// abort if the nVidia extensions are not present
if (fncEnumGpusNV == null) return 0;
// enumerate nVidia adapters
HGLRCByReference hGPU = new HGLRCByReference();
for (int i = 0; i < 16; i++) {
Boolean ok = (Boolean) fncEnumGpusNV.invoke(Boolean.class, new Object[] { Integer.valueOf(i), hGPU, });
if (!ok.booleanValue()) return i;
}