/// <summary>Gets the next packet or null if the end of the stream was reached.</summary>
/// <param name="packet">The packet.</param>
/// <param name="time">The time.</param>
/// <returns></returns>
/// <exception cref="ObjectDisposedException"></exception>
public bool GetNextPacket(out CdgPacket packet, out TimeSpan time)
{
if (m_Reader == null)
{
throw new ObjectDisposedException(nameof(CdgReader));
}
// can we check the position in the stream ? yes -> can we read another packet ? no -> exit
if (m_Reader.BaseStream.CanSeek && m_Reader.Available < 24)
{
packet = default(CdgPacket);
time = default(TimeSpan);
return(false);
}
try
{
packet = m_Reader.ReadStruct <CdgPacket>();
time = new TimeSpan(m_PacketNumber++ *TimeSpan.TicksPerSecond / PacketPerSecond);
return(true);
}
catch (EndOfStreamException)
{
packet = default(CdgPacket);
time = default(TimeSpan);
return(false);
}
}
void ParseMemoryPreset(SynchronizedLyricsItemBuilder sl, CdgPacket packet)
{
int repeat = packet.Data[1] & 0x0F;
if (repeat == 0)
{
sl.Commands.Add(new SlcWithColorIndex(SynchronizedLyricsCommandType.ClearScreen, (byte)(packet.Data[0] & 0x0F)));
}
}
void ParseLoadColorTable(SynchronizedLyricsItemBuilder sl, CdgPacket packet, bool higherTable)
{
int offset = higherTable ? 8 : 0;
ARGB[] palette = new ARGB[8];
for (int i = 0; i < 8; i++)
{
byte r = (byte)((packet.Data[i * 2] & 0x3C) << 2);
byte g = (byte)(((packet.Data[i * 2] & 0x03) << 6) | (packet.Data[(i * 2) + 1] & 0x30));
byte b = (byte)((packet.Data[(i * 2) + 1] & 0x0F) << 4);
palette[i] = ARGB.FromColor(r, g, b);
}
sl.Commands.Add(new SlcReplacePaletteColors((byte)offset, palette));
}
void ParseScroll(SynchronizedLyricsItemBuilder sl, CdgPacket packet, bool roll)
{
int colorIndex = packet.Data[0] & 0x0F;
int cdgHScroll = packet.Data[1] & 0x3F;
int cdgVScroll = packet.Data[2] & 0x3F;
sbyte hScroll = 0;
sbyte vScroll = 0;
switch (cdgHScroll >> 4)
{
default:
case 0: /*no scroll*/ break;
case 1: /*right 6px*/ hScroll = 6; break;
case 2: /*left 6px*/ hScroll = -6; break;
}
switch (cdgVScroll >> 4)
{
default:
case 0: /*no scroll*/ break;
case 1: /*down 12px*/ vScroll = 12; break;
case 2: /*up 12px*/ vScroll = -12; break;
}
if (hScroll != 0 || vScroll != 0)
{
if (roll)
{
sl.Commands.Add(new SlcScreenRoll(hScroll, vScroll));
}
else
{
sl.Commands.Add(new SlcScreenScroll((byte)colorIndex, hScroll, vScroll));
}
}
sbyte hOffset = (sbyte)((cdgHScroll & 0xF) % 6);
sbyte vOffset = (sbyte)((cdgVScroll & 0xF) % 12);
if (hOffset != currentOffsetHorizontal || vOffset != currentOffsetVertical)
{
sl.Commands.Add(new SlcScreenOffset(hOffset, vOffset));
currentOffsetHorizontal = hOffset;
currentOffsetVertical = vOffset;
}
}
void ParseTileBlock(SynchronizedLyricsItemBuilder sl, CdgPacket packet, bool xor)
{
byte color0 = (byte)(packet.Data[0] & 0x0F);
byte color1 = (byte)(packet.Data[1] & 0x0F);
int y = (packet.Data[2] & 0x1F) * 12;
int x = (packet.Data[3] & 0x3F) * 6;
int w = 6;
int h = 12;
if (x + w > BufferWidth || y + h > BufferHeight)
{
Trace.TraceError(string.Format("Subchannel decode error x={0} y={1}", x, y));
return;
}
byte[] data = new byte[12];
Array.Copy(packet.Data, 4, data, 0, 12);
SynchronizedLyricsCommandType cmd = xor ? SynchronizedLyricsCommandType.SetSprite2ColorsXOR : SynchronizedLyricsCommandType.SetSprite2Colors;
sl.Commands.Add(new SlcSetSprite2Colors(cmd, w, h, x, y, color0, color1, data));
}
void ParseDefineTransparentColor(SynchronizedLyricsItemBuilder sl, CdgPacket packet)
{
sl.Commands.Add(new SlcWithColorIndex(SynchronizedLyricsCommandType.SetTransparentColor, (byte)(packet.Data[0] & 0x0F)));
}