html - 在 SVG 的 textPath 元素内翻转文本

Question

我在这里遇到了一个大问题。我需要翻转 180 度的 svg 元素的 textPath 标记中有一些文本。我已经使用了所有适用于 css 的方法，但绝对没有用。谁能帮我翻转元素内的文本。

function Init() {
  let w = wrap.clientWidth;
  let h = wrap.clientHeight;
  ellipse.setAttributeNS(null, "viewBox", `0 0 ${w}  ${h}`);
  let d = `M${w / 10},${h / 2}A${4 * w / 10},${4 * h / 10} 0 0 0 ${9 *
    w /
    10} ${5 * h / 10} A${4 * w / 10},${4 * h / 10} 0 0 0 ${w / 10} ${5 *
    h /
    10} A${4 * w / 10},${4 * h / 10} 0 0 0 ${9 * w / 10} ${5 * h / 10} A${4 *
    w /
    10},${4 * h / 10} 0 0 0 ${w / 10} ${5 * h / 10}`;

  thePath.setAttributeNS(null, "d", d);
  let path_length =  thePath.getTotalLength();
  
  
  //begin at a bigger size than needed
  let font_size = 100;
  ellipse.style.fontSize = font_size+"px"; 
  
  // while the text length is bigger than half path length 
  while(tp.getComputedTextLength() > path_length / 2 ){
    //reduce the font size
    font_size -=.25;
    //reset the font size 
    ellipse.style.fontSize = font_size+"px";
  }
}



window.setTimeout(function() {
  Init();
  window.addEventListener("resize", Init, false);
}, 15);

let so = 0;

function Marquee() {
  requestAnimationFrame(Marquee);
  tp.setAttributeNS(null, "startOffset", so + "%");
  if (so >= 50) {
    so = 0;
  }
  so += 0.02;
}

Marquee();

html, body {
    margin: 0;
    height: 100%;
    width: 100%;
}

body {
    font-family: "Arimo", sans-serif;
}

#wrap{
    width:100%;
    height:100%;
    position: fixed;
    top: 0;
    left: 0;  
}
text {
    text-transform: uppercase;
    font-weight: lighter;
}

<div id="wrap">
    <svg id="ellipse" version="1.1" viewBox="0 0 1000 1000">
    <path id="thePath" fill="transparent" d="M100,500A400,400 0 0 0 900 500 A400,400 0 0 0 100 500"  />

       <text stroke="black">
          <textPath xlink:href="#thePath" dy="5" id="tp" lengthAdjust="spacingAndGlyphs">Coming Soon • Coming Soon • Coming Soon • Coming Soon • Coming Soon • Coming Soon • Coming Soon •</textPath>
        </text>
    </svg>
</div>

Answer 1

正如我所评论的，您需要改变路径。由于路径由脚本控制，因此您需要更改函数 Init 中 d 变量的值

function Init() {
  let w = wrap.clientWidth;
  let h = wrap.clientHeight;
  ellipse.setAttributeNS(null, "viewBox", `0 0 ${w}  ${h}`);
  let d = `M${9*w / 10},${h / 2}
  A${4 * w / 10},${4 * h / 10} 0 0 1 ${w / 10} ${5 * h / 10}
  A${4 * w / 10},${4 * h / 10} 0 0 1 ${9 * w / 10} ${5 * h / 10} 
  A${4 * w / 10},${4 * h / 10} 0 0 1 ${w / 10} ${5 * h / 10} 
  A${4 * w / 10},${4 * h / 10} 0 0 1 ${9 * w / 10} ${5 * h / 10} `;

  thePath.setAttributeNS(null, "d", d);
  let path_length =  thePath.getTotalLength();
  
  
  //begin at a bigger size than needed
  let font_size = 100;
  ellipse.style.fontSize = font_size+"px"; 
  
  // while the text length is bigger than half path length 
  while(tp.getComputedTextLength() > path_length / 2 ){
    //reduce the font size
    font_size -=.25;
    //reset the font size 
    ellipse.style.fontSize = font_size+"px";
  }
}



window.setTimeout(function() {
  Init();
  window.addEventListener("resize", Init, false);
}, 15);

let so = 0;

function Marquee() {
  requestAnimationFrame(Marquee);
  tp.setAttributeNS(null, "startOffset", so + "%");
  if (so >= 50) {
    so = 0;
  }
  so += 0.02;
}

Marquee();

html, body {
    margin: 0;
    height: 100%;
    width: 100%;
}

body {
    font-family: "Arimo", sans-serif;
}

#wrap{
    width:100%;
    height:100%;
    position: fixed;
    top: 0;
    left: 0;  
}
text {
    text-transform: uppercase;
    font-weight: lighter;
}

<div id="wrap">
    <svg id="ellipse" version="1.1" viewBox="0 0 1000 1000">
    <path id="thePath" fill="transparent"  />

       <text stroke="black">
          <textPath xlink:href="#thePath" dy="5" id="tp" lengthAdjust="spacingAndGlyphs">Coming Soon • Coming Soon • Coming Soon • Coming Soon • Coming Soon • Coming Soon • Coming Soon •</textPath>
        </text>
    </svg>
</div>

另请阅读相关博文:https://codepen.io/enxaneta/post/animate-marquee-on-svg-curve

更新

OP 正在询问；

Is there anyway to make the svg spin anti clockwise

我不太清楚他的意思，因为原始演示是逆时针旋转的。请尝试像这样更改 function Marquee():不要增加 startOffset，而是减少它。

let so = 50;

function Marquee() {
  requestAnimationFrame(Marquee);
  tp.setAttributeNS(null, "startOffset", so + "%");
  if (so <= 0) {
    so = 50;
  }
  so -= 0.02;
}

Marquee();