Windows tool for resizing Minecraft to a specific frame size

resize_mc.c

#include <windows.h>

#define MC_LAUNCHER_WINDOW_TITLE L"Minecraft Launcher"
#define MC_GAME_WINDOW_TITLE L"Minecraft"
#define TARGET_WIDTH 432
#define TARGET_HEIGHT 240

// method by Guy Lecky-Thompson
// http://www.suite101.com/content/client-area-size-with-movewindow-a17846

BOOL WindowClientResize(HWND hWnd, int nWidth, int nHeight) {
	RECT rcClient, rcWindow;
	POINT ptDiff;
	GetClientRect(hWnd, &rcClient);
	GetWindowRect(hWnd, &rcWindow);
	ptDiff.x = (rcWindow.right - rcWindow.left) - rcClient.right;
	ptDiff.y = (rcWindow.bottom - rcWindow.top) - rcClient.bottom;
	return MoveWindow(hWnd,rcWindow.left, rcWindow.top, nWidth + ptDiff.x,
	  nHeight + ptDiff.y, TRUE);
}

int main() {
	// first try finding the launcher window
	HWND mcWindow = FindWindowW(NULL, MC_LAUNCHER_WINDOW_TITLE);
	if (mcWindow == NULL) {
		// if that doesn't succeed, look for the actual game window
		mcWindow = FindWindowW(NULL, MC_GAME_WINDOW_TITLE);
	}
	if (mcWindow != NULL) {
		// 0 when resizing was successful, 1 otherwise
		return !WindowClientResize(mcWindow, TARGET_WIDTH, TARGET_HEIGHT);
	}
	else {
		// no Minecraft window found
		return 2;
	}
}