CoopAllTheThings/tests/dinput_hook_test.cpp

// In-process self-test for the DirectInput forwarding path of the MKB subsystem.
//
// Drives the REAL shipping code (mkb_hook.cpp): creates the IPC block + MKB ring, installs the MKB
// hooks (which vtable-swap IDirectInputDevice8::GetDeviceState via a probe device), pushes a
// synthetic key + mouse-button event through the ring, pumps it (so the hook's synthesized state is
// set), then creates its *own* DirectInput keyboard + mouse device and calls GetDeviceState -- and
// asserts the forwarded input shows up in the returned device state. This process plays host + game.
// Skips cleanly if DirectInput can't acquire a device (e.g. no input stack on a CI box).
#include <cstdint>
#include <cstdio>

#include <windows.h>

#include <objbase.h>

#define DIRECTINPUT_VERSION 0x0800
#include <dinput.h>

#include "coop/protocol.hpp"
#include "coop/shared_memory.hpp"
#include "ipc_client.hpp"
#include "mkb_hook.hpp"

using namespace coop;

namespace {
int g_failures = 0;
void check(bool ok, const char* what)
{
	std::printf("%s %s\n", ok ? "  ok:" : "FAIL:", what);
	if (!ok) {
		++g_failures;
	}
}

// A hidden window so DirectInput devices can SetCooperativeLevel/Acquire.
HWND make_window()
{
	WNDCLASSEXW wc{};
	wc.cbSize = sizeof(wc);
	wc.lpfnWndProc = DefWindowProcW;
	wc.hInstance = GetModuleHandleW(nullptr);
	wc.lpszClassName = L"coop_dinput_test";
	RegisterClassExW(&wc);
	return CreateWindowExW(0, wc.lpszClassName, L"", WS_OVERLAPPEDWINDOW, 0, 0, 16, 16, nullptr, nullptr, wc.hInstance,
	                       nullptr);
}

// Create + acquire a DI device of `kind` (GUID_SysKeyboard / GUID_SysMouse) with `fmt`. Returns null
// on any failure (treated as a skip).
IDirectInputDevice8W* make_device(IDirectInput8W* di, const GUID& kind, const DIDATAFORMAT* fmt, HWND hwnd)
{
	IDirectInputDevice8W* dev = nullptr;
	if (FAILED(di->CreateDevice(kind, &dev, nullptr)) || dev == nullptr) {
		return nullptr;
	}
	if (FAILED(dev->SetDataFormat(fmt)) || FAILED(dev->SetCooperativeLevel(hwnd, DISCL_BACKGROUND | DISCL_NONEXCLUSIVE))
	    || FAILED(dev->Acquire())) {
		dev->Release();
		return nullptr;
	}
	return dev;
}
} // namespace

int main()
{
	const bool com = SUCCEEDED(CoInitializeEx(nullptr, COINIT_APARTMENTTHREADED));

	// Host side: the IPC block + a couple of forwarded events.
	SharedMemory shm;
	if (!shm.create(shared_memory_name(GetCurrentProcessId()), sizeof(SharedBlock))) {
		std::printf("Could not create shared memory -- skipping.\n");
		return 0;
	}
	auto* block = shm.as<SharedBlock>();
	block->version = kProtocolVersion;
	block->sequence.store(0, std::memory_order_relaxed);
	block->magic = kProtocolMagic;

	hook::IpcClient ipc;
	check(ipc.connect(10, 5), "IPC client connect");
	check(hook::install_mkb_hooks(ipc), "install MKB hooks");

	// Forward 'A' down and a left-mouse-button down, then pump them into the hook's synth state.
	const UINT vk = 'A';
	MkbEvent key{Mkb_KeyDown, vk, 0, 0};
	MkbEvent mouse{Mkb_MouseDown, 0 /*left*/, 100, 80};
	push_mkb_event(block->mkb, key);
	push_mkb_event(block->mkb, mouse);
	hook::mkb_pump(ipc);

	HWND hwnd = make_window();

	IDirectInput8W* di = nullptr;
	if (FAILED(DirectInput8Create(GetModuleHandleW(nullptr), DIRECTINPUT_VERSION, IID_IDirectInput8W,
	                              reinterpret_cast<void**>(&di), nullptr))
	    || di == nullptr) {
		std::printf("DirectInput8Create failed -- skipping.\n");
		hook::remove_mkb_hooks();
		return 0;
	}

	// Keyboard: GetDeviceState must show our forwarded key (at its DIK = scan code).
	if (IDirectInputDevice8W* kbd = make_device(di, GUID_SysKeyboard, &c_dfDIKeyboard, hwnd)) {
		BYTE keys[256] = {};
		const HRESULT hr = kbd->GetDeviceState(sizeof(keys), keys);
		const BYTE dik = static_cast<BYTE>(MapVirtualKeyW(vk, MAPVK_VK_TO_VSC) & 0xFF);
		std::printf("   keyboard GetDeviceState hr=0x%08lX dik=0x%02X state=0x%02X\n", static_cast<unsigned long>(hr),
		            dik, keys[dik]);
		check(SUCCEEDED(hr), "keyboard GetDeviceState succeeded");
		check((keys[dik] & 0x80) != 0, "forwarded 'A' appears in the DirectInput keyboard state");
		kbd->Unacquire();
		kbd->Release();
	} else {
		std::printf("   keyboard device unavailable -- skipping keyboard assertion.\n");
	}

	// Mouse: GetDeviceState must show our forwarded left button.
	if (IDirectInputDevice8W* ms = make_device(di, GUID_SysMouse, &c_dfDIMouse, hwnd)) {
		DIMOUSESTATE m{};
		const HRESULT hr = ms->GetDeviceState(sizeof(m), &m);
		std::printf("   mouse GetDeviceState hr=0x%08lX btn0=0x%02X\n", static_cast<unsigned long>(hr),
		            static_cast<unsigned>(static_cast<BYTE>(m.rgbButtons[0])));
		check(SUCCEEDED(hr), "mouse GetDeviceState succeeded");
		check((m.rgbButtons[0] & 0x80) != 0, "forwarded left button appears in the DirectInput mouse state");
		ms->Unacquire();
		ms->Release();
	} else {
		std::printf("   mouse device unavailable -- skipping mouse assertion.\n");
	}

	di->Release();
	hook::remove_mkb_hooks();
	if (hwnd != nullptr) {
		DestroyWindow(hwnd);
	}
	if (com) {
		CoUninitialize();
	}

	std::printf(g_failures == 0 ? "PASS dinput_hook_test\n" : "FAILED dinput_hook_test (%d)\n", g_failures);
	return g_failures == 0 ? 0 : 1;
}