Add a support for parsing hsl() and hsla() color formats.

Fixes alafr#187.
petrkotek · Jul 6, 2024 · c9c1a14 · c9c1a14
1 parent b091ebd
commit c9c1a14
Showing 1 changed file with 46 additions and 0 deletions.
diff --git a/source.js b/source.js
@@ -468,6 +468,41 @@ var SVGtoPDF = function(doc, svg, x, y, options) {
         else {return mt;}
       }));
     }
+    /**
+     * Converts an HSL color value to RGB. Conversion formula
+     * adapted from https://en.wikipedia.org/wiki/HSL_color_space.
+     * Assumes h, s, and l are contained in the set [0, 1] and
+     * returns r, g, and b in the set [0, 255].
+     *
+     * @param   {number}  h       The hue
+     * @param   {number}  s       The saturation
+     * @param   {number}  l       The lightness
+     * @return  {Array}           The RGB representation
+     */
+    function hslToRgb(h, s, l) {
+      let r, g, b;
+
+      if (s === 0) {
+        r = g = b = l; // achromatic
+      } else {
+        const q = l < 0.5 ? l * (1 + s) : l + s - l * s;
+        const p = 2 * l - q;
+        r = hueToRgb(p, q, h + 1/3);
+        g = hueToRgb(p, q, h);
+        b = hueToRgb(p, q, h - 1/3);
+      }
+
+      return [Math.round(r * 255), Math.round(g * 255), Math.round(b * 255)];
+    }
+
+    function hueToRgb(p, q, t) {
+      if (t < 0) t += 1;
+      if (t > 1) t -= 1;
+      if (t < 1/6) return p + (q - p) * 6 * t;
+      if (t < 1/2) return q;
+      if (t < 2/3) return p + (q - p) * (2/3 - t) * 6;
+      return p;
+    }
     function parseColor(raw) {
       let temp, result;
       raw = (raw || '').trim();
@@ -493,6 +528,17 @@ var SVGtoPDF = function(doc, svg, x, y, options) {
         if (temp[1] < 256 && temp[2] < 256 && temp[3] < 256) {
           result = [temp.slice(1, 4), 1];
         }
+      } else if (temp = raw.match(/^hsl\(\s*([0-9]+)\s*,\s*([0-9]+)%\s*,\s*([0-9]+)%\s*\)$/i)) {
+        temp[1] = parseInt(temp[1]); temp[2] = parseInt(temp[2]); temp[3] = parseInt(temp[3]);
+        if (temp[1] <= 360 && temp[2] <= 100 && temp[3] <= 100) {
+          console.log(temp)
+          result = [hslToRgb(temp[1]/360, temp[2]/100, temp[3]/100), 1];
+        }
+      } else if (temp = raw.match(/^hsla\(\s*([0-9]+)\s*,\s*([0-9]+)%\s*,\s*([0-9]+)%\s*,\s*([0-9.]+)\s*\)$/i)) {
+        temp[1] = parseInt(temp[1]); temp[2] = parseInt(temp[2]); temp[3] = parseInt(temp[3]); temp[4] = parseFloat(temp[4]);
+        if (temp[1] <= 360 && temp[2] <= 100 && temp[3] <= 100 && temp[4] <= 1) {
+          result = [hslToRgb(temp[1]/360, temp[2]/100, temp[3]/100), temp[4]];
+        }
       } else if (temp = raw.match(/^#([0-9a-f]{2})([0-9a-f]{2})([0-9a-f]{2})$/i)) {
         result = [[parseInt(temp[1], 16), parseInt(temp[2], 16), parseInt(temp[3], 16)], 1];
       } else if (temp = raw.match(/^#([0-9a-f])([0-9a-f])([0-9a-f])$/i)) {