src/mesa/main/light.c

   1 /* $Id: light.c,v 1.52 2002/09/16 17:56:02 brianp Exp $ */
   2
   3 /*
   4  * Mesa 3-D graphics library
   5  * Version:  4.1
   6  *
   7  * Copyright (C) 1999-2002  Brian Paul   All Rights Reserved.
   8  *
   9  * Permission is hereby granted, free of charge, to any person obtaining a
  10  * copy of this software and associated documentation files (the "Software"),
  11  * to deal in the Software without restriction, including without limitation
  12  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  13  * and/or sell copies of the Software, and to permit persons to whom the
  14  * Software is furnished to do so, subject to the following conditions:
  15  *
  16  * The above copyright notice and this permission notice shall be included
  17  * in all copies or substantial portions of the Software.
  18  *
  19  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  20  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  21  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  22  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  23  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  24  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  25  */
  26
  27
  28 #ifdef PC_HEADER
  29 #include "all.h"
  30 #else
  31 #include "glheader.h"
  32 #include "colormac.h"
  33 #include "context.h"
  34 #include "enums.h"
  35 #include "light.h"
  36 #include "macros.h"
  37 #include "mem.h"
  38 #include "mmath.h"
  39 #include "simple_list.h"
  40 #include "mtypes.h"
  41
  42 #include "math/m_xform.h"
  43 #include "math/m_matrix.h"
  44 #endif
  45
  46
  47 /* XXX this is a bit of a hack needed for compilation within XFree86 */
  48 #ifndef FLT_MIN
  49 #define FLT_MIN 1e-37
  50 #endif
  51
  52
  53 void
  54 _mesa_ShadeModel( GLenum mode )
  55 {
  56    GET_CURRENT_CONTEXT(ctx);
  57    ASSERT_OUTSIDE_BEGIN_END(ctx);
  58
  59    if (MESA_VERBOSE & VERBOSE_API)
  60       _mesa_debug(ctx, "glShadeModel %s\n", _mesa_lookup_enum_by_nr(mode));
  61
  62    if (mode != GL_FLAT && mode != GL_SMOOTH) {
  63       _mesa_error( ctx, GL_INVALID_ENUM, "glShadeModel" );
  64       return;
  65    }
  66
  67    if (ctx->Light.ShadeModel == mode)
  68       return;
  69
  70    FLUSH_VERTICES(ctx, _NEW_LIGHT);
  71    ctx->Light.ShadeModel = mode;
  72    ctx->_TriangleCaps ^= DD_FLATSHADE;
  73    if (ctx->Driver.ShadeModel)
  74       (*ctx->Driver.ShadeModel)( ctx, mode );
  75 }
  76
  77
  78
  79 void
  80 _mesa_Lightf( GLenum light, GLenum pname, GLfloat param )
  81 {
  82    _mesa_Lightfv( light, pname, &param );
  83 }
  84
  85
  86 void
  87 _mesa_Lightfv( GLenum light, GLenum pname, const GLfloat *params )
  88 {
  89    GET_CURRENT_CONTEXT(ctx);
  90    GLint i = (GLint) (light - GL_LIGHT0);
  91    struct gl_light *l = &ctx->Light.Light[i];
  92
  93    if (i < 0 || i >= (GLint) ctx->Const.MaxLights) {
  94       _mesa_error( ctx, GL_INVALID_ENUM, "glLight(light=0x%x)", light );
  95       return;
  96    }
  97
  98    switch (pname) {
  99    case GL_AMBIENT:
 100       if (TEST_EQ_4V(l->Ambient, params))
 101          return;
 102       FLUSH_VERTICES(ctx, _NEW_LIGHT);
 103       COPY_4V( l->Ambient, params );
 104       break;
 105    case GL_DIFFUSE:
 106       if (TEST_EQ_4V(l->Diffuse, params))
 107          return;
 108       FLUSH_VERTICES(ctx, _NEW_LIGHT);
 109       COPY_4V( l->Diffuse, params );
 110       break;
 111    case GL_SPECULAR:
 112       if (TEST_EQ_4V(l->Specular, params))
 113          return;
 114       FLUSH_VERTICES(ctx, _NEW_LIGHT);
 115       COPY_4V( l->Specular, params );
 116       break;
 117    case GL_POSITION: {
 118       GLfloat tmp[4];
 119       /* transform position by ModelView matrix */
 120       TRANSFORM_POINT( tmp, ctx->ModelviewMatrixStack.Top->m, params );
 121       if (TEST_EQ_4V(l->EyePosition, tmp))
 122          return;
 123       FLUSH_VERTICES(ctx, _NEW_LIGHT);
 124       COPY_4V(l->EyePosition, tmp);
 125       if (l->EyePosition[3] != 0.0F)
 126          l->_Flags |= LIGHT_POSITIONAL;
 127       else
 128          l->_Flags &= ~LIGHT_POSITIONAL;
 129       break;
 130    }
 131    case GL_SPOT_DIRECTION: {
 132       GLfloat tmp[4];
 133       /* transform direction by inverse modelview */
 134       if (ctx->ModelviewMatrixStack.Top->flags & MAT_DIRTY_INVERSE) {
 135          _math_matrix_analyse( ctx->ModelviewMatrixStack.Top );
 136       }
 137       TRANSFORM_NORMAL( tmp, params, ctx->ModelviewMatrixStack.Top->inv );
 138       if (TEST_EQ_3V(l->EyeDirection, tmp))
 139          return;
 140       FLUSH_VERTICES(ctx, _NEW_LIGHT);
 141       COPY_3V(l->EyeDirection, tmp);
 142       break;
 143    }
 144    case GL_SPOT_EXPONENT:
 145       if (params[0]<0.0 || params[0]>128.0) {
 146          _mesa_error( ctx, GL_INVALID_VALUE, "glLight" );
 147          return;
 148       }
 149       if (l->SpotExponent == params[0])
 150          return;
 151       FLUSH_VERTICES(ctx, _NEW_LIGHT);
 152       l->SpotExponent = params[0];
 153       _mesa_invalidate_spot_exp_table( l );
 154       break;
 155    case GL_SPOT_CUTOFF:
 156       if ((params[0]<0.0 || params[0]>90.0) && params[0]!=180.0) {
 157          _mesa_error( ctx, GL_INVALID_VALUE, "glLight" );
 158          return;
 159       }
 160       if (l->SpotCutoff == params[0])
 161          return;
 162       FLUSH_VERTICES(ctx, _NEW_LIGHT);
 163       l->SpotCutoff = params[0];
 164       l->_CosCutoff = (GLfloat) cos(params[0]*DEG2RAD);
 165       if (l->_CosCutoff < 0)
 166          l->_CosCutoff = 0;
 167       if (l->SpotCutoff != 180.0F)
 168          l->_Flags |= LIGHT_SPOT;
 169       else
