Gpe Compiles But Does Not Run

[Dantrasoft]

Hello,

Im new to this place and to C++ programming. I have installed the GP2XSDK and have it compiling my program which is the 2nd tutorial found on Lazy Foo's site. So it compiles to a gpe but when i put it on my SD card I get a blank screen. Anyone come across this problem or knows what im doing wrong? Do I need to do anything to the SDL library on the GP2X? My GP2X is Firmware version 2 and ive had it for about a week. Im using DEV ++ to code and compile.

Cheers.

Dan

CODE:

//The headers
#include "SDL/SDL.h"
#include <string>

//The attributes of the screen
const int SCREEN_WIDTH = 320;
const int SCREEN_HEIGHT = 240;
const int SCREEN_BPP = 16;

//The surfaces that will be used
SDL_Surface *message = NULL;
SDL_Surface *background = NULL;
SDL_Surface *screen = NULL;

SDL_Surface *load_image( std::string filename )
{
//Temporary storage for the image that's loaded
SDL_Surface* loadedImage = NULL;

//The optimized image that will be used
SDL_Surface* optimizedImage = NULL;

//Load the image
loadedImage = SDL_LoadBMP( filename.c_str() );

//If nothing went wrong in loading the image
if( loadedImage != NULL )
{
//Create an optimized image
optimizedImage = SDL_DisplayFormat( loadedImage );

//Free the old image
SDL_FreeSurface( loadedImage );
}

//Return the optimized image
return optimizedImage;
}

void apply_surface( int x, int y, SDL_Surface* source, SDL_Surface* destination )
{
//Make a temporary rectangle to hold the offsets
SDL_Rect offset;

//Give the offsets to the rectangle
offset.x = x;
offset.y = y;

//Blit the surface
SDL_BlitSurface( source, NULL, destination, &offset );
}

int main( int argc, char* args[] )
{
//Initialize all SDL subsystems
if( SDL_Init( SDL_INIT_EVERYTHING ) == -1 )
{
return 1;
}

//Set up the screen
screen = SDL_SetVideoMode( SCREEN_WIDTH, SCREEN_HEIGHT, SCREEN_BPP, SDL_SWSURFACE );

//If there was in error in setting up the screen
if( screen == NULL )
{
return 1;
}

//Load the images
message = load_image( "hello_world.bmp" );
background = load_image( "background.bmp" );

//Apply the background to the screen
apply_surface( 0, 0, background, screen );

//Apply the message to the screen
apply_surface( 180, 140, message, screen );

//Update the screen
if( SDL_Flip( screen ) == -1 )
{
return 1;
}

//Wait 2 seconds
SDL_Delay( 2000 );

//Free the surfaces
SDL_FreeSurface( message );
SDL_FreeSurface( background );

//Quit SDL
SDL_Quit();

return 0;
}

 

[Parkydr]

Use telnet to login into the GP2X and run it from there then you'll be able to see any error messages

 

[Dantrasoft]

Ok i have telnet the gp2x and run the program and i get the following message:

[root@gp2x root]$/mnt/sd/Games/movingdot/motion.gpe
Segmentation fault

What does this mean?

 

[Squidge]

It means your program has attempted to do something naughty, like dereference an invalid pointer.

EDIT: Try to put some printf's in your code to see where it is crashing, or use the GDB from the archives to step through your code.