更改 SVG 视口的高度会更改 viewBox 起始原点 <min-x>
Changing SVG viewport's height changes viewBox starting origin point <min-x>
更改视口的坐标系高度会更改 X 轴上的用户坐标系起始原点，我不明白为什么。这里是什么关系？它不应该影响用户坐标系的 Y 轴，因为我们正在改变视口的高度（Y 轴）吗？
视口坐标系：1250x1250。用户坐标系：500x500。当宽高比是这样的时候，不管我给viewBox 属性 (viewBox = <min-x> <min-y> <width> <height>) min-x of viewbox 什么宽度和高度总是从0开始，也就是屏幕的左上角。但是，例如，如果我将视口坐标系更改为 1250x329，则 0 值的 min-x 将从屏幕中间的某处开始，而不是从左侧开始。这是为什么？
这是一个实时代码笔 https://codepen.io/Limpuls/pen/LYNXQPK，SVG 元素的高度 CSS 设置为 100%，提供完美的居中和从左角开始的原点，因为视口为 1250x1250。改为将其更改为 100vh（在 CSS 中注释掉代码）然后视口变为 1250x329 并抛出 viewBox 的起点打破了我的 Javascript SVG 路径居中逻辑。
是什么导致了这种行为？我如何修改我在 JS 中的计算以适应任何视口高度，而不仅仅是当它是像 1250x1250 或 700x700 这样的完美数字时？
代码：
<div class="container-fluid">
<section class="row first">
<div class="col-lg-12">
<div class="svg">
<svg viewBox="0 0 500 500" fill="none" xmlns="http://www.w3.org/2000/svg">
<path d="M26 2V30H19.52V18.52H6.80001V30H0.320007V2H6.80001V13.04H19.52V2H26Z" fill="black"/>
<path d="M53.2647 19.32C53.2647 19.4 53.2247 19.96 53.1447 21H36.8647C37.158 22.3333 37.8514 23.3867 38.9447 24.16C40.038 24.9333 41.398 25.32 43.0247 25.32C44.1447 25.32 45.1314 25.16 45.9847 24.84C46.8647 24.4933 47.678 23.96 48.4247 23.24L51.7447 26.84C49.718 29.16 46.758 30.32 42.8647 30.32C40.438 30.32 38.2914 29.8533 36.4247 28.92C34.558 27.96 33.118 26.64 32.1047 24.96C31.0914 23.28 30.5847 21.3733 30.5847 19.24C30.5847 17.1333 31.078 15.24 32.0647 13.56C33.078 11.8533 34.4514 10.5333 36.1847 9.6C37.9447 8.64 39.9047 8.16 42.0647 8.16C44.1714 8.16 46.078 8.61333 47.7847 9.52C49.4914 10.4267 50.8247 11.7333 51.7847 13.44C52.7714 15.12 53.2647 17.08 53.2647 19.32ZM42.1047 12.88C40.6914 12.88 39.5047 13.28 38.5447 14.08C37.5847 14.88 36.998 15.9733 36.7847 17.36H47.3847C47.1714 16 46.5847 14.92 45.6247 14.12C44.6647 13.2933 43.4914 12.88 42.1047 12.88Z" fill="black"/>
<path d="M57.4191 0.319998H63.6591V30H57.4191V0.319998Z" fill="black"/>
<path d="M69.4503 0.319998H75.6903V30H69.4503V0.319998Z" fill="black"/>
<path d="M91.7216 30.32C89.4549 30.32 87.4149 29.8533 85.6016 28.92C83.8149 27.96 82.4149 26.64 81.4016 24.96C80.3882 23.28 79.8816 21.3733 79.8816 19.24C79.8816 17.1067 80.3882 15.2 81.4016 13.52C82.4149 11.84 83.8149 10.5333 85.6016 9.6C87.4149 8.64 89.4549 8.16 91.7216 8.16C93.9882 8.16 96.0149 8.64 97.8016 9.6C99.5882 10.5333 100.988 11.84 102.002 13.52C103.015 15.2 103.522 17.1067 103.522 19.24C103.522 21.3733 103.015 23.28 102.002 24.96C100.988 26.64 99.5882 27.96 97.8016 28.92C96.0149 29.8533 93.9882 30.32 91.7216 30.32ZM91.7216 25.2C93.3216 25.2 94.6282 24.6667 95.6416 23.6C96.6816 22.5067 97.2016 21.0533 97.2016 19.24C97.2016 17.4267 96.6816 15.9867 95.6416 14.92C94.6282 13.8267 93.3216 13.28 91.7216 13.28C90.1216 13.28 88.8016 13.8267 87.7616 14.92C86.7216 15.9867 86.2016 17.4267 86.2016 19.24C86.2016 21.0533 86.7216 22.5067 87.7616 23.6C88.8016 24.6667 90.1216 25.2 91.7216 25.2Z" fill="black"/>
