ZoomSliderHelper

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using SAS.Core.CommonObjects;

namespace SAS.Core.UtilityClasses {
    public class ZoomSliderHelper {
        private Range<double> m_ValueRange = new Range<double>(0, 100);
        public Range<double> ValueRange {
            get {
                return m_ValueRange;
            }
            set {
                m_ValueRange = value;
            }
        }

        private Range<double> m_ZoomRange = new Range<double>(0.1, 4);
        public Range<double> ZoomRange {
            get {
                return m_ZoomRange;
            }
            set {
                m_ZoomRange = value;
            }
        }

        public double ValStepSize {
            get {
                return m_ValueRange.Size / (m_NumSteps - 1);
            }
        }

        public double ZoomStepSize {
            get {
                return Math.Pow(m_ZoomRange.Max / m_ZoomRange.Min, ValStepSize / m_ValueRange.Max) - 1;
            }
        }

        private double m_NumSteps = 40;
        public double NumSteps {
            get {
                return m_NumSteps;
            }
            set {
                m_NumSteps = value;
            }
        }

        public double SliderToZoom(double val) {
            return m_ZoomRange.Min * Math.Pow(1 + ZoomStepSize, val / ValStepSize);
        }

        public double ZoomToSlider(double val) {
            return ValStepSize * Math.Log(val / m_ZoomRange.Min) / Math.Log(1 + ZoomStepSize);
        }
    }
}