From 59608c7409f35c94e2e9766d05813990a687216c Mon Sep 17 00:00:00 2001
From: yutent <yutent.io@gmail.com>
Date: Mon, 5 Feb 2024 17:10:41 +0800
Subject: [PATCH] update

---
 src/lib/svg/index.js    |  55 +++++++++++++
 src/lib/svg/path.js     | 175 ++++++++++++++++++++++++++++++++++++++++
 src/lib/svg/view_box.js | 122 ++++++++++++++++++++++++++++
 3 files changed, 352 insertions(+)
 create mode 100644 src/lib/svg/index.js
 create mode 100644 src/lib/svg/path.js
 create mode 100644 src/lib/svg/view_box.js

diff --git a/src/lib/svg/index.js b/src/lib/svg/index.js
new file mode 100644
index 0000000..e830816
--- /dev/null
+++ b/src/lib/svg/index.js
@@ -0,0 +1,55 @@
+/**
+ * {}
+ * @author yutent<yutent.io@gmail.com>
+ * @date 2024/02/05 16:19:45
+ */
+
+import { DOMParser } from '@xmldom/xmldom'
+import svgpath from 'svgpath'
+
+import { PATH_DECIMAL } from '../config.js'
+import { normalizePath, pathify } from './path.js'
+import { generateAmendTrans } from './view_box.js'
+
+/**
+ * 翻转svgpath
+ * @param  {string} path     path序列
+ * @return {string}         反转后的path序列
+ */
+export function reversal(path) {
+  return svgpath(path).scale(1, -1).round(PATH_DECIMAL).toString()
+}
+
+/**
+ * 转换svg为一个path,并且按照目标高度，偏移进行拉伸
+ * @param  {string} svg     原始svg
+ * @param  {object} options.targetHeight 目标高度
+ * @return {object}         path序列和viewbox
+ */
+export function normalizeSvg(svg, options) {
+  let svgDocNode = new DOMParser().parseFromString(
+    pathify(svg),
+    'application/xml'
+  )
+  let svgNode = svgDocNode.getElementsByTagName('svg')[0]
+
+  //解决所有的变换，生成一个path
+  let path = normalizePath(svgNode)
+
+  let trans = svgpath(path)
+
+  //根据目标viewbox进行变换
+  let targetHeight = options.targetHeight
+
+  if (targetHeight) {
+    let viewObj = generateAmendTrans(svgNode, targetHeight)
+    viewObj.transforms.forEach(function (viewTrans) {
+      trans[viewTrans[0]].apply(trans, viewTrans[1])
+    })
+  }
+
+  return {
+    viewbox: viewObj.targetViewbox,
+    path: trans.round(PATH_DECIMAL).toString()
+  }
+}
diff --git a/src/lib/svg/path.js b/src/lib/svg/path.js
new file mode 100644
index 0000000..4eb34fe
--- /dev/null
+++ b/src/lib/svg/path.js
@@ -0,0 +1,175 @@
+/**
+ * {}
+ * @author yutent<yutent.io@gmail.com>
+ * @date 2024/02/05 16:12:14
+ */
+
+import { DOMParser, XMLSerializer } from '@xmldom/xmldom'
+import svgpath from 'svgpath'
+
+const shape = {
+  $translatePath(convertObj, attributes) {
+    let data = {}
+    attributes.forEach(function (attribute) {
+      data[attribute.name] = attribute.value
+    })
+
+    return convertObj.template(data)
+  },
+  generatePathNode(doc, node) {
+    let convertObj, attributes, path, tagName
+
+    tagName = String(node.tagName).toLowerCase()
+    //polyline与polygon是同一个东西
+    if (tagName === 'polyline') {
+      tagName = 'polygon'
+    }
+
+    convertObj = shape[tagName]
+    if (!convertObj) {
+      return
+    }
+
+    path = shape.$translatePath(convertObj, node.attributes)
+    if (!path) {
+      return
+    }
+
+    newPathNode = doc.createElement('path')
+    //赋值d属性
+    newPathNode.setAttribute('d', path)
+    //保留其他属性
+    node.attributes.forEach(function (attribute) {
+      if (!convertObj.attrs.includes(attribute.name)) {
