更新

2026-03-30 01:04:46 +08:00
parent 050aa421b1
commit f627244b8f
5978 changed files with 1502187 additions and 2947 deletions
@@ -0,0 +1,160 @@
+'use strict';
+/**
+ * @type {{[key:string]: {[key:string]: number}}}
+ */
+const conversions = {
+  // Absolute length units
+  px: {
+    px: 1,
+    cm: 96 / 2.54,
+    mm: 96 / 25.4,
+    q: 96 / 101.6,
+    in: 96,
+    pt: 96 / 72,
+    pc: 16,
+  },
+  cm: {
+    px: 2.54 / 96,
+    cm: 1,
+    mm: 0.1,
+    q: 0.025,
+    in: 2.54,
+    pt: 2.54 / 72,
+    pc: 2.54 / 6,
+  },
+  mm: {
+    px: 25.4 / 96,
+    cm: 10,
+    mm: 1,
+    q: 0.25,
+    in: 25.4,
+    pt: 25.4 / 72,
+    pc: 25.4 / 6,
+  },
+  q: {
+    px: 101.6 / 96,
+    cm: 40,
+    mm: 4,
+    q: 1,
+    in: 101.6,
+    pt: 101.6 / 72,
+    pc: 101.6 / 6,
+  },
+  in: {
+    px: 1 / 96,
+    cm: 1 / 2.54,
+    mm: 1 / 25.4,
+    q: 1 / 101.6,
+    in: 1,
+    pt: 1 / 72,
+    pc: 1 / 6,
+  },
+  pt: {
+    px: 0.75,
+    cm: 72 / 2.54,
+    mm: 72 / 25.4,
+    q: 72 / 101.6,
+    in: 72,
+    pt: 1,
+    pc: 12,
+  },
+  pc: {
+    px: 0.0625,
+    cm: 6 / 2.54,
+    mm: 6 / 25.4,
+    q: 6 / 101.6,
+    in: 6,
+    pt: 6 / 72,
+    pc: 1,
+  },
+  // Angle units
+  deg: {
+    deg: 1,
+    grad: 0.9,
+    rad: 180 / Math.PI,
+    turn: 360,
+  },
+  grad: {
+    deg: 400 / 360,
+    grad: 1,
+    rad: 200 / Math.PI,
+    turn: 400,
+  },
+  rad: {
+    deg: Math.PI / 180,
+    grad: Math.PI / 200,
+    rad: 1,
+    turn: Math.PI * 2,
+  },
+  turn: {
+    deg: 1 / 360,
+    grad: 0.0025,
+    rad: 0.5 / Math.PI,
+    turn: 1,
+  },
+  // Duration units
+  s: {
+    s: 1,
+    ms: 0.001,
+  },
+  ms: {
+    s: 1000,
+    ms: 1,
+  },
+  // Frequency units
+  hz: {
+    hz: 1,
+    khz: 1000,
+  },
+  khz: {
+    hz: 0.001,
+    khz: 1,
+  },
+  // Resolution units
+  dpi: {
+    dpi: 1,
+    dpcm: 1 / 2.54,
+    dppx: 1 / 96,
+  },
+  dpcm: {
+    dpi: 2.54,
+    dpcm: 1,
+    dppx: 2.54 / 96,
+  },
+  dppx: {
+    dpi: 96,
+    dpcm: 96 / 2.54,
+    dppx: 1,
+  },
+};
+/**
+ * @param {number} value
+ * @param {string} sourceUnit
+ * @param {string} targetUnit
+ * @param {number|false} precision
+ */
+function convertUnit(value, sourceUnit, targetUnit, precision) {
+  const sourceUnitNormalized = sourceUnit.toLowerCase();
+  const targetUnitNormalized = targetUnit.toLowerCase();
+
+  if (!conversions[targetUnitNormalized]) {
+    throw new Error('Cannot convert to ' + targetUnit);
+  }
+
+  if (!conversions[targetUnitNormalized][sourceUnitNormalized]) {
+    throw new Error('Cannot convert from ' + sourceUnit + ' to ' + targetUnit);
+  }
+
+  const converted =
+    conversions[targetUnitNormalized][sourceUnitNormalized] * value;
+
+  if (precision !== false) {
+    precision = Math.pow(10, Math.ceil(precision) || 5);
+
+    return Math.round(converted * precision) / precision;
+  }
+
+  return converted;
+}
+
+module.exports = convertUnit;