 170          l->_Flags &= ~LIGHT_SPOT;
 171       break;
 172    case GL_CONSTANT_ATTENUATION:
 173       if (params[0]<0.0) {
 174          _mesa_error( ctx, GL_INVALID_VALUE, "glLight" );
 175          return;
 176       }
 177       if (l->ConstantAttenuation == params[0])
 178          return;
 179       FLUSH_VERTICES(ctx, _NEW_LIGHT);
 180       l->ConstantAttenuation = params[0];
 181       break;
 182    case GL_LINEAR_ATTENUATION:
 183       if (params[0]<0.0) {
 184          _mesa_error( ctx, GL_INVALID_VALUE, "glLight" );
 185          return;
 186       }
 187       if (l->LinearAttenuation == params[0])
 188          return;
 189       FLUSH_VERTICES(ctx, _NEW_LIGHT);
 190       l->LinearAttenuation = params[0];
 191       break;
 192    case GL_QUADRATIC_ATTENUATION:
 193       if (params[0]<0.0) {
 194          _mesa_error( ctx, GL_INVALID_VALUE, "glLight" );
 195          return;
 196       }
 197       if (l->QuadraticAttenuation == params[0])
 198          return;
 199       FLUSH_VERTICES(ctx, _NEW_LIGHT);
 200       l->QuadraticAttenuation = params[0];
 201       break;
 202    default:
 203       _mesa_error( ctx, GL_INVALID_ENUM, "glLight(pname=0x%x)", pname );
 204       return;
 205    }
 206
 207    if (ctx->Driver.Lightfv)
 208       ctx->Driver.Lightfv( ctx, light, pname, params );
 209 }
 210
 211
 212 void
 213 _mesa_Lighti( GLenum light, GLenum pname, GLint param )
 214 {
 215    _mesa_Lightiv( light, pname, &param );
 216 }
 217
 218
 219 void
 220 _mesa_Lightiv( GLenum light, GLenum pname, const GLint *params )
 221 {
 222    GLfloat fparam[4];
 223
 224    switch (pname) {
 225       case GL_AMBIENT:
 226       case GL_DIFFUSE:
 227       case GL_SPECULAR:
 228          fparam[0] = INT_TO_FLOAT( params[0] );
 229          fparam[1] = INT_TO_FLOAT( params[1] );
 230          fparam[2] = INT_TO_FLOAT( params[2] );
 231          fparam[3] = INT_TO_FLOAT( params[3] );
 232          break;
 233       case GL_POSITION:
 234          fparam[0] = (GLfloat) params[0];
 235          fparam[1] = (GLfloat) params[1];
 236          fparam[2] = (GLfloat) params[2];
 237          fparam[3] = (GLfloat) params[3];
 238          break;
 239       case GL_SPOT_DIRECTION:
 240          fparam[0] = (GLfloat) params[0];
 241          fparam[1] = (GLfloat) params[1];
 242          fparam[2] = (GLfloat) params[2];
 243          break;
 244       case GL_SPOT_EXPONENT:
 245       case GL_SPOT_CUTOFF:
 246       case GL_CONSTANT_ATTENUATION:
 247       case GL_LINEAR_ATTENUATION:
 248       case GL_QUADRATIC_ATTENUATION:
 249          fparam[0] = (GLfloat) params[0];
 250          break;
 251       default:
 252          /* error will be caught later in gl_Lightfv */
 253          ;
 254    }
 255
 256    _mesa_Lightfv( light, pname, fparam );
 257 }
 258
 259
 260
 261 void
 262 _mesa_GetLightfv( GLenum light, GLenum pname, GLfloat *params )
 263 {
 264    GET_CURRENT_CONTEXT(ctx);
 265    GLint l = (GLint) (light - GL_LIGHT0);
 266    ASSERT_OUTSIDE_BEGIN_END(ctx);
 267
 268    if (l < 0 || l >= (GLint) ctx->Const.MaxLights) {
 269       _mesa_error( ctx, GL_INVALID_ENUM, "glGetLightfv" );
 270       return;
 271    }
 272
 273    switch (pname) {
 274       case GL_AMBIENT:
 275          COPY_4V( params, ctx->Light.Light[l].Ambient );
 276          break;
 277       case GL_DIFFUSE:
 278          COPY_4V( params, ctx->Light.Light[l].Diffuse );
 279          break;
 280       case GL_SPECULAR:
 281          COPY_4V( params, ctx->Light.Light[l].Specular );
 282          break;
 283       case GL_POSITION:
 284          COPY_4V( params, ctx->Light.Light[l].EyePosition );
 285          break;
 286       case GL_SPOT_DIRECTION:
 287          COPY_3V( params, ctx->Light.Light[l].EyeDirection );
 288          break;
 289       case GL_SPOT_EXPONENT:
 290          params[0] = ctx->Light.Light[l].SpotExponent;
 291          break;
 292       case GL_SPOT_CUTOFF:
 293          params[0] = ctx->Light.Light[l].SpotCutoff;
 294          break;
 295       case GL_CONSTANT_ATTENUATION:
 296          params[0] = ctx->Light.Light[l].ConstantAttenuation;
 297          break;
 298       case GL_LINEAR_ATTENUATION:
 299          params[0] = ctx->Light.Light[l].LinearAttenuation;
 300          break;
 301       case GL_QUADRATIC_ATTENUATION:
 302          params[0] = ctx->Light.Light[l].QuadraticAttenuation;
 303          break;
 304       default:
 305          _mesa_error( ctx, GL_INVALID_ENUM, "glGetLightfv" );
 306          break;
 307    }
 308 }
 309
 310
 311
 312 void
 313 _mesa_GetLightiv( GLenum light, GLenum pname, GLint *params )
 314 {
 315    GET_CURRENT_CONTEXT(ctx);
 316    GLint l = (GLint) (light - GL_LIGHT0);
 317    ASSERT_OUTSIDE_BEGIN_END(ctx);
 318
 319    if (l < 0 || l >= (GLint) ctx->Const.MaxLights) {
 320       _mesa_error( ctx, GL_INVALID_ENUM, "glGetLightiv" );
 321       return;
 322    }
 323
 324    switch (pname) {
 325       case GL_AMBIENT:
 326          params[0] = FLOAT_TO_INT(ctx->Light.Light[l].Ambient[0]);
 327          params[1] = FLOAT_TO_INT(ctx->Light.Light[l].Ambient[1]);
 328          params[2] = FLOAT_TO_INT(ctx->Light.Light[l].Ambient[2]);
 329          params[3] = FLOAT_TO_INT(ctx->Light.Light[l].Ambient[3]);
 330          break;
 331       case GL_DIFFUSE:
 332          params[0] = FLOAT_TO_INT(ctx->Light.Light[l].Diffuse[0]);
 333          params[1] = FLOAT_TO_INT(ctx->Light.Light[l].Diffuse[1]);
 334          params[2] = FLOAT_TO_INT(ctx->Light.Light[l].Diffuse[2]);
 335          params[3] = FLOAT_TO_INT(ctx->Light.Light[l].Diffuse[3]);
 336          break;
 337       case GL_SPECULAR:
