hooks.cpp

/*
 * hooks.cpp
 *
 *  Created on: Oct 4, 2016
 *      Author: nullifiedcat
 */

#include "hooks.h"

#include "logging.h"

#include <stdlib.h>

unsigned int hooks::offCreateMove = 22;
unsigned int hooks::offPaintTraverse = 42;
unsigned int hooks::offOverrideView = 17;
unsigned int hooks::offFrameStageNotify = 35;
unsigned int hooks::offCanPacket = 57;
unsigned int hooks::offSendNetMsg = 41;
unsigned int hooks::offShutdown = 37;
unsigned int hooks::offKeyEvent = 20;
unsigned int hooks::offHandleInputEvent = 78;
unsigned int hooks::offLevelInit = 23;
unsigned int hooks::offLevelShutdown = 24;
unsigned int hooks::offBeginFrame = 5;

// This thing had been copypasted from somewhere, maybe from F1Public.

bool hooks::IsHooked(void* inst) {
	return hooks::GetVMT(inst, 0)[-2] == (void*)VMTHook::GUARD;
}

unsigned int hooks::CountMethods(void** vmt) {
	unsigned int i = -1;
	do ++i; while (vmt[i]);
	return i;
}

void**& hooks::GetVMT(void* inst, unsigned int offset) {
	return *reinterpret_cast<void***>((char*)inst + offset);
}

void hooks::VMTHook::Init(void* inst, unsigned int offset) {
	vmt = &GetVMT(inst, offset);
	oldvmt = *vmt;
	unsigned int cnt = CountMethods(oldvmt);
	void **arr = array = (void**)malloc((cnt + 4) * sizeof(void*));
	arr[0] = this;
	arr[1] = (void* )GUARD;
	(arr + 3)[cnt] = 0;
	unsigned int i = -1;
	do arr[i + 3] = oldvmt[i]; while (++i < cnt);
}

void hooks::VMTHook::Kill() {
	if (vmt)
		*vmt = oldvmt;
	vmt = 0;
	free(array);
	array = 0;
}

void hooks::VMTHook::HookMethod(void* func, unsigned int idx) {
	array[idx + 3] = func;
}

void* hooks::VMTHook::GetMethod(unsigned int idx) const {
	return oldvmt[idx];
}

void hooks::VMTHook::Apply() {
	*vmt = array + 3;
}

hooks::VMTHook* hooks::hkClientMode = 0;
hooks::VMTHook* hooks::hkPanel = 0;
hooks::VMTHook* hooks::hkClient = 0;
hooks::VMTHook* hooks::hkNetChannel = 0;
hooks::VMTHook* hooks::hkClientDLL = 0;
hooks::VMTHook* hooks::hkMatSurface = 0;
hooks::VMTHook* hooks::hkStudioRender = 0;