Internal speedhack - Same three hooks as Cheat Engine

#include <Windows.h>
#include "detours.h"																// Version 3.0 use for this hook. Be sure to include the library and includes to your project in visual studio
																					// Detours: https://www.microsoft.com/en-us/research/project/detours/

#pragma comment(lib,"detours.lib")													// Need to include this so we can use Detours
#pragma comment(lib,"Kernel32.lib")													// Need to include this since we're hooking QueryPerformanceCounter and GetTickCount which reside inside the Kernel32 library
#pragma comment(lib,"Winmm.lib")													// Neet to include this since we're hooking timeGetTime which resides inside the Winmm library

extern"C" {
	static BOOL(WINAPI *originalQueryPerformanceCounter)(LARGE_INTEGER *performanceCounter) = QueryPerformanceCounter;
	static DWORD(WINAPI *originalGetTickCount)() = GetTickCount;
	static DWORD(WINAPI *originalTimeGetTime)() = timeGetTime;
}

HMODULE hModule;

float multiplier = 2;																// Game speed multiplier

LARGE_INTEGER prevLi;
LARGE_INTEGER currentLi;
LARGE_INTEGER falseLi;

// QueryPerformanceCounter is generally what is used to calculate how much time has passed between frames. It will set the performanceCounter to the amount of micro seconds the machine has been running
// https://msdn.microsoft.com/en-us/library/windows/desktop/ms644904(v=vs.85).aspx

BOOL WINAPI newQueryPerformanceCounter(LARGE_INTEGER *counter) {
	originalQueryPerformanceCounter(&currentLi);									// Get real current performance counter
	falseLi.QuadPart += ((currentLi.QuadPart - prevLi.QuadPart) * multiplier);		// Add the difference between this frame and the pervious * our multiplier to our false counter variable
	prevLi = currentLi;																// Set the previous to our current we just calculated

	*counter = falseLi;																// Make sure the caller gets our fake counter value
	return true;																	// Return true
}


DWORD prevTickCount;
DWORD currentTickCount;
DWORD falseTickCount;

// GetTickCount can also be used to calculate time between frames, but is used less since it's less accurate than QueryPerformanceCounter
// https://msdn.microsoft.com/en-us/library/windows/desktop/ms724408%28v=vs.85%29.aspx

DWORD WINAPI newGetTickCount() {
	currentTickCount = originalGetTickCount();										// Get the real current tick count
	falseTickCount += ((currentTickCount - prevTickCount) * multiplier);			// Add the difference between this frame and the pervious * our multiplier to our false tick count variable
	prevTickCount = currentTickCount;												// Set the previous to our current we just calculated

	return falseTickCount;															// Return false tick count
}

DWORD prevTime;
DWORD currentTime;
DWORD falseTime;

// timeGetTime can also be used to caluclate time between frames, as with GetTickCount it isn't as accurate as QueryPerformanceCounter
// https://msdn.microsoft.com/en-us/library/windows/desktop/dd757629(v=vs.85).aspx

DWORD WINAPI newTimeGetTime() {
	currentTime = originalTimeGetTime();											// Get real current time
	falseTime += ((currentTime - prevTime) * multiplier);							// Add the difference between this frame and the pervious * our multiplier to our false tick count variable
	prevTime = currentTime;															// Set the previous to our current we just calculated

	return falseTime;																// Return false time
}


void enable() {																		// Enable speedhack by hooking the 3 functions games use to keep track of time between frames 

																					// Set initial values for hooked calculations
	originalQueryPerformanceCounter(&prevLi);										// Set previous frame QueryPerformanceCounter since it hasn't been hooked yet
	falseLi = prevLi;																// Set false value which we use to keep track of the returned value each frame

	prevTickCount = originalGetTickCount();											// Set previous frame GetTickCount since it hasn't been hooked yet
	falseTickCount = prevTickCount;													// Set false value which we use to keep track of the returned value each frame

	prevTime = originalTimeGetTime();												// Set previous frame timeGetTime since it hasn't been hooked yet
	falseTime = prevTime;															// Set false value which we use to keep track of the returned value each frame

																					// Basic detours
	DisableThreadLibraryCalls(hModule);												
	DetourTransactionBegin();
	DetourUpdateThread(GetCurrentThread());
	DetourAttach(&(PVOID&)originalQueryPerformanceCounter, newQueryPerformanceCounter);
	DetourAttach(&(PVOID&)originalGetTickCount, newGetTickCount);
	DetourAttach(&(PVOID&)originalTimeGetTime, newTimeGetTime);
	DetourTransactionCommit();
}

BOOL APIENTRY DllMain(HMODULE hModule,
	DWORD ul_reason_for_call,
	LPVOID lpReserved
)
{
	switch (ul_reason_for_call)
	{

	case DLL_PROCESS_ATTACH:
		CreateThread(NULL, 0, (LPTHREAD_START_ROUTINE)enable, NULL, 0, NULL);		// Detours the 3 functions, enabling the speed hack
		break;
	case DLL_PROCESS_DETACH:
		break;
	case DLL_THREAD_ATTACH:
		break;
	case DLL_THREAD_DETACH:
		break;

	}
	return TRUE;
}