source/light.cpp

   1 #include <stdexcept>
   2 #include <msp/gl/extensions/msp_legacy_features.h>
   3 #include <msp/strings/format.h>
   4 #include "light.h"
   5 #include "lightunit.h"
   6 #include "matrix.h"
   7 #include "misc.h"
   8 #include "programdata.h"
   9
  10 using namespace std;
  11
  12 namespace Msp {
  13 namespace GL {
  14
  15 Light::Light():
  16         diffuse(1),
  17         specular(1),
  18         position(0, 0, 1, 0),
  19         spot_dir(0, 0, -1),
  20         spot_exp(0),
  21         spot_cutoff(Geometry::Angle<float>::straight())
  22 {
  23         attenuation[0] = 1;
  24         attenuation[1] = 0;
  25         attenuation[2] = 0;
  26 }
  27
  28 Light::~Light()
  29 {
  30         while(LightUnit *unit = LightUnit::find_unit(this))
  31                 unbind_from(unit->get_index());
  32 }
  33
  34 void Light::update_parameter(int mask, int index) const
  35 {
  36         if(index<0)
  37         {
  38                 LightUnit *unit = LightUnit::find_unit(this);
  39                 if(!unit)
  40                         return;
  41
  42                 index = unit->get_index();
  43         }
  44
  45         GLenum l = GL_LIGHT0+index;
  46         if(mask&DIFFUSE)
  47                 glLightfv(l, GL_DIFFUSE, &diffuse.r);
  48         if(mask&SPECULAR)
  49                 glLightfv(l, GL_SPECULAR, &specular.r);
  50         if(mask&POSITION)
  51                 glLightfv(l, GL_POSITION, &position.x);
  52         if(mask&SPOT_DIR)
  53                 glLightfv(l, GL_SPOT_DIRECTION, &spot_dir.x);
  54         if(mask&SPOT_EXP)
  55                 glLightf(l, GL_SPOT_EXPONENT, spot_exp);
  56         if(mask&SPOT_CUTOFF)
  57                 glLightf(l, GL_SPOT_CUTOFF, spot_cutoff.degrees());
  58         if(mask&ATTENUATION)
  59         {
  60                 glLightf(l, GL_CONSTANT_ATTENUATION, attenuation[0]);
  61                 glLightf(l, GL_LINEAR_ATTENUATION, attenuation[1]);
  62                 glLightf(l, GL_QUADRATIC_ATTENUATION, attenuation[2]);
  63         }
  64 }
  65
  66 void Light::update_matrix()
  67 {
  68         Vector3 up_dir;
  69         if(20*abs(direction.z)>abs(direction.x)+abs(direction.y))
  70                 up_dir.y = 1;
  71         else
  72                 up_dir.z = 1;
  73         Vector3 right_dir = normalize(cross(direction, up_dir));
  74
  75         Vector4 columns[4];
  76         columns[0] = compose(right_dir, 0.0f);
  77         columns[1] = compose(cross(right_dir, direction), 0.0f);
  78         columns[2] = compose(-direction, 0.0f);
  79         columns[3] = position;
  80         matrix = Matrix::from_columns(columns);
  81 }
  82
  83 void Light::set_diffuse(const Color &c)
  84 {
  85         diffuse = c;
  86         update_parameter(DIFFUSE);
  87 }
  88
  89 void Light::set_specular(const Color &c)
  90 {
  91         specular = c;
  92         update_parameter(SPECULAR);
  93 }
  94
  95 void Light::set_matrix(const Matrix &m)
  96 {
  97         Placeable::set_matrix(m);
  98         position = matrix.column(3);
  99         spot_dir = normalize(-matrix.column(2).slice<3>(0));
 100         direction = (position.w ? spot_dir : normalize(-position.slice<3>(0)));
 101         update_parameter(POSITION|SPOT_DIR);
 102         update_matrix();
 103 }
 104
 105 void Light::set_position(const Vector4 &p)
 106 {
 107         position = p;
 108         update_parameter(POSITION);
 109         if(!position.w)
 110                 direction = normalize(-position.slice<3>(0));
 111         update_matrix();
 112 }
 113
 114 void Light::set_spot_direction(const Vector3 &d)
 115 {
 116         spot_dir = normalize(d);
