private void CalcCoordsAndUpdate(ColorHandler.Hsv hsv)
{
// Convert color to real-world coordinates and then calculate
// the various points. HSV.Hue represents the degrees (0 to 360),
// HSV.Saturation represents the radius.
// This procedure doesn't draw anything--it simply
// updates class-level variables. The UpdateDisplay
// procedure uses these values to update the screen.
// Given the angle (HSV.Hue), and distance from
// the center (HSV.Saturation), and the center,
// calculate the point corresponding to
// the selected color, on the color wheel.
_colorPoint = GetPoint((double)hsv.Hue / 255 * 360, (double)hsv.Saturation / 255 * _radius, _centerPoint);
// Given the brightness (HSV.value), calculate the
// point corresponding to the brightness indicator.
_brightnessPoint = CalcBrightnessPoint(hsv.Value);
// Store information about the selected color.
_brightness = hsv.Value;
_selectedColor = ColorHandler.HsvToColor(hsv);
_argb = ColorHandler.HsvToRgb(hsv);
// The full color is the same as HSV, except that the
// brightness is set to full (255). This is the top-most
// color in the brightness gradient.
_fullColor = ColorHandler.HsvToColor(hsv.Alpha, hsv.Hue, hsv.Saturation, 255);
}
public void Draw(Graphics g, Point mousePoint)
{
try
{
// You've moved the mouse.
// Now update the screen to match.
// Keep track of the previous color pointer point,
// so you can put the mouse there in case the
// user has clicked outside the circle.
Point newColorPoint = _colorPoint;
Point newBrightnessPoint = _brightnessPoint;
// Store this away for later use.
_g = g;
if (_currentState == MouseState.MouseUp)
{
if (!mousePoint.IsEmpty)
{
if (_colorRegion.IsVisible(mousePoint))
{
// Is the mouse point within the color circle?
// If so, you just clicked on the color wheel.
_currentState = MouseState.ClickOnColor;
}
else if (_brightnessRegion.IsVisible(mousePoint))
{
// Is the mouse point within the brightness area?
// You clicked on the brightness area.
_currentState = MouseState.ClickOnBrightness;
}
else
{
// Clicked outside the color and the brightness
// regions. In that case, just put the
// pointers back where they were.
_currentState = MouseState.ClickOutsideRegion;
}
}
}
switch (_currentState)
{
case MouseState.ClickOnBrightness:
case MouseState.DragInBrightness:
// Calculate new color information
// based on the brightness, which may have changed.
Point newPoint = mousePoint;
if (newPoint.Y < _brightnessMin)
{
newPoint.Y = _brightnessMin;
}
else if (newPoint.Y > _brightnessMax)
{
newPoint.Y = _brightnessMax;
}
newBrightnessPoint = new Point(_brightnessX, newPoint.Y);
_brightness = (int)((_brightnessMax - newPoint.Y) * _brightnessScaling);
_hsv.Value = _brightness;
_brightness = byte.MaxValue;
_argb = ColorHandler.HsvToRgb(_hsv);
_brightness = (_argb.Red + _argb.Green + _argb.Blue) / 3;
break;
case MouseState.ClickOnColor:
case MouseState.DragInColor:
// Calculate new color information
// based on selected color, which may have changed.
newColorPoint = mousePoint;
// Calculate x and y distance from the center,
// and then calculate the angle corresponding to the
// new location.
Point delta = new Point(mousePoint.X - _centerPoint.X, mousePoint.Y - _centerPoint.Y);
int degrees = CalcDegrees(delta);
// Calculate distance from the center to the new point
// as a fraction of the radius. Use your old friend,
// the Pythagorean theorem, to calculate this value.
double distance = Math.Sqrt(delta.X * delta.X + delta.Y * delta.Y) / _radius;
if (_currentState == MouseState.DragInColor)
{
if (distance > 1)
{
// Mouse is down, and outside the circle, but you
// were previously dragging in the color circle.
// What to do?
// In that case, move the point to the edge of the
// circle at the correct angle.
distance = 1;
newColorPoint = GetPoint(degrees, _radius, _centerPoint);
}
}
// Calculate the new HSV and RGB values.
_hsv.Hue = (degrees * 255 / 360);
_hsv.Saturation = (int)(distance * 255);
_brightness = byte.MaxValue;
_hsv.Value = _brightness;
_argb = ColorHandler.HsvToRgb(_hsv);
if (_argb.Red < 0 || _argb.Red > byte.MaxValue || _argb.Green < 0 || _argb.Green > byte.MaxValue || _argb.Blue < 0 || _argb.Blue > byte.MaxValue)
{
UpdateDisplay();
return;
}
_brightness = (_argb.Red + _argb.Green + _argb.Blue) / 3;
_fullColor = ColorHandler.HsvToColor(_hsv.Alpha, _hsv.Hue, _hsv.Saturation, 255);
break;
}
_selectedColor = ColorHandler.HsvToColor(_hsv);
// Raise an event back to the parent form,
// so the form can update any UI it's using
// to display selected color values.
OnColorChanged(_argb, _hsv);
// On the way out, set the new state.
switch (_currentState)
{
case MouseState.ClickOnBrightness:
_currentState = MouseState.DragInBrightness;
break;
case MouseState.ClickOnColor:
_currentState = MouseState.DragInColor;
break;
case MouseState.ClickOutsideRegion:
_currentState = MouseState.DragOutsideRegion;
break;
}
// Store away the current points for next time.
_colorPoint = newColorPoint;
_brightnessPoint = newBrightnessPoint;
// Draw the gradients and points.
UpdateDisplay();
}
catch (Exception e)
{
System.Windows.Forms.MessageBox.Show(e.Message);
}
}