 338          params[0] = FLOAT_TO_INT(ctx->Light.Light[l].Specular[0]);
 339          params[1] = FLOAT_TO_INT(ctx->Light.Light[l].Specular[1]);
 340          params[2] = FLOAT_TO_INT(ctx->Light.Light[l].Specular[2]);
 341          params[3] = FLOAT_TO_INT(ctx->Light.Light[l].Specular[3]);
 342          break;
 343       case GL_POSITION:
 344          params[0] = (GLint) ctx->Light.Light[l].EyePosition[0];
 345          params[1] = (GLint) ctx->Light.Light[l].EyePosition[1];
 346          params[2] = (GLint) ctx->Light.Light[l].EyePosition[2];
 347          params[3] = (GLint) ctx->Light.Light[l].EyePosition[3];
 348          break;
 349       case GL_SPOT_DIRECTION:
 350          params[0] = (GLint) ctx->Light.Light[l].EyeDirection[0];
 351          params[1] = (GLint) ctx->Light.Light[l].EyeDirection[1];
 352          params[2] = (GLint) ctx->Light.Light[l].EyeDirection[2];
 353          break;
 354       case GL_SPOT_EXPONENT:
 355          params[0] = (GLint) ctx->Light.Light[l].SpotExponent;
 356          break;
 357       case GL_SPOT_CUTOFF:
 358          params[0] = (GLint) ctx->Light.Light[l].SpotCutoff;
 359          break;
 360       case GL_CONSTANT_ATTENUATION:
 361          params[0] = (GLint) ctx->Light.Light[l].ConstantAttenuation;
 362          break;
 363       case GL_LINEAR_ATTENUATION:
 364          params[0] = (GLint) ctx->Light.Light[l].LinearAttenuation;
 365          break;
 366       case GL_QUADRATIC_ATTENUATION:
 367          params[0] = (GLint) ctx->Light.Light[l].QuadraticAttenuation;
 368          break;
 369       default:
 370          _mesa_error( ctx, GL_INVALID_ENUM, "glGetLightiv" );
 371          break;
 372    }
 373 }
 374
 375
 376
 377 /**********************************************************************/
 378 /***                        Light Model                             ***/
 379 /**********************************************************************/
 380
 381
 382 void
 383 _mesa_LightModelfv( GLenum pname, const GLfloat *params )
 384 {
 385    GLenum newenum;
 386    GLboolean newbool;
 387    GET_CURRENT_CONTEXT(ctx);
 388    ASSERT_OUTSIDE_BEGIN_END(ctx);
 389
 390    switch (pname) {
 391       case GL_LIGHT_MODEL_AMBIENT:
 392          if (TEST_EQ_4V( ctx->Light.Model.Ambient, params ))
 393             return;
 394          FLUSH_VERTICES(ctx, _NEW_LIGHT);
 395          COPY_4V( ctx->Light.Model.Ambient, params );
 396          break;
 397       case GL_LIGHT_MODEL_LOCAL_VIEWER:
 398          newbool = (params[0]!=0.0);
 399          if (ctx->Light.Model.LocalViewer == newbool)
 400             return;
 401          FLUSH_VERTICES(ctx, _NEW_LIGHT);
 402          ctx->Light.Model.LocalViewer = newbool;
 403          break;
 404       case GL_LIGHT_MODEL_TWO_SIDE:
 405          newbool = (params[0]!=0.0);
 406          if (ctx->Light.Model.TwoSide == newbool)
 407             return;
 408          FLUSH_VERTICES(ctx, _NEW_LIGHT);
 409          ctx->Light.Model.TwoSide = newbool;
 410
 411          if (ctx->Light.Enabled && ctx->Light.Model.TwoSide)
 412             ctx->_TriangleCaps |= DD_TRI_LIGHT_TWOSIDE;
 413          else
 414             ctx->_TriangleCaps &= ~DD_TRI_LIGHT_TWOSIDE;
 415          break;
 416       case GL_LIGHT_MODEL_COLOR_CONTROL:
 417          if (params[0] == (GLfloat) GL_SINGLE_COLOR)
 418             newenum = GL_SINGLE_COLOR;
 419          else if (params[0] == (GLfloat) GL_SEPARATE_SPECULAR_COLOR)
 420             newenum = GL_SEPARATE_SPECULAR_COLOR;
 421          else {
 422             _mesa_error( ctx, GL_INVALID_ENUM, "glLightModel(param=0x0%x)",
 423                          (GLint) params[0] );
 424             return;
 425          }
 426          if (ctx->Light.Model.ColorControl == newenum)
 427             return;
 428          FLUSH_VERTICES(ctx, _NEW_LIGHT);
 429          ctx->Light.Model.ColorControl = newenum;
 430
 431          if ((ctx->Light.Enabled &&
 432               ctx->Light.Model.ColorControl==GL_SEPARATE_SPECULAR_COLOR)
 433              || ctx->Fog.ColorSumEnabled)
 434             ctx->_TriangleCaps |= DD_SEPARATE_SPECULAR;
 435          else
 436             ctx->_TriangleCaps &= ~DD_SEPARATE_SPECULAR;
 437
 438          break;
 439       default:
 440          _mesa_error( ctx, GL_INVALID_ENUM, "glLightModel(pname=0x%x)", pname );
 441          break;
 442    }
 443
 444    if (ctx->Driver.LightModelfv)
 445       ctx->Driver.LightModelfv( ctx, pname, params );
 446 }
 447
 448
 449 void
 450 _mesa_LightModeliv( GLenum pname, const GLint *params )
 451 {
 452    GLfloat fparam[4];
 453
 454    switch (pname) {
 455       case GL_LIGHT_MODEL_AMBIENT:
 456          fparam[0] = INT_TO_FLOAT( params[0] );
 457          fparam[1] = INT_TO_FLOAT( params[1] );
 458          fparam[2] = INT_TO_FLOAT( params[2] );
 459          fparam[3] = INT_TO_FLOAT( params[3] );
 460          break;
 461       case GL_LIGHT_MODEL_LOCAL_VIEWER:
 462       case GL_LIGHT_MODEL_TWO_SIDE:
 463       case GL_LIGHT_MODEL_COLOR_CONTROL:
 464          fparam[0] = (GLfloat) params[0];
 465          break;
 466       default:
 467          /* Error will be caught later in gl_LightModelfv */
 468          ;
 469    }
 470    _mesa_LightModelfv( pname, fparam );
 471 }
 472
 473
 474 void
 475 _mesa_LightModeli( GLenum pname, GLint param )
 476 {
 477    _mesa_LightModeliv( pname, &param );
 478 }
 479
 480
 481 void
 482 _mesa_LightModelf( GLenum pname, GLfloat param )
 483 {
 484    _mesa_LightModelfv( pname, &param );
 485 }
 486
 487
 488
 489 /********** MATERIAL **********/
 490
 491
 492 /*
 493  * Given a face and pname value (ala glColorMaterial), compute a bitmask
 494  * of the targeted material values.
