It seems GCC likes my code better than VS 2010

Basically, my code is just meant to load a BMP file, just to test SDL in Visual Studio. It works in Code::Blocks with MingW, and it worked in VS up until I added

Code:

Uint32 colorkey = SDL_MapRGB(img->format, 0xFF, 0, 0xFF); //declare the key
SDL_SetColorKey(img, SDL_SRCCOLORKEY, colorkey); // set the key

VS is pointing towards the key's declaration line, and saying "Unhandled exception at 0x00d9158a in SDL_Tutorial.exe: 0xC0000005: Access violation reading location 0x00000004." My entire program:

Code:

#include <SDL.h>


int main( int argc, char* args[] )
{
	//Start SDL
    SDL_Init( SDL_INIT_EVERYTHING );
	//vars
	SDL_Surface *img;
	SDL_Surface *buffer;
	SDL_Rect crop;
	SDL_Rect loc;
	crop.x = 0;
	crop.y = 0;
	crop.w = 32;
	crop.h = 32;
	loc.x = 280;
	loc.y = 280;

	

   
    
	//load image onto screen
	img = SDL_LoadBMP("snakey.bmp");
	Uint32 colorkey = SDL_MapRGB(img->format, 0xFF, 0, 0xFF);

	SDL_SetColorKey(img, SDL_SRCCOLORKEY, colorkey); //make magneta invisible
	buffer = SDL_SetVideoMode( 640, 480, 32, SDL_SWSURFACE );
	SDL_BlitSurface(img, &crop, buffer, &loc);
	SDL_Flip(buffer);
	SDL_Delay(2000);
	//Quit SDL
	SDL_FreeSurface(buffer);
	SDL_FreeSurface(img);
    SDL_Quit();
    
    return 0;    
}

Perhaps SDL_LoadBMP simply fails? Check return values.

Well, I edited it a little, to this:

Code:

#include <SDL.h>


int main( int argc, char* args[] )
{
	//Start SDL
    SDL_Init( SDL_INIT_EVERYTHING );
	//vars
	SDL_Surface *img;
	SDL_Surface *buffer;
	SDL_Rect crop;
	SDL_Rect loc;
	crop.x = 0;
	crop.y = 0;
	crop.w = 32;
	crop.h = 32;
	loc.x = 280;
	loc.y = 280;

	

   
    
	//load image onto screen
	img = SDL_LoadBMP("snakey.bmp");
	Uint32 colorkey = SDL_MapRGB(img->format, 0xFF, 0, 0xFF);

	SDL_SetColorKey(img, SDL_SRCCOLORKEY, colorkey); //make magneta invisible
	buffer = SDL_SetVideoMode( 640, 480, 32, SDL_SWSURFACE );
	SDL_BlitSurface(img, &crop, buffer, &loc);
	SDL_Flip(buffer);
	SDL_Delay(2000);
	//Quit SDL
	SDL_FreeSurface(buffer);
	SDL_FreeSurface(img);
    SDL_Quit();
    
    return 0;    
}

but this only runs if I run the executable directly. Is that normal?

By checking return values I meant something like this:

Code:

img = SDL_LoadBMP("snakey.bmp");
if (!img) {
    //output error message and quit
}

It looks from the exception that your program is dereferencing a NULL pointer (or rather an offset of 4 bytes from NULL), presumably img being NULL.

The cause of the problem might be that different IDEs may set a different working directory when you run a program from the IDE, and the file doesn't happen to be in that directory. See if giving a full path to the image file helps and see if the IDE lets you set that path to wherever the executable (and the image) is.

Sorry, I replied right after I posted without checking for other posts, so...latepost
but yeah, ill try that

I did that, and I have it exiting if it didn't load (doesn't do much, but atleast it tells me what's going on). I tried adding the file - snakey.bmp - as a Resource file, but that didn't work either. It only works if i run the EXE without VS, from the debug folder.

Fixed it

It means that your app is being launched with a different working directory when being run through the debugger. This is very common.