Function ScaleAndWriteToBMP

shared/LoadImage.c:217–341

}

BOOL ScaleAndWriteToBMP(HBITMAP hBitmap, DWORD width, DWORD height, LPCWSTR outputPath) {
	BOOL result = FALSE;
	if (!hBitmap) {
		TRACE(L"Null bitmap");
		return FALSE;
	}

	HDC hdc = GetDC(NULL);
	HDC hdcMem = CreateCompatibleDC(hdc);
	HDC hdcMemScaled = NULL;
	HGLOBAL handle = NULL;
	HANDLE file = INVALID_HANDLE_VALUE;
	HBITMAP oldBitmap = NULL;
	HBITMAP oldScaledBitmap = NULL;
	HRESULT hr = S_OK;

	HBITMAP scaledBitmap = CreateCompatibleBitmap(hdc, width, height);
	if (!scaledBitmap) {
		hr = HRESULT_FROM_WIN32(GetLastError());
		CHECK_HR(L"CreateCompatibleBitmap failed");
		goto end;
	}

	BITMAP bmp = {0};
	if (!GetObject(hBitmap, sizeof(BITMAP), &bmp)) {
		hr = HRESULT_FROM_WIN32(GetLastError());
		CHECK_HR(L"GetObject failed");
		goto end;
	}

	hdcMemScaled = CreateCompatibleDC(hdc);
	SetStretchBltMode(hdcMemScaled, HALFTONE);

	oldBitmap = SelectObject(hdcMem, hBitmap);
	oldScaledBitmap = SelectObject(hdcMemScaled, scaledBitmap);

	if (!StretchBlt(hdcMemScaled,
		0, 0, width, height, hdcMem,
		0, 0, bmp.bmWidth, bmp.bmHeight, SRCCOPY)) {
		hr = HRESULT_FROM_WIN32(GetLastError());
		CHECK_HR(L"StretchBlt failed");
		goto end;
	}

	BITMAPINFOHEADER bmih = {0};
	bmih.biSize = sizeof(BITMAPINFOHEADER);
	bmih.biWidth = width;
	bmih.biHeight = height;
	bmih.biPlanes = 1;
	bmih.biBitCount = bmp.bmBitsPixel;
	bmih.biCompression = BI_RGB;
	bmih.biSizeImage = ((width * bmp.bmBitsPixel + 31) / 32) * 4 * height;

	BITMAPFILEHEADER bmfh = {0};
	bmfh.bfType = 0x4D42;
	bmfh.bfOffBits = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER);
	bmfh.bfSize = bmfh.bfOffBits + bmih.biSizeImage;