| /* ==================================================================== |
| Licensed to the Apache Software Foundation (ASF) under one or more |
| contributor license agreements. See the NOTICE file distributed with |
| this work for additional information regarding copyright ownership. |
| The ASF licenses this file to You 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 org.apache.poi.xdgf.geom; |
| |
| import com.graphbuilder.curve.ControlPath; |
| import com.graphbuilder.curve.GroupIterator; |
| import com.graphbuilder.curve.NURBSpline; |
| import com.graphbuilder.curve.ShapeMultiPath; |
| import com.graphbuilder.curve.ValueVector; |
| |
| |
| public class SplineRenderer { |
| |
| public static ShapeMultiPath createNurbsSpline(ControlPath controlPoints, |
| ValueVector knots, ValueVector weights, int degree) { |
| |
| double firstKnot = knots.get(0); |
| final int count = knots.size(); |
| double lastKnot = knots.get(count - 1); |
| |
| // scale knots to [0, 1] based on first/last knots |
| for (int i = 0; i < count; i++) { |
| knots.set((knots.get(i) - firstKnot) / lastKnot, i); |
| } |
| |
| // if we don't have enough knots, duplicate the last knot until we do |
| final int knotsToAdd = controlPoints.numPoints() + degree + 1; |
| for (int i = count; i < knotsToAdd; i++) { |
| knots.add(1); |
| } |
| |
| GroupIterator gi = new GroupIterator("0:n-1", controlPoints.numPoints()); |
| |
| NURBSpline spline = new NURBSpline(controlPoints, gi); |
| |
| spline.setDegree(degree); |
| spline.setKnotVectorType(NURBSpline.NON_UNIFORM); |
| spline.setKnotVector(knots); |
| |
| if (weights == null) { |
| spline.setUseWeightVector(false); |
| } else { |
| spline.setWeightVector(weights); |
| } |
| |
| // now that this is done, add it to the path |
| ShapeMultiPath shape = new ShapeMultiPath(); |
| shape.setFlatness(0.01); |
| |
| spline.appendTo(shape); |
| return shape; |
| } |
| |
| } |