quakespasm/source/gl_fog.c

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2022-02-08 19:06:54 +00:00
/*
Copyright (C) 1996-2001 Id Software, Inc.
Copyright (C) 2002-2009 John Fitzgibbons and others
Copyright (C) 2007-2008 Kristian Duske
Copyright (C) 2010-2014 QuakeSpasm developers
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
//gl_fog.c -- global and volumetric fog
#include "quakedef.h"
//==============================================================================
//
// GLOBAL FOG
//
//==============================================================================
#define DEFAULT_DENSITY 0.0
#define DEFAULT_GRAY 0.3
float fog_start;
float fog_end;
float fog_density_gl;
float fog_red;
float fog_green;
float fog_blue;
float old_density;
float old_red;
float old_green;
float old_blue;
float fade_time; //duration of fade
float fade_done; //time when fade will be done
/*
=============
Fog_Update
update internal variables
=============
*/
void Fog_Update (float density, float red, float green, float blue, float time)
{
//save previous settings for fade
if (time > 0)
{
//check for a fade in progress
if (fade_done > cl.time)
{
float f;
f = (fade_done - cl.time) / fade_time;
old_density = f * old_density + (1.0 - f) * fog_density_gl;
old_red = f * old_red + (1.0 - f) * fog_red;
old_green = f * old_green + (1.0 - f) * fog_green;
old_blue = f * old_blue + (1.0 - f) * fog_blue;
}
else
{
old_density = fog_density_gl;
old_red = fog_red;
old_green = fog_green;
old_blue = fog_blue;
}
}
fog_density_gl = density;
fog_red = red;
fog_green = green;
fog_blue = blue;
fade_time = time;
fade_done = cl.time + time;
}
/*
=============
Fog_ParseServerMessage
handle an SVC_FOG message from server
=============
*/
void Fog_ParseServerMessage (void)
{
float density, red, green, blue, time;
density = MSG_ReadByte() / 255.0;
red = MSG_ReadByte() / 255.0;
green = MSG_ReadByte() / 255.0;
blue = MSG_ReadByte() / 255.0;
time = q_max(0.0, MSG_ReadShort() / 100.0);
Fog_Update (density, red, green, blue, time);
}
/*
=============
Fog_FogCommand_f
handle the 'fog' console command
=============
*/
void Fog_FogCommand_f (void)
{
switch (Cmd_Argc())
{
default:
case 1:
Con_Printf("usage:\n");
Con_Printf(" fog <density>\n");
Con_Printf(" fog <red> <green> <blue>\n");
Con_Printf(" fog <density> <red> <green> <blue>\n");
Con_Printf("current values:\n");
Con_Printf(" \"density\" is \"%f\"\n", fog_density_gl);
Con_Printf(" \"red\" is \"%f\"\n", fog_red);
Con_Printf(" \"green\" is \"%f\"\n", fog_green);
Con_Printf(" \"blue\" is \"%f\"\n", fog_blue);
break;
case 2:
Fog_Update(q_max(0.0, atof(Cmd_Argv(1))),
fog_red,
fog_green,
fog_blue,
0.0);
break;
case 3: //TEST
Fog_Update(q_max(0.0, atof(Cmd_Argv(1))),
fog_red,
fog_green,
fog_blue,
atof(Cmd_Argv(2)));
break;
case 4:
Fog_Update(fog_density_gl,
CLAMP(0.0, atof(Cmd_Argv(1)), 1.0),
CLAMP(0.0, atof(Cmd_Argv(2)), 1.0),
CLAMP(0.0, atof(Cmd_Argv(3)), 1.0),
0.0);
break;
case 5:
Fog_Update(q_max(0.0, atof(Cmd_Argv(1))),
CLAMP(0.0, atof(Cmd_Argv(2)), 1.0),
CLAMP(0.0, atof(Cmd_Argv(3)), 1.0),
CLAMP(0.0, atof(Cmd_Argv(4)), 1.0),
0.0);
break;
case 6: //TEST
Fog_Update(q_max(0.0, atof(Cmd_Argv(1))),
CLAMP(0.0, atof(Cmd_Argv(2)), 1.0),
CLAMP(0.0, atof(Cmd_Argv(3)), 1.0),
CLAMP(0.0, atof(Cmd_Argv(4)), 1.0),
atof(Cmd_Argv(5)));
break;
}
}
/*
=============
Fog_ParseWorldspawn
called at map load
=============
*/
void Fog_ParseWorldspawn (void)
{
char key[128], value[4096];
const char *data;
//initially no fog
fog_density_gl = DEFAULT_DENSITY;
fog_red = DEFAULT_GRAY;
fog_green = DEFAULT_GRAY;
fog_blue = DEFAULT_GRAY;
old_density = DEFAULT_DENSITY;
old_red = DEFAULT_GRAY;
old_green = DEFAULT_GRAY;
old_blue = DEFAULT_GRAY;
fade_time = 0.0;
fade_done = 0.0;
data = COM_Parse(cl.worldmodel->entities);
