/// <summary>
/// Repaint the control.
/// </summary>
/// <param name="zoomcenter">The point on which to center when zooming.</param>
/// <param name="hdcDest">The DC handle to paint on.</param>
private void Redraw(PointF zoomcenter, IntPtr hdcDest)
{
#if MAC
return;
#endif
// no map loaded
if (this.hdcSrcBackground == IntPtr.Zero)
{
Graphics gr = Graphics.FromHdc(hdcDest);
try
{
gr.Clear(Color.FromArgb(60, 60, 60));
}
catch { } // known bug in GDI: http://connect.microsoft.com/VisualStudio/feedback/ViewFeedback.aspx?FeedbackID=96873
gr.Dispose();
this.prevZoomFactor = this.zoomFactor;
return;
}
// scale & letterbox
this.Xout = false;
this.Yout = false;
if (this.Width > (fullWidth * this.zoomFactor))
{
this.rectSrc.X = 0;
this.rectSrc.Width = fullWidth;
this.rectDest.X = (this.Width - (fullWidth * this.zoomFactor)) / 2F;
this.rectDest.Width = fullWidth * this.zoomFactor;
Gdi32.BitBlt(hdcDest, 0, 0, (int)Math.Round(this.rectDest.X), this.Height, this.hdcSrcBackground, 0, 0, Gdi32.TernaryRasterOperations.BLACKNESS);
Gdi32.BitBlt(hdcDest, (int)Math.Round(this.rectDest.Right), 0, (int)Math.Round(this.rectDest.X), this.Height, this.hdcSrcBackground, 0, 0, Gdi32.TernaryRasterOperations.BLACKNESS);
}
else
{
this.rectSrc.X += ((this.Width / this.prevZoomFactor) - (this.Width / this.zoomFactor)) / ((this.Width + 0.001F) / zoomcenter.X);
this.rectSrc.Width = this.Width / this.zoomFactor;
this.rectDest.X = 0;
this.rectDest.Width = this.Width;
}
if (this.Height > (fullHeight * this.zoomFactor))
{
this.rectSrc.Y = 0;
this.rectSrc.Height = fullHeight;
this.rectDest.Y = (this.Height - (fullHeight * this.zoomFactor)) / 2F;
this.rectDest.Height = fullHeight * this.zoomFactor;
Gdi32.BitBlt(hdcDest, 0, 0, this.Width, (int)Math.Round(this.rectDest.Y), this.hdcSrcBackground, 0, 0, Gdi32.TernaryRasterOperations.BLACKNESS);
Gdi32.BitBlt(hdcDest, 0, (int)Math.Round(this.rectDest.Bottom), this.Width, (int)Math.Round(this.rectDest.Y), this.hdcSrcBackground, 0, 0, Gdi32.TernaryRasterOperations.BLACKNESS);
}
else
{
this.rectSrc.Y += ((this.Height / this.prevZoomFactor) - (this.Height / this.zoomFactor)) / ((this.Height + 0.001F) / zoomcenter.Y);
this.rectSrc.Height = this.Height / this.zoomFactor;
this.rectDest.Y = 0;
this.rectDest.Height = this.Height;
}
this.prevZoomFactor = this.zoomFactor;
if (this.rectSrc.Right > fullWidth)
{
this.Xout = true;
this.rectSrc.X = fullWidth - this.rectSrc.Width;
}
if (this.rectSrc.X < 0)
{
this.Xout = true;
this.rectSrc.X = 0;
}
if (this.rectSrc.Bottom > fullHeight)
{
this.Yout = true;
this.rectSrc.Y = fullHeight - this.rectSrc.Height;
}
if (this.rectSrc.Y < 0)
{
this.Yout = true;
this.rectSrc.Y = 0;
}
// draw
if (this.MapFastScaling)
{
Gdi32.SetStretchBltMode(hdcDest, Gdi32.StretchMode.STRETCH_DELETESCANS);
}
else
{
Gdi32.SetStretchBltMode(hdcDest, Gdi32.StretchMode.STRETCH_HALFTONE);
}
if (this.hdcSrcOverlay == IntPtr.Zero)
{
// no overlay, just draw resized
Gdi32.StretchBlt(hdcDest,
(int)Math.Round(rectDest.X),
(int)Math.Round(rectDest.Y),
(int)Math.Round(rectDest.Width),
(int)Math.Round(rectDest.Height),
this.hdcSrcBackground,
