private static RLEPacketType PacketType(Color32[] _arData, int _iPacketPosition)
{
if ((_iPacketPosition != _arData.Length - 1) && ExtTexture.Equals(_arData[_iPacketPosition], _arData[_iPacketPosition + 1]))
{
return(RLEPacketType.RLE);
}
else
{
return(RLEPacketType.RAW);
}
}
/// <summary>
///
/// </summary>
/// <param name="_texture2D"></param>
/// <returns></returns>
public static byte[] EncodeToTGA(this Texture2D _texture2D)
{
const int iTgaHeaderSize = 18;
const int iBytesPerPixelRGB24 = 3; // 1 byte per channel (rgb)
const int iBytesPerPixelARGB32 = 4; // ~ (rgba)
var useAlpha = SupportsAlpha(_texture2D.format);
int iBytesPerPixel = useAlpha ? iBytesPerPixelARGB32 : iBytesPerPixelRGB24;
//
using (MemoryStream memoryStream = new MemoryStream(iTgaHeaderSize + _texture2D.width * _texture2D.height * iBytesPerPixel))
{
using (BinaryWriter binaryWriter = new BinaryWriter(memoryStream))
{
// Write TGA Header
binaryWriter.Write((byte)0); // IDLength (not in use)
binaryWriter.Write((byte)0); // ColorMapType (not in use)
binaryWriter.Write((byte)10); // DataTypeCode == 10 (Runlength encoded RGB images)
binaryWriter.Write((short)0); // ColorMapOrigin (not in use)
binaryWriter.Write((short)0); // ColorMapLength (not in use)
binaryWriter.Write((byte)0); // ColorMapDepth (not in use)
binaryWriter.Write((short)0); // Origin X
binaryWriter.Write((short)0); // Origin Y
binaryWriter.Write((short)_texture2D.width); // Width
binaryWriter.Write((short)_texture2D.height); // Height
binaryWriter.Write((byte)(iBytesPerPixel * 8)); // Bits Per Pixel
binaryWriter.Write((byte)0); // ImageDescriptor (not in use)
// Write RLE Encoded Pixels
Color32[] arPixels = _texture2D.GetPixels32();
const int iMaxPacketLength = 128;
int iPacketStart = 0;
int iPacketEnd = 0;
while (iPacketStart < arPixels.Length)
{
Color32 c32PreviousPixel = arPixels[iPacketStart];
// Get current Packet Type
RLEPacketType packetType = ExtTexture.PacketType(arPixels, iPacketStart);
// Find Packet End
int iReadEnd = Mathf.Min(iPacketStart + iMaxPacketLength, arPixels.Length);
for (iPacketEnd = iPacketStart + 1; iPacketEnd < iReadEnd; ++iPacketEnd)
{
bool bPreviousEqualsCurrent = ExtTexture.Equals(arPixels[iPacketEnd - 1], arPixels[iPacketEnd]);
// Packet End if change in Packet Type or if max Packet-Size reached
if (packetType == RLEPacketType.RAW && bPreviousEqualsCurrent ||
packetType == RLEPacketType.RLE && !bPreviousEqualsCurrent)
{
break;
}
}
// Write Packet
int iPacketLength = iPacketEnd - iPacketStart;
switch (packetType)
{
case RLEPacketType.RLE:
// Add RLE-Bit to PacketLength
binaryWriter.Write((byte)((iPacketLength - 1) | (1 << 7)));
binaryWriter.Write(c32PreviousPixel.b);
binaryWriter.Write(c32PreviousPixel.g);
binaryWriter.Write(c32PreviousPixel.r);
if (useAlpha)
{
binaryWriter.Write(c32PreviousPixel.a);
}
break;
case RLEPacketType.RAW:
binaryWriter.Write((byte)(iPacketLength - 1));
for (int iPacketPosition = iPacketStart; iPacketPosition < iPacketEnd; ++iPacketPosition)
{
binaryWriter.Write(arPixels[iPacketPosition].b);
binaryWriter.Write(arPixels[iPacketPosition].g);
binaryWriter.Write(arPixels[iPacketPosition].r);
if (useAlpha)
{
binaryWriter.Write(arPixels[iPacketPosition].a);
}
}
break;
}
iPacketStart = iPacketEnd;
}
}
return(memoryStream.GetBuffer());
}
}