Pinta.ImageManipulation.Effects.AddNoiseEffect.InitLookup C# (CSharp) Method

		private static void InitLookup ()
		{
			double l = 5;
			double r = 10;
			double scale = 50;
			double sum = 0;

			while (r - l > 0.0000001) {
				sum = 0;
				scale = (l + r) * 0.5;

				for (var i = 0; i < tableSize; ++i) {
					sum += NormalCurve (16.0 * ((double)i - tableSize / 2) / tableSize, scale);

					if (sum > 1000000) {
						break;
					}
				}

				if (sum > tableSize) {
					r = scale;
				} else if (sum < tableSize) {
					l = scale;
				} else {
					break;
				}
			}

			lookup = new int[tableSize];
			sum = 0;
			int roundedSum = 0, lastRoundedSum;

			for (var i = 0; i < tableSize; ++i) {
				sum += NormalCurve (16.0 * ((double)i - tableSize / 2) / tableSize, scale);
				lastRoundedSum = roundedSum;
				roundedSum = (int)sum;

				for (var j = lastRoundedSum; j < roundedSum; ++j) {
					lookup[j] = (i - tableSize / 2) * 65536 / tableSize;
				}
			}
		}
		#endregion