if (!data)
return; // error
if (com_token[0] != '{')
return; // error
while (1)
{
data = COM_Parse(data);
if (!data)
return; // error
if (com_token[0] == '}')
break; // end of worldspawn
if (com_token[0] == '_')
strcpy(key, com_token + 1);
else
strcpy(key, com_token);
while (key[strlen(key)-1] == ' ') // remove trailing spaces
key[strlen(key)-1] = 0;
data = COM_Parse(data);
if (!data)
return; // error
strcpy(value, com_token);
if (!strcmp("fog", key))
{
sscanf(value, "%f %f %f %f %f", &fog_start, &fog_end, &fog_red, &fog_green, &fog_blue);
}
fog_density_gl = ((fog_end - fog_start))/6000;
}
}
/*
=============
Fog_GetColor
calculates fog color for this frame, taking into account fade times
=============
*/
float *Fog_GetColor (void)
{
static float c[4] = {0.3f, 0.3f, 0.3f, 1.0f};
#ifndef VITA
float f;
int i;
if (fade_done > cl.time)
{
f = (fade_done - cl.time) / fade_time;
c[0] = f * old_red + (1.0 - f) * fog_red;
c[1] = f * old_green + (1.0 - f) * fog_green;
c[2] = f * old_blue + (1.0 - f) * fog_blue;
c[3] = 1.0;
}
else
{
c[0] = fog_red;
c[1] = fog_green;
c[2] = fog_blue;
c[3] = 1.0;
}
//find closest 24-bit RGB value, so solid-colored sky can match the fog perfectly
for (i=0;i<3;i++)
c[i] = (float)(Q_rint(c[i] * 255)) / 255.0f;
#endif
return c;
}
/*
=============
Fog_GetDensity
returns current density of fog
=============
*/
float Fog_GetDensity (void)
{
float f;
if (fade_done > cl.time)
{
f = (fade_done - cl.time) / fade_time;
return f * old_density + (1.0 - f) * fog_density_gl;
}
else
return fog_density_gl;
}
/*
=============
Fog_SetupFrame
called at the beginning of each frame
=============
*/
void Fog_SetupFrame (void)
{
glFogfv(GL_FOG_COLOR, Fog_GetColor());
glFogf(GL_FOG_DENSITY, Fog_GetDensity() / 64.0);
}
/*
=============
Fog_EnableGFog
called before drawing stuff that should be fogged
=============
*/
void Fog_EnableGFog (void)
{
if (Fog_GetDensity() > 0)
glEnable(GL_FOG);
}
/*
=============
Fog_DisableGFog
called after drawing stuff that should be fogged
=============
*/
void Fog_DisableGFog (void)
{
if (Fog_GetDensity() > 0)
glDisable(GL_FOG);
}
/*
=============
Fog_StartAdditive
called before drawing stuff that is additive blended -- sets fog color to black
=============
*/
void Fog_StartAdditive (void)
{
vec3_t color = {0,0,0};
if (Fog_GetDensity() > 0)
glFogfv(GL_FOG_COLOR, color);
}
/*
=============
Fog_StopAdditive
called after drawing stuff that is additive blended -- restores fog color
=============
*/
void Fog_StopAdditive (void)
{
if (Fog_GetDensity() > 0)
glFogfv(GL_FOG_COLOR, Fog_GetColor());
}
//==============================================================================
//
// VOLUMETRIC FOG
//
//==============================================================================
cvar_t r_vfog = {"r_vfog", "1", CVAR_NONE};
void Fog_DrawVFog (void){}
void Fog_MarkModels (void){}
//==============================================================================
//
// INIT
//
//==============================================================================
/*
=============
Fog_NewMap
called whenever a map is loaded
=============
*/
void Fog_NewMap (void)
{
Fog_ParseWorldspawn (); //for global fog
Fog_MarkModels (); //for volumetric fog
}
/*
=============
Fog_Init
called when quake initializes
=============
*/
void Fog_Init (void)
{
Cmd_AddCommand ("fog",Fog_FogCommand_f);
//Cvar_RegisterVariable (&r_vfog);
//set up global fog
fog_density_gl = DEFAULT_DENSITY;
fog_red = DEFAULT_GRAY;
fog_green = DEFAULT_GRAY;
fog_blue = DEFAULT_GRAY;
Fog_SetupState ();
}
/*
=============
Fog_SetupState
ericw -- moved from Fog_Init, state that needs to be setup when a new context is created
=============
*/
void Fog_SetupState (void)
{
glFogi(GL_FOG_MODE, GL_EXP2);
}