Add SCSS Math functions

assets/styles/main.scss

@@ -13,6 +13,7 @@
 // Tools
 // ==========================================================================
 
+@import "tools/maths";
 @import "tools/functions";
 @import "tools/mixins";
 @import "tools/fonts";

assets/styles/tools/_maths.scss

@@ -0,0 +1,123 @@
+// ==========================================================================
+// Tools / Maths
+// ==========================================================================
+
+// Remove units from the given number
+// @param  {number} $number The number with units
+// @return {number}
+
+@function strip-units($number) {
+    @return $number / ($number * 0 + 1);
+}
+
+// Square root function
+//
+// @param  {string} $number     The number
+// @return {string}             The sqrt number
+
+@function sqrt($number) {
+    $x: 1;
+    $value: $x;
+    @for $i from 1 through 10 {
+    $value: $x - ($x * $x - abs($number)) / (2 * $x);
+    $x: $value;
+    }
+    @return $value;
+}
+
+// Power function
+//
+// @param  {number} $number Number to apply power
+// @param  {number} $exp    The exponant for the power
+// @return {number}         The powered number
+
+@function pow($number, $exp) {
+    $value: 1;
+    @if $exp > 0 {
+        @for $i from 1 through $exp {
+            $value: $value * $number;
+        }
+    } @else if $exp < 0 {
+        @for $i from 1 through -$exp {
+            $value: $value / $number;
+        }
+    }
+    @return $value;
+}
+
+// Factorial function
+//
+// @param  {number} $number The number to factorize
+// @return {number}         The factorised number
+
+@function fact($number) {
+    $value: 1;
+    @if $number > 0 {
+        @for $i from 1 through $number {
+            $value: $value * $i;
+        }
+    }
+    @return $value;
+}
+
+// Pi reference
+//
+// @return {number} Retrun PI with 11 decimals
+
+@function pi() {
+    @return 3.14159265359;
+}
+
+// Convert deg to rad
+//
+// @param  {string} $angle The angle to convert
+// @return {number}        The unitless angle converted to rad
+
+@function rad($angle) {
+    $unit: unit($angle);
+    $unitless: $angle / ($angle * 0 + 1);
+    // If the angle has 'deg' as unit, convert to radians.
+    @if $unit == deg {
+        $unitless: $unitless / 180 * pi();
+    }
+    @return $unitless;
+}
+
+// Calculate the sinus of an angle
+//
+// @param  {string} $angle The angle to compute
+// @return {number}        The sinus of the given angle
+
+@function sin($angle) {
+    $sin: 0;
+    $angle: rad($angle);
+    // Iterate a bunch of times.
+    @for $i from 0 through 10 {
+        $sin: $sin + pow(-1, $i) * pow($angle, (2 * $i + 1)) / fact(2 * $i + 1);
+    }
+    @return $sin;
+}
+
+// Calculate the cosinus of an angle
+//
+// @param  {string} $angle The angle to compute
+// @return {number}        The cosinus of the given angle
+
+@function cos($angle) {
+    $cos: 0;
+    $angle: rad($angle);
+    // Iterate a bunch of times.
+    @for $i from 0 through 10 {
+        $cos: $cos + pow(-1, $i) * pow($angle, 2 * $i) / fact(2 * $i);
+    }
+    @return $cos;
+}
+
+// Calculate the tangent of an angle
+//
+// @param  {string} $angle The angle to compute
+// @return {number}        The tangent of the given angle
+
+@function tan($angle) {
+    @return sin($angle) / cos($angle);
+}