i decided to stick with ogl 1.1 (ok i didn’t decide i just couldn’t find a
newer interface ;()
anyway i’m new to programing c++ and all that stuff… i did this:
char *bytes = (char *)sdl_surface->pixels;
char tmp;
int size = sdl_surface->w * sdl_surface->h;
for (int s=0; s<size; s+=3)
{
tmp = bytes[s];
bytes[s] = bytes[s+2];
bytes[s+2] = tmp;
}
and it makes the nehe logo blueish to around 2/3 of it the rest still looks
like bgr… so i guess i did something stupid in counting the num of bytes,
size …
it’s not as simple as w * h?
please help me out !
pozdroofki
gz.
apologies for posting stupid questions and bad english…
bytesize should be: width * height * 3;
pozdroofki
gz…
i decided to stick with ogl 1.1 (ok i didn’t decide i just couldn’t
find a newer interface ;()
anyway i’m new to programing c++ and all that stuff… i did this:
char *bytes = (char *)sdl_surface->pixels;
char tmp;
int size = sdl_surface->w * sdl_surface->h;
Well, assuming that the surface pitch equals w*BytesPerPixel (which is
not a safe assumption!), this is correct…
for (int s=0; s<size; s+=3)
…but this isn’t. You’re terminating the loop after processing w*h
bytes, while you should count pixels. 
[…]
it’s not as simple as w * h?
Returning to that; no, it’s not always wh. You should make it a habit to
use surface->pitch instead of w * BytesPerPixel to index along the Y
axis. Also, don’t access any skipped bytes between the end of a row
(wBytesPerPixel) and the first pixel of the next row - weird things may
happen.
//David Olofson — Programmer, Reologica Instruments AB
.- M A I A -------------------------------------------------.
| Multimedia Application Integration Architecture |
| A Free/Open Source Plugin API for Professional Multimedia |
----------------------------> http://www.linuxdj.com/maia -' .- David Olofson -------------------------------------------. | Audio Hacker - Open Source Advocate - Singer - Songwriter |-------------------------------------> http://olofson.net -'On Friday 26 October 2001 22:45, grzesio furga wrote: