public static void ApplyIPSPatch(string romname, string patchname)
{
// Noobish Noobsicle wrote this IPS patching code
// romname is the original ROM, patchname is the patch to apply
FileStream romstream = new FileStream(romname, FileMode.Open, FileAccess.ReadWrite, FileShare.ReadWrite);
FileStream ipsstream = new FileStream(patchname, FileMode.Open, FileAccess.ReadWrite, FileShare.ReadWrite);
int lint = (int)ipsstream.Length;
byte[] ipsbyte = new byte[ipsstream.Length];
byte[] rombyte = new byte[romstream.Length];
IAsyncResult romresult;
IAsyncResult ipsresult = ipsstream.BeginRead(ipsbyte, 0, lint, null, null);
ipsstream.EndRead(ipsresult);
int ipson = 5;
int totalrepeats = 0;
int offset = 0;
bool keepgoing = true;
while (keepgoing == true)
{
offset = ipsbyte[ipson] * 0x10000 + ipsbyte[ipson + 1] * 0x100 + ipsbyte[ipson + 2];
ipson++;
ipson++;
ipson++;
if (ipsbyte[ipson] * 256 + ipsbyte[ipson + 1] == 0)
{
ipson++;
ipson++;
totalrepeats = ipsbyte[ipson] * 256 + ipsbyte[ipson + 1];
ipson++;
ipson++;
byte[] repeatbyte = new byte[totalrepeats];
for (int ontime = 0; ontime < totalrepeats; ontime++)
repeatbyte[ontime] = ipsbyte[ipson];
romstream.Seek(offset, SeekOrigin.Begin);
romresult = romstream.BeginWrite(repeatbyte, 0, totalrepeats, null, null);
romstream.EndWrite(romresult);
ipson++;
}
else
{
totalrepeats = ipsbyte[ipson] * 256 + ipsbyte[ipson + 1];
ipson++;
ipson++;
romstream.Seek(offset, SeekOrigin.Begin);
romresult = romstream.BeginWrite(ipsbyte, ipson, totalrepeats, null, null);
romstream.EndWrite(romresult);
ipson = ipson + totalrepeats;
}
if (ipsbyte[ipson] == 69 && ipsbyte[ipson + 1] == 79 && ipsbyte[ipson + 2] == 70)
keepgoing = false;
}
romstream.Close();
ipsstream.Close();
}