 117         if(position.w)
 118                 direction = spot_dir;
 119         update_parameter(SPOT_DIR);
 120         update_matrix();
 121 }
 122
 123 void Light::set_spot_exponent(float e)
 124 {
 125         if(e<0)
 126                 throw invalid_argument("Light::set_spot_exponent");
 127
 128         spot_exp = e;
 129         update_parameter(SPOT_EXP);
 130 }
 131
 132 void Light::set_spot_cutoff(float c)
 133 {
 134         set_spot_cutoff(Geometry::Angle<float>::from_degrees(c));
 135 }
 136
 137 void Light::set_spot_cutoff(const Geometry::Angle<float> &c)
 138 {
 139         if(c<Geometry::Angle<float>::zero() || (c>Geometry::Angle<float>::right() && c!=Geometry::Angle<float>::straight()))
 140                 throw invalid_argument("Light::set_spot_cutoff");
 141
 142         spot_cutoff = c;
 143         update_parameter(SPOT_CUTOFF);
 144 }
 145
 146 void Light::disable_spot_cutoff()
 147 {
 148         set_spot_cutoff(Geometry::Angle<float>::straight());
 149 }
 150
 151 void Light::set_attenuation(float c, float l, float q)
 152 {
 153         attenuation[0] = c;
 154         attenuation[1] = l;
 155         attenuation[2] = q;
 156         update_parameter(ATTENUATION);
 157 }
 158
 159 void Light::update_shader_data(ProgramData &shdata, const Matrix &view_matrix, unsigned i) const
 160 {
 161         string base = format("light_sources[%d]", i);
 162         shdata.uniform(base+".position", view_matrix*position);
 163         shdata.uniform(base+".diffuse", diffuse);
 164         shdata.uniform(base+".specular", specular);
 165 }
 166
 167 void Light::bind_to(unsigned i) const
 168 {
 169         static Require _req(MSP_legacy_features);
 170
 171         LightUnit &unit = LightUnit::get_unit(i);
 172         if(unit.set_light(this))
 173         {
 174                 enable(GL_LIGHT0+unit.get_index());
 175                 update_parameter(-1, unit.get_index());
 176         }
 177 }
 178
 179 const Light *Light::current(unsigned i)
 180 {
 181         return LightUnit::get_unit(i).get_light();
 182 }
 183
 184 void Light::unbind_from(unsigned i)
 185 {
 186         LightUnit &unit = LightUnit::get_unit(i);
 187         if(unit.set_light(0))
 188                 disable(GL_LIGHT0+unit.get_index());
 189 }
 190
 191
 192 Light::Loader::Loader(Light &l):
 193         DataFile::ObjectLoader<Light>(l)
 194 {
 195         add("attenuation", &Loader::attenuation);
 196         add("diffuse", &Loader::diffuse);
 197         add("position", &Loader::position);
 198         add("specular", &Loader::specular);
 199         add("spot_direction", &Loader::spot_direction);
 200         add("spot_exponent", &Loader::spot_exponent);
 201         add("spot_cutoff", &Loader::spot_cutoff);
 202 }
 203
 204 void Light::Loader::attenuation(float c, float l, float q)
 205 {
 206         obj.set_attenuation(c, l, q);
 207 }
 208
 209 void Light::Loader::diffuse(float r, float g, float b)
 210 {
 211         obj.set_diffuse(Color(r, g, b));
 212 }
 213
 214 void Light::Loader::position(float x, float y, float z, float w)
 215 {
 216         obj.set_position(Vector4(x, y, z, w));
 217 }
 218
 219 void Light::Loader::specular(float r, float g, float b)
 220 {
 221         obj.set_specular(Color(r, g, b));
 222 }
 223
 224 void Light::Loader::spot_direction(float x, float y, float z)
 225 {
 226         obj.set_spot_direction(Vector3(x, y, z));
 227 }
 228
 229 void Light::Loader::spot_exponent(float e)
 230 {
 231         obj.set_spot_exponent(e);
 232 }
 233
 234 void Light::Loader::spot_cutoff(float c)
 235 {
 236         obj.set_spot_cutoff(Geometry::Angle<float>::from_degrees(c));
 237 }
 238
 239 } // namespace GL
 240 } // namespace Msp