 495  */
 496 GLuint
 497 _mesa_material_bitmask( GLcontext *ctx, GLenum face, GLenum pname,
 498                         GLuint legal, const char *where )
 499 {
 500    GLuint bitmask = 0;
 501
 502    /* Make a bitmask indicating what material attribute(s) we're updating */
 503    switch (pname) {
 504       case GL_EMISSION:
 505          bitmask |= FRONT_EMISSION_BIT | BACK_EMISSION_BIT;
 506          break;
 507       case GL_AMBIENT:
 508          bitmask |= FRONT_AMBIENT_BIT | BACK_AMBIENT_BIT;
 509          break;
 510       case GL_DIFFUSE:
 511          bitmask |= FRONT_DIFFUSE_BIT | BACK_DIFFUSE_BIT;
 512          break;
 513       case GL_SPECULAR:
 514          bitmask |= FRONT_SPECULAR_BIT | BACK_SPECULAR_BIT;
 515          break;
 516       case GL_SHININESS:
 517          bitmask |= FRONT_SHININESS_BIT | BACK_SHININESS_BIT;
 518          break;
 519       case GL_AMBIENT_AND_DIFFUSE:
 520          bitmask |= FRONT_AMBIENT_BIT | BACK_AMBIENT_BIT;
 521          bitmask |= FRONT_DIFFUSE_BIT | BACK_DIFFUSE_BIT;
 522          break;
 523       case GL_COLOR_INDEXES:
 524          bitmask |= FRONT_INDEXES_BIT  | BACK_INDEXES_BIT;
 525          break;
 526       default:
 527          _mesa_error( ctx, GL_INVALID_ENUM, where );
 528          return 0;
 529    }
 530
 531    if (face==GL_FRONT) {
 532       bitmask &= FRONT_MATERIAL_BITS;
 533    }
 534    else if (face==GL_BACK) {
 535       bitmask &= BACK_MATERIAL_BITS;
 536    }
 537    else if (face != GL_FRONT_AND_BACK) {
 538       _mesa_error( ctx, GL_INVALID_ENUM, where );
 539       return 0;
 540    }
 541
 542    if (bitmask & ~legal) {
 543       _mesa_error( ctx, GL_INVALID_ENUM, where );
 544       return 0;
 545    }
 546
 547    return bitmask;
 548 }
 549
 550
 551 /* Perform a straight copy between pairs of materials.
 552  */
 553 void _mesa_copy_material_pairs( struct gl_material dst[2],
 554                              const struct gl_material src[2],
 555                              GLuint bitmask )
 556 {
 557    if (bitmask & FRONT_EMISSION_BIT) {
 558       COPY_4FV( dst[0].Emission, src[0].Emission );
 559    }
 560    if (bitmask & BACK_EMISSION_BIT) {
 561       COPY_4FV( dst[1].Emission, src[1].Emission );
 562    }
 563    if (bitmask & FRONT_AMBIENT_BIT) {
 564       COPY_4FV( dst[0].Ambient, src[0].Ambient );
 565    }
 566    if (bitmask & BACK_AMBIENT_BIT) {
 567       COPY_4FV( dst[1].Ambient, src[1].Ambient );
 568    }
 569    if (bitmask & FRONT_DIFFUSE_BIT) {
 570       COPY_4FV( dst[0].Diffuse, src[0].Diffuse );
 571    }
 572    if (bitmask & BACK_DIFFUSE_BIT) {
 573       COPY_4FV( dst[1].Diffuse, src[1].Diffuse );
 574    }
 575    if (bitmask & FRONT_SPECULAR_BIT) {
 576       COPY_4FV( dst[0].Specular, src[0].Specular );
 577    }
 578    if (bitmask & BACK_SPECULAR_BIT) {
 579       COPY_4FV( dst[1].Specular, src[1].Specular );
 580    }
 581    if (bitmask & FRONT_SHININESS_BIT) {
 582       dst[0].Shininess = src[0].Shininess;
 583    }
 584    if (bitmask & BACK_SHININESS_BIT) {
 585       dst[1].Shininess = src[1].Shininess;
 586    }
 587    if (bitmask & FRONT_INDEXES_BIT) {
 588       dst[0].AmbientIndex = src[0].AmbientIndex;
 589       dst[0].DiffuseIndex = src[0].DiffuseIndex;
 590       dst[0].SpecularIndex = src[0].SpecularIndex;
 591    }
 592    if (bitmask & BACK_INDEXES_BIT) {
 593       dst[1].AmbientIndex = src[1].AmbientIndex;
 594       dst[1].DiffuseIndex = src[1].DiffuseIndex;
 595       dst[1].SpecularIndex = src[1].SpecularIndex;
 596    }
 597 }
 598
 599
 600 /*
 601  * Check if the global material has to be updated with info that was
 602  * associated with a vertex via glMaterial.
 603  * This function is used when any material values get changed between
 604  * glBegin/glEnd either by calling glMaterial() or by calling glColor()
 605  * when GL_COLOR_MATERIAL is enabled.
 606  *
 607  * src[0] is front material, src[1] is back material
 608  *
 609  * Additionally keeps the precomputed lighting state uptodate.
 610  */
 611 void _mesa_update_material( GLcontext *ctx,
 612                          const struct gl_material src[2],
 613                          GLuint bitmask )
 614 {
 615    struct gl_light *light, *list = &ctx->Light.EnabledList;
 616
 617    if (ctx->Light.ColorMaterialEnabled)
 618       bitmask &= ~ctx->Light.ColorMaterialBitmask;
 619
 620    if (MESA_VERBOSE&VERBOSE_IMMEDIATE)
 621       _mesa_debug(ctx, "_mesa_update_material, mask 0x%x\n", bitmask);
 622
 623    if (!bitmask)
 624       return;
 625
 626    /* update material emission */
 627    if (bitmask & FRONT_EMISSION_BIT) {
 628       struct gl_material *mat = &ctx->Light.Material[0];
 629       COPY_4FV( mat->Emission, src[0].Emission );
 630    }
 631    if (bitmask & BACK_EMISSION_BIT) {
 632       struct gl_material *mat = &ctx->Light.Material[1];
 633       COPY_4FV( mat->Emission, src[1].Emission );
 634    }
 635
 636    /* update material ambience */
 637    if (bitmask & FRONT_AMBIENT_BIT) {
 638       struct gl_material *mat = &ctx->Light.Material[0];
 639       COPY_4FV( mat->Ambient, src[0].Ambient );
 640       foreach (light, list) {
 641          SCALE_3V( light->_MatAmbient[0], light->Ambient, src[0].Ambient);
 642       }
 643    }
 644    if (bitmask & BACK_AMBIENT_BIT) {
 645       struct gl_material *mat = &ctx->Light.Material[1];
 646       COPY_4FV( mat->Ambient, src[1].Ambient );
 647       foreach (light, list) {
 648          SCALE_3V( light->_MatAmbient[1], light->Ambient, src[1].Ambient);
 649       }
 650    }
 651
 652    /* update BaseColor = emission + scene's ambience * material's ambience */
 653    if (bitmask & (FRONT_EMISSION_BIT | FRONT_AMBIENT_BIT)) {
 654       struct gl_material *mat = &ctx->Light.Material[0];
 655       COPY_3V( ctx->Light._BaseColor[0], mat->Emission );
 656       ACC_SCALE_3V( ctx->Light._BaseColor[0], mat->Ambient,
 657                     ctx->Light.Model.Ambient );
