Ejemplo n.º 1
0
            private Graphics CreateBuffer(IntPtr src, int offsetX, int offsetY, int width, int height)
            {
                //NativeMethods.POINT pVp = new NativeMethods.POINT();

                if (width <= bufferWidth && height <= bufferHeight && compatDC != IntPtr.Zero)
                {
                    virtualWidth  = width;
                    virtualHeight = height;

                    Debug.WriteLineIf(DoubleBuffering.TraceInfo, "Reusing compatible DC");
                    if (compatGraphics != null)
                    {
                        Debug.WriteLineIf(DoubleBuffering.TraceInfo, "    Disposing compatGraphics");
                        compatGraphics.Dispose();
                        compatGraphics = null;
                    }

                    //SafeNativeMethods.SetViewportOrgEx(compatDC, offsetX, offsetY, pVp);
                    Debug.WriteLineIf(DoubleBuffering.TraceInfo, "    Create compatGraphics");
                    compatGraphics = Graphics.FromHdcInternal(compatDC);
                    compatGraphics.TranslateTransform(-targetX, -targetY);
                    return(compatGraphics);
                }

                int optWidth  = bufferWidth;
                int optHeight = bufferHeight;

                Dispose();

                Debug.WriteLineIf(DoubleBuffering.TraceInfo, "allocating new buffer: " + width + " x " + height);
                Debug.WriteLineIf(DoubleBuffering.TraceInfo, "    old size         : " + optWidth + " x " + optHeight);
                optWidth  = Math.Max(width, optWidth);
                optHeight = Math.Max(height, optHeight);

                Debug.WriteLineIf(DoubleBuffering.TraceInfo, "    new size         : " + optWidth + " x " + optHeight);
                IntPtr pvbits = IntPtr.Zero;

                dib      = CreateCompatibleDIB(src, IntPtr.Zero, optWidth, optHeight, ref pvbits);
                compatDC = UnsafeNativeMethods.CreateCompatibleDC(new HandleRef(null, src));

                oldBitmap = SafeNativeMethods.SelectObject(new HandleRef(this, compatDC), new HandleRef(this, dib));

                //SafeNativeMethods.SetViewportOrgEx(compatDC, offsetX, offsetY, pVp);
                Debug.WriteLineIf(DoubleBuffering.TraceInfo, "    Create compatGraphics");
                compatGraphics = Graphics.FromHdcInternal(compatDC);
                compatGraphics.TranslateTransform(-targetX, -targetY);
                bufferWidth   = optWidth;
                bufferHeight  = optHeight;
                virtualWidth  = width;
                virtualHeight = height;

                return(compatGraphics);
            }