+        newPathNode.setAttribute(attribute.name, attribute.value)
+      }
+    })
+
+    return newPathNode
+  },
+  rect: {
+    attrs: ['x', 'y', 'width', 'height', 'rx', 'ry'],
+    template(data) {
+      // 需要做一个保护，如果没有写属性值那么默认为0
+      if (!data.x) {
+        data.x = '0'
+      }
+
+      if (!data.y) {
+        data.y = '0'
+      }
+
+      if (!data.rx && data.ry) {
+        data.rx = data.ry
+      }
+
+      if (!data.ry && data.rx) {
+        data.ry = data.rx
+      }
+
+      if (!data.ry && !data.rx) {
+        data.ry = data.rx = '0'
+      }
+
+      return `M${data.x},${data.y}m${data.rx},0l${data.width - 2 * data.rx},0q${
+        data.rx
+      },0 ${data.rx},${data.ry}l0,${data.height - 2 * data.ry}q0,${
+        data.ry
+      } ${-data.rx},${data.ry}l${
+        -data.width + 2 * data.rx
+      },0q${-data.rx},0 ${-data.rx},${-data.ry}l0,${
+        -data.height + 2 * data.ry
+      }q0,${-data.ry},${data.rx},${-data.ry}Z`
+    }
+  },
+  circle: {
+    attrs: ['cx', 'cy', 'r'],
+    template(data) {
+      return `M${data.cx},${data.cy}m${-data.r},0a${data.r},${data.r},0,1,0,${
+        data.r * 2
+      },0a${data.r},${data.r},0,1,0,-${data.r * 2},0Z`
+    }
+  },
+  line: {
+    attrs: ['x1', 'y1', 'x2', 'y2'],
+    template(data) {
+      return `M${data.x1},${data.y1}L${data.x2},${data.y2}L${data.x1},${data.y1}Z`
+    }
+  },
+  ellipse: {
+    attrs: ['cx', 'cy', 'rx', 'ry'],
+    template(data) {
+      return `M${data.cx - data.rx},${data.cy}a${data.rx},${data.ry},0,1,0,${
+        data.rx * 2
+      },0a${data.rx},${data.ry},0,1,0,-${data.rx * 2},0Z`
+    }
+  },
+  polygon: {
+    attrs: ['points'],
+    template(data) {
+      data.points = data.points.replace(/(^\s*)|(\s*$)/g, '')
+      let points = data.points.split(' ')
+      let p = ''
+      points.forEach(function (point, index) {
+        if (index === 0) {
+          p += 'M' + point
+        } else {
+          p += 'L' + point
+        }
+      })
+      p += 'Z'
+
+      return p
+    }
+  }
+}
+
+function generatePath(path, transforms) {
+  let t = svgpath(path).abs()
+  transforms.forEach(it => t.transform(it))
+  return t.toString()
+}
+
+export function normalizePath(node, transforms) {
+  let path = ''
+  let newTransForms = transforms ? [...transforms] : []
+
+  if (node.getAttribute && node.getAttribute('transform')) {
+    newTransForms.push(node.getAttribute('transform'))
+  }
+
+  if (!node.hasChildNodes() && node.tagName === 'path') {
+    path = generatePath(node.getAttribute('d'), newTransForms)
+  }
+
+  if (node.hasChildNodes()) {
+    node.childNodes.forEach(function (childNode) {
+      path += normalizePath(childNode, newTransForms)
+    })
+  }
+
+  return path
+}
+
+function transNode(doc, node) {
+  let convertObj, newPathNode
+
+  //基本的图形都是没有子结点的
+  if (!node.hasChildNodes() && node.nodeName !== 'path') {
+    newPathNode = shape.generatePathNode(doc, node)
+    newPathNode && node.parentNode.replaceChild(newPathNode, node)
+    return
+  }
+
+  node.childNodes.forEach(function (child) {
+    transNode(doc, child)
+  })
+}
+
+export function pathify(svgString) {
+  let doc = new DOMParser().parseFromString(svgString, 'application/xml')
+
+  transNode(doc, doc)
+
+  return new XMLSerializer().serializeToString(doc)
+}
diff --git a/src/lib/svg/view_box.js b/src/lib/svg/view_box.js
new file mode 100644
index 0000000..21c6104
--- /dev/null
+++ b/src/lib/svg/view_box.js
@@ -0,0 +1,122 @@
+/**
+ * {}
+ * @author yutent<yutent.io@gmail.com>
+ * @date 2024/02/05 16:04:06
+ */
+
+function getViewBox(svgNode) {
+  if (!svgNode) {
+    return
+  }
+
+  let width, height
+  let viewbox = svgNode.getAttribute('viewBox').replace(',', ' ').split(' ')
+
+  if (viewbox && viewbox.length === 4) {
+    return viewbox.map(v => +v)
+  }
+
+  width = +svgNode.getAttribute('width')
+  height = +svgNode.getAttribute('height')
+  if (width != 0 && height != 0) {
+    return [0, 0, width, height]
+  }
+}
+
+function getViewPort(svgNode) {
+  let width, height, viewbox
+  width = +svgNode.getAttribute('width')
+  height = +svgNode.getAttribute('height')
+
+  viewbox = svgNode.getAttribute('viewBox').replace(',', ' ').split(' ')
+  if (!width) {
+    width = +viewbox[2]
+  }
+  if (!height) {
+    height = +viewbox[3]
+  }
+
+  return [width, height]
+}
+
+// 根据 targetHeight 缩放 width
+// 如: normalizeViewport([1024, 2048], 1024)
+// #=> [0,0,512, 1024]
+function getTargetViewbox(viewport, targetHeight) {
+  let width = viewport[0]
+  let height = viewport[1]
+
+  if (height != targetHeight) {
+    width = ~~((targetHeight / height) * width)
+    height = targetHeight
+  }
+
+  return [0, 0, width, height]
+}
+
+function normalizeXY(viewbox, targetViewbox) {
+  let x, y, targetX, targetY
+
+  x = viewbox[0]
+  y = viewbox[1]
+  targetX = targetViewbox[0]
+  targetY = targetViewbox[1]
+  //可能会有x,y偏移的情况，所以这边需要做出相应的转换
+  if (x != targetX || y != targetY) {
+    return [['translate', [targetX - x, targetY - y]]]
+  }
+  return []
+}
+
+function normalizeWidthHeight(viewbox, targetViewbox) {
+  let width, height, targetWidth, targetHeight, widthScale, heightScale
+
+  width = viewbox[2]
+  height = viewbox[3]
+  targetWidth = targetViewbox[2]
+  targetHeight = targetViewbox[3]
+
+  widthScale = width / targetWidth
+  heightScale = height / targetHeight
+  //比较正常的等比缩放
+  if (widthScale == heightScale) {
+    return [['scale', [1 / widthScale, 1 / widthScale]]]
+  }
+
+  //下面是不等比缩放
+  //不等比缩放后
+  let maxScale = Math.max(widthScale, heightScale)
+  let transforms = [],
+    newWidth,
+    newHeight
+
+  if (widthScale < heightScale) {
+    newWidth = targetWidth * maxScale
+    transforms.push(['translate', [(newWidth - width) / 2, 0]])
+  } else if (widthScale > heightScale) {
+    newHeight = newHeight * maxScale
+    transforms.push(['translate', [0, (newHeight - height) / 2]])
+  }
+
+  transforms.push(['scale', [1 / maxScale, 1 / maxScale]])
+
+  return transforms
+}
+
+//返回需要进行的转换数组
+function normalizeViewBox(viewbox, targetViewbox) {
+  return normalizeXY(viewbox, targetViewbox).concat(
+    normalizeWidthHeight(viewbox, targetViewbox)
+  )
+}
+
+export function generateAmendTrans(svgNode, targetHeight) {
+  let viewport = getViewPort(svgNode)
+  let viewbox = getViewBox(svgNode)
+  let targetViewbox = getTargetViewbox(viewport, targetHeight)
+
+  return {
+    transforms: normalizeViewBox(viewbox, targetViewbox),
+    targetViewbox: targetViewbox
+  }
+}