 658    }
 659    if (bitmask & (BACK_EMISSION_BIT | BACK_AMBIENT_BIT)) {
 660       struct gl_material *mat = &ctx->Light.Material[1];
 661       COPY_3V( ctx->Light._BaseColor[1], mat->Emission );
 662       ACC_SCALE_3V( ctx->Light._BaseColor[1], mat->Ambient,
 663                     ctx->Light.Model.Ambient );
 664    }
 665
 666    /* update material diffuse values */
 667    if (bitmask & FRONT_DIFFUSE_BIT) {
 668       struct gl_material *mat = &ctx->Light.Material[0];
 669       COPY_4FV( mat->Diffuse, src[0].Diffuse );
 670       foreach (light, list) {
 671          SCALE_3V( light->_MatDiffuse[0], light->Diffuse, mat->Diffuse );
 672       }
 673    }
 674    if (bitmask & BACK_DIFFUSE_BIT) {
 675       struct gl_material *mat = &ctx->Light.Material[1];
 676       COPY_4FV( mat->Diffuse, src[1].Diffuse );
 677       foreach (light, list) {
 678          SCALE_3V( light->_MatDiffuse[1], light->Diffuse, mat->Diffuse );
 679       }
 680    }
 681
 682    /* update material specular values */
 683    if (bitmask & FRONT_SPECULAR_BIT) {
 684       struct gl_material *mat = &ctx->Light.Material[0];
 685       COPY_4FV( mat->Specular, src[0].Specular );
 686       foreach (light, list) {
 687          SCALE_3V( light->_MatSpecular[0], light->Specular, mat->Specular);
 688       }
 689    }
 690    if (bitmask & BACK_SPECULAR_BIT) {
 691       struct gl_material *mat = &ctx->Light.Material[1];
 692       COPY_4FV( mat->Specular, src[1].Specular );
 693       foreach (light, list) {
 694          SCALE_3V( light->_MatSpecular[1], light->Specular, mat->Specular);
 695       }
 696    }
 697
 698    if (bitmask & FRONT_SHININESS_BIT) {
 699       ctx->Light.Material[0].Shininess = src[0].Shininess;
 700       _mesa_invalidate_shine_table( ctx, 0 );
 701    }
 702    if (bitmask & BACK_SHININESS_BIT) {
 703       ctx->Light.Material[1].Shininess = src[1].Shininess;
 704       _mesa_invalidate_shine_table( ctx, 1 );
 705    }
 706
 707    if (bitmask & FRONT_INDEXES_BIT) {
 708       ctx->Light.Material[0].AmbientIndex = src[0].AmbientIndex;
 709       ctx->Light.Material[0].DiffuseIndex = src[0].DiffuseIndex;
 710       ctx->Light.Material[0].SpecularIndex = src[0].SpecularIndex;
 711    }
 712    if (bitmask & BACK_INDEXES_BIT) {
 713       ctx->Light.Material[1].AmbientIndex = src[1].AmbientIndex;
 714       ctx->Light.Material[1].DiffuseIndex = src[1].DiffuseIndex;
 715       ctx->Light.Material[1].SpecularIndex = src[1].SpecularIndex;
 716    }
 717
 718    if (0) {
 719       struct gl_material *mat = &ctx->Light.Material[0];
 720       _mesa_debug(ctx, "update_mat  emission : %f %f %f\n",
 721                   mat->Emission[0], mat->Emission[1], mat->Emission[2]);
 722       _mesa_debug(ctx, "update_mat  specular : %f %f %f\n",
 723                   mat->Specular[0], mat->Specular[1], mat->Specular[2]);
 724       _mesa_debug(ctx, "update_mat  diffuse : %f %f %f\n",
 725                   mat->Diffuse[0], mat->Diffuse[1], mat->Diffuse[2]);
 726       _mesa_debug(ctx, "update_mat  ambient : %f %f %f\n",
 727                   mat->Ambient[0], mat->Ambient[1], mat->Ambient[2]);
 728    }
 729 }
 730
 731
 732
 733
 734
 735
 736
 737 /*
 738  * Update the current materials from the given rgba color
 739  * according to the bitmask in ColorMaterialBitmask, which is
 740  * set by glColorMaterial().
 741  */
 742 void _mesa_update_color_material( GLcontext *ctx,
 743                                   const GLfloat color[4] )
 744 {
 745    struct gl_light *light, *list = &ctx->Light.EnabledList;
 746    GLuint bitmask = ctx->Light.ColorMaterialBitmask;
 747
 748    if (MESA_VERBOSE&VERBOSE_IMMEDIATE)
 749       _mesa_debug(ctx, "_mesa_update_color_material, mask 0x%x\n", bitmask);
 750
 751    /* update emissive colors */
 752    if (bitmask & FRONT_EMISSION_BIT) {
 753       struct gl_material *mat = &ctx->Light.Material[0];
 754       COPY_4FV( mat->Emission, color );
 755    }
 756
 757    if (bitmask & BACK_EMISSION_BIT) {
 758       struct gl_material *mat = &ctx->Light.Material[1];
 759       COPY_4FV( mat->Emission, color );
 760    }
 761
 762    /* update light->_MatAmbient = light's ambient * material's ambient */
 763    if (bitmask & FRONT_AMBIENT_BIT) {
 764       struct gl_material *mat = &ctx->Light.Material[0];
 765       foreach (light, list) {
 766          SCALE_3V( light->_MatAmbient[0], light->Ambient, color);
 767       }
 768       COPY_4FV( mat->Ambient, color );
 769    }
 770
 771    if (bitmask & BACK_AMBIENT_BIT) {
 772       struct gl_material *mat = &ctx->Light.Material[1];
 773       foreach (light, list) {
 774          SCALE_3V( light->_MatAmbient[1], light->Ambient, color);
 775       }
 776       COPY_4FV( mat->Ambient, color );
 777    }
 778
 779    /* update BaseColor = emission + scene's ambience * material's ambience */
 780    if (bitmask & (FRONT_EMISSION_BIT | FRONT_AMBIENT_BIT)) {
 781       struct gl_material *mat = &ctx->Light.Material[0];
 782       COPY_3V( ctx->Light._BaseColor[0], mat->Emission );
 783       ACC_SCALE_3V( ctx->Light._BaseColor[0], mat->Ambient, ctx->Light.Model.Ambient );
 784    }
 785
 786    if (bitmask & (BACK_EMISSION_BIT | BACK_AMBIENT_BIT)) {
 787       struct gl_material *mat = &ctx->Light.Material[1];
 788       COPY_3V( ctx->Light._BaseColor[1], mat->Emission );
 789       ACC_SCALE_3V( ctx->Light._BaseColor[1], mat->Ambient, ctx->Light.Model.Ambient );
 790    }
 791
 792    /* update light->_MatDiffuse = light's diffuse * material's diffuse */
 793    if (bitmask & FRONT_DIFFUSE_BIT) {
 794       struct gl_material *mat = &ctx->Light.Material[0];
 795       COPY_4FV( mat->Diffuse, color );
 796       foreach (light, list) {
 797          SCALE_3V( light->_MatDiffuse[0], light->Diffuse, mat->Diffuse );
 798       }
 799    }
 800
 801    if (bitmask & BACK_DIFFUSE_BIT) {
 802       struct gl_material *mat = &ctx->Light.Material[1];
 803       COPY_4FV( mat->Diffuse, color );
 804       foreach (light, list) {
 805          SCALE_3V( light->_MatDiffuse[1], light->Diffuse, mat->Diffuse );
 806       }
 807    }
 808
 809    /* update light->_MatSpecular = light's specular * material's specular */
 810    if (bitmask & FRONT_SPECULAR_BIT) {
 811       struct gl_material *mat = &ctx->Light.Material[0];
 812       COPY_4FV( mat->Specular, color );
 813       foreach (light, list) {
 814          ACC_SCALE_3V( light->_MatSpecular[0], light->Specular, mat->Specular);
 815       }
 816    }
 817
 818    if (bitmask & BACK_SPECULAR_BIT) {
 819       struct gl_material *mat = &ctx->Light.Material[1];
 820       COPY_4FV( mat->Specular, color );
 821       foreach (light, list) {
 822          ACC_SCALE_3V( light->_MatSpecular[1], light->Specular, mat->Specular);
 823       }
 824    }
 825
 826    if (0) {
 827       struct gl_material *mat = &ctx->Light.Material[0];
 828       _mesa_debug(ctx, "update_color_mat  emission : %f %f %f\n",
 829                   mat->Emission[0], mat->Emission[1], mat->Emission[2]);
 830       _mesa_debug(ctx, "update_color_mat  specular : %f %f %f\n",
 831                   mat->Specular[0], mat->Specular[1], mat->Specular[2]);
 832       _mesa_debug(ctx, "update_color_mat  diffuse : %f %f %f\n",
 833                   mat->Diffuse[0], mat->Diffuse[1], mat->Diffuse[2]);
 834       _mesa_debug(ctx, "update_color_mat  ambient : %f %f %f\n",
 835                   mat->Ambient[0], mat->Ambient[1], mat->Ambient[2]);
 836    }
 837 }
 838
 839
 840
 841
 842 void
 843 _mesa_ColorMaterial( GLenum face, GLenum mode )
 844 {
 845    GET_CURRENT_CONTEXT(ctx);
 846    GLuint bitmask;
 847    GLuint legal = (FRONT_EMISSION_BIT | BACK_EMISSION_BIT |
 848                    FRONT_SPECULAR_BIT | BACK_SPECULAR_BIT |
 849                    FRONT_DIFFUSE_BIT  | BACK_DIFFUSE_BIT  |
 850                    FRONT_AMBIENT_BIT  | BACK_AMBIENT_BIT);
 851    ASSERT_OUTSIDE_BEGIN_END(ctx);
 852
 853    if (MESA_VERBOSE&VERBOSE_API)
 854       _mesa_debug(ctx, "glColorMaterial %s %s\n",
 855                   _mesa_lookup_enum_by_nr(face),
 856                   _mesa_lookup_enum_by_nr(mode));
 857
 858    bitmask = _mesa_material_bitmask(ctx, face, mode, legal, "glColorMaterial");
 859
 860    if (ctx->Light.ColorMaterialBitmask == bitmask &&
 861        ctx->Light.ColorMaterialFace == face &&
 862        ctx->Light.ColorMaterialMode == mode)
 863       return;
 864
 865    FLUSH_VERTICES(ctx, _NEW_LIGHT);
 866    ctx->Light.ColorMaterialBitmask = bitmask;
 867    ctx->Light.ColorMaterialFace = face;
 868    ctx->Light.ColorMaterialMode = mode;
 869
 870    if (ctx->Light.ColorMaterialEnabled) {
 871       FLUSH_CURRENT( ctx, 0 );
 872       _mesa_update_color_material(ctx,ctx->Current.Attrib[VERT_ATTRIB_COLOR0]);
 873    }
 874
 875    if (ctx->Driver.ColorMaterial)
 876       (*ctx->Driver.ColorMaterial)( ctx, face, mode );
 877 }
 878
 879
 880
 881
 882
 883 void
 884 _mesa_GetMaterialfv( GLenum face, GLenum pname, GLfloat *params )
 885 {
 886    GET_CURRENT_CONTEXT(ctx);
 887    GLuint f;
 888    ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx); /* update materials */
 889
 890    if (face==GL_FRONT) {
 891       f = 0;
 892    }
 893    else if (face==GL_BACK) {
 894       f = 1;
 895    }
 896    else {
 897       _mesa_error( ctx, GL_INVALID_ENUM, "glGetMaterialfv(face)" );
 898       return;
 899    }
 900    switch (pname) {
 901       case GL_AMBIENT:
 902          COPY_4FV( params, ctx->Light.Material[f].Ambient );
 903          break;
 904       case GL_DIFFUSE:
 905          COPY_4FV( params, ctx->Light.Material[f].Diffuse );
 906          break;
 907       case GL_SPECULAR:
 908          COPY_4FV( params, ctx->Light.Material[f].Specular );
 909          break;
 910       case GL_EMISSION:
 911          COPY_4FV( params, ctx->Light.Material[f].Emission );
 912          break;
 913       case GL_SHININESS:
 914          *params = ctx->Light.Material[f].Shininess;
 915          break;
 916       case GL_COLOR_INDEXES:
 917          params[0] = ctx->Light.Material[f].AmbientIndex;
 918          params[1] = ctx->Light.Material[f].DiffuseIndex;
 919          params[2] = ctx->Light.Material[f].SpecularIndex;
 920          break;
 921       default:
 922          _mesa_error( ctx, GL_INVALID_ENUM, "glGetMaterialfv(pname)" );
 923    }
 924 }
 925
 926
 927
 928 void
 929 _mesa_GetMaterialiv( GLenum face, GLenum pname, GLint *params )
 930 {
 931    GET_CURRENT_CONTEXT(ctx);
 932    GLuint f;
 933    ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx); /* update materials */
 934
 935    if (face==GL_FRONT) {
 936       f = 0;
 937    }
 938    else if (face==GL_BACK) {
 939       f = 1;
 940    }
 941    else {
 942       _mesa_error( ctx, GL_INVALID_ENUM, "glGetMaterialiv(face)" );
 943       return;
 944    }
 945    switch (pname) {
 946       case GL_AMBIENT:
 947          params[0] = FLOAT_TO_INT( ctx->Light.Material[f].Ambient[0] );
 948          params[1] = FLOAT_TO_INT( ctx->Light.Material[f].Ambient[1] );
 949          params[2] = FLOAT_TO_INT( ctx->Light.Material[f].Ambient[2] );
 950          params[3] = FLOAT_TO_INT( ctx->Light.Material[f].Ambient[3] );
 951          break;
 952       case GL_DIFFUSE:
 953          params[0] = FLOAT_TO_INT( ctx->Light.Material[f].Diffuse[0] );
 954          params[1] = FLOAT_TO_INT( ctx->Light.Material[f].Diffuse[1] );
 955          params[2] = FLOAT_TO_INT( ctx->Light.Material[f].Diffuse[2] );
 956          params[3] = FLOAT_TO_INT( ctx->Light.Material[f].Diffuse[3] );
 957          break;
 958       case GL_SPECULAR:
 959          params[0] = FLOAT_TO_INT( ctx->Light.Material[f].Specular[0] );
 960          params[1] = FLOAT_TO_INT( ctx->Light.Material[f].Specular[1] );
 961          params[2] = FLOAT_TO_INT( ctx->Light.Material[f].Specular[2] );
 962          params[3] = FLOAT_TO_INT( ctx->Light.Material[f].Specular[3] );
