private bool HandleFramebufferUpdate()
{
this.c.ReceiveByte(); // padding
var numRects = this.c.ReceiveUInt16BE();
var rects = new List <VncRectangle>();
var encoding = VncEncoding.DesktopSize;
for (int i = 0; i < numRects; i++)
{
var r = this.c.ReceiveRectangle();
int x = r.X, y = r.Y, w = r.Width, h = r.Height;
VncStream.SanityCheck(w > 0 && w < 0x8000);
VncStream.SanityCheck(h > 0 && h < 0x8000);
int fbW = this.Framebuffer.Width, fbH = this.Framebuffer.Height, bpp = this.Framebuffer.PixelFormat.BytesPerPixel;
var inRange = w <= fbW && h <= fbH && x <= fbW - w && y <= fbH - h;
byte[] pixels;
encoding = (VncEncoding)this.c.ReceiveUInt32BE();
switch (encoding)
{
case VncEncoding.Hextile: // KVM seems to avoid this now that I support Zlib.
var background = new byte[bpp];
var foreground = new byte[bpp];
for (int ty = 0; ty < h; ty += 16)
{
int th = Math.Min(16, h - ty);
for (int tx = 0; tx < w; tx += 16)
{
int tw = Math.Min(16, w - tx);
var subencoding = this.c.ReceiveByte();
pixels = this.AllocateFramebufferScratch(tw * th * bpp);
if ((subencoding & 1) != 0)
{
// raw
this.c.Receive(pixels, 0, tw * th * bpp);
if (inRange)
{
lock (this.Framebuffer.SyncRoot)
{
this.CopyToFramebuffer(x + tx, y + ty, tw, th, pixels);
}
}
}
else
{
pixels = this.AllocateFramebufferScratch(tw * th * bpp);
if ((subencoding & 2) != 0)
{
background = this.c.Receive(bpp);
}
if ((subencoding & 4) != 0)
{
foreground = this.c.Receive(bpp);
}
int ptr = 0;
for (int pp = 0; pp < tw * th; pp++)
{
for (int pe = 0; pe < bpp; pe++)
{
pixels[ptr++] = background[pe];
}
}
int nsubrects = (subencoding & 8) != 0 ? this.c.ReceiveByte() : 0;
if (nsubrects > 0)
{
var subrectsColored = (subencoding & 16) != 0;
for (int subrect = 0; subrect < nsubrects; subrect++)
{
var color = subrectsColored ? this.c.Receive(bpp) : foreground;
var srxy = this.c.ReceiveByte();
var srwh = this.c.ReceiveByte();
int srx = (srxy >> 4) & 0xf, srw = ((srwh >> 4) & 0xf) + 1;
int sry = (srxy >> 0) & 0xf, srh = ((srwh >> 0) & 0xf) + 1;
if (srx + srw > tw || sry + srh > th)
{
continue;
}
for (int py = 0; py < srh; py++)
{
for (int px = 0; px < srw; px++)
{
int off = bpp * (((py + sry) * tw) + (px + srx));
for (int pe = 0; pe < bpp; pe++)
{
pixels[off + pe] = color[pe];
}
}
}
}
}
lock (this.Framebuffer.SyncRoot)
{
this.CopyToFramebuffer(x + tx, y + ty, tw, th, pixels);
}
}
}
}
break;
case VncEncoding.CopyRect:
var srcx = (int)this.c.ReceiveUInt16BE();
var srcy = (int)this.c.ReceiveUInt16BE();
if (srcx + w > fbW)
{
w = fbW - srcx;
}
if (srcy + h > fbH)
{
h = fbH - srcy;
}
if (w < 1 || h < 1)
{
continue;
}
pixels = this.AllocateFramebufferScratch(w * h * bpp);
lock (this.Framebuffer.SyncRoot)
{
this.CopyToGeneral(0, 0, w, h, pixels, srcx, srcy, fbW, fbH, this.Framebuffer.GetBuffer(), w, h);
this.CopyToFramebuffer(x, y, w, h, pixels);
}
break;
case VncEncoding.Raw:
pixels = this.AllocateFramebufferScratch(w * h * bpp);
this.c.Receive(pixels, 0, w * h * bpp);
if (inRange)
{
lock (this.Framebuffer.SyncRoot)
{
this.CopyToFramebuffer(x, y, w, h, pixels);
}
}
break;
case VncEncoding.Zlib:
int bytesDesired = w * h * bpp;
int size = (int)this.c.ReceiveUInt32BE(); VncStream.SanityCheck(size >= 0 && size < 0x10000000);
VncUtility.AllocateScratch(size, ref this.zlibScratch);
this.c.Receive(this.zlibScratch, 0, size);
this.zlibMemoryStream.Position = 0;
this.zlibMemoryStream.Write(this.zlibScratch, 0, size);
this.zlibMemoryStream.SetLength(size);
this.zlibMemoryStream.Position = 0;
if (this.zlibInflater == null)
{
// Zlib has a two-byte header.
VncStream.SanityCheck(size >= 2);
this.zlibMemoryStream.Position = 2;
this.zlibInflater = new DeflateStream(this.zlibMemoryStream, CompressionMode.Decompress, false);
}
pixels = this.AllocateFramebufferScratch(bytesDesired);
for (int j = 0; j < bytesDesired;)
{
int count = 0;
try
{
count = this.zlibInflater.Read(pixels, j, bytesDesired - j);
}
catch (InvalidDataException)
{
VncStream.Require(
false,
"Bad data compressed.",
VncFailureReason.UnrecognizedProtocolElement);
}
VncStream.Require(
count > 0,
"No data compressed.",
VncFailureReason.UnrecognizedProtocolElement);
j += count;
}
if (inRange)
{
lock (this.Framebuffer.SyncRoot)
{
this.CopyToFramebuffer(x, y, w, h, pixels);
}
}
break;
case VncEncoding.PseudoDesktopSize:
this.Framebuffer = new VncFramebuffer(this.Framebuffer.Name, w, h, this.Framebuffer.PixelFormat);
continue; // Don't call OnFramebufferChanged for this one.
default:
VncStream.Require(
false,
"Unsupported encoding.",
VncFailureReason.UnrecognizedProtocolElement);
break;
}
rects.Add(new VncRectangle(x, y, w, h));
}
if (rects.Count > 0)
{
this.OnFramebufferChanged(new FramebufferChangedEventArgs(rects));
}
return(encoding != VncEncoding.DesktopSize);
}
private byte[] AllocateFramebufferScratch(int bytes)
{
return(VncUtility.AllocateScratch(bytes, ref this.framebufferScratch));
}