offline.cpp

#include "offline.h"

static std::string offline_patch_mask = "xxxxxx";
static BYTE offline_patch_each_template[] = {0xFF, 0x15, 0x00, 0x00, 0x00, 0x00};
static BYTE offline_patch_repl[] = {0xB8, 0x00, 0x00, 0x00, 0x00, 0x90};

static std::string offline_patch_templ_mask = "xx....xx....xx....xx....xx";
static BYTE offline_patch_templ_find[] = {0x89, 0xB3, 0x00, 0x00, 0x00, 0x00, 0x89, 0xB3, 0x00, 0x00, 0x00, 0x00, 0x89, 0xB3, 0x00, 0x00, 0x00, 0x00, 0x89, 0xB3, 0x00, 0x00, 0x00, 0x00, 0xFF, 0x15};

static BYTE offline_btest[] = {0x8B, 0x10, 0x8B, 0x52, 0x70, 0x6A, 0x00, 0x6A, 0x00, 0x6A, 0x01};

OfflinePatch::~OfflinePatch() {
	for(BYTE* ptr : original_values) {
		delete[] ptr;
	}
}

OfflinePatch::OfflinePatch(std::shared_ptr<Spelunky> spel) : 
	Patch(spel), 
	is_valid(true),
	anti_achiev(std::make_shared<AntiAchievementPatch>(spel))
{
	BYTE offline_patch_each[sizeof(offline_patch_each_template)];
	{
		std::memcpy(offline_patch_each, offline_patch_each_template, sizeof(offline_patch_each));
		Address fill_addr = spel->find_mem(offline_patch_templ_find, offline_patch_templ_mask);
		if(fill_addr != 0) {
			fill_addr += 0x18;
			spel->read_mem(fill_addr, offline_patch_each, sizeof(offline_patch_each));
		
			DBG_EXPR(std::cout << "[OfflinePatch] Found offline patch template fill at " << std::setbase(16) << fill_addr << std::endl);
		}
		else 
		{
			DBG_EXPR(std::cout << "[OfflinePatch] Warning: Could not find offline patch template fill." << std::endl);
			return;
		}
	}

	BYTE buf[sizeof(offline_btest)];

	Address current = 0x0;
	while((current = spel->find_mem(offline_patch_each, offline_patch_mask, current)) > 0) {
		spel->read_mem(current+12, buf, sizeof(offline_btest));

		if(std::equal(buf, buf+sizeof(offline_btest), offline_btest)) {
			current++;
			continue;
		}

		BYTE* buf2 = new BYTE[sizeof(offline_patch_repl)];
		spel->read_mem(current, buf2, sizeof(offline_patch_repl));
			
		DBG_EXPR(std::cout << "[OfflinePatch] Offline patch at " << std::setbase(16) << current << std::endl);

		original_values.push_back(buf2);
		patched_addrs.push_back(current);
		current++;
	}
		
	if(patched_addrs.empty()) {
		DBG_EXPR(std::cout << "[OfflinePatch] Warning: No addresses found for patching." << std::endl);
		return; //If these are empty, either GOG or Spelunky pre-patched.
	}
}

bool OfflinePatch::_undo() {
	//int idx = 0;
	//for(Address addr : patched_addrs) {
	//	BYTE* orig = original_values[idx];
	//	spel->write_mem(addr, orig, sizeof(offline_patch_repl));
	//	idx++;
	//}
	anti_achiev->undo();
	return true;
}

bool OfflinePatch::_perform() {
	anti_achiev->perform();

	for(Address addr : patched_addrs) {
		spel->write_mem(addr, offline_patch_repl, sizeof(offline_patch_repl));
	}

	return true;
}

bool OfflinePatch::valid() {
	return is_valid;
}