gwt.g2d.client.graphics.visitor.QuadraticCurveVisitor.java Source code

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Here is the source code for gwt.g2d.client.graphics.visitor.QuadraticCurveVisitor.java

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/*
 * Copyright 2009 Hao Nguyen
 * 
 * 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 gwt.g2d.client.graphics.visitor;

import com.google.gwt.canvas.dom.client.Context2d;

import gwt.g2d.client.graphics.Surface;
import gwt.g2d.shared.math.Vector2;

/**
 * Adds the given end point to the current path, connected to the start point 
 * by a quadratic Bezier curve with the given control point.
 * The new position will be set to the given end point.
 * 
 * @author hao1300@gmail.com
 */
public class QuadraticCurveVisitor implements ShapeVisitor {
    private final double startPointX, startPointY, controlPointX, controlPointY, endPointX, endPointY;

    /**
     * Adds a curve that connects the start point (startPointX, startPointY) in 
     * the subpath to the given point (endPointX, endPointY), using the control 
     * point (controlPointX, controlPointY).
     */
    public QuadraticCurveVisitor(double startPointX, double startPointY, double controlPointX, double controlPointY,
            double endPointX, double endPointY) {
        this.startPointX = startPointX;
        this.startPointY = startPointY;
        this.controlPointX = controlPointX;
        this.controlPointY = controlPointY;
        this.endPointX = endPointX;
        this.endPointY = endPointY;
    }

    /**
     * Adds a curve that connects the startPoint to the endPoint, using the 
     * control point controlPoint.
     */
    public QuadraticCurveVisitor(Vector2 startPoint, Vector2 controlPoint, Vector2 endPoint) {
        this(startPoint.getX(), startPoint.getY(), controlPoint.getX(), controlPoint.getY(), endPoint.getX(),
                endPoint.getY());
    }

    @Override
    public void visit(Surface surface) {
        Context2d context = surface.getContext();
        context.moveTo(startPointX, startPointY);
        context.quadraticCurveTo(controlPointX, controlPointY, endPointX, endPointY);
    }
}