itgmania212121/src/archutils/Common/HidDevice.cpp

#include "global.h"
#include "HidDevice.h"
#include "RageLog.h"

HidDevice::HidDevice(int vid, int pid, int interfaceNum) : path{ GetPath(vid, pid, interfaceNum) }
{
	bool result = TryConnect();

	if (!result) {

		LOG->Warn("HID device with VID/PID %x/%x not found.", vid, pid);
		hid_exit();
		return;
	}
	else
	{
		path = path;
		hid_set_nonblocking(handle, 1);
	}
}

HidDevice::~HidDevice()
{
	if (handle != nullptr)
		hid_close(handle);

	hid_exit();
}

void HidDevice::Close()
{
	hid_close(handle);
	handle = nullptr;
}

bool HidDevice::Open()
{
	handle = hid_open_path(path);

	return handle != nullptr;
}

bool HidDevice::TryConnect()
{
	if (path == nullptr)
		return false;

	return Open();
}

bool HidDevice::IsConnected() {
	if (handle == nullptr)
		return TryConnect();

	return handle != nullptr;
}

char* HidDevice::GetPath(int vid, int pid, int interfaceNumber)
{
	struct hid_device_info* devs, * cur_dev;

	devs = hid_enumerate(vid, pid);
	cur_dev = devs;

	if (devs && cur_dev)
	{
		// Look for the desired devices by iterating connected ones
		while (cur_dev)
		{
			if (cur_dev->vendor_id == vid &&
				cur_dev->product_id == pid)
			{
				if (interfaceNumber == -1)
				{
					return cur_dev->path;
				}
				else
				{
					if(cur_dev->interface_number == interfaceNumber)
						return cur_dev->path;
				}
			}

			cur_dev = cur_dev->next;
		}
	}

	return nullptr;
}

void HidDevice::Read(unsigned char* data, size_t length)
{
	if (!IsConnected())
		return;

	hid_read(handle, data, length);
}

void HidDevice::Write(const unsigned char* data, size_t length)
{
	if (!IsConnected())
		return;

	int result = hid_write(handle, data, length);

	if (result != length)
		Close();
}