nel/src/3d/light.cpp

   1 // NeL - MMORPG Framework <http://dev.ryzom.com/projects/nel/>
   2 // Copyright (C) 2010  Winch Gate Property Limited
   3 //
   4 // This program is free software: you can redistribute it and/or modify
   5 // it under the terms of the GNU Affero General Public License as
   6 // published by the Free Software Foundation, either version 3 of the
   7 // License, or (at your option) any later version.
   8 //
   9 // This program is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU Affero General Public License for more details.
  13 //
  14 // You should have received a copy of the GNU Affero General Public License
  15 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16
  17 #include "std3d.h"
  18
  19 #include "nel/3d/light.h"
  20
  21 using namespace NLMISC;
  22
  23 #ifdef DEBUG_NEW
  24 #define new DEBUG_NEW
  25 #endif
  26
  27 namespace NL3D
  28 {
  29
  30 // ***************************************************************************
  31
  32 void CLight::setupDirectional (const CRGBA& ambiant, const CRGBA& diffuse, const CRGBA& specular, const CVector& direction,
  33                                                            float constant, float linear, float quadratic)
  34 {
  35         // Set the mode
  36         setMode (DirectionalLight);
  37
  38         // Set the colors
  39         setAmbiant (ambiant);
  40         setDiffuse (diffuse);
  41         setSpecular (specular);
  42
  43         // Set the direction
  44         setDirection (direction);
  45
  46         // Set attenuation
  47         setConstantAttenuation (constant);
  48         setLinearAttenuation (linear);
  49         setQuadraticAttenuation (quadratic);
  50
  51         // Dummy to avoid uninit data, and problems of cache
  52         setPosition(CVector::Null);
  53         setExponent(0.f);
  54         setCutoff(0.f);
  55 }
  56
  57 // ***************************************************************************
  58
  59 void CLight::setupPointLight (const CRGBA& ambiant, const CRGBA& diffuse, const CRGBA& specular, const CVector& position,
  60                                                 const CVector& direction, float constant, float linear, float quadratic)
  61 {
  62         // Set the mode
  63         setMode (PointLight);
  64
  65         // Set the colors
  66         setAmbiant (ambiant);
  67         setDiffuse (diffuse);
  68         setSpecular (specular);
  69
  70         // Set the position and direction
  71         setPosition (position);
  72         setDirection (direction);
  73
  74         // Set attenuation
  75         setConstantAttenuation (constant);
  76         setLinearAttenuation (linear);
  77         setQuadraticAttenuation (quadratic);
  78
  79         // Dummy to avoid uninit data, and problems of cache
  80         setExponent(0.f);
  81         setCutoff(0.f);
  82 }
  83
  84 // ***************************************************************************
  85
  86 void CLight::setupSpotLight (const CRGBA& ambiant, const CRGBA& diffuse, const CRGBA& specular, const CVector& position,
  87                                                 const CVector& direction, float exponent, float cutoff, float constant, float linear, float quadratic)
  88 {
  89         // Set the mode
  90         setMode (SpotLight);
  91
  92         // Set the colors
  93         setAmbiant (ambiant);
  94         setDiffuse (diffuse);
  95         setSpecular (specular);
  96
  97         // Set the position and direction
  98         setPosition (position);
  99         setDirection (direction);
 100
 101         // Set spotlight parameters
 102         setExponent (exponent);
 103         setCutoff (cutoff);
 104
 105         // Set attenuation
 106         setConstantAttenuation (constant);
 107         setLinearAttenuation (linear);
 108         setQuadraticAttenuation (quadratic);
 109 }
 110
 111 // ***************************************************************************
 112 void CLight::setupAttenuation (float farAttenuationBegin, float farAttenuationEnd)
 113 {
 114         /* Yoyo: I changed this method because it did not work well for me
 115                 The most important in a light is its farAttenuationEnd (anything beyond should not be lighted)
 116                 The old compute had too smooth decrease, regarding this (at farAttenuationEnd, the light could be
 117                 attenuated by a factor of 0.7 (instead of 0) and slowly decreased).
 118         */
 119
 120         // limit case
 121         if(farAttenuationEnd<=0)
 122         {
 123                 _ConstantAttenuation= 1000000;
 124                 _LinearAttenuation= 0;
 125                 _QuadraticAttenuation= 0;
 126         }
 127         else
 128         {
 129                 // The following factors are "it feels good for farAttenuationBegin=0/farAttenuationEnd=1" factors.
 130                 // btw, at r=farAttenuationEnd=1, att= 1/11 ~= 0.
 131                 const float     constant= 1.0f;
 132                 const float     linear= 0.f;
 133                 const float     quadratic= 10.0f;
 134
 135                 /*
 136                         With GL/D3D   'att=1/(c+l*r+q*r2)'  formula, I think it is impossible to simulate correctly
 137                         farAttenuationBegin (very big decrase if for instance farAttenuationBegin is near farAttenuationEnd),
 138                         hence I simulate it very badly by multiplying the farAttenuationEnd by some factor
 139                 */
 140                 float   factor= 1.f;
 141                 if(farAttenuationBegin/farAttenuationEnd>0.5f)
 142                         factor= 2.f;
 143                 else if(farAttenuationBegin>0)
 144                         factor= 1.f + 2*farAttenuationBegin/farAttenuationEnd;
 145                 farAttenuationEnd*= factor;
 146
 147                 // scale according to farAttenuationEnd.
 148                 _ConstantAttenuation= constant;
 149                 _LinearAttenuation= linear/farAttenuationEnd;
 150                 _QuadraticAttenuation= quadratic/sqr(farAttenuationEnd);
 151         }
 152 }
 153
 154 // ***************************************************************************
 155
 156 void CLight::setupSpotExponent (float hotSpotAngle)
 157 {
 158         float divid=(float)log (cos (hotSpotAngle));
 159         if (divid==0.f)
 160                 divid=0.0001f;
 161         setExponent ((float)(log (0.9)/divid));
 162 }
 163
 164 // ***************************************************************************
 165
 166 void CLight::setNoAttenuation ()
 167 {
 168         _ConstantAttenuation=1.f;
 169         _QuadraticAttenuation=0.f;
 170         _LinearAttenuation=0.f;
 171 }
 172
 173 // ***************************************************************************
 174
 175 } // NL3D