/*
* Copyright (C) 2011-2015, Peter Abeles. All Rights Reserved.
*
* This file is part of Geometric Regression Library (GeoRegression).
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package georegression.transform.se;
import georegression.metric.UtilAngle;
import georegression.struct.se.Se2_F32;
/**
* Performs linear interpolation between two rigid body transforms
*
* @author Peter Abeles
*/
public class InterpolateLinearSe2_F32 {
/**
* Perform linear interpolation
*
* @param a The first transform
* @param b The second transform
* @param where from 0 to 1, inclusive. 0 means it will be more similar to 'a'.
* @param output The interpolated transform
*/
public static void interpolate(Se2_F32 a , Se2_F32 b , float where, Se2_F32 output) {
float w0 = 1.0f-where;
output.T.x = a.T.x*w0 + b.T.x*where;
output.T.y = a.T.y*w0 + b.T.y*where;
// interpolating rotation is more difficult
// This only works well if the difference between the two angles is small
float yaw0 = a.getYaw();
float yaw1 = b.getYaw();
float cw = UtilAngle.distanceCW(yaw0, yaw1);
float ccw = UtilAngle.distanceCCW(yaw0,yaw1);
float yaw;
if( cw > ccw ) {
yaw = yaw0+ccw*where;
} else {
yaw = yaw0-cw*where;
}
output.setYaw(yaw);
}
}