feat: add RGB to HSL color format conversion algorithm

Author: piyushk77

Conversions/RgbHslConversion.js

@@ -0,0 +1,94 @@
+/**
+ * Given a color in RGB format, convert it to HSL format.
+ *
+ * For more info: https://www.niwa.nu/2013/05/math-behind-colorspace-conversions-rgb-hsl/
+ *
+ * @param {number[]} colorRgb - One dimensional array of integers (RGB color format).
+ * @returns {number[]} - One dimensional array of integers (HSL color format).
+ *
+ * @example
+ * const colorRgb = [24, 98, 118]
+ *
+ * const result = rgbToHsl(colorRgb)
+ *
+ * // The function returns the corresponding color in HSL format:
+ * // result = [193, 66, 28]
+ */
+
+const checkRgbFormat = (colorRgb) => {
+  if (colorRgb[0] <= 255 && colorRgb[0] >= 0) {
+    if (colorRgb[1] <= 255 && colorRgb[1] >= 0) {
+      if (colorRgb[2] <= 255 && colorRgb[2] >= 0) {
+        return true
+      }
+    }
+  }
+  return false
+}
+
+const rgbToHsl = (colorRgb) => {
+  if (checkRgbFormat(colorRgb) === false) {
+    return 'Input is not a valid RGB color.'
+  }
+
+  let colorHsl = colorRgb
+
+  let red = Math.round(colorRgb[0])
+  let green = Math.round(colorRgb[1])
+  let blue = Math.round(colorRgb[2])
+
+  const limit = 255
+
+  colorHsl[0] = red / limit
+  colorHsl[1] = green / limit
+  colorHsl[2] = blue / limit
+
+  let minValue = Math.min(...colorHsl)
+  let maxValue = Math.max(...colorHsl)
+
+  let channel = 0
+
+  if (maxValue === colorHsl[1]) {
+    channel = 1
+  } else if (maxValue === colorHsl[2]) {
+    channel = 2
+  }
+
+  let luminance = (minValue + maxValue) / 2
+
+  let saturation = 0
+
+  if (minValue !== maxValue) {
+    if (luminance <= 0.5) {
+      saturation = (maxValue - minValue) / (maxValue + minValue)
+    } else {
+      saturation = (maxValue - minValue) / (2 - maxValue - minValue)
+    }
+  }
+
+  let hue = 0
+
+  if (saturation !== 0) {
+    if (channel === 0) {
+      hue = (colorHsl[1] - colorHsl[2]) / (maxValue - minValue)
+    } else if (channel === 1) {
+      hue = 2 + (colorHsl[2] - colorHsl[0]) / (maxValue - minValue)
+    } else {
+      hue = 4 + (colorHsl[0] - colorHsl[1]) / (maxValue - minValue)
+    }
+  }
+
+  hue *= 60
+
+  if (hue < 0) {
+    hue += 360
+  }
+
+  colorHsl[0] = Math.round(hue)
+  colorHsl[1] = Math.round(saturation * 100)
+  colorHsl[2] = Math.round(luminance * 100)
+
+  return colorHsl
+}
+
+export { rgbToHsl }