public void DrawImage(INativeImage image, int x, int y)
{
x += offset.X;
y += offset.Y;
// todo: allow null?
Win32Image win32Image = (Win32Image)image;
var bitmap = Gdi32API.CreateDIBSectionChecked(hdc, new BITMAPINFO(win32Image.Width, win32Image.Height), out IntPtr buffer);
IntPtr hdcMem = IntPtr.Zero;
try
{
Marshal.Copy(win32Image.Pixels, 0, buffer, win32Image.Pixels.Length);
hdcMem = Gdi32API.CreateCompatibleDCChecked(hdc);
var oldBitmap = Gdi32API.SelectObjectChecked(hdcMem, bitmap);
Gdi32API.GdiAlphaBlend
(
hdc,
x, y, win32Image.Width, win32Image.Height,
hdcMem,
0, 0, win32Image.Width, win32Image.Height,
BLENDFUNCTION.SourceAlpha()
);
Gdi32API.SelectObjectChecked(hdcMem, oldBitmap);
}
finally
{
Gdi32API.SafeDeleteObject(hdcMem);
Gdi32API.DeleteObject(bitmap);
}
}
public static Win32Bitmap Create(IntPtr hdc, int width, int height)
{
IntPtr bitmapPtr = IntPtr.Zero;
IntPtr bitmapHdc = IntPtr.Zero;
try
{
bitmapPtr = Gdi32API.CreateCompatibleBitmapChecked(hdc, width, height);
bitmapHdc = Gdi32API.CreateCompatibleDCChecked(hdc);
Gdi32API.SelectObjectChecked(bitmapHdc, bitmapPtr);
var bitmap = new Win32Bitmap(bitmapPtr, bitmapHdc, width, height);
bitmapPtr = IntPtr.Zero;
bitmapHdc = IntPtr.Zero;
return(bitmap);
}
finally
{
if (bitmapHdc != IntPtr.Zero)
{
Gdi32API.DeleteDC(bitmapHdc);
}
if (bitmapPtr != IntPtr.Zero)
{
Gdi32API.DeleteObject(bitmapPtr);
}
}
}
private void WithTransparentCanvas(Rectangle rect, byte alpha, bool copySource, Action <Win32Canvas> action)
{
if (rect.Width <= 0 || rect.Height <= 0 || alpha == 0)
{
return;
}
IntPtr memoryHdc = Gdi32API.CreateCompatibleDCChecked(hdc);
try
{
IntPtr memoryBitmap = Gdi32API.CreateCompatibleBitmapChecked(hdc, rect.Width, rect.Height);
try
{
var originalBitmap = Gdi32API.SelectObjectChecked(memoryHdc, memoryBitmap);
try
{
if (copySource)
{
Gdi32API.BitBlt(memoryHdc, 0, 0, rect.Width, rect.Height, hdc, rect.X, rect.Y, GDI32RasterOperation.SRCCOPY);
}
using (Win32Canvas memoryCanvas = new Win32Canvas(memoryHdc, offset, objectCache))
{
action(memoryCanvas);
}
Gdi32API.GdiAlphaBlend
(
hdc,
rect.X, rect.Y, rect.Width, rect.Height,
memoryHdc,
0, 0, rect.Width, rect.Height,
BLENDFUNCTION.ConstantAlpha(alpha)
);
}
finally
{
Gdi32API.SelectObjectChecked(memoryHdc, originalBitmap);
}
}
finally
{
Gdi32API.DeleteObject(memoryBitmap);
}
}
finally
{
Gdi32API.DeleteDC(memoryHdc);
}
}
public void SetClipRectangle(int x, int y, int width, int height)
{
x += offset.X;
y += offset.Y;
var region = Gdi32API.CreateRectRgnChecked(x, y, x + width, y + height);
try
{
Gdi32API.SelectClipRgn(hdc, region);
}
finally
{
Gdi32API.DeleteObject(region);
}
}
private void FillOpaqueRectangleGDI(Color color, int x, int y, int width, int height)
{
// todo: check that width and height are exact
var region = Gdi32API.CreateRectRgnChecked(x, y, x + width, y + height);
try
{
// todo: pick FillRgn or PaintRgn
Gdi32API.FillRgn(hdc, region, objectCache.GetSolidBrush(color));
// SelectSolidBrush(color);
// Gdi32API.PaintRgn(hdc, region);
}
finally
{
Gdi32API.DeleteObject(region);
}
}
public void Dispose()
{
Gdi32API.DeleteDC(bitmapHdc);
Gdi32API.DeleteObject(bitmapPtr);
}
