VERY strange error

SDL Development
1

Hello everyone!

Okay, this works perfectly fine on Windows, but on Linux it screws up the
most strange way ever.

I want to blit an image onto the screen, but the behavior changes every time
I compile the program without changing any code.

It alternates between these:

  • Segmentation fault.
  • Works but image is darker.

Any, erm, clues?

Here are all of the code I use this image on: (all lines on different
functions)

spritesImg = SDL_LoadBMP(“sprites.bmp”);
if (spritesImg == NULL) return -1;
SDL_DisplayFormat(spritesImg);

/* Replace all cyan(bg1) and light yellow (bg2) colors with magenta (bgd) */

for (x = 0; x < surf->w; x++)
{
for (y = 0; y < surf->h; y++)
{
px = sge_GetPixel(surf, x, y);
if (px == bg1 || px == bg2)
sge_PutPixel(surf, x, y, bgd);
}
}
SDL_SetColorKey(s, SDL_SRCCOLORKEY, bgd))

Any idears? Everything else was loaded at 24-bit, including the screen, and
if I remember correctly this image is also 24-bit.

Thanks in advance, kind people of SDL!

2

Leo28C wrote:

Hello everyone!
…
Here are all of the code I use this image on: (all lines on different
functions)

spritesImg = SDL_LoadBMP(“sprites.bmp”);
if (spritesImg == NULL) return -1;
SDL_DisplayFormat(spritesImg);

/* Replace all cyan(bg1) and light yellow (bg2) colors with magenta (bgd)
*/

for (x = 0; x < surf->w; x++)
{
for (y = 0; y < surf->h; y++)
{
px = sge_GetPixel(surf, x, y);
if (px == bg1 || px == bg2)
sge_PutPixel(surf, x, y, bgd);
}
}
SDL_SetColorKey(s, SDL_SRCCOLORKEY, bgd))

…

I’ll try to answer as best as I can. Haven’t tried manipulating the pixels
directly.

  1. What is the “surf” variable?

  2. What are the definition of sge_GetPixel & sge_PutPixel? I reckon it is
    similar with the getpixel() and putpixel() method from the documentation,
    right?

  3. AFAIK, to manipulate a surface, you must lock the surface first.

Fare thee well,
Bawenang R. P. P.----------------
ERROR: Brain not found. Please insert a new brain!

?Do nothing which is of no use.? - Miyamoto Musashi.

“I live for my dream. And my dream is to live my life to the fullest.”

3

Uh, nevermind that - turned out I was overflowing an array… Sorry for
wasting your time! :blush:

benang at cs.its.ac.id wrote:> Leo28C wrote:

Hello everyone!
…
Here are all of the code I use this image on: (all lines on different
functions)

spritesImg = SDL_LoadBMP(“sprites.bmp”);
if (spritesImg == NULL) return -1;
SDL_DisplayFormat(spritesImg);

/* Replace all cyan(bg1) and light yellow (bg2) colors with magenta (bgd)
*/

for (x = 0; x < surf->w; x++)
{
for (y = 0; y < surf->h; y++)
{
px = sge_GetPixel(surf, x, y);
if (px == bg1 || px == bg2)
sge_PutPixel(surf, x, y, bgd);
}
}
SDL_SetColorKey(s, SDL_SRCCOLORKEY, bgd))

…

I’ll try to answer as best as I can. Haven’t tried manipulating the pixels
directly.

  1. What is the “surf” variable?

  2. What are the definition of sge_GetPixel & sge_PutPixel? I reckon it is
    similar with the getpixel() and putpixel() method from the documentation,
    right?

  3. AFAIK, to manipulate a surface, you must lock the surface first.

Fare thee well,
Bawenang R. P. P.

ERROR: Brain not found. Please insert a new brain!

?Do nothing which is of no use.? - Miyamoto Musashi.

“I live for my dream. And my dream is to live my life to the fullest.”

4

Hi,

Watch out for SGE… After looking through the source code, I’ve noticed it doesn’t always handle endianness correctly (it doesn’t define PI correctly either, among other things). It is a really old library now, so I’m working on a new version here: http://pubpages.unh.edu/~jmb97

Jonny D> To: sdl at libsdl.org> From: kixdemp at gmail.com> Date: Thu, 27 Sep 2007 02:30:32 -0400> Subject: Re: [SDL] VERY strange error…> > Uh, nevermind that - turned out I was overflowing an array… Sorry for > wasting your time! :$> > benang at cs.its.ac.id wrote:> > Leo28C wrote:> >> Hello everyone!> >> …> >> Here are all of the code I use this image on: (all lines on different> >> functions)> >>> >> spritesImg = SDL_LoadBMP(“sprites.bmp”);> >> if (spritesImg == NULL) return -1;> >> SDL_DisplayFormat(spritesImg);> >>> >> /* Replace all cyan(bg1) and light yellow (bg2) colors with magenta (bgd)> >> */> >>> >> for (x = 0; x < surf->w; x++)> >> {> >> for (y = 0; y < surf->h; y++)> >> {> >> px = sge_GetPixel(surf, x, y);> >> if (px == bg1 || px == bg2)> >> sge_PutPixel(surf, x, y, bgd);> >> }> >> }> >> SDL_SetColorKey(s, SDL_SRCCOLORKEY, bgd))> >>> >> …> > > > I’ll try to answer as best as I can. Haven’t tried manipulating the pixels> > directly.> > > > 1. What is the “surf” variable?> > > > 2. What are the definition of sge_GetPixel & sge_PutPixel? I reckon it is> > similar with the getpixel() and putpixel() method from the documentation,> > right?> > > > 3. AFAIK, to manipulate a surface, you must lock the surface first.> > > > Fare thee well,> > Bawenang R. P. P.> > > > ----------------> > ERROR: Brain not found. Please insert a new brain!> > > > ?Do nothing which is of no use.? - Miyamoto Musashi.> > > > “I live for my dream. And my dream is to live my life to the fullest.”> > _______________________________________________> SDL mailing list> SDL at lists.libsdl.org> http://lists.libsdl.org/listinfo.cgi/sdl-libsdl.org

Connect to the next generation of MSN Messenger?
http://imagine-msn.com/messenger/launch80/default.aspx?locale=en-us&source=wlmailtagline