create_sub_bitmap

create_sub_bitmap

Miles Lombardi

Member #5,876

May 2005

What exactly does this do?
Does it blit part of the parent to a newly created child?
Or does it set up like a pointer within the BITMAP* and a clip x y and a width and height?
It's just for efficiency reasons you see.

The Phreake Network

Raf256

Member #3,501

May 2003

AFAIR it is closer to the second method - just faslty setup some pointers/integers (clipping) to access something insied other bitmap's data

Neil Walker

Member #210

April 2000

second point. but you still need to destroy it when finished, and of course destroy it before you destroy the master.

Neil.
MAME Cabinet Blog / AXL LIBRARY (a games framework) / AXL Documentation and Tutorial

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Ceagon Xylas

Member #5,495

February 2005

Yeah I use it in situations like when I have a sprite sheet.

BITMAP *sprite_sheet=load_pcx("blah/blah.pcx",NULL);
BITMAP *frame=create_sub_bitmap(sprite_sheet,0,0,0,0);
draw_sprite(buffer,frame,x,y);
destroy_bitmap(frame);

Or
draw_sprite(buffer,create_sub_bitmap(sprite_sheet,0,0,0,0),x,y);

Thomas Fjellstrom

Member #476

June 2000

Quote:

draw_sprite(buffer,create_sub_bitmap(sprite_sheet,0,0,0,0),x,y);

Except thats a horrible memory leak.

--
Thomas Fjellstrom - [website] - [email] - [Allegro Wiki] - [Allegro TODO]
"If you can't think of a better solution, don't try to make a better solution." -- weapon_S
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Ceagon Xylas

Member #5,495

February 2005

Figures. My code usually winds up being terrible.
So stick to method 1? =]