OpenCV image zoomed in - c++

Question

I'm using this function to make a screenshot of a window. It works fine but at games like Minecraft it's zoomed in.
Normal
Screenshot
cv::Mat getMat(HWND hWND) {
HDC deviceContext = GetDC(hWND);
HDC memoryDeviceContext = CreateCompatibleDC(deviceContext);
RECT windowRect;
GetClientRect(hWND, &windowRect);
int height = windowRect.bottom;
int width = windowRect.right;
HBITMAP bitmap = CreateCompatibleBitmap(deviceContext, width, height);
SelectObject(memoryDeviceContext, bitmap);
//copy data into bitmap
BitBlt(memoryDeviceContext, 0, 0, width, height, deviceContext, 0, 0, SRCCOPY);
//specify format by using bitmapinfoheader!
BITMAPINFOHEADER bi;
bi.biSize = sizeof(BITMAPINFOHEADER);
bi.biWidth = width;
bi.biHeight = -height;
bi.biPlanes = 1;
bi.biBitCount = 32;
bi.biCompression = BI_RGB;
bi.biSizeImage = 0; //because no compression
bi.biXPelsPerMeter = 1;
bi.biYPelsPerMeter = 2;
bi.biClrUsed = 3;
bi.biClrImportant = 4;
cv::Mat mat = cv::Mat(height, width, CV_8UC4); // 8 bit unsigned ints 4 Channels -> RGBA
//transform data and store into mat.data
GetDIBits(memoryDeviceContext, bitmap, 0, height, mat.data, (BITMAPINFO*)&bi, DIB_RGB_COLORS);
//clean up!
DeleteObject(bitmap);
DeleteDC(memoryDeviceContext); //delete not release!
ReleaseDC(hWND, deviceContext);
return mat;
}

Answer 1

According to the documentation, windowRect.bottom is not the height. Or windowRect.right is not the width. https://learn.microsoft.com/en-us/windows/win32/api/windef/ns-windef-rect
So, you should do something like this:
int height = windowRect.bottom - windowRect.top;
int width = windowRect.right - windowRect.left;
EDIT1:
I have found an issue similar to yours. Maybe it could help you as well.
ClientRect mysteriously smaller than WindowRect?
Cheers.