d3.js将缩放行为更改为语义缩放

Question

我正在用d3.js做一些关于缩放的测试.目前,我已经在我的测试中成功实现了几何缩放,但它有一个缺点:缩放下的元素g正在缩放.据我了解,这可以通过使用语义缩放来解决.

问题是我需要scale在我的测试中,因为我正在将它与jQuery.UI滑块同步value.

另一方面,我希望text调整元素大小以在缩放操作后保持其大小.

我有我目前尝试的例子在这里.

我无法更改代码以适应此目的.任何人都可以分享一些见解/想法吗？

Answer 1

对于您的解决方案,我合并了两个示例:

• 语义缩放
• 程序化缩放

代码片段:

function zoom() {
  text.attr("transform", transform);
  var scale = zoombehavior.scale();
  //to make the scale rounded to 2 decimal digits
  scale = Math.round(scale * 100) / 100;
  //setting the slider to the new value
  $("#slider").slider( "option", "value", scale );
  //setting the slider text to the new value
  $("#scale").val(scale);
}
//note here we are not handling the scale as its Semantic Zoom
function transform(d) {
  //translate string
  return "translate(" + x(d[0]) + "," + y(d[1]) + ")";
}

function interpolateZoom(translate, scale) {
  zoombehavior
        .scale(scale)//we are setting this zoom only for detecting the scale for slider..we are not zoooming using scale.
        .translate(translate);
      zoom();
}
var slider = $(function() {
  $("#slider").slider({
    value: zoombehavior.scaleExtent()[0],//setting the value
    min: zoombehavior.scaleExtent()[0],//setting the min value
    max: zoombehavior.scaleExtent()[1],//settinng the ax value
    step: 0.01,
    slide: function(event, ui) {
      var newValue = ui.value;
      var  center = [centerX, centerY],
        extent = zoombehavior.scaleExtent(),
        translate = zoombehavior.translate(),
        l = [],
        view = {
          x: translate[0],
          y: translate[1],
          k: zoombehavior.scale()
        };
      //translate w.r.t the center
      translate0 = [(center[0] - view.x) / view.k, (center[1] - view.y) / view.k];
      view.k = newValue;//the scale as per the slider
      //the translate after the scale(so we are multiplying the translate)
      l = [translate0[0] * view.k + view.x, translate0[1] * view.k + view.y];

      view.x += center[0] - l[0];
      view.y += center[1] - l[1];

      interpolateZoom([view.x, view.y], view.k);

    }
  });
});

我正在缩放250,250,这是剪辑圈的中心.

这里的工作代码(添加了必要的评论)

希望这可以帮助!