<path d="M109.819 22.56C110.939 22.56 111.859 22.92 112.579 23.64C113.299 24.3333 113.659 25.2533 113.659 26.4C113.659 26.9333 113.592 27.4667 113.459 28C113.326 28.5333 113.032 29.3333 112.579 30.4L110.299 36.16H106.339L108.099 29.8C107.432 29.5333 106.899 29.1067 106.499 28.52C106.126 27.9067 105.939 27.2 105.939 26.4C105.939 25.2533 106.299 24.3333 107.019 23.64C107.766 22.92 108.699 22.56 109.819 22.56Z" fill="black"/>
<path d="M171.976 2L162.816 30H155.856L149.696 11.04L143.336 30H136.416L127.216 2H133.936L140.256 21.68L146.856 2H152.856L159.256 21.84L165.776 2H171.976Z" fill="black"/>
<path d="M183.792 30.32C181.525 30.32 179.485 29.8533 177.672 28.92C175.885 27.96 174.485 26.64 173.472 24.96C172.459 23.28 171.952 21.3733 171.952 19.24C171.952 17.1067 172.459 15.2 173.472 13.52C174.485 11.84 175.885 10.5333 177.672 9.6C179.485 8.64 181.525 8.16 183.792 8.16C186.059 8.16 188.085 8.64 189.872 9.6C191.659 10.5333 193.059 11.84 194.072 13.52C195.085 15.2 195.592 17.1067 195.592 19.24C195.592 21.3733 195.085 23.28 194.072 24.96C193.059 26.64 191.659 27.96 189.872 28.92C188.085 29.8533 186.059 30.32 183.792 30.32ZM183.792 25.2C185.392 25.2 186.699 24.6667 187.712 23.6C188.752 22.5067 189.272 21.0533 189.272 19.24C189.272 17.4267 188.752 15.9867 187.712 14.92C186.699 13.8267 185.392 13.28 183.792 13.28C182.192 13.28 180.872 13.8267 179.832 14.92C178.792 15.9867 178.272 17.4267 178.272 19.24C178.272 21.0533 178.792 22.5067 179.832 23.6C180.872 24.6667 182.192 25.2 183.792 25.2Z" fill="black"/>
<path d="M205.723 11.32C206.469 10.28 207.469 9.49333 208.723 8.96C210.003 8.42667 211.469 8.16 213.123 8.16V13.92C212.429 13.8667 211.963 13.84 211.723 13.84C209.936 13.84 208.536 14.3467 207.523 15.36C206.509 16.3467 206.003 17.84 206.003 19.84V30H199.763V8.48H205.723V11.32Z" fill="black"/>
<path d="M216.833 0.319998H223.073V30H216.833V0.319998Z" fill="black"/>
