Re: [AD] Some questions

[Sven Sandberg <sven.sandberg.1977@xxxxxxxxxx>]

Laurence Withers wrote:
> 1. Is using bmp_write_line et al. as fast as using line[] access? If 
>    not, what sort of difference is there?

There is probably a very small overhead with bmp_write_line(). But note 
that you only need to call bmp_write_line() once per scanline. So if you 
are drawing one scanline at a time then the overhead is negligible. 
AFAIK Allegro never makes a special case for pure memory bitmaps in 
order to use line[] instead of bmp_write_line().

> 3. I take it that something special has to be done with Mode-X bitmaps?
>    If so, is it easy stuff or should I provide a backup renderer which  
>    uses get/putpixel()?

It's quite complicated but not impossible to figure out. You can take a 
look at how, e.g., rotate_sprite() does it. I don't know if it applies 
to you, but if you are copying from one bitmap to another, then 
getpixel() also allows you to have screen bitmaps in the source.

Sven