 963          break;
 964       case GL_EMISSION:
 965          params[0] = FLOAT_TO_INT( ctx->Light.Material[f].Emission[0] );
 966          params[1] = FLOAT_TO_INT( ctx->Light.Material[f].Emission[1] );
 967          params[2] = FLOAT_TO_INT( ctx->Light.Material[f].Emission[2] );
 968          params[3] = FLOAT_TO_INT( ctx->Light.Material[f].Emission[3] );
 969          break;
 970       case GL_SHININESS:
 971          *params = ROUNDF( ctx->Light.Material[f].Shininess );
 972          break;
 973       case GL_COLOR_INDEXES:
 974          params[0] = ROUNDF( ctx->Light.Material[f].AmbientIndex );
 975          params[1] = ROUNDF( ctx->Light.Material[f].DiffuseIndex );
 976          params[2] = ROUNDF( ctx->Light.Material[f].SpecularIndex );
 977          break;
 978       default:
 979          _mesa_error( ctx, GL_INVALID_ENUM, "glGetMaterialfv(pname)" );
 980    }
 981 }
 982
 983
 984
 985
 986 /**********************************************************************/
 987 /*****                  Lighting computation                      *****/
 988 /**********************************************************************/
 989
 990
 991 /*
 992  * Notes:
 993  *   When two-sided lighting is enabled we compute the color (or index)
 994  *   for both the front and back side of the primitive.  Then, when the
 995  *   orientation of the facet is later learned, we can determine which
 996  *   color (or index) to use for rendering.
 997  *
 998  *   KW: We now know orientation in advance and only shade for
 999  *       the side or sides which are actually required.
1000  *
1001  * Variables:
1002  *   n = normal vector
1003  *   V = vertex position
1004  *   P = light source position
1005  *   Pe = (0,0,0,1)
1006  *
1007  * Precomputed:
1008  *   IF P[3]==0 THEN
1009  *       // light at infinity
1010  *       IF local_viewer THEN
1011  *           _VP_inf_norm = unit vector from V to P      // Precompute
1012  *       ELSE
1013  *           // eye at infinity
1014  *           _h_inf_norm = Normalize( VP + <0,0,1> )     // Precompute
1015  *       ENDIF
1016  *   ENDIF
1017  *
1018  * Functions:
1019  *   Normalize( v ) = normalized vector v
1020  *   Magnitude( v ) = length of vector v
1021  */
1022
1023
1024
1025 /*
1026  * Whenever the spotlight exponent for a light changes we must call
1027  * this function to recompute the exponent lookup table.
1028  */
1029 void
1030 _mesa_invalidate_spot_exp_table( struct gl_light *l )
1031 {
1032    l->_SpotExpTable[0][0] = -1;
1033 }
1034
1035 static void validate_spot_exp_table( struct gl_light *l )
1036 {
1037    GLint i;
1038    GLdouble exponent = l->SpotExponent;
1039    GLdouble tmp = 0;
1040    GLint clamp = 0;
1041
1042    l->_SpotExpTable[0][0] = 0.0;
1043
1044    for (i = EXP_TABLE_SIZE - 1; i > 0 ;i--) {
1045       if (clamp == 0) {
1046          tmp = pow(i / (GLdouble) (EXP_TABLE_SIZE - 1), exponent);
1047          if (tmp < FLT_MIN * 100.0) {
1048             tmp = 0.0;
1049             clamp = 1;
1050          }
1051       }
1052       l->_SpotExpTable[i][0] = (GLfloat) tmp;
1053    }
1054    for (i = 0; i < EXP_TABLE_SIZE - 1; i++) {
1055       l->_SpotExpTable[i][1] = (l->_SpotExpTable[i+1][0] -
1056                                 l->_SpotExpTable[i][0]);
1057    }
1058    l->_SpotExpTable[EXP_TABLE_SIZE-1][1] = 0.0;
1059 }
1060
1061
1062
1063
1064 /* Calculate a new shine table.  Doing this here saves a branch in
1065  * lighting, and the cost of doing it early may be partially offset
1066  * by keeping a MRU cache of shine tables for various shine values.
1067  */
1068 void
1069 _mesa_invalidate_shine_table( GLcontext *ctx, GLuint i )
1070 {
1071    if (ctx->_ShineTable[i])
1072       ctx->_ShineTable[i]->refcount--;
1073    ctx->_ShineTable[i] = 0;
1074 }
1075
1076 static void validate_shine_table( GLcontext *ctx, GLuint i, GLfloat shininess )
1077 {
1078    struct gl_shine_tab *list = ctx->_ShineTabList;
1079    struct gl_shine_tab *s;
1080
1081    foreach(s, list)
1082       if ( s->shininess == shininess )
1083          break;
1084
1085    if (s == list) {
1086       GLint j;
1087       GLfloat *m;
1088
1089       foreach(s, list)
1090          if (s->refcount == 0)
1091             break;
1092
1093       m = s->tab;
1094       m[0] = 0.0;
1095       if (shininess == 0.0) {
1096          for (j = 1 ; j <= SHINE_TABLE_SIZE ; j++)
1097             m[j] = 1.0;
1098       }
1099       else {
1100          for (j = 1 ; j < SHINE_TABLE_SIZE ; j++) {
1101             GLdouble t, x = j / (GLfloat) (SHINE_TABLE_SIZE - 1);
1102             if (x < 0.005) /* underflow check */
1103                x = 0.005;
1104             t = pow(x, shininess);
1105             if (t > 1e-20)
1106                m[j] = (GLfloat) t;
1107             else
1108                m[j] = 0.0;
1109          }
1110          m[SHINE_TABLE_SIZE] = 1.0;
1111       }
1112
1113       s->shininess = shininess;
1114    }
1115
1116    if (ctx->_ShineTable[i])
1117       ctx->_ShineTable[i]->refcount--;
1118
1119    ctx->_ShineTable[i] = s;
1120    move_to_tail( list, s );
1121    s->refcount++;
1122 }
1123
1124 void
1125 _mesa_validate_all_lighting_tables( GLcontext *ctx )
1126 {
1127    GLint i;
1128    GLfloat shininess;
1129
1130    shininess = ctx->Light.Material[0].Shininess;
1131    if (!ctx->_ShineTable[0] || ctx->_ShineTable[0]->shininess != shininess)
1132       validate_shine_table( ctx, 0, shininess );
1133
1134    shininess = ctx->Light.Material[1].Shininess;
1135    if (!ctx->_ShineTable[1] || ctx->_ShineTable[1]->shininess != shininess)
1136       validate_shine_table( ctx, 1, shininess );
1137
1138    for (i = 0 ; i < MAX_LIGHTS ; i++)
1139       if (ctx->Light.Light[i]._SpotExpTable[0][0] == -1)
1140          validate_spot_exp_table( &ctx->Light.Light[i] );
1141 }
1142
1143
1144
1145
1146 /*
1147  * Examine current lighting parameters to determine if the optimized lighting
1148  * function can be used.
