/// <summary>
/// Constructor
/// </summary>
public KnobColorTable()
{
_KnobFaceColor = new LinearGradientColorTable();
_KnobFaceColor.ColorTableChanged += KnobColorTableChanged;
_KnobIndicatorColor = new LinearGradientColorTable();
_KnobIndicatorColor.ColorTableChanged += KnobColorTableChanged;
_MinZoneIndicatorColor = new LinearGradientColorTable();
_MinZoneIndicatorColor.ColorTableChanged += KnobColorTableChanged;
_MaxZoneIndicatorColor = new LinearGradientColorTable();
_MaxZoneIndicatorColor.ColorTableChanged += KnobColorTableChanged;
_MidZoneIndicatorColor = new LinearGradientColorTable();
_MidZoneIndicatorColor.ColorTableChanged += KnobColorTableChanged;
}
/// <summary>
/// Renders a gradient indicator arc by dividing
/// the arc into sub-arcs, enabling us to utilize normal
/// rectangle gradient support
/// </summary>
/// <param name="g"></param>
/// <param name="a1">Starting angle</param>
/// <param name="s1">Sweep angle</param>
/// <param name="ct"></param>
private void RenderArc(Graphics g, float a1, float s1, LinearGradientColorTable ct)
{
float n1 = Math.Abs(s1);
Color c1 = ct.Start;
Color c2 = ct.End.IsEmpty == false ? ct.End : ct.Start;
// Calculate our rect and inflate to
// make room for the indicator arc
Rectangle rect = new
Rectangle(ZoneIndicatorBounds.Location, ZoneIndicatorBounds.Size);
int dw = (int)(ZoneIndWidth / 2);
rect.Inflate(-dw, -dw);
// Calculate the RGB color deltas
float dr = (c2.R - c1.R) / n1;
float dg = (c2.G - c1.G) / n1;
float db = (c2.B - c1.B) / n1;
// Set our initial starting color and range
Color c3 = Color.FromArgb(c1.ToArgb());
float s2 = s1;
float a2 = a1;
int pa = (s1 > 0) ? 100 : -100;
// Loop through the arc, processing sub-arcs less
// than 180 degrees so that we can use GDI+ built-in
// gradient rectangle support
while (s2 != 0)
{
// Limit our sweep angle pass to 90 degrees
float sw = (s2 > 0) ?
Math.Min(s2, 90) : Math.Max(s2, -90);
// Calculate our sub-sweep angle points. This
// enables us to create an associated bounding
// rectangle for the sub-sweep arc
Point pt1 = CalcCoord(a2);
Point pt2 = CalcCoord(a2 + sw);
Rectangle r = new Rectangle();
r.Location = new Point(Math.Min(pt1.X, pt2.X), Math.Min(pt1.Y, pt2.Y));
r.Size = new Size(Math.Abs(pt1.X - pt2.X), Math.Abs(pt1.Y - pt2.Y));
if (r.Width == 0)
r.Width = 1;
if (r.Height == 0)
r.Height = 1;
// Calculate the terminal color for the
// sub-sweep arc
float n = Math.Abs(sw);
int red = (int)(c3.R + n * dr);
red = Math.Max(Math.Min(red, 255), 0);
int green = (int)(c3.G + n * dg);
green = Math.Max(Math.Min(green, 255), 0);
int blue = (int)(c3.B + n * db);
blue = Math.Max(Math.Min(blue, 255), 0);
Color c4 = Color.FromArgb(red, green, blue);
// Tally up this sub-sweep
s2 -= sw;
// Render the sub-arc with an appropriately
// orientated gradient brush, and draw the arc
using (LinearGradientBrush lbr = new LinearGradientBrush(r, c3, c4, a2 + pa))
{
using (Pen pen = new Pen(lbr, (int)ZoneIndWidth))
g.DrawArc(pen, rect, a2, sw);
}
// Bump up our starting angle to reflect the
// processing of this sub-arc
a2 += sw;
// Set the next starting color to the
// ending color for this arc
c3 = c4;
}
// Render the bounding indicator arcs
using (GraphicsPath p1 = new GraphicsPath())
{
rect.Inflate(-dw, -dw);
p1.AddArc(ZoneIndicatorBounds, a1, s1);
p1.AddArc(rect, a1 + s1, -s1);
// Let Windows close the arcs, and then
// render them
p1.CloseFigure();
using (Pen pen = new Pen(ZoneIndicatorColor, MinorTickSize.Width))
g.DrawPath(pen, p1);
}
}
/// <summary>
/// ApplyColor
/// </summary>
/// <param name="c"></param>
/// <param name="d"></param>
/// <returns></returns>
private LinearGradientColorTable ApplyColor(
LinearGradientColorTable c, LinearGradientColorTable d)
{
if (c.IsEmpty == true)
return (d);
if (c.Start.IsEmpty == false && c.End.IsEmpty == false)
return (c);
return (new LinearGradientColorTable(
c.Start.IsEmpty ? d.Start : c.Start,
c.End.IsEmpty ? d.End : c.End, c.GradientAngle));
}
/// <summary>
/// MyColorConverter
/// </summary>
/// <param name="ct">ColorTable</param>
/// <param name="cvt">ColorConverter</param>
/// <returns>string or null</returns>
private string MyColorConverter(LinearGradientColorTable ct, ColorConverter cvt)
{
if (ct.Start.IsEmpty == false)
return (cvt.ConvertToString(ct.Start));
if (ct.End.IsEmpty == false)
return (cvt.ConvertToString(ct.Start));
return (null);
}
public void ResetMidZoneIndicatorColor()
{
MidZoneIndicatorColor = LinearGradientColorTable.Empty;
}
public void ResetKnobIndicatorColor()
{
KnobIndicatorColor = LinearGradientColorTable.Empty;
}
public void ResetKnobFaceColor()
{
KnobFaceColor = LinearGradientColorTable.Empty;
}
