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Legacy GM Drawing alpha blended sprites on surface


Hey y'all,

I've been trying to make a texturing tool for my 2d game. I want to blend multiple textures into a surface and use that as background.

I'm using black sprites to "cut out" a part of the texture. So basically, this is the alphamask of the texture.

Now, you see the problem below - this is a screenshot from the surface itself. Its not blending the black circles' darkness.

I know its a known thing, but I can't seem to figure out _how_ to merge the alpha channels. What am i doing wrong? I would want this to result in 1 closed shape. It looks like the way this is drawn differs completely from how GM draws it normally (it even states so here http://www.yoyogames.com/blog/60) yet when i set the blend mode to bm_normal, this still happens. I've tried enabling draw_alpha_blend() but that didn't help either.

What am i missing? This can't be _that_ hard, can it?


Also, now that i take a look at it, sorry for making it look like male genitalia.