/// <summary>
/// Converts a <see cref="System.Drawing.Bitmap"/> object into a <see cref="SharpDX.Direct2D1.Bitmap"/> object for rendering.
/// </summary>
/// <param name="renderTarget">The <see cref="SharpDX.Direct2D1.RenderTarget"/> object that images are drawn on.</param>
/// <param name="bmp">The .NET native bitmap image.</param>
/// <returns>A <see cref="SharpDX.Direct2D1.Bitmap"/> containing the image data retrieved from the <see cref="System.Drawing.Bitmap"/> object.</returns>
public static Bitmap FromSysBMP(RenderTarget renderTarget, SystemBitmap bmp)
{
var imageArea = new System.Drawing.Rectangle(0, 0, bmp.Width, bmp.Height);
var bmpProps = new BitmapProperties(new SharpDX.Direct2D1.PixelFormat(Format.R8G8B8A8_UNorm, AlphaMode.Premultiplied));
// Unmanaged buffer needs proper disposal
using (var dataStream = new DataStream(bmp.ByteSize(), true, true))
{
var bmpData = bmp.LockBits(imageArea, ImageLockMode.ReadOnly, System.Drawing.Imaging.PixelFormat.Format32bppPArgb);
for (int y = 0; y < bmp.Height; y++)
{
int offset = y * bmpData.Stride;
for (int x = 0; x < bmp.Width; x++)
{
// System bitmaps store pixel values as BGRA byte arrays
byte b = Marshal.ReadByte(bmpData.Scan0, offset++);
byte g = Marshal.ReadByte(bmpData.Scan0, offset++);
byte r = Marshal.ReadByte(bmpData.Scan0, offset++);
byte a = Marshal.ReadByte(bmpData.Scan0, offset++);
// Convert BGRA to RGBA (stored as a 32 bit = 4 byte integer)
int rgba = r | (g << 8) | (b << 16) | (a << 24);
// Write the RGBA value to the data buffer
dataStream.Write(rgba);
}
}
// Release the lock on the bitmap & reset the buffer position pointer
bmp.UnlockBits(bmpData);
dataStream.Position = 0;
return new Bitmap(renderTarget, new Size2(bmp.Width, bmp.Height), dataStream, bmpData.Stride, bmpProps);
}
}
