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CnC_Renegade/Code/ww3d2/lightenvironment.h

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/*
** Command & Conquer Renegade(tm)
** Copyright 2025 Electronic Arts Inc.
**
** 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 3 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, see <http://www.gnu.org/licenses/>.
*/
/***********************************************************************************************
*** C O N F I D E N T I A L --- W E S T W O O D S T U D I O S ***
***********************************************************************************************
* *
* Project Name : WWPhys *
* *
* $Archive:: /Commando/Code/ww3d2/lightenvironment.h $*
* *
* Original Author:: Greg Hjelstrom *
* *
* $Author:: Naty_h $*
* *
* $Modtime:: 4/01/01 12:01a $*
* *
* $Revision:: 4 $*
* *
*---------------------------------------------------------------------------------------------*
* Functions: *
* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
#if defined(_MSC_VER)
#pragma once
#endif
#ifndef LIGHTENVIRONMENT_H
#define LIGHTENVIRONMENT_H
#include "always.h"
#include "vector3.h"
class Matrix3D;
class LightClass;
/**
** LightEnvironmentClass
** This class represents an approximation of the local lighting for a given point. The idea
** is to collect all of the point light sources affecting an object at any given time and
** create temporary directional light sources representing them. Any distance or directional
** attenuation will be precalculated into the overall intensity of the light and a vector from
** the light source to the center of the bounding sphere of the model will be used as the
** directional component.
** In addition, the engine will provide the ambient component which will be determined by
** a combination of the ambient setting for the level and sampling the light maps in the area.
**
** Notes:
** - will need fast collection of the lights affecting any one given object
** - intensity of these lights should take into account attenuation of the original light
** - intensity should also take into account spot attenuation (no-per vertex atten...)
** - we need the direction of the lights in eye-space
** - the ambient light from all lights should be added into the ambient light (not just scene)
*/
class LightEnvironmentClass
{
public:
LightEnvironmentClass(void);
~LightEnvironmentClass(void);
/*
** Usage (starting from scratch each frame):
** - Reset the object
** - Set the scene ambient light (will be derived from lightmap sampling probably)
** - Add in all overlapping lights, this object will keep the most important ones
** - When ready to render, call Pre_Render_Update and push into the gerd.
**
** Usage (caching the lights, only done if the object and the lights are not moving)
** - Reset and collect the lights once and keep this object around
** - When ready to render, call Pre_Render_Update and push into the gerd.
*/
void Reset(const Vector3 & object_center,const Vector3 & scene_ambient);
void Add_Light(const LightClass & light);
void Pre_Render_Update(const Matrix3D & camera_tm);
/*
** Accessors
*/
const Vector3 & Get_Equivalent_Ambient(void) const { return OutputAmbient; }
int Get_Light_Count(void) const { return LightCount; }
const Vector3 & Get_Light_Direction(int i) const { return InputLights[i].Direction; }
const Vector3 & Get_Light_Diffuse(int i) const { return InputLights[i].Diffuse; }
/*
** Lighting LOD. This is a static setting that is used to convert weak diffuse lights
** into pure ambient lights.
*/
static void Set_Lighting_LOD_Cutoff(float inten);
static float Get_Lighting_LOD_Cutoff(void);
protected:
enum { MAX_LIGHTS = 4 };
struct InputLightStruct
{
void Init(const LightClass & light,const Vector3 & object_center);
void Init_From_Point_Or_Spot_Light(const LightClass & light,const Vector3 & object_center);
void Init_From_Directional_Light(const LightClass & light,const Vector3 & object_center);
float Contribution(void);
Vector3 Direction;
Vector3 Ambient;
Vector3 Diffuse;
bool DiffuseRejected;
};
struct OutputLightStruct
{
void Init(const InputLightStruct & input,const Matrix3D & camera_tm);
Vector3 Direction; // direction to the light.
Vector3 Diffuse; // diffuse color * attenuation
};
/*
** Member variables
*/
int LightCount;
Vector3 ObjectCenter; // center of the object to be lit
InputLightStruct InputLights[MAX_LIGHTS]; // input lights
Vector3 OutputAmbient; // scene ambient + lights' ambients
OutputLightStruct OutputLights[MAX_LIGHTS]; // ouput lights
};
#endif //LIGHTENVIRONMENT_H