SDL_WM_SetIcon (3) - Linux Manuals
SDL_WM_SetIcon: Sets the icon for the display window.
NAME
SDL_WM_SetIcon - Sets the icon for the display window.SYNOPSIS
#include "SDL.h"
void SDL_WM_SetIcon(SDL_Surface *icon, Uint8 *mask);
DESCRIPTION
Sets the icon for the display window. Win32 icons must be 32x32.
This function must be called before the first call to SDL_SetVideoMode.
It takes an icon surface, and a mask in MSB format.
If mask is NULL, the entire icon surface will be used as the icon.
EXAMPLE
SDL_WM_SetIcon(SDL_LoadBMP("icon.bmp"), NULL);
SEE ALSO
SDL_SetVideoMode, SDL_WM_SetCaption