public PicViewer()
{
InitializeComponent();
DoubleBuffered = true;
Font = new Font("Tahoma", 8.25f, FontStyle.Regular);
MinScale = minZoom;
MaxScale = maxZoom;
CurrentScale = 1.0f;
var ck = new Curve();
ck.Add(0.0f, 1.0f);
ck.Add(0.75f, 3.0f);
ck.Add(1.0f, 6.0f);
ZoomCurve = ck;
}
public static float CatRomEval(Curve curve, float t)
{
if (curve == null || curve.Keys.Count == 0)
{
return 0.0f;
}
int i2 = 0;
foreach (var a in curve.Keys)
{
if (t < a.Time)
{
break;
}
i2++;
}
if (i2 == 0)
{
return curve.Keys[0].Value;
}
if (i2 == curve.Keys.Count)
{
return curve.Keys[curve.Keys.Count - 1].Value;
}
int i1 = i2 - 1;
// Previous point if it exists, otherwise point opposite first from second:
// Four points are: prev-first-second-next
float prevValue, nextValue;
if (i1 == 0)
{
prevValue = 2.0f * curve.Keys[i1].Value + (-1.0f * curve.Keys[i2].Value);
}
else
{
prevValue = curve.Keys[i1 - 1].Value;
}
// Previous point if it exists, otherwise point opposite second from first
int n = i2 + 1;
if (n >= curve.Keys.Count - 1)
{
nextValue = 2.0f * curve.Keys[i2].Value + (-1.0f * curve.Keys[i1].Value);
}
else
{
nextValue = curve.Keys[n].Value;
}
// interp
t = (t - curve.Keys[i1].Time) / (curve.Keys[i2].Time - curve.Keys[i1].Time);
return ((-t + 2.0f) * t - 1.0f) * t / 2.0f * prevValue +
(((3.0f * t - 5.0f) * t) * t + 2.0f) / 2.0f * curve.Keys[i1].Value +
((-3.0f * t + 4.0f) * t + 1.0f) * t / 2.0f * curve.Keys[i2].Value +
((t - 1.0f) * t * t) / 2.0f * nextValue;
}