public void SaveScreenshot(string path)
{
var s = window.SurfaceSize;
var raw = new byte[s.Width * s.Height * 4];
OpenGL.glPushClientAttrib(OpenGL.GL_CLIENT_PIXEL_STORE_BIT);
OpenGL.glPixelStoref(OpenGL.GL_PACK_ROW_LENGTH, s.Width);
OpenGL.glPixelStoref(OpenGL.GL_PACK_ALIGNMENT, 1);
unsafe
{
fixed(byte *pRaw = raw)
OpenGL.glReadPixels(0, 0, s.Width, s.Height,
OpenGL.GL_BGRA, OpenGL.GL_UNSIGNED_BYTE, (IntPtr)pRaw);
}
OpenGL.glFinish();
OpenGL.glPopClientAttrib();
ThreadPool.QueueUserWorkItem(_ =>
{
// Convert GL pixel data into format expected by png
// - Flip vertically
// - BGRA to RGBA
// - Force A to 255 (no transparent pixels!)
var data = new byte[raw.Length];
for (var y = 0; y < s.Height; y++)
{
for (var x = 0; x < s.Width; x++)
{
var iData = 4 * (y * s.Width + x);
var iRaw = 4 * ((s.Height - y - 1) * s.Width + x);
data[iData] = raw[iRaw + 2];
data[iData + 1] = raw[iRaw + 1];
data[iData + 2] = raw[iRaw + 0];
data[iData + 3] = byte.MaxValue;
}
}
var screenshot = new Png(data, window.SurfaceSize.Width, window.SurfaceSize.Height);
screenshot.Save(path);
});
}
public Bitmap TakeScreenshot()
{
var rect = new Rectangle(Point.Empty, WindowSize);
var bitmap = new Bitmap(rect.Width, rect.Height, System.Drawing.Imaging.PixelFormat.Format32bppArgb);
var data = bitmap.LockBits(rect,
System.Drawing.Imaging.ImageLockMode.WriteOnly, System.Drawing.Imaging.PixelFormat.Format32bppArgb);
OpenGL.glPushClientAttrib(OpenGL.GL_CLIENT_PIXEL_STORE_BIT);
OpenGL.glPixelStoref(OpenGL.GL_PACK_ROW_LENGTH, data.Stride / 4f);
OpenGL.glPixelStoref(OpenGL.GL_PACK_ALIGNMENT, 1);
OpenGL.glReadPixels(rect.X, rect.Y, rect.Width, rect.Height, OpenGL.GL_BGRA, OpenGL.GL_UNSIGNED_BYTE, data.Scan0);
OpenGL.glFinish();
OpenGL.glPopClientAttrib();
bitmap.UnlockBits(data);
// OpenGL standard defines the origin in the bottom left corner which is why this is upside-down by default.
bitmap.RotateFlip(RotateFlipType.RotateNoneFlipY);
return(bitmap);
}
