GameMaker Draw GUI/ draw_surface alpha issue

[angusbeer]

I'm doing a Windows port of my browser game which was made in a 1:1 aspect ratio. When stretching the window horizontally or vertically, I wanted to fill the black space with an infinite background, like this:



This is the code I used in Draw GUI:

draw_sprite_tiled(spr_background_hearts,0,0,0); //the infinite background
draw_surface(application_surface,0,0);

It's mostly working, but anything with alpha elements just looks off. I made an example sprite to show what I mean; on the right is with Draw GUI elements turned on. Notice how you can see through to the background around the edge.
Any idea on what's happening and how to fix it?

 

[FoxyOfJungle]

Watch this video, this is probably what you are looking for:

 

[Nocturne]

Try disabling alpha writing when you draw the sprite that is giving you issues... See this function: https://manual-en.yoyogames.com/Gam...ing/GPU_Control/gpu_set_colourwriteenable.htm

So you'd use that function setting the alpha write to false then draw the sprite, then call the same function again to set the alpha write back to true again to keep drawing.