Thanks. But, I'm not discoved that black/white render actually, since I found that trick in surfacefix's depth of field example, and just modified it a bit to suit with my bloomI'm sure you will find it.
Yes, I'm using fewer but bigger surfaces.
And maybe I'll upload a full-blown tutorial about these kind of visual effects, when I hopefuly find the best looking and fastest running method.
You discoverd a very clever trick with the black/white render.
I didn't knew it was possible to work around the black color before this.
Even, I never knew before that we can actually call draw event in another event
And.. I think I found something! By replacing draw_clear_alpha() on sur2 drawing with drawing a semi-transparent black sprite we'll get an "Afterimage" effect, which was kind of light motion blurring that will enhance the bloom, the more transparent the sprite the longer the trail effect. But becareful the bloom might be too bright and too wide spread.