1149  * Also, precompute some lighting values such as the products of light
1150  * source and material ambient, diffuse and specular coefficients.
1151  */
1152 void
1153 _mesa_update_lighting( GLcontext *ctx )
1154 {
1155    struct gl_light *light;
1156    ctx->_NeedEyeCoords &= ~NEED_EYE_LIGHT;
1157    ctx->_NeedNormals &= ~NEED_NORMALS_LIGHT;
1158    ctx->Light._Flags = 0;
1159
1160    if (!ctx->Light.Enabled)
1161       return;
1162
1163    ctx->_NeedNormals |= NEED_NORMALS_LIGHT;
1164
1165    foreach(light, &ctx->Light.EnabledList) {
1166       ctx->Light._Flags |= light->_Flags;
1167    }
1168
1169    ctx->Light._NeedVertices =
1170       ((ctx->Light._Flags & (LIGHT_POSITIONAL|LIGHT_SPOT)) ||
1171        ctx->Light.Model.ColorControl == GL_SEPARATE_SPECULAR_COLOR ||
1172        ctx->Light.Model.LocalViewer);
1173
1174    if ((ctx->Light._Flags & LIGHT_POSITIONAL) ||
1175        ctx->Light.Model.LocalViewer)
1176       ctx->_NeedEyeCoords |= NEED_EYE_LIGHT;
1177
1178
1179    /* XXX: This test is overkill & needs to be fixed both for software and
1180     * hardware t&l drivers.  The above should be sufficient & should
1181     * be tested to verify this.
1182     */
1183    if (ctx->Light._NeedVertices)
1184       ctx->_NeedEyeCoords |= NEED_EYE_LIGHT;
1185
1186
1187    /* Precompute some shading values.  Although we reference
1188     * Light.Material here, we can get away without flushing
1189     * FLUSH_UPDATE_CURRENT, as when any outstanding material changes
1190     * are flushed, they will update the derived state at that time.
1191     */
1192    if (ctx->Visual.rgbMode) {
1193       GLuint sides = ctx->Light.Model.TwoSide ? 2 : 1;
1194       GLuint side;
1195       for (side=0; side < sides; side++) {
1196          struct gl_material *mat = &ctx->Light.Material[side];
1197
1198          COPY_3V(ctx->Light._BaseColor[side], mat->Emission);
1199          ACC_SCALE_3V(ctx->Light._BaseColor[side],
1200                       ctx->Light.Model.Ambient,
1201                       mat->Ambient);
1202       }
1203
1204       foreach (light, &ctx->Light.EnabledList) {
1205          for (side=0; side< sides; side++) {
1206             const struct gl_material *mat = &ctx->Light.Material[side];
1207             SCALE_3V( light->_MatDiffuse[side], light->Diffuse, mat->Diffuse );
1208             SCALE_3V( light->_MatAmbient[side], light->Ambient, mat->Ambient );
1209             SCALE_3V( light->_MatSpecular[side], light->Specular,
1210                       mat->Specular);
1211          }
1212       }
1213    }
1214    else {
1215       static const GLfloat ci[3] = { .30F, .59F, .11F };
1216       foreach(light, &ctx->Light.EnabledList) {
1217          light->_dli = DOT3(ci, light->Diffuse);
1218          light->_sli = DOT3(ci, light->Specular);
1219       }
1220    }
1221 }
1222
1223
1224 /* _NEW_MODELVIEW
1225  * _NEW_LIGHT
1226  * _TNL_NEW_NEED_EYE_COORDS
1227  *
1228  * Update on (_NEW_MODELVIEW | _NEW_LIGHT) when lighting is enabled.
1229  * Also update on lighting space changes.
1230  */
1231 void
1232 _mesa_compute_light_positions( GLcontext *ctx )
1233 {
1234    struct gl_light *light;
1235    static const GLfloat eye_z[3] = { 0, 0, 1 };
1236
1237    if (!ctx->Light.Enabled)
1238       return;
1239
1240    if (ctx->_NeedEyeCoords) {
1241       COPY_3V( ctx->_EyeZDir, eye_z );
1242    }
1243    else {
1244       TRANSFORM_NORMAL( ctx->_EyeZDir, eye_z, ctx->ModelviewMatrixStack.Top->m );
1245    }
1246
1247    foreach (light, &ctx->Light.EnabledList) {
1248
1249       if (ctx->_NeedEyeCoords) {
1250          COPY_4FV( light->_Position, light->EyePosition );
1251       }
1252       else {
1253          TRANSFORM_POINT( light->_Position, ctx->ModelviewMatrixStack.Top->inv,
1254                           light->EyePosition );
1255       }
1256
1257       if (!(light->_Flags & LIGHT_POSITIONAL)) {
1258          /* VP (VP) = Normalize( Position ) */
1259          COPY_3V( light->_VP_inf_norm, light->_Position );
1260          NORMALIZE_3FV( light->_VP_inf_norm );
1261
1262          if (!ctx->Light.Model.LocalViewer) {
1263             /* _h_inf_norm = Normalize( V_to_P + <0,0,1> ) */
1264             ADD_3V( light->_h_inf_norm, light->_VP_inf_norm, ctx->_EyeZDir);
1265             NORMALIZE_3FV( light->_h_inf_norm );
1266          }
1267          light->_VP_inf_spot_attenuation = 1.0;
1268       }
1269
1270       if (light->_Flags & LIGHT_SPOT) {
1271          if (ctx->_NeedEyeCoords) {
1272             COPY_3V( light->_NormDirection, light->EyeDirection );
1273          }
1274          else {
1275             TRANSFORM_NORMAL( light->_NormDirection,
1276                               light->EyeDirection,
1277                               ctx->ModelviewMatrixStack.Top->m);
1278          }
1279
1280          NORMALIZE_3FV( light->_NormDirection );
1281
1282          if (!(light->_Flags & LIGHT_POSITIONAL)) {
1283             GLfloat PV_dot_dir = - DOT3(light->_VP_inf_norm,
1284                                         light->_NormDirection);
1285
1286             if (PV_dot_dir > light->_CosCutoff) {
1287                double x = PV_dot_dir * (EXP_TABLE_SIZE-1);
1288                int k = (int) x;
1289                light->_VP_inf_spot_attenuation =
1290                   (GLfloat) (light->_SpotExpTable[k][0] +
1291                    (x-k)*light->_SpotExpTable[k][1]);
1292             }
1293             else {
1294                light->_VP_inf_spot_attenuation = 0;
1295             }
1296          }
1297       }
1298    }
1299 }