To my knowledge this is a GM windows issue since from around GM6/GM7... Basically when you scale the game (are you scaling the game to fullscreen, or larger than the original room size at all?) it will scale in a blurry way rather than crisp, depending on your hardware configuration. I.e. it will be blurry on some computers but not on others. Even if you un-check color interpolation.
In GM:S it seems like this is happening less
but still happening.
In GM7/8 the solution was to draw all graphics to a surface, and then draw that surface to the full viewport as surfaces do not blur when scaled. This should work in GM:S as well although my old examples relied on screen_refresh()/screen_redraw() which are now obsolete so I have not yet been able to test this properly in GM:S.
Edited by Bisse, 28 June 2012 - 01:06 PM.