a test to mess with the windows gamepad API to show a friend a bare minimum example for collecting joystick data

Joystickthing.cpp

#pragma comment(lib, "hid.lib")
#include <stdio.h>
#include <Windows.h>
#include <hidsdi.h>
LRESULT CALLBACK dummy_wndproc(HWND wnd, UINT msg, WPARAM wp, LPARAM lp) {
	if (msg == WM_INPUT) {
		UINT bufferSize;
		//get the rawinput data
		GetRawInputData((HRAWINPUT)lp, RID_INPUT, 0, &bufferSize, sizeof(RAWINPUTHEADER));
		PRAWINPUT rawinput = (PRAWINPUT)malloc(bufferSize);
		GetRawInputData((HRAWINPUT)lp, RID_INPUT, rawinput, &bufferSize, sizeof(RAWINPUTHEADER));
		//get the preparsed input
		GetRawInputDeviceInfo(rawinput->header.hDevice, RIDI_PREPARSEDDATA, 0, &bufferSize);
		PHIDP_PREPARSED_DATA preparsedData = (PHIDP_PREPARSED_DATA)malloc(bufferSize);
		GetRawInputDeviceInfo(rawinput->header.hDevice, RIDI_PREPARSEDDATA, preparsedData, &bufferSize);
		//get the value caps
		HIDP_CAPS caps;
		HidP_GetCaps(preparsedData, &caps);
		USHORT axisCount = caps.NumberInputValueCaps;
		PHIDP_VALUE_CAPS valueCaps = (PHIDP_VALUE_CAPS)malloc(sizeof(HIDP_VALUE_CAPS)*axisCount);
		HidP_GetValueCaps(HidP_Input, valueCaps, &axisCount, preparsedData);
		//get the value of Axis #0 (this was the Y axis on my xbox controller)
		int axis_id = 0;
		ULONG value = 0;
		HidP_GetUsageValue(HidP_Input, valueCaps[axis_id].UsagePage, 0, valueCaps[axis_id].Range.UsageMin, &value, preparsedData, (PCHAR)rawinput->data.hid.bRawData, rawinput->data.hid.dwSizeHid);
		printf("%d\n", (LONG)value);
		//free the structures allocated
		free(valueCaps);
		free(preparsedData);
		free(rawinput);
	}
	return 0;
}
int main() {
	HWND dummy_wnd = CreateWindowEx(0, "STATIC", "I'm invisible!", 0, 0, 0, 100, 100, 0, 0, 0, 0);
	RAWINPUTDEVICE rid;
	rid.usUsagePage = 1; //no idea what this is
	rid.usUsage = 5; //apparently this tells it it's a gamepad??
	rid.dwFlags = RIDEV_INPUTSINK;
	rid.hwndTarget = dummy_wnd;
	SetWindowLong(dummy_wnd, GWL_WNDPROC, (LONG)dummy_wndproc);
	if (!RegisterRawInputDevices(&rid, 1, sizeof(RAWINPUTDEVICE)))
		return -1; //it broke D:
	MSG msg;
	while (GetMessage(&msg, dummy_wnd, 0, 0)) {
		TranslateMessage(&msg);
		DispatchMessage(&msg);
	}
	return 0;
}