void Paint (WidgetType widgetType, Rectangle bounds, IDeviceContext dc, TransparencyType transparencyType, Color background, DeviceContextType deviceContextType, Rectangle clippingArea, Painter painter, Rectangle excludedArea)
{
Rectangle painted_area = Rectangle.Intersect (bounds, clippingArea);
if (painted_area.Width == 0 || painted_area.Height == 0)
return;
painted_area.Offset (-bounds.X, -bounds.Y);
excludedArea.Offset (-bounds.X, -bounds.Y);
GdkDrawablePointer drawable = gdk_pixmap_new (IntPtr.Zero, bounds.Width, bounds.Height, 24);
painter.AttachStyle (widgetType, drawable, this);
GdkPixbufPointer pixbuf;
IntPtr pixel_data;
int rowstride;
GdkGCPointer gc = gdk_gc_new (drawable);
GdkColor color = new GdkColor (background);
gdk_gc_set_rgb_fg_color (gc, ref color);
Paint (drawable, gc, bounds, widgetType, out pixbuf, out pixel_data, out rowstride, painted_area, painter, excludedArea);
GdkPixbufPointer white_pixbuf = IntPtr.Zero;
IntPtr white_pixel_data = IntPtr.Zero;
int white_rowstride = 0;
GdkColor white_color = new GdkColor();
if (transparencyType == TransparencyType.Alpha) {
white_color.red = guint16.MaxValue;
white_color.green = guint16.MaxValue;
white_color.blue = guint16.MaxValue;
gdk_gc_set_rgb_fg_color (gc, ref white_color);
Paint (drawable, gc, bounds, widgetType, out white_pixbuf, out white_pixel_data, out white_rowstride, painted_area, painter, excludedArea);
}
g_object_unref (gc);
unsafe {
byte* row = (byte*)pixel_data;
byte* pixel;
byte* white_row = (byte*)white_pixel_data;
byte* white_pixel;
for (int row_index = 0; row_index < painted_area.Height; row_index++) {
pixel = row;
white_pixel = white_row;
for (int pixel_index = 0; pixel_index < painted_area.Width; pixel_index++) {
const int GdkRedOffset = 0;
const int GdkGreenOffset = 1;
const int GdkBlueOffset = 2;
const int BitmapAlphaOffset = 3;
const int BitmapRedOffset = 2;
const int BitmapBlueOffset = 0;
switch (transparencyType) {
case TransparencyType.Alpha:
pixel [BitmapAlphaOffset] = (byte)(pixel [GdkRedOffset] - white_pixel [GdkRedOffset] + byte.MaxValue);
break;
case TransparencyType.Color:
if (
pixel [GdkRedOffset] == background.R &&
pixel [GdkGreenOffset] == background.G &&
pixel [GdkBlueOffset] == background.B) {
const int AlphaFullyTransparent = 0;
pixel [BitmapAlphaOffset] = AlphaFullyTransparent;
}
break;
}
byte temporary = pixel [GdkRedOffset];
pixel [BitmapBlueOffset] = pixel [GdkBlueOffset];
pixel [BitmapRedOffset] = temporary;
const int PixelSize = 4;
pixel += PixelSize;
white_pixel += PixelSize;
}
row += rowstride;
white_row += white_rowstride;
}
}
if (transparencyType == TransparencyType.Alpha)
g_object_unref (white_pixbuf);
g_object_unref (drawable);
Bitmap bitmap = new Bitmap (painted_area.Width, painted_area.Height, rowstride, PixelFormat.Format32bppPArgb, pixel_data);
Graphics g;
bool graphics_is_from_hdc = false;
switch (deviceContextType) {
case DeviceContextType.Graphics:
g = (Graphics)dc;
break;
case DeviceContextType.Native:
g = Graphics.FromHdc (dc.GetHdc ());
break;
default:
g = dc as Graphics;
if (g == null) {
graphics_is_from_hdc = true;
g = Graphics.FromHdc (dc.GetHdc ());
} else
graphics_is_from_hdc = false;
break;
}
painted_area.Offset (bounds.X, bounds.Y);
g.DrawImage (bitmap, painted_area.Location);
switch (deviceContextType) {
case DeviceContextType.Graphics:
break;
case DeviceContextType.Native:
g.Dispose ();
dc.ReleaseHdc ();
break;
default:
if (graphics_is_from_hdc) {
g.Dispose ();
dc.ReleaseHdc ();
}
break;
}
bitmap.Dispose ();
g_object_unref (pixbuf);
}