<path d="M250.784 0.319998V30H244.824V27.52C243.278 29.3867 241.038 30.32 238.104 30.32C236.078 30.32 234.238 29.8667 232.584 28.96C230.958 28.0533 229.678 26.76 228.744 25.08C227.811 23.4 227.344 21.4533 227.344 19.24C227.344 17.0267 227.811 15.08 228.744 13.4C229.678 11.72 230.958 10.4267 232.584 9.52C234.238 8.61333 236.078 8.16 238.104 8.16C240.851 8.16 242.998 9.02667 244.544 10.76V0.319998H250.784ZM239.184 25.2C240.758 25.2 242.064 24.6667 243.104 23.6C244.144 22.5067 244.664 21.0533 244.664 19.24C244.664 17.4267 244.144 15.9867 243.104 14.92C242.064 13.8267 240.758 13.28 239.184 13.28C237.584 13.28 236.264 13.8267 235.224 14.92C234.184 15.9867 233.664 17.4267 233.664 19.24C233.664 21.0533 234.184 22.5067 235.224 23.6C236.264 24.6667 237.584 25.2 239.184 25.2Z" fill="black"/>
</svg>
</div>
</div>
</section>
</div>
CSS
section {
height: 100vh;
width: 100vw;
}
svg {
height: 100%;
//height: 100vh;
width: 100%;
display: flex;
justify-content: center;
align-items: center;
}
Javascript 通过使用公式计算 viewBox <min-x> 动态居中 SVG <path> 的摘录：((Viewport width - total SVG <path> width) / 2) / Viewport to viewBox 宽度比例
let totalSVGwidth = 0;
let totalSVGheight = 0;
let totalSpacingBetweenLetters = 0;
let viewBoxScaleX = 500;
let winViewportSVGwidthDiff = 0;
let svgViewportWidth = document.querySelector(".svg").offsetWidth;
let totalSVGwidthWithSpaces = 0;
let viewportCoordSpaceUserCoordSpaceRatio = document.querySelector(".svg").offsetWidth / viewBoxScaleX;
document.querySelectorAll("path").forEach((path, index) => {
totalSVGwidth = totalSVGwidth + path.getBoundingClientRect().width;
if ((index + 1) < document.querySelectorAll("path").length) {
totalSpacingBetweenLetters += (document.querySelectorAll("path")[index + 1].getBoundingClientRect().x - path.getBoundingClientRect().x) - path.getBoundingClientRect().width;
}
totalSVGwidthWithSpaces += totalSpacingBetweenLetters + totalSVGwidth;
// formula
document.querySelectorAll("svg")[0].setAttribute("viewBox", (0 - ((svgViewportWidth - (totalSpacingBetweenLetters + totalSVGwidth)) / 2) / viewportCoordSpaceUserCoordSpaceRatio) + " " + 0 + " " + viewBoxScaleX + " " + viewBoxScaleX);
});
您需要仔细阅读 viewBox 的工作原理。
但总而言之，如果视口（即 <svg> width 和 height）的宽高比与 viewBox 的宽度和高度不同，则通过默认情况下，由 viewBox 表示的区域将在视口中居中。
下面的代码片段试图表现这种行为。
<svg width="1250" height="329" viewBox="0 0 500 500">
<rect x="-700" width="1898" height="500" fill="none" stroke="green" stroke-width="2"/>
<text x="-600" y="100" fill="green" font-size="20">1250 x 329 viewport</text>
<rect width="500" height="500" fill="red" fill-opacity="0.05" stroke="red" stroke-width="2"/>
<text x="10" y="20" fill="red" font-size="20">(0,0)</text>
<text x="250" y="250" fill="red" font-size="20" text-anchor="middle">500 x 500 viewBox area</text>
</svg>
(0,0) 保留在 viewBox 区域的左上角。不是视口。
您可以通过 preserveAspectRatio 属性控制纵横比不匹配时发生的情况。如果你想让 viewBox 区域始终卡在视口的左上角，那么使用 preserveAspectRatio="xMinYMin meet".
