slightly improved CMP1 decompression performance.

This commit is contained in:
morkt 2015-08-21 02:21:31 +04:00
parent d38386ae16
commit 18e7d1f849

View File

@ -45,7 +45,7 @@ namespace GameRes.Formats.Riddle
public class GcpFormat : ImageFormat
{
public override string Tag { get { return "GCP"; } }
public override string Description { get { return "Riddle Soft RGB image format"; } }
public override string Description { get { return "Riddle Soft compressed bitmap"; } }
public override uint Signature { get { return 0x31504d43u; } } // 'CMP1'
public override void Write (Stream file, ImageData image)
@ -62,8 +62,7 @@ namespace GameRes.Formats.Riddle
int pack_size = LittleEndian.ToInt32 (header, 8);
if (data_size < 54)
return null;
using (var reader = new Reader (stream, pack_size, 0x22)) // BMP header
{
var reader = new CmpReader (stream, pack_size, 0x22); // BMP header
reader.Unpack();
var bmp = reader.Data;
if (bmp[0] != 'B' || bmp[1] != 'M')
@ -80,7 +79,6 @@ namespace GameRes.Formats.Riddle
PackedSize = pack_size,
};
}
}
public override ImageData Read (Stream stream, ImageMetaData info)
{
@ -89,8 +87,7 @@ namespace GameRes.Formats.Riddle
throw new ArgumentException ("GcpFormat.Read should be supplied with GcpMetaData", "info");
stream.Position = 12;
using (var reader = new Reader (stream, meta.PackedSize, meta.DataSize))
{
var reader = new CmpReader (stream, meta.PackedSize, meta.DataSize);
reader.Unpack();
using (var bmp = new MemoryStream (reader.Data, false))
{
@ -102,9 +99,8 @@ namespace GameRes.Formats.Riddle
}
}
}
}
internal class Reader : IDisposable
internal class CmpReader
{
Stream m_input;
byte[] m_output;
@ -113,7 +109,7 @@ namespace GameRes.Formats.Riddle
public byte[] Data { get { return m_output; } }
public Reader (Stream file, int src_size, int dst_size)
public CmpReader (Stream file, int src_size, int dst_size)
{
m_input = file;
m_output = new byte[dst_size];
@ -129,7 +125,7 @@ namespace GameRes.Formats.Riddle
shift[i] = 0x20;
while (dst < m_output.Length)
{
int bit = GetNextBit();
int bit = GetBits (1);
if (-1 == bit)
break;
if (1 == bit)
@ -164,46 +160,23 @@ namespace GameRes.Formats.Riddle
}
int m_bits = 0;
int m_cached_bits = 0;
int GetNextBit ()
int GetBits (int count)
{
bool bit = 0 != (m_bits & 0x80);
m_bits <<= 1;
if (0 == (m_bits & 0xff))
while (m_cached_bits < count)
{
if (m_src_count++ >= m_src_total)
return -1;
m_bits = m_input.ReadByte();
if (-1 == m_bits)
throw new EndOfStreamException ("Invalid compressed stream");
bit = 0 != (m_bits & 0x80);
m_bits = (m_bits << 1) | 1;
}
return bit ? 1 : 0;
}
int GetBits (int count, int data = 0)
{
while (count > 0)
{
int bit = GetNextBit();
if (-1 == bit)
int b = m_input.ReadByte();
if (-1 == b)
return -1;
data = (data << 1) | bit;
--count;
m_bits = (m_bits << 8) | b;
m_cached_bits += 8;
}
int mask = (1 << count) - 1;
m_cached_bits -= count;
return (m_bits >> m_cached_bits) & mask;
}
return data;
}
#region IDisposable Members
public void Dispose ()
{
if (null != m_input)
{
m_input = null;
}
GC.SuppressFinalize (this);
}
#endregion
}
}