loplugin:fpcomparison in slideshow/

Change-Id: Ic910deea47065d1f69748b95e59d19c6cda5d29b
Reviewed-on: https://gerrit.libreoffice.org/21863Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Noel Grandin <noelgrandin@gmail.com>

slideshow/source/engine/color.cxx

@@ -69,11 +69,11 @@ namespace slideshow
                         nDelta/(2.0-nMax-nMin) :
                         nDelta/(nMax + nMin);
 
-                    if( nRed == nMax )
+                    if( rtl::math::approxEqual(nRed, nMax) )
                         aRes.mnHue = (nGreen - nBlue)/nDelta;
-                    else if( nGreen == nMax )
+                    else if( rtl::math::approxEqual(nGreen, nMax) )
                         aRes.mnHue = 2.0 + (nBlue - nRed)/nDelta;
-                    else if( nBlue == nMax )
+                    else if( rtl::math::approxEqual(nBlue, nMax) )
                         aRes.mnHue = 4.0 + (nRed - nGreen)/nDelta;
 
                     aRes.mnHue *= 60.0;