拉斐尔纸缩放动画

Question

我设法做了一些 hack 来缩放 raphael paper，因为 setviewbox 不适合我，这是我编写的函数：

function setCTM(element, matrix) {
    var s = "matrix(" + matrix.a + "," + matrix.b + "," + matrix.c + "," + matrix.d + "," + matrix.e + "," + matrix.f + ")";

    element.setAttribute("transform", s);
}

Raphael.fn.zoomAndMove = function(coordx,coordy,zoom) {

    var svg = document.getElementsByTagName("svg")[0];

    var z = zoom;

    var g = document.getElementById("viewport1");
    var p = svg.createSVGPoint();

    p.x = coordx; 
    p.y = coordy;

    p = p.matrixTransform(g.getCTM().inverse());

    var k = svg.createSVGMatrix().scale(z).translate(-p.x, -p.y);
    setCTM(g, g.getCTM().multiply(k));
} 

其中 viewport1 元素定义为：

var gelem = document.createElementNS('http://www.w3.org/2000/svg', 'g');
gelem.id = 'viewport1';

paper.canvas.appendChild(gelem);
paper.canvas = gelem;

然后我可以调用： paper.zoomAndMove(minx ,miny,zoomRatio);

是否可以对函数进行改造，使其平滑缩放？

Answer 1

对于任何想要缩放和缩放的人（像我一样）平滑平移动画看看这里：

https://groups.google.com/forum/?fromgroups #!topic/raphaeljs/7eA9xq4enDo

这个片段帮助我自动缩放和平移到画布上的特定点并设置动画。 （支持威尔·摩根）

Raphael.fn.animateViewBox = function(currentViewBox, viewX, viewY, width, height, duration, callback) {

    duration = duration || 250;

    var originals = currentViewBox, //current viewBox Data from where the animation should start
        differences = {
                x: viewX - originals.x,
                y: viewY - originals.y,
                width: width - originals.width,
                height: height - originals.height
        },
        delay = 13,
        stepsNum = Math.ceil(duration / delay),
        stepped = {
                x: differences.x / stepsNum,
                y: differences.y / stepsNum,
                width: differences.width / stepsNum,
                height: differences.height / stepsNum
        }, i,
        canvas = this;

    /**
     * Using a lambda to protect a variable with its own scope.
     * Otherwise, the variable would be incremented inside the loop, but its
     * final value would be read at run time in the future.
     */
    function timerFn(iterator) {
            return function() {
                    canvas.setViewBox(
                            originals.x + (stepped.x * iterator),
                            originals.y + (stepped.y * iterator),
                            originals.width + (stepped.width * iterator),
                            originals.height + (stepped.height * iterator)
                    );
                    // Run the callback as soon as possible, in sync with the last step
                    if(iterator == stepsNum && callback) {
                            callback(viewX, viewY, width, height);
                    }
            }
    }

    // Schedule each animation step in to the future
    // Todo: use some nice easing
    for(i = 1; i <= stepsNum; ++i) {
            setTimeout(timerFn(i), i * delay);
    }

} 

Answer 2

请参阅这个 JS Fiddle 示例，了解如何利用 jQuery 和 Raphael 的 setViewBox，它可以平滑地进行缩放和平移。我们在更复杂和更大的环境中使用完全相同的功能，即使在屏幕上绘制大量项目，它也能完美运行并保持流畅。

基本上，不要尝试重新发明轮子。我知道这可能不是您正在寻找的答案，但它几乎肯定是您的最佳选择。

编辑：
我已经修复了附加的小提琴（由于 JSFiddle 对网站所做的更改而损坏），但显然不允许我在不包含一些代码的情况下保存 JSFiddle 链接，所以...

console.log("hello world!");

Answer 3

对 patrics 的回答进行了小修改，以摆脱“currentViewBox”...这适用于 Raphael 2.1.0：

Raphael.fn.animateViewBox = function(viewX, viewY, width, height, duration, callback) {

    duration = duration || 250;

    //current viewBox Data from where the animation should start
    var originals = {
            x: this._viewBox[0], 
            y: this._viewBox[1], 
            width: this._viewBox[2], 
            height: this._viewBox[3]
    }, 
    differences = {
            x: viewX - originals.x,
            y: viewY - originals.y,
            width: width - originals.width,
            height: height - originals.height
    },
    delay = 13,
    stepsNum = Math.ceil(duration / delay),
    stepped = {
            x: differences.x / stepsNum,
            y: differences.y / stepsNum,
            width: differences.width / stepsNum,
            height: differences.height / stepsNum
    }, i,
    canvas = this;

    /**
     * Using a lambda to protect a variable with its own scope.
     * Otherwise, the variable would be incremented inside the loop, but its
     * final value would be read at run time in the future.
     */
    function timerFn(iterator) {
        return function() {
                canvas.setViewBox(
                        originals.x + (stepped.x * iterator),
                        originals.y + (stepped.y * iterator),
                        originals.width + (stepped.width * iterator),
                        originals.height + (stepped.height * iterator),
                        true
                );
                // Run the callback as soon as possible, in sync with the last step
                if(iterator == stepsNum && callback) {
                        callback(viewX, viewY, width, height);
                }
        }
    }

    // Schedule each animation step in to the future
    // Todo: use some nice easing
    for(i = 1; i <= stepsNum; ++i) {
        setTimeout(timerFn(i), i * delay);
    }
} 

如果发布 mod 是不礼貌的行为，请原谅。请随意将其合并到 patrics 的版本中，但这样注释就没有意义了。

Answer 4

与上面类似，但有区别：

• 不依赖于内部结构（此后已更改）
• 不需要任何全局设置（它已为您处理）
• 使用 requestAnimationFrame，产生更流畅的动画（但 不在 IE9 或更低版本中工作）
• 使用 Raphael 的缓动函数（线性、easeIn、easeOut、easeInOut、backIn、backOut、elastic、bounce）

由于这是完全重写，因此我没有修改上面的内容。

 Raphael.fn.animateViewBox = function(viewX, viewY, width, height, duration, callback, easing) {
    var start = window.performance.now(),
      canvas = this;

    easing = Raphael.easing_formulas[ easing || 'linear' ];
    duration = duration === undefined ? 250 : duration;

    if (canvas.currentViewBox == undefined) {
        canvas.currentViewBox = {
            x: 0,
            y: 0,
            width: this._viewBox ? this._viewBox[2] : canvas.width,
            height: this._viewBox ? this._viewBox[3] : canvas.height 
        }
    }

    function step(timestamp) {
        var progress = timestamp - start;
        var progressFraction = progress/duration;

        if (progressFraction > 1) {
            progressFraction = 1;
        }

        var easedProgress = easing( progressFraction );
        var newViewBox = {
            x: canvas.currentViewBox.x + (viewX - canvas.currentViewBox.x) * easedProgress,
            y: canvas.currentViewBox.y + (viewY - canvas.currentViewBox.y) * easedProgress,
            width: canvas.currentViewBox.width + (width - canvas.currentViewBox.width) * easedProgress,
            height: canvas.currentViewBox.height + (height - canvas.currentViewBox.height) * easedProgress
        };
        canvas.setViewBox(newViewBox.x, newViewBox.y, newViewBox.width, newViewBox.height, false);

        if (progressFraction < 1) {
            window.requestAnimationFrame(step);
        } else {
            canvas.currentViewBox = newViewBox;
            if (callback) {
                callback(newViewBox.x, newViewBox.y, newViewBox.width, newViewBox.height);
            }
        }
    }
    window.requestAnimationFrame(step);
}