bsnes/snespurify/nall/ips.hpp

111 lines
2.7 KiB
C++
Executable File

#ifndef NALL_IPS_HPP
#define NALL_IPS_HPP
#include <nall/file.hpp>
#include <nall/stdint.hpp>
#include <nall/string.hpp>
namespace nall {
struct ips {
inline bool apply();
inline void source(const uint8_t *data, unsigned size);
inline void modify(const uint8_t *data, unsigned size);
inline bool source(const string &filename);
inline bool modify(const string &filename);
inline ips();
inline ~ips();
uint8_t *data;
unsigned size;
const uint8_t *sourceData;
unsigned sourceSize;
const uint8_t *modifyData;
unsigned modifySize;
};
bool ips::apply() {
if(modifySize < 8) return false;
if(modifyData[0] != 'P') return false;
if(modifyData[1] != 'A') return false;
if(modifyData[2] != 'T') return false;
if(modifyData[3] != 'C') return false;
if(modifyData[4] != 'H') return false;
if(data) delete[] data;
data = new uint8_t[16 * 1024 * 1024 + 65536](); //maximum size of IPS patch + single-tag padding
size = sourceSize;
memcpy(data, sourceData, sourceSize);
unsigned offset = 5;
while(true) {
unsigned address, length;
if(offset > modifySize - 3) break;
address = modifyData[offset++] << 16;
address |= modifyData[offset++] << 8;
address |= modifyData[offset++] << 0;
if(address == 0x454f46) { //EOF
if(offset == modifySize) return true;
if(offset == modifySize - 3) {
size = modifyData[offset++] << 16;
size |= modifyData[offset++] << 8;
size |= modifyData[offset++] << 0;
return true;
}
}
if(offset > modifySize - 2) break;
length = modifyData[offset++] << 8;
length |= modifyData[offset++] << 0;
if(length) { //Copy
if(offset > modifySize - length) break;
while(length--) data[address++] = modifyData[offset++];
} else { //RLE
if(offset > modifySize - 3) break;
length = modifyData[offset++] << 8;
length |= modifyData[offset++] << 0;
if(length == 0) break; //illegal
while(length--) data[address++] = modifyData[offset];
offset++;
}
size = max(size, address);
}
delete[] data;
data = 0;
return false;
}
void ips::source(const uint8_t *data, unsigned size) {
sourceData = data, sourceSize = size;
}
void ips::modify(const uint8_t *data, unsigned size) {
modifyData = data, modifySize = size;
}
bool ips::source(const string &filename) {
return file::read(filename, sourceData, sourceSize);
}
bool ips::modify(const string &filename) {
return file::read(filename, modifyData, modifySize);
}
ips::ips() : data(0), sourceData(0), modifyData(0) {
}
ips::~ips() {
if(data) delete[] data;
if(sourceData) delete[] sourceData;
if(modifyData) delete[] modifyData;
}
}
#endif