(int)Math.Round(rectSrc.X),
(int)Math.Round(rectSrc.Y),
(int)Math.Round(rectSrc.Width),
(int)Math.Round(rectSrc.Height),
Gdi32.TernaryRasterOperations.SRCCOPY);
}
else
{
// overlay, create merged image and draw
IntPtr hdcBuffer = Gdi32.CreateCompatibleDC(IntPtr.Zero);
//Gdi32.SetStretchBltMode( hdcBuffer, Gdi32.StretchMode.STRETCH_HALFTONE );
IntPtr hBmpBuffer = Gdi32.CreateCompatibleBitmap(hdcSrcBackground, (int)Math.Round(rectSrc.Width), (int)Math.Round(rectSrc.Height));
Gdi32.SelectObject(hdcBuffer, hBmpBuffer);
// copy background source rect into buffer
Gdi32.BitBlt(hdcBuffer,
0,
0,
(int)Math.Round(rectSrc.Width),
(int)Math.Round(rectSrc.Height),
hdcSrcBackground,
(int)Math.Round(rectSrc.X),
(int)Math.Round(rectSrc.Y),
Gdi32.TernaryRasterOperations.SRCCOPY);
// alpha blend overlay source rect into buffer
Gdi32.AlphaBlend(hdcBuffer,
0,
0,
(int)Math.Round(rectSrc.Width),
(int)Math.Round(rectSrc.Height),
hdcSrcOverlay,
(int)Math.Round(rectSrc.X),
(int)Math.Round(rectSrc.Y),
(int)Math.Round(rectSrc.Width),
(int)Math.Round(rectSrc.Height),
new Gdi32.BLENDFUNCTION(Gdi32.AC_SRC_OVER, 0, 0xff, Gdi32.AC_SRC_ALPHA));
// draw buffer to destination resized
Gdi32.StretchBlt(hdcDest,
(int)Math.Round(rectDest.X),
(int)Math.Round(rectDest.Y),
(int)Math.Round(rectDest.Width),
(int)Math.Round(rectDest.Height),
hdcBuffer,
0, 0,
(int)Math.Round(rectSrc.Width),
(int)Math.Round(rectSrc.Height),
Gdi32.TernaryRasterOperations.SRCCOPY);
// clean up buffer
Gdi32.DeleteDC(hdcBuffer);
hdcBuffer = IntPtr.Zero;
Gdi32.DeleteObject(hBmpBuffer);
hBmpBuffer = IntPtr.Zero;
}
}
/// <summary>
/// Load a new background map image into memory for display.
/// </summary>
/// <param name="image">The Bitmap to load (will be destroyed).</param>
public void LoadMap(Bitmap image)
{
if (this.hdcSrcBackground != IntPtr.Zero)
{
Gdi32.DeleteDC(this.hdcSrcBackground);
this.hdcSrcBackground = IntPtr.Zero;
Gdi32.DeleteObject(this.hBmpSrcBackground);
this.hBmpSrcBackground = IntPtr.Zero;
Gdi32.DeleteDC(this.hdcSrcOverlay);
this.hdcSrcOverlay = IntPtr.Zero;
Gdi32.DeleteObject(this.hBmpSrcOverlay);
this.hBmpSrcOverlay = IntPtr.Zero;
}
this.hdcSrcBackground = Gdi32.CreateCompatibleDC(IntPtr.Zero);
if (this.hdcSrcBackground == IntPtr.Zero)
{
throw new ApplicationException("CreateCompatibleDC() failed");
}
this.hBmpSrcBackground = image.GetHbitmap();
if (this.hBmpSrcBackground == IntPtr.Zero)
{
throw new ApplicationException("GetHbitmap() failed");
}
IntPtr ret = Gdi32.SelectObject(this.hdcSrcBackground, this.hBmpSrcBackground);
if (ret == IntPtr.Zero)
{
throw new ApplicationException("SelectObject() failed");
}
Size newMapSize = new Size(image.Width, image.Height);
this.fullHeight = newMapSize.Height;
this.fullWidth = newMapSize.Width;
if (newMapSize != prevMapSize) // recenter
{
PointF prevCenter = this.Center; // must have already called InitSize()
this.Center = new PointF((prevCenter.X / prevMapSize.Width) * newMapSize.Width,
(prevCenter.Y / prevMapSize.Height) * newMapSize.Height);
this.prevMapSize = newMapSize;
}
image.Dispose();
image = null;
GC.Collect();
// update map zoom
this.Zoom();
}