Sforno on Genesis 6:6/ספורנו על בראשית ו׳:ו׳

1ויתעצב אל לבו, seeing that G’d does not want even the guilty to die instead of finding their way back. The opposite “emotion” of G’d to the one expressed here is found in Psalms 104,31 ישמח ה' במעשיו, “the Lord ‘enjoys’ the deeds of His creatures.”