Bitmap fonts and memory allocation woes

SDL Development
1

Hi, I wrote a little bitmap font library to use in a game I’m making but
I’m sort of stuck. I use an array of structs:

struct font
{
int charnum;
int *loffset;
int *roffset;
SDL_Surface *fontmap;
};

to store my font. The font bitmap is stored in fonts[i].fontmap, the
number of characters in charnum and loffset and roffset are pointers to
arrays of ints which are allocated at runtime depending on charnum.

struct font *fonts;

[…]
[determine number of fonts to load from config file]

/* allocate memory for sufficient number of font structures /
if( (fonts = malloc(maxfontssizeof(font))) == NULL)
{
printf(“Unable to allocate memory for font structures!\n”);
exit(1);
}

[…]

// determine number of chars
fonts[fontcount].charnum = fonts[fontcount].fontmap->h /
fonts[fontcount].fontmap->w;

// allocate memory for offset arrays
fonts[fontcount].loffset = malloc(fonts[fontcount].charnumsizeof(int));
fonts[fontcount].roffset = malloc(fonts[fontcount].charnumsizeof(int));

up until here, everything works beautifully, I can access the arrays
like so:
fonts[i].loffset[k] and they work, however, when it comes to freeing
the allocated memory I get a segfault:

for(i = 0; i<maxfonts; i++)
{
SDL_FreeSurface(fonts[i].fontmap);
free(fonts[i].loffset); // <-- segfault
free(fonts[i].roffset); // <-- segfault
}

also I cannot free the initially allocated memory for the array fonts of
font structures

free(fonts) gives me illegal type

any ideas?

Thanks!

Bartek

2

Okay, solved it. The code was good but the implementation was not quite.
I initialized the *fonts array and the instance of the font struct in
the main program file, obviously, in the font module it was impossible
to free it. It works like a charm after moving the intialization fully
into the font library.On Mon, 2005-07-04 at 08:40 +0100, Bartek Kostrzewa wrote:

Hi, I wrote a little bitmap font library to use in a game I’m making but
I’m sort of stuck. I use an array of structs:

struct font
{
int charnum;
int *loffset;
int *roffset;
SDL_Surface *fontmap;
};

to store my font. The font bitmap is stored in fonts[i].fontmap, the
number of characters in charnum and loffset and roffset are pointers to
arrays of ints which are allocated at runtime depending on charnum.

struct font *fonts;

[…]
[determine number of fonts to load from config file]

/* allocate memory for sufficient number of font structures /
if( (fonts = malloc(maxfontssizeof(font))) == NULL)
{
printf(“Unable to allocate memory for font structures!\n”);
exit(1);
}

[…]

// determine number of chars
fonts[fontcount].charnum = fonts[fontcount].fontmap->h /
fonts[fontcount].fontmap->w;

// allocate memory for offset arrays
fonts[fontcount].loffset = malloc(fonts[fontcount].charnumsizeof(int));
fonts[fontcount].roffset = malloc(fonts[fontcount].charnumsizeof(int));

up until here, everything works beautifully, I can access the arrays
like so:
fonts[i].loffset[k] and they work, however, when it comes to freeing
the allocated memory I get a segfault:

for(i = 0; i<maxfonts; i++)
{
SDL_FreeSurface(fonts[i].fontmap);
free(fonts[i].loffset); // <-- segfault
free(fonts[i].roffset); // <-- segfault
}

also I cannot free the initially allocated memory for the array fonts of
font structures

free(fonts) gives me illegal type

any ideas?

Thanks!

Bartek

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