I've worked out a little trick to give a surface an alpha layer, after trying my best to understand extended blend modes and checking out GearGod's metaball example.
Created a "light" system where they don't brighten up the contents, but bring them into color!Of course, it requires you to draw the screen twice and with different backgrounds/sprites etc. so (although I'm not sure) the effect seems kinda expensive.Still, pretty neat :D Also, reckon that background's style is OK? I'm not sure about it…
At first I was hoping you found a way to do it without different backgrounds and sprites. Curses.
Okay, that's pretty damn cool.
Yeah I'm sure there's some way to do it somehow but for now it's not too bad. The extra trouble's worth it though, at least because I want to base my next project around the effect :)
All efficient graphical methods use a screen buffer, something that you can't access directly in GM. However, there is a solution. You can turn off automatic drawing and commit all graphics to a surface the size of the display. Then using that surface, you can apply graphical effects to your heart's content. This removes the need for so-called dual drawing. Expect an 80% increase in frame rates.