<svg width="1250" height="329" viewBox="0 0 500 500" preserveAspectRatio="xMinYMin meet">
<rect x="0" width="1898" height="500" fill="none" stroke="green" stroke-width="2"/>
<text x="-600" y="100" fill="green" font-size="20">1250 x 329 viewport</text>
<rect width="500" height="500" fill="red" fill-opacity="0.05" stroke="red" stroke-width="2"/>
<text x="10" y="20" fill="red" font-size="20">(0,0)</text>
<text x="250" y="250" fill="red" font-size="20" text-anchor="middle">500 x 500 viewBox area</text>
</svg>
更改视口的坐标系高度会更改 X 轴上的用户坐标系起始原点，我不明白为什么。这里是什么关系？它不应该影响用户坐标系的 Y 轴，因为我们正在改变视口的高度（Y 轴）吗？
视口坐标系：1250x1250。用户坐标系：500x500。当宽高比是这样的时候，不管我给viewBox 属性 (viewBox = <min-x> <min-y> <width> <height>) min-x of viewbox 什么宽度和高度总是从0开始，也就是屏幕的左上角。但是，例如，如果我将视口坐标系更改为 1250x329，则 0 值的 min-x 将从屏幕中间的某处开始，而不是从左侧开始。这是为什么？
这是一个实时代码笔 https://codepen.io/Limpuls/pen/LYNXQPK，SVG 元素的高度 CSS 设置为 100%，提供完美的居中和从左角开始的原点，因为视口为 1250x1250。改为将其更改为 100vh（在 CSS 中注释掉代码）然后视口变为 1250x329 并抛出 viewBox 的起点打破了我的 Javascript SVG 路径居中逻辑。
是什么导致了这种行为？我如何修改我在 JS 中的计算以适应任何视口高度，而不仅仅是当它是像 1250x1250 或 700x700 这样的完美数字时？
代码：
<div class="container-fluid">
<section class="row first">
<div class="col-lg-12">
<div class="svg">
<svg viewBox="0 0 500 500" fill="none" xmlns="http://www.w3.org/2000/svg">
<path d="M26 2V30H19.52V18.52H6.80001V30H0.320007V2H6.80001V13.04H19.52V2H26Z" fill="black"/>
<path d="M53.2647 19.32C53.2647 19.4 53.2247 19.96 53.1447 21H36.8647C37.158 22.3333 37.8514 23.3867 38.9447 24.16C40.038 24.9333 41.398 25.32 43.0247 25.32C44.1447 25.32 45.1314 25.16 45.9847 24.84C46.8647 24.4933 47.678 23.96 48.4247 23.24L51.7447 26.84C49.718 29.16 46.758 30.32 42.8647 30.32C40.438 30.32 38.2914 29.8533 36.4247 28.92C34.558 27.96 33.118 26.64 32.1047 24.96C31.0914 23.28 30.5847 21.3733 30.5847 19.24C30.5847 17.1333 31.078 15.24 32.0647 13.56C33.078 11.8533 34.4514 10.5333 36.1847 9.6C37.9447 8.64 39.9047 8.16 42.0647 8.16C44.1714 8.16 46.078 8.61333 47.7847 9.52C49.4914 10.4267 50.8247 11.7333 51.7847 13.44C52.7714 15.12 53.2647 17.08 53.2647 19.32ZM42.1047 12.88C40.6914 12.88 39.5047 13.28 38.5447 14.08C37.5847 14.88 36.998 15.9733 36.7847 17.36H47.3847C47.1714 16 46.5847 14.92 45.6247 14.12C44.6647 13.2933 43.4914 12.88 42.1047 12.88Z" fill="black"/>
<path d="M57.4191 0.319998H63.6591V30H57.4191V0.319998Z" fill="black"/>
<path d="M69.4503 0.319998H75.6903V30H69.4503V0.319998Z" fill="black"/>
<path d="M91.7216 30.32C89.4549 30.32 87.4149 29.8533 85.6016 28.92C83.8149 27.96 82.4149 26.64 81.4016 24.96C80.3882 23.28 79.8816 21.3733 79.8816 19.24C79.8816 17.1067 80.3882 15.2 81.4016 13.52C82.4149 11.84 83.8149 10.5333 85.6016 9.6C87.4149 8.64 89.4549 8.16 91.7216 8.16C93.9882 8.16 96.0149 8.64 97.8016 9.6C99.5882 10.5333 100.988 11.84 102.002 13.52C103.015 15.2 103.522 17.1067 103.522 19.24C103.522 21.3733 103.015 23.28 102.002 24.96C100.988 26.64 99.5882 27.96 97.8016 