bitmap transparency

bitmap transparency

Antone333

Member #15,545

March 2014

I know its possible to make a color completely invisible. I use this already in my game. But I was wondering is there a way to draw a bitmap that is still visible but see through?

Edgar Reynaldo

Major Reynaldo

May 2007

Yes. Use 32 bit color and alpha channels on your images.

Eagle and Allegro 5 binaries | Older Allegro 4 and 5 binaries | Allegro 5 compile guide
King Piccolo will make it so Then I could just flip it with some sweet, sweet matrix math. In either case, I’ll ride this wagon until the wheels fall off. Thanks to those that keep it running

#00JMP00

Member #14,740

November 2012

If you want to draw translucent bitmaps onto others, you can use draw_trans. This will exactly do what you want. Other ways may fail :-))

Dizzy Egg

Member #10,824

March 2009

Yeah, what Edgar said. You can create an image in your 'graphics software' with an alpha channel; then, if you save it as something like .png you can load it in A5 and it will use the alpha channel, 32 bits (24 for the colours RGB and 8 bits for the alpha transparency....probably).

----------------------------------------------------
Please check out my songs:
https://soundcloud.com/dont-rob-the-machina

Antone333

Member #15,545

March 2014

could you point me to draw trans in the manual? i can't find it.

Chris Katko

Member #1,881

January 2002

Allegro 4 or 5?

-----sig:
“Programs should be written for people to read, and only incidentally for machines to execute.” - Structure and Interpretation of Computer Programs
"Political Correctness is fascism disguised as manners" --George Carlin

Antone333

Member #15,545

March 2014

Allegro 5

Aikei_c

Member #14,871

January 2013

If you want to draw a bitmap half-transparent only sometimes, instead of editing it to include alpha channel, you could draw it tinted like that:

al_draw_tinted_bitmap(yourBitmap,al_map_rgba_f(0.5,0.5,0.5,0.5),x,y,0);