private void FlipOut(Gdi mem, Rectangle canvas, IntPtr dc, IntPtr stretchDC, double transitionPct)
{
int margin = (int)((double)_CanvasMiddle * transitionPct);
using (Gdi stretch = Gdi.FromHdc(stretchDC, Rectangle.Empty))
{
stretch.FillRect(canvas, Color.Gainsboro);
stretch.StretchBlt(0, 0, canvas.Width - margin*2, canvas.Height,
dc,
0, 0, canvas.Width, canvas.Height, TernaryRasterOperations.SRCCOPY);
}
var currLine = BuildPath(_FlipOutLeftPath[margin].X, _FlipOutLeftPath[margin].Y, _FlipOutTopPath[margin].X,
_FlipOutTopPath[margin].Y);
for (int i = 0; i < currLine.Count - 1; i++)
{
mem.StretchBlt(currLine[i].X, currLine[i].Y, 1, canvas.Height - currLine[i].Y*2,
stretchDC,
i, 0, 1, canvas.Height,
TernaryRasterOperations.SRCCOPY);
}
}