Question

我有一个循环扇区，我希望逐渐将该扇区动画为一个完整的圆圈，我怎样才能用Rapheal.js制作它。

BTW，我是SVG的新手，我使用svg-editor使用SVG绘制形状。

这是我的代码

  var arcPath1 = paper.path("m325.30255,127.93972c33.86002,6.238 52.02301,8.85 90.823,49.616l105.53491,-65.494c-44.84491,-59.9466 -101.70261,-109.25547 -201.98761,-108.83956l5.6297,124.71756z");

arcPath1.attr({
    "fill": "#003a60",
    stroke: 'none'
});

arcPath1.rotate(1.0569896697998047 ,420.6666870117177,90.38764953613116);
arcPath1.node.id= "arch1";

这是我的代码http://jsfiddle.net/v2KeV/

的示例

如何让动画完成完整圈子的路径？

注意：动画我只是测试路径动画..

Answer 1

嗯，首先要做的事情是：为了优雅地为弧段设置动画，我们需要能够以编程方式生成它们。考虑一下这种笨拙的三角学：

// arcPath:
// cx, cy are the center point
// inner_radius and outer_radius describe the distance of the arc segment's inner and outer boundaries from the center point.
// starting_radians describes the offset of the segment start;
// arc_radians describes the width of the arg segment.

function arcPath( cx, cy, inner_radius, outer_radius, starting_radians, arc_radians )
{
    var x1 = cx + Math.cos( starting_radians ) * inner_radius;
    var y1 = cy + Math.sin( starting_radians ) * inner_radius;
    var x2 = cx + Math.cos( starting_radians ) * outer_radius;
    var y2 = cy + Math.sin( starting_radians ) * outer_radius;
    var x3 = cx + Math.cos( starting_radians + arc_radians ) * outer_radius;
    var y3 = cy + Math.sin( starting_radians + arc_radians ) * outer_radius;
    var x4 = cx + Math.cos( starting_radians + arc_radians ) * inner_radius;
    var y4 = cy + Math.sin( starting_radians + arc_radians ) * inner_radius;

    var pathstr = "M" + x1 + "," + y1 + " "
                    + "L" + x2 + "," + y2 + " "
                    + "A" + outer_radius + "," + outer_radius + " " + arc_radians + " " + ( arc_radians > Math.PI ? "1" : "0" ) + " 1 " + x3 + "," + y3 + " "
                    + "L" + x4 + "," + y4 + " "
                    + "A" + inner_radius + "," + inner_radius + " " + ( 0 - arc_radians ) + " " + ( arc_radians > Math.PI ? "1" : "0" ) + " 0 " + x1 + "," + y1 + " z";

     return pathstr;                   
}

使用更简单的几何构造，您可以简单地为从部分弧段到整个弧段的路径设置动画，并让Raphael进行提升，如下所示：

var arcPath1 = paper.path(arcPath( 150, 150, 75, 125, Math.PI / 2, Math.PI * 0.65 ) )
    .attr({ fill: "#003a60", 'fill-opacity': 0.5, stroke: 'black' });

arcPath1.click(function () 
    {
        arcPath1.animate( { path: arcPath( 150, 150, 75, 125, Math.PI / 2, Math.PI * 2 - 0.0001 ) }, 2000, "<>" );
    });

不幸的是，拉斐尔在这方面做得非常糟糕，所以你会得到一个相交弧段的爆炸，将自己重塑成一个完整的圆圈而不是所需的弧扫。所以为了让它做你想做的事，我们必须手动执行动画。

function arcSweep( arc, x, y, inner, outer, angle_offset, from_sweep, to_sweep, duration )
{
    var steps = 100;
    var current_step = 0;
    var intervalID = setInterval( function()
                 {
                     current_step++;
                     if ( current_step >= steps )
                         clearInterval( intervalID );
                     arc.attr( { path: arcPath( x, y, inner, outer, angle_offset, from_sweep + ( ( to_sweep - from_sweep ) * ( current_step / steps ) ) ) } );
                 }, duration / steps );
}

所以基本上我们只计算一系列中间弧并按顺序进行，直到我们达到目标角度。除了目标结束角度（不能是Math.PI * 2 - 因为它计算为空弧段！）时，动画功能需要弧的所有原始参数。可能需要将其抽象为一个类，以便弧段的每个实例都可以跟踪它自己的变量。

这是展示成品的fiddle。

如何使用Rapheal.js库逐渐将路径设置为圆形动画

1 个答案: