SDL_BlitSurface Segmentation fault - c++

Question

I'm getting a segmentation fault from SDL_BlitSurface in C++.
here's the code
mainScreen->draw( 0, 0, background, NULL );
(where mainScreen is an instance of the Screen class) and the draw function of the Screen class is implemented as
void Screen::draw( float x, float y, Texture* source, SDL_Rect* clip)
{
SDL_Rect offset;
offset.x = x;
offset.y = y;
if ( source->myimage == NULL ) throw 5;
if ( this->screen == NULL ) throw 6;
SDL_BlitSurface( source->myimage, NULL, this->screen, &offset );
}
and Texture is defined as follows:
class Texture
{
public:
Texture(std::string imagepath);
~Texture();
private:
SDL_Surface* myimage;
float width;
float height;
friend class Screen;
//friend void Screen::draw( float x, float y, Texture source, SDL_Rect* clip);
};
and implemented
#include "Texture.h"
Texture::Texture(std::string filepath)
{
// Initialize the image to NULL to avoid any pointer issues
myimage = NULL;
// OPTIMIZED FOR PNGs
SDL_Surface* loadedImage = NULL;
SDL_Surface* optimizedImage = NULL;
loadedImage = IMG_Load( filepath.c_str() );
if ( loadedImage != NULL )
{
optimizedImage = SDL_DisplayFormatAlpha( loadedImage ); // Notice no colour keying (use transparent PNGs)
}
myimage = optimizedImage;
SDL_FreeSurface( loadedImage );
SDL_FreeSurface( optimizedImage );
if (myimage == NULL)
{
// Some kind of error
throw 4;
}
}
Texture::~Texture()
{
SDL_FreeSurface( myimage );
}
I've stepped through the area where the image is loaded into the Texture class and that seems to work fine.
Also, I know the this->screen is loaded correctly as I use SDL_FillRect with it in a separate function.

Answer 1

Don't do this:
SDL_FreeSurface( optimizedImage );
You aren't done with the surface (it gets assigned to myimage).