gecko/mobile/android/base/gfx/PointUtils.java
2012-07-17 17:54:54 -07:00

62 lines
2.2 KiB
Java

/* -*- Mode: Java; c-basic-offset: 4; tab-width: 20; indent-tabs-mode: nil; -*-
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
package org.mozilla.gecko.gfx;
import android.graphics.Point;
import android.graphics.PointF;
import org.json.JSONObject;
import org.json.JSONException;
import org.mozilla.gecko.FloatUtils;
public final class PointUtils {
public static PointF add(PointF one, PointF two) {
return new PointF(one.x + two.x, one.y + two.y);
}
public static PointF subtract(PointF one, PointF two) {
return new PointF(one.x - two.x, one.y - two.y);
}
public static PointF scale(PointF point, float factor) {
return new PointF(point.x * factor, point.y * factor);
}
public static Point round(PointF point) {
return new Point(Math.round(point.x), Math.round(point.y));
}
/* Returns a new point that is a linear interpolation between start and end points. weight conrols the weighting
* of each of the original points (weight = 1 returns endPoint, weight = 0 returns startPoint)
*/
public static PointF interpolate(PointF startPoint, PointF endPoint, float weight) {
float x = FloatUtils.interpolate(startPoint.x, endPoint.x, weight);
float y = FloatUtils.interpolate(startPoint.y, endPoint.y, weight);
return new PointF(x, y);
}
/* Computes the magnitude of the given vector. */
public static float distance(PointF point) {
return (float)Math.sqrt(point.x * point.x + point.y * point.y);
}
/** Computes the scalar distance between two points. */
public static float distance(PointF one, PointF two) {
return PointF.length(one.x - two.x, one.y - two.y);
}
public static JSONObject toJSON(PointF point) throws JSONException {
// Ensure we put ints, not longs, because Gecko message handlers call getInt().
int x = Math.round(point.x);
int y = Math.round(point.y);
JSONObject json = new JSONObject();
json.put("x", x);
json.put("y", y);
return json;
}
}