Function 
-  Defines fog. 

Functions 
-  void mrnFogInit( MrnFog *fog )
  Initializes mrnFog. 

-  Gfx *mrnFogGenerateGfx( MrnFog *fog_ptr, Gfx *gfx_ptr );
  Generates a gfx of the mrnFog settings. 

History 
  1998/ 9/22  Takamitsu Hirata 
    Fog.h, fog.c :  Initial version 
