/// <summary>
/// Draw the image on the graphics with GDI+ blur effect
/// </summary>
/// <returns>false if there is no GDI+ available or an exception occured</returns>
public static bool DrawWithBlur(Graphics graphics, Bitmap image, Rectangle source, Matrix transform, ImageAttributes imageAttributes, int radius, bool expandEdges)
{
if (!IsBlurPossible(radius))
{
return(false);
}
var hBlurParams = IntPtr.Zero;
var hEffect = IntPtr.Zero;
try
{
// Create a BlurParams struct and set the values
var blurParams = BlurParams.Create(radius, expandEdges);
// Allocate space in unmanaged memory
hBlurParams = Marshal.AllocHGlobal(Marshal.SizeOf(blurParams));
// Copy the structure to the unmanaged memory
Marshal.StructureToPtr(blurParams, hBlurParams, true);
// Create the GDI+ BlurEffect, using the Guid
var status = GdipCreateEffect(BlurEffectGuid, out hEffect);
if (status != GdiPlusStatus.Ok)
{
Log.Error().WriteLine("Couldn't create effect {0}: {1}", BlurEffectGuid, status);
return(false);
}
// Set the blurParams to the effect
status = GdipSetEffectParameters(hEffect, hBlurParams, (uint)Marshal.SizeOf(blurParams));
if (status != GdiPlusStatus.Ok)
{
Log.Error().WriteLine("Couldn't apply parameters: {0}", status);
return(false);
}
// Somewhere it said we can use destinationBitmap.GetHbitmap(), this doesn't work!!
// Get the private nativeImage property from the Bitmap
var hBitmap = GetNativeImage(image);
var hGraphics = GetNativeGraphics(graphics);
var hMatrix = GetNativeMatrix(transform);
var hAttributes = GetNativeImageAttributes(imageAttributes);
// Create a RECT from the Rectangle
NativeRectFloat sourceRectangleF = source;
// Apply the effect to the bitmap in the specified area
status = GdipDrawImageFX(hGraphics, hBitmap, ref sourceRectangleF, hMatrix, hEffect, hAttributes, GpUnit.UnitPixel);
if (status == GdiPlusStatus.Ok)
{
// Everything worked, return true
return(true);
}
Log.Error().WriteLine("Couldn't draw image: {0}", status);
return(false);
}
catch (Exception ex)
{
_isBlurEnabled = false;
Log.Error().WriteLine(ex, "Problem using GdipDrawImageFX: ");
return(false);
}
finally
{
try
{
if (hEffect != IntPtr.Zero)
{
// Delete the effect
var status = GdipDeleteEffect(hEffect);
if (status != GdiPlusStatus.Ok)
{
Log.Error().WriteLine("Couldn't delete effect: {0}", status);
}
}
if (hBlurParams != IntPtr.Zero)
{
// Free the memory
Marshal.FreeHGlobal(hBlurParams);
}
}
catch (Exception ex)
{
_isBlurEnabled = false;
Log.Error().WriteLine(ex, "Problem cleaning up DrawWithBlur: ");
}
}
}
