/// <summary>
/// Adds next GIF frame. The frame is not written immediately, but is actually deferred
/// until the next frame is received so that timing data can be inserted. Invoking
/// <code>Finish()</code> flushes all frames.
/// </summary>
/// <param name="frame">GifFrame containing frame to write.</param>
public void AddFrame(GifFrame frame)
{
if ((frame == null))
throw new ArgumentNullException("Can't add a null frame to the gif.");
if (!m_HasStarted)
throw new InvalidOperationException("Call Start() before adding frames to the gif.");
// Use first frame's size
if (!m_IsSizeSet)
SetSize(frame.Width, frame.Height);
m_CurrentFrame = frame;
GetImagePixels();
AnalyzePixels();
if (m_IsFirstFrame)
{
WriteLSD();
WritePalette();
if (m_Repeat >= 0)
WriteNetscapeExt();
}
WriteGraphicCtrlExt();
WriteImageDesc();
if (!m_IsFirstFrame)
WritePalette();
WritePixels();
m_IsFirstFrame = false;
}
/// <summary>
/// Flushes any pending data and closes output file.
/// If writing to an OutputStream, the stream is not closed.
/// </summary>
public void Finish()
{
if (!m_HasStarted)
throw new InvalidOperationException("Can't finish a non-started gif.");
m_HasStarted = false;
try
{
m_FileStream.WriteByte(0x3b); // Gif trailer
m_FileStream.Flush();
if (m_ShouldCloseStream)
m_FileStream.Close();
}
catch (IOException e)
{
throw e;
}
// Reset for subsequent use
m_FileStream = null;
m_CurrentFrame = null;
m_Pixels = null;
m_IndexedPixels = null;
m_ColorTab = null;
m_ShouldCloseStream = false;
m_IsFirstFrame = true;
}
