Flex:在形状之间绘制连接线

qyyhg6bp  于 2022-09-21  发布在  Apache
关注(0)|答案(3)|浏览(185)

我正在使用Adobe Flex3构建一个图表工具。我即将实现连接线,我有一个问题。

想象一下我在画布上的任意位置有两个正方形。我需要在它们之间绘制一条带箭头的连接线。我需要它靠近目标正方形的中心,但在它的边界结束。

我怎样才能找出划线的准确位置呢?

谢谢

sycxhyv7

sycxhyv71#

下面是一个做你想做的事情的例子。

package
{
    import flash.display.Shape;
    import flash.display.Sprite;
    import flash.events.Event;
    import flash.geom.Matrix;
    import flash.geom.Point;
    import flash.ui.Mouse;

    /**
     * Sample class to draw squares and arrows between them.
     */
    public class SquareArrows extends Sprite
    {
        /**
         * Initialize the scene as soon as we can.
         */
        public function SquareArrows()
        {
            if(stage) {
                init();
            }
            else {
                addEventListener(Event.ADDED_TO_STAGE, init);
            }
        }

        /**
         * Draw two squares and an arrow between them.
         */
        private function init(e : Event = null) : void
        {
            if(hasEventListener(Event.ADDED_TO_STAGE)) {
                removeEventListener(Event.ADDED_TO_STAGE, init);
            }

            // Drawing random-sized squares.
            var squareOne : Shape =
                    getSquareShape((Math.random() * 50) + 20, 0xBBBBBB);
            var squareTwo : Shape =
                    getSquareShape((Math.random() * 50) + 20, 0xDDDDDD);
            addChild(squareOne);
            addChild(squareTwo);

            // Draw the connector.
            var connector : Shape = getConnectorShape(squareOne, squareTwo);
            addChild(connector);
        }

        /**
         * Draw a connector arrow between two square shapes.
         */
        private function getConnectorShape(connectFrom : Shape, connectTo : Shape) : Shape
        {
            // Getting the center of the first square.
            var centerFrom : Point = new Point();
            centerFrom.x = connectFrom.x + (connectFrom.width / 2);
            centerFrom.y = connectFrom.y + (connectFrom.height / 2);

            // Getting the center of the second square.
            var centerTo : Point = new Point();
            centerTo.x = connectTo.x + (connectTo.width / 2);
            centerTo.y = connectTo.y + (connectTo.height / 2);

            // Getting the angle between those two.
            var angleTo : Number =
                Math.atan2(centerTo.x - centerFrom.x, centerTo.y - centerFrom.y);
            var angleFrom : Number =
                Math.atan2(centerFrom.x - centerTo.x, centerFrom.y - centerTo.y);

            // Getting the points on both borders.
            var pointFrom : Point = getSquareBorderPointAtAngle(connectFrom, angleTo);
            var pointTo : Point = getSquareBorderPointAtAngle(connectTo, angleFrom);

            // Calculating arrow edges.
            var arrowSlope : Number = 30;
            var arrowHeadLength : Number = 10;
            var vector : Point =
                new Point(-(pointTo.x - pointFrom.x), -(pointTo.y - pointFrom.y));

            // First edge of the head...
            var edgeOneMatrix : Matrix = new Matrix();
            edgeOneMatrix.rotate(arrowSlope * Math.PI / 180);
            var edgeOneVector : Point = edgeOneMatrix.transformPoint(vector);
            edgeOneVector.normalize(arrowHeadLength);
            var edgeOne : Point = new Point();
            edgeOne.x = pointTo.x + edgeOneVector.x;
            edgeOne.y = pointTo.y + edgeOneVector.y;

            // And second edge of the head.
            var edgeTwoMatrix : Matrix = new Matrix();
            edgeTwoMatrix.rotate((0 - arrowSlope) * Math.PI / 180);
            var edgeTwoVector : Point = edgeTwoMatrix.transformPoint(vector);
            edgeTwoVector.normalize(arrowHeadLength);
            var edgeTwo : Point = new Point();
            edgeTwo.x = pointTo.x + edgeTwoVector.x;
            edgeTwo.y = pointTo.y + edgeTwoVector.y;

            // Drawing the arrow.
            var arrow : Shape = new Shape();
            with(arrow.graphics) {
                lineStyle(2);
                // Drawing the line.
                moveTo(pointFrom.x, pointFrom.y);
                lineTo(pointTo.x, pointTo.y);

                // Drawing the arrow head.
                lineTo(edgeOne.x, edgeOne.y);
                moveTo(pointTo.x, pointTo.y);
                lineTo(edgeTwo.x, edgeTwo.y);
            }
            return arrow;
        }

        /**
         * Utility method to get a point on a square border at a certain angle.
         */
        private function getSquareBorderPointAtAngle(square : Shape, angle : Number) : Point
        {
            // Calculating rays of inner and outer circles.
            var minRay : Number = Math.SQRT2 * square.width / 2;
            var maxRay : Number = square.width / 2;

            // Calculating the weight of each rays depending on the angle.
            var rayAtAngle : Number = ((maxRay - minRay) * Math.abs(Math.cos(angle * 2))) + minRay;

            // We have our point.
            var point : Point = new Point();
            point.x = rayAtAngle * Math.sin(angle) + square.x + (square.width / 2);
            point.y = rayAtAngle * Math.cos(angle) + square.y + (square.height / 2);
            return point;
        }

        /**
         * Utility method to draw a square of a given size in a new shape.
         */
        private function getSquareShape(edgeSize : Number, fillColor : Number) : Shape
        {
            // Draw the square.
            var square : Shape = new Shape();
            with(square.graphics) {
                lineStyle(1);
                beginFill(fillColor);
                drawRect(0, 0, edgeSize, edgeSize);
                endFill();
            }

            // Set a random position.
            square.x = Math.random() * (stage.stageWidth - square.width);
            square.y = Math.random() * (stage.stageHeight - square.height);

            return square;
        }
    }
}

这段代码并没有完全优化。这个想法更多的是为了解释它是如何工作的。基本上,我们定义了两个(随机的)正方形,并在它们之间画了一条线。为了跟踪这条线,我们计算从第一个正方形的中心到第二个正方形的中心的Angular ,并使用一种特殊的方法(getSquareBorderPointAtAngle)在正方形边界上提取一个正确方向的点。

此方法是此代码段的第一个关键点。我们使用简单的圆几何进行计算,并对如何使点与边界匹配而不是与正方形周围或内部的圆匹配进行了一些复杂的处理。

然后,我们画一个箭头。为此,我们使用了Flash Matrix类,因为这种方法比从头开始计算要容易得多。

现在我们做完了。

vjrehmav

vjrehmav2#

一个月前,我在这里读了答案,因为我需要同样的东西。在此期间找到了这个连接器绘图示例,并认为我应该分享该链接。

该示例在uicComponents之间绘制连接线,并在拖曳连接线时更新这些线。好样的!

(来源:sammyjoeosborne.com)

http://sammyjoeosborne.com/Examples/Connector/ConnectorExample.html

wbrvyc0a

wbrvyc0a3#

最简单的方法可能是使用flash.geom.Point。取两个中心c1c2。以向量d为例,这就是它们的区别。根据其Angular (315到45、45到135、135到225、225到315),您将知道涉及哪些边(分别为:右和左、上和下、左和右、下和上)。

然后计算每条边和连接中心的线之间的交点。

连接中心的直线可以表示为p=t*v+c1(以向量表示)。将边表示为一条线,然后计算t,使两个方程产生相同的点p,这就是您要寻找的交点。

相关问题