Fix vflip, hflip, and optimize scanline drawing a little
Fix vflip, hflip, and optimize scanline drawing a little

JershXL/gbajs,JershXL/gbajs,matthewbauer/gbajs,ElliottAYoung/gbajs,matthewbauer/gbajs,ElliottAYoung/gbajs,endrift/gbajs,endrift/gbajs