I've made a simple function that takes a screenshot of the Windows desktop. Now I want to be able to scale the resulting bitmap. But I'm not sure how to do this, the bitmap I now have is a Windows-thingy called HBITMAP, and I'm not sure how to work with it since I don't really know what format it is. It's probably very similar to a normal bmp-file.
I tried a windows-function called StretchBlt, but the result isn't very good. It's a very brute force smoshing together of pixels type of approach and I would like to have a bit higher quality bitmap when I'm done.
Perhaps I can send the HBITMAP to a function in a crate that does the scaling for me, but I guess this assumes it knows how to work with the HBITMAP?
Anyhow, this is what I have so far and I would love to have som suggestions how I can scale my screenshot.
fn take_screenshot() {
// get screen size
let x1 = unsafe { GetSystemMetrics(SM_XVIRTUALSCREEN) };
let y1 = unsafe { GetSystemMetrics(SM_YVIRTUALSCREEN) };
let x2 = unsafe { GetSystemMetrics(SM_CXVIRTUALSCREEN) };
let y2 = unsafe { GetSystemMetrics(SM_CYVIRTUALSCREEN) };
let w = x2 - x1;
let h = y2 - y1;
// copy screen to bitmap
let hscreen = unsafe { GetDC(None) };
let hdc = unsafe { CreateCompatibleDC(hscreen) };
let hbitmap = unsafe { CreateCompatibleBitmap(hscreen, w / 3, h / 3) };
let old_obj = unsafe { SelectObject(hdc, hbitmap) };
// let _bret = unsafe { BitBlt(hdc, 0, 0, w, h, hscreen, x1, y1, SRCCOPY) };
let _bret = unsafe { StretchBlt(hdc, 0, 0, w / 3, h / 3, hscreen, x1, y1, w, h, SRCCOPY) };
// save bitmap to clipboard
unsafe {
OpenClipboard(None);
EmptyClipboard();
let _ = SetClipboardData(CF_BITMAP.0 as u32, HANDLE(hbitmap.0));
CloseClipboard();
}
// cleanup
unsafe {
SelectObject(hdc, old_obj);
DeleteDC(hdc);
ReleaseDC(None, hscreen);
DeleteObject(hbitmap);
}
}