Differences

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--- fuss:javascript [2017/05/28 19:56]
office [RGB Color to Hexadecimal Color]
+++ fuss:javascript [2017/05/28 19:56] (current)
office [Hexadecimal Color to RGB Color]
@@ Line 1: / Line 1: @@
+====== Wizardry and Steamworks JavaScript Libraries ======
+^ Name       ^ Link ^ Description ^
+| ''was.js'' | [[javascript/bower/packages/was.js|was.js]] | General Purpose Library |
+====== Compare Arrays ======
+The following code:
+<code javascript>
+// attach the .equals method to Array's prototype to call it on any array
+Array.prototype.equals = function (array) {
+    // if the other array is a falsy value, return
+    if (!array)
+        return false;
+    // compare lengths - can save a lot of time
+    if (this.length != array.length)
+        return false;
+    for (var i = 0, l=this.length; i < l; i++) {
+        // Check if we have nested arrays
+        if (this[i] instanceof Array && array[i] instanceof Array) {
+            // recurse into the nested arrays
+            if (!this[i].equals(array[i]))
+                return false;
+        }
+        else if (this[i] != array[i]) {
+            // Warning - two different object instances will never be equal: {x:20} != {x:20}
+            return false;
+        }
+    }
+    return true;
+}
+</code>
+will add an ''.equals'' call to arrays so you can use it as:
+<code javascript>
+var a = [ "a", "b" ];
+var b = [ "a", "c" ];
+alert(a.equals(b));
+</code>
+====== Linearly Map a Value in a Range into another Range ======
+Following the formula to [[fuss/mathematics/algebra#linearly_map_a_value_in_a_range_into_another_range|linearly map a value in a range to another range]], the javascript variation thereof can be found here.
+<code javascript>
+/*************************************************************************/
+/*    Copyright (C) 2015 Wizardry and Steamworks - License: GNU GPLv3    */
+/*************************************************************************/
+function wasMapValueToRange(value, xMin, xMax, yMin, yMax) {
+    return yMin + (
+        ( yMax - yMin ) * ( value - xMin ) / ( xMax - xMin )
+    );
+}
+</code>
+====== RGB Color to Hexadecimal Color ======
+<code javascript>
+function wasRGBToHex(r, g, b) {
+    return "#" + (
+        (1 << 24) +
+        (r << 16) +
+        (g << 8) +
+        b
+    ).toString(16).slice(1);
+}
+</code>
+where ''r'', ''g'' and ''b'' are in the range $[0-255]$.
+====== Hexadecimal Color to RGB Color ======
+<code javascript>
+function wasHexToRGB(hex) {
+    var shortRegEx = /^#?([a-f\d])([a-f\d])([a-f\d])$/i;
+    hex = hex.replace(
+        shortRegEx,
+        function(m, r, g, b) {
+            return r + r + g + g + b + b;
+        }
+    );
+    var result = /^#?([a-f\d]{2})([a-f\d]{2})([a-f\d]{2})$/i.exec(hex);
+    return result ? {
+        r: parseInt(result[1], 16),
+        g: parseInt(result[2], 16),
+        b: parseInt(result[3], 16)
+    } : null;
+}
+</code>
+where ''hex'' can be in long or short CSS notation.