28.92C96.0149 29.8533 93.9882 30.32 91.7216 30.32ZM91.7216 25.2C93.3216 25.2 94.6282 24.6667 95.6416 23.6C96.6816 22.5067 97.2016 21.0533 97.2016 19.24C97.2016 17.4267 96.6816 15.9867 95.6416 14.92C94.6282 13.8267 93.3216 13.28 91.7216 13.28C90.1216 13.28 88.8016 13.8267 87.7616 14.92C86.7216 15.9867 86.2016 17.4267 86.2016 19.24C86.2016 21.0533 86.7216 22.5067 87.7616 23.6C88.8016 24.6667 90.1216 25.2 91.7216 25.2Z" fill="black"/>
<path d="M109.819 22.56C110.939 22.56 111.859 22.92 112.579 23.64C113.299 24.3333 113.659 25.2533 113.659 26.4C113.659 26.9333 113.592 27.4667 113.459 28C113.326 28.5333 113.032 29.3333 112.579 30.4L110.299 36.16H106.339L108.099 29.8C107.432 29.5333 106.899 29.1067 106.499 28.52C106.126 27.9067 105.939 27.2 105.939 26.4C105.939 25.2533 106.299 24.3333 107.019 23.64C107.766 22.92 108.699 22.56 109.819 22.56Z" fill="black"/>
<path d="M171.976 2L162.816 30H155.856L149.696 11.04L143.336 30H136.416L127.216 2H133.936L140.256 21.68L146.856 2H152.856L159.256 21.84L165.776 2H171.976Z" fill="black"/>
<path d="M183.792 30.32C181.525 30.32 179.485 29.8533 177.672 28.92C175.885 27.96 174.485 26.64 173.472 24.96C172.459 23.28 171.952 21.3733 171.952 19.24C171.952 17.1067 172.459 15.2 173.472 13.52C174.485 11.84 175.885 10.5333 177.672 9.6C179.485 8.64 181.525 8.16 183.792 8.16C186.059 8.16 188.085 8.64 189.872 9.6C191.659 10.5333 193.059 11.84 194.072 13.52C195.085 15.2 195.592 17.1067 195.592 19.24C195.592 21.3733 195.085 23.28 194.072 24.96C193.059 26.64 191.659 27.96 189.872 28.92C188.085 29.8533 186.059 30.32 183.792 30.32ZM183.792 25.2C185.392 25.2 186.699 24.6667 187.712 23.6C188.752 22.5067 189.272 21.0533 189.272 19.24C189.272 17.4267 188.752 15.9867 187.712 14.92C186.699 13.8267 185.392 13.28 183.792 13.28C182.192 13.28 180.872 13.8267 179.832 14.92C178.792 15.9867 178.272 17.4267 178.272 19.24C178.272 21.0533 178.792 22.5067 179.832 23.6C180.872 24.6667 182.192 25.2 183.792 25.2Z" fill="black"/>
<path d="M205.723 11.32C206.469 10.28 207.469 9.49333 208.723 8.96C210.003 8.42667 211.469 8.16 213.123 8.16V13.92C212.429 13.8667 211.963 13.84 211.723 13.84C209.936 13.84 208.536 14.3467 207.523 15.36C206.509 16.3467 206.003 17.84 206.003 19.84V30H199.763V8.48H205.723V11.32Z" fill="black"/>
<path d="M216.833 0.319998H223.073V30H216.833V0.319998Z" fill="black"/>
<path d="M250.784 0.319998V30H244.824V27.52C243.278 29.3867 241.038 30.32 238.104 30.32C236.078 30.32 234.238 29.8667 232.584 28.96C230.958 28.0533 229.678 26.76 228.744 25.08C227.811 23.4 227.344 21.4533 227.344 19.24C227.344 17.0267 227.811 15.08 228.744 13.4C229.678 11.72 230.958 10.4267 232.584 9.52C234.238 8.61333 236.078 8.16 238.104 8.16C240.851 8.16 242.998 9.02667 244.544 10.76V0.319998H250.784ZM239.184 25.2C240.758 25.2 242.064 24.6667 243.104 23.6C244.144 22.5067 244.664 21.0533 244.664 19.24C244.664 17.4267 244.144 15.9867 243.104 14.92C242.064 13.8267 240.758 13.28 239.184 13.28C237.584 13.28 236.264 13.8267 235.224 14.92C234.184 15.9867 233.664 17.4267 233.664 19.24C233.664 21.0533 234.184 22.5067 235.224 23.6C236.264 24.6667 237.584 25.2 239.184 25.2Z" fill="black"/>
