how are you drawing your surfaces?
I create a surface with:
light = surface_create(view_xview,view_yview)
(But I have imported the view gml from GMS1.4)
I create the colored overlay with:
surface_set_target(light);
draw_set_color(the color overlay)
draw_rectangle(0,0,view_wview,view_hview,false);
surface_reset_target();
I draw the light circle with:
gpu_set_blendmode(bm_subtract);
surface_set_target(light);
draw_ellipse_color(x - radius / 2 - view_xview, y - radius / 2 - view_yview, x + radius / 2 - view_xview, y + radius / 2 - view_yview, c_orange, c_black, false);
surface_reset_target();
gpu_set_blendmode(bm_normal);
I draw the color overlay with:
gpu_set_blendmode(bm_subtract);
draw_surface(the surface, view_xview, view_yview);
gpu_set_blendmode(bm_normal);
I hope you can help me!