MathExtensions.cs

namespace asim.unity.extensions
{
    public static class MathExtensions
    {
        //====================================================================================================
        //====================================================================================================

        /// <summary>
        /// Remap the current value from a current range to another range
        /// e.g remap value of 0.5f with range of 0-1 to range of 0-255 will return 127.5f
        /// </summary>
        public static float remap(this float value,
            float startMin, float startMax, float endMin, float endMax)
        {
            return endMin + (endMax - endMin) * ((value - startMin) / (startMax - startMin));
        }

        /// <summary>
        /// Remap the current value from a current range to another range
        /// e.g remap value of 0.5 with range of 0-1 to range of 0-255 will return 127.5
        /// </summary>
        public static double remap(this double value,
            double startMin, double startMax, double endMin, double endMax)
        {
            return endMin + (endMax - endMin) * ((value - startMin) / (startMax - startMin));
        }

        //====================================================================================================
        //====================================================================================================

        /// <summary>
        /// modulus that works with negative numbers
        /// e.g mod(-2,5) = 3 , e.g mod(-2,-5) = 3
        /// </summary>
        public static int mod(int a, int b)
        {
            int m = a % b;
            if (m < 0)
            {
                m = (b < 0) ? m - b : m + b;
            }

            return m;
        }
        /// <summary>
        /// modulus that works with negative divisors and returns based on negative number
        /// e.g mod(2,-5) = -3
        /// </summary>
        public static int nagativemod(int a, int b)
        {
            int m = a % b;
            if (m < 0)
            {
                m = (b < 0) ? m - b : m + b;
            }

            return m;
        }
        //====================================================================================================
        //====================================================================================================

        /// <summary>
        /// Count the number between indices in a list, looped
        /// </summary>
        public static int CountFromToIndexLoop(int start, int end, int listCount)
        {
            int count = end - start;
            if (count < 0) count += listCount;
            return count;
        }
        public static int IndexLoop(int index, int max)
        {
            if (index < 0) return index + max;
            return index % max;
        }
    }
}