Recurse iterations
if (0 <= -- iterations) {
var tmp = [];
Array.prototype.push.apply( tmp, hilbert2D ( vec[ 0 ], half, iterations, v0, v3, v2, v1 ) );
Array.prototype.push.apply( tmp, hilbert2D ( vec[ 1 ], half, iterations, v0, v1, v2, v3 ) );
Array.prototype.push.apply( tmp, hilbert2D ( vec[ 2 ], half, iterations, v0, v1, v2, v3 ) );
Array.prototype.push.apply( tmp, hilbert2D ( vec[ 3 ], half, iterations, v2, v1, v0, v3 ) );
// Return recursive call
return tmp;
}
// Return complete Hilbert Curve.
return vec;
}