Engine global fog

Copyright info

All code in this tutorial is protected by the [GPL License].
All text in this tutorial is protected by the [FDL License].

Tutorial by: GGodis

Mailto: ggodis@yahoo.com

First of all sorry for my bad english.
In this tutorial you will see how to add fog effect to "ref_gl"

Ok, open the "REF_GL" Project, and go into "gl_local.h", find the line that says :

 
 
 extern cvar_t *gl_lockpvs;
 
 

And paste this below it :

 
 
//========== Engine Fog =================
extern cvar_t *gl_fogenable; // Enable
extern cvar_t *gl_fogred; // Red
extern cvar_t *gl_foggreen; // Green
extern cvar_t *gl_fogblue; // Blue
extern cvar_t *gl_fogstart; // Start
extern cvar_t *gl_fogend; // End
extern cvar_t *gl_fogdensity; // Density
//============== End =====================
 
 

Now open "gl_rmain.c file, go to the line :

 
 
cvar_t *gl_lockpvs;
 
 

And paste this below it :

 
 
//========= Engine Fog ==============
cvar_t *gl_fogenable; // Enable
cvar_t *gl_fogred; // Red
cvar_t *gl_foggreen; // Green
cvar_t *gl_fogblue; // Blue
cvar_t *gl_fogstart; // Start
cvar_t *gl_fogend; // End
cvar_t *gl_fogdensity; // Density
//============ End ===================
 
 

Now still in the same file go to the "R_RenderView" function. This is where the all Fog code is. At the begining of the function paste this :

 
 
 vec3_t colors; // Fog
 
 

And now go to the bottom of this function, until you see this :

 
 
 if (r_speeds->value)
 {
 ri.Con_Printf (PRINT_ALL, "%4i wpoly %4i epoly %i tex %i lmaps\n",
 c_brush_polys, 
 c_alias_polys, 
 c_visible_textures, 
 c_visible_lightmaps); 
 }
 
 

Right after it paste this code :

 
 
//===================== Engine Fog ============================
 qglDisable(GL_FOG);
 
 if (gl_fogenable->value)
 {
 qglFogi(GL_FOG_MODE, GL_LINEAR);
 colors[0] = gl_fogred->value;
 colors[1] = gl_foggreen->value;
 colors[2] = gl_fogblue->value; 
 qglFogfv(GL_FOG_COLOR, colors); 
 qglFogf(GL_FOG_START, gl_fogstart->value); 
 qglFogf(GL_FOG_END, gl_fogend->value);
 qglFogf(GL_FOG_DENSITY, gl_fogdensity->value);
 qglEnable(GL_FOG);
 } 
 else
 {
 qglDisable(GL_FOG);
}
//====================== End ==========================
 
 

And we are allmost done. All we need is to go to the line that look like this :

 
 
 gl_3dlabs_broken = ri.Cvar_Get( "gl_3dlabs_broken", "1", CVAR_ARCHIVE );
 
 

And paste this below :

 
 
//========================== Engine Fog ============================
 
 gl_fogenable = ri.Cvar_Get( "gl_fogenable", "1", 0 ); 
 gl_fogstart = ri.Cvar_Get( "gl_fogstart", "50.0", 0 ); 
 gl_fogend = ri.Cvar_Get( "gl_fogend", "800.0", 0 ); 
 gl_fogdensity = ri.Cvar_Get( "gl_fogdensity", "0.8", 0 ); 
 gl_fogred = ri.Cvar_Get( "gl_fogred","0.6", 0 ); 
 gl_foggreen = ri.Cvar_Get( "gl_foggreen","0.5", 0 ); 
 gl_fogblue = ri.Cvar_Get( "gl_fogblue","0.4", 0 ); 
 
//============================= End ================================
 
 

Ok now its all. Now you can have a fog, and controll it from console. How to controll it i think you know :)
If you hawe any qestions, please mail me :)

Tutorial Originally found at: