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using System;
using System.Drawing;
namespace QuickRoute.BusinessEntities
{
public enum PenStyles
{
PS_SOLID = 0,
PS_DASH = 1,
PS_DOT = 2,
PS_DASHDOT = 3,
PS_DASHDOTDOT = 4
}
public static class RubberBandRectangle
{
// These values come from the larger set of defines in WinGDI.h,
// but are all that are needed for this application. If this class
// is expanded for more generic rectangle drawing, they should be
// replaced by enums from those sets of defones.
private const int NULL_BRUSH = 5;
private const int R2_XORPEN = 7;
private const int BLACK_PEN = 0;
public static void DrawXORRectangle( Graphics grp, int X1, int Y1, int X2, int Y2, PenStyles PenStyle )
{
// Extract the Win32 HDC from the Graphics object supplied.
IntPtr hdc = grp.GetHdc();
// Create a pen with a dotted style to draw the border of the
// rectangle.
IntPtr gdiPen = CreatePen( PenStyle,
1, BLACK_PEN );
// Set the ROP cdrawint mode to XOR.
SetROP2( hdc, R2_XORPEN );
// Select the pen into the device context.
IntPtr oldPen = SelectObject( hdc, gdiPen );
// Create a stock NULL_BRUSH brush and select it into the device
// context so that the rectangle isn't filled.
IntPtr oldBrush = SelectObject( hdc,
GetStockObject( NULL_BRUSH ) );
// Now XOR the hollow rectangle on the Graphics object with
// a dotted outline.
Rectangle( hdc, X1, Y1, X2, Y2 );
// Put the old stuff back where it was.
SelectObject( hdc, oldBrush ); // no need to delete a stock object
SelectObject( hdc, oldPen );
DeleteObject( gdiPen ); // but we do need to delete the pen
// Return the device context to Windows.
grp.ReleaseHdc( hdc );
}
// Use Interop to call the corresponding Win32 GDI functions
[System.Runtime.InteropServices.DllImportAttribute( "gdi32.dll" )]
private static extern int SetROP2(
IntPtr hdc, // Handle to a Win32 device context
int enDrawMode // Drawing mode
);
[System.Runtime.InteropServices.DllImportAttribute( "gdi32.dll" )]
private static extern IntPtr CreatePen(
PenStyles enPenStyle, // Pen style from enum PenStyles
int nWidth, // Width of pen
int crColor // Color of pen
);
[System.Runtime.InteropServices.DllImportAttribute( "gdi32.dll" )]
private static extern bool DeleteObject(
IntPtr hObject // Win32 GDI handle to object to delete
);
[System.Runtime.InteropServices.DllImportAttribute( "gdi32.dll" )]
private static extern IntPtr SelectObject(
IntPtr hdc, // Win32 GDI device context
IntPtr hObject // Win32 GDI handle to object to select
);
[System.Runtime.InteropServices.DllImportAttribute( "gdi32.dll" )]
private static extern void Rectangle(
IntPtr hdc, // Handle to a Win32 device context
int X1, // x-coordinate of top left corner
int Y1, // y-cordinate of top left corner
int X2, // x-coordinate of bottom right corner
int Y2 // y-coordinate of bottm right corner
);
[System.Runtime.InteropServices.DllImportAttribute( "gdi32.dll" )]
private static extern IntPtr GetStockObject(
int brStyle // Selected from the WinGDI.h BrushStyles enum
);
// C# version of Win32 RGB macro
private static int RGB( int R, int G, int B )
{
return ( R | (G<<8) | (B<<16) );
}
}
public static class GraphicsUtil
{
public static Color AlphaAdjustColor(Color color, double alphaAdjustment)
{
alphaAdjustment = Math.Max(-1, Math.Min(1, alphaAdjustment));
int alpha;
if (alphaAdjustment < 0)
{
alpha = (int)((1 + alphaAdjustment) * (double)color.A);
}
else
{
alpha = (int)((double)color.A + (double)(255 - color.A) * alphaAdjustment);
}
return Color.FromArgb(alpha, color);
}
public static double CombineAlphaAdjustments(double aa1, double aa2)
{
if(aa2 < 0)
{
return aa1 - (aa2 + 1) * (aa1 + 1);
}
return aa1 + (1 - aa2)*(1 - aa1);
}
public static Color CombineColors(params Color[] colors)
{
int a = 0, r = 0, g = 0, b = 0;
foreach(var color in colors)
{
a += color.A;
r += color.R;
g += color.G;
b += color.B;
}
return Color.FromArgb(
(int)Math.Round((double)a / colors.Length),
(int)Math.Round((double)r / colors.Length),
(int)Math.Round((double)g / colors.Length),
(int)Math.Round((double)b / colors.Length));
}
}
}
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