</svg>
</div>
</div>
</section>
</div>
CSS
section {
height: 100vh;
width: 100vw;
}
svg {
height: 100%;
//height: 100vh;
width: 100%;
display: flex;
justify-content: center;
align-items: center;
}
Javascript 通过使用公式计算 viewBox <min-x> 动态居中 SVG <path> 的摘录：((Viewport width - total SVG <path> width) / 2) / Viewport to viewBox 宽度比例
let totalSVGwidth = 0;
let totalSVGheight = 0;
let totalSpacingBetweenLetters = 0;
let viewBoxScaleX = 500;
let winViewportSVGwidthDiff = 0;
let svgViewportWidth = document.querySelector(".svg").offsetWidth;
let totalSVGwidthWithSpaces = 0;
let viewportCoordSpaceUserCoordSpaceRatio = document.querySelector(".svg").offsetWidth / viewBoxScaleX;
document.querySelectorAll("path").forEach((path, index) => {
totalSVGwidth = totalSVGwidth + path.getBoundingClientRect().width;
if ((index + 1) < document.querySelectorAll("path").length) {
totalSpacingBetweenLetters += (document.querySelectorAll("path")[index + 1].getBoundingClientRect().x - path.getBoundingClientRect().x) - path.getBoundingClientRect().width;
}
totalSVGwidthWithSpaces += totalSpacingBetweenLetters + totalSVGwidth;
// formula
document.querySelectorAll("svg")[0].setAttribute("viewBox", (0 - ((svgViewportWidth - (totalSpacingBetweenLetters + totalSVGwidth)) / 2) / viewportCoordSpaceUserCoordSpaceRatio) + " " + 0 + " " + viewBoxScaleX + " " + viewBoxScaleX);
});
您需要仔细阅读 viewBox 的工作原理。
但总而言之，如果视口（即 <svg> width 和 height）的宽高比与 viewBox 的宽度和高度不同，则通过默认情况下，由 viewBox 表示的区域将在视口中居中。
下面的代码片段试图表现这种行为。
<svg width="1250" height="329" viewBox="0 0 500 500">
<rect x="-700" width="1898" height="500" fill="none" stroke="green" stroke-width="2"/>
<text x="-600" y="100" fill="green" font-size="20">1250 x 329 viewport</text>
<rect width="500" height="500" fill="red" fill-opacity="0.05" stroke="red" stroke-width="2"/>
<text x="10" y="20" fill="red" font-size="20">(0,0)</text>
<text x="250" y="250" fill="red" font-size="20" text-anchor="middle">500 x 500 viewBox area</text>
</svg>
(0,0) 保留在 viewBox 区域的左上角。不是视口。
您可以通过 preserveAspectRatio 属性控制纵横比不匹配时发生的情况。如果你想让 viewBox 区域始终卡在视口的左上角，那么使用 preserveAspectRatio="xMinYMin meet".
<svg width="1250" height="329" viewBox="0 0 500 500" preserveAspectRatio="xMinYMin meet">
<rect x="0" width="1898" height="500" fill="none" stroke="green" stroke-width="2"/>
<text x="-600" y="100" fill="green" font-size="20">1250 x 329 viewport</text>
<rect width="500" height="500" fill="red" fill-opacity="0.05" stroke="red" stroke-width="2"/>
<text x="10" y="20" fill="red" font-size="20">(0,0)</text>
<text x="250" y="250" fill="red" font-size="20" text-anchor="middle">500 x 500 viewBox area</text>
</svg>