src/mesa/program/prog_statevars.c

   1 /*
   2  * Mesa 3-D graphics library
   3  *
   4  * Copyright (C) 1999-2007  Brian Paul   All Rights Reserved.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the "Software"),
   8  * to deal in the Software without restriction, including without limitation
   9  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  10  * and/or sell copies of the Software, and to permit persons to whom the
  11  * Software is furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included
  14  * in all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  17  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  20  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  21  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  22  * OTHER DEALINGS IN THE SOFTWARE.
  23  */
  24
  25 /**
  26  * \file prog_statevars.c
  27  * Program state variable management.
  28  * \author Brian Paul
  29  */
  30
  31
  32 #include <stdio.h>
  33 #include "main/glheader.h"
  34 #include "main/context.h"
  35 #include "main/blend.h"
  36 #include "main/imports.h"
  37 #include "main/macros.h"
  38 #include "main/mtypes.h"
  39 #include "main/fbobject.h"
  40 #include "prog_statevars.h"
  41 #include "prog_parameter.h"
  42 #include "main/samplerobj.h"
  43 #include "main/framebuffer.h"
  44
  45
  46 #define ONE_DIV_SQRT_LN2 (1.201122408786449815)
  47
  48
  49 /**
  50  * Use the list of tokens in the state[] array to find global GL state
  51  * and return it in <value>.  Usually, four values are returned in <value>
  52  * but matrix queries may return as many as 16 values.
  53  * This function is used for ARB vertex/fragment programs.
  54  * The program parser will produce the state[] values.
  55  */
  56 static void
  57 _mesa_fetch_state(struct gl_context *ctx, const gl_state_index16 state[],
  58                   gl_constant_value *val)
  59 {
  60    GLfloat *value = &val->f;
  61
  62    switch (state[0]) {
  63    case STATE_MATERIAL:
  64       {
  65          /* state[1] is either 0=front or 1=back side */
  66          const GLuint face = (GLuint) state[1];
  67          const struct gl_material *mat = &ctx->Light.Material;
  68          assert(face == 0 || face == 1);
  69          /* we rely on tokens numbered so that _BACK_ == _FRONT_+ 1 */
  70          assert(MAT_ATTRIB_FRONT_AMBIENT + 1 == MAT_ATTRIB_BACK_AMBIENT);
  71          /* XXX we could get rid of this switch entirely with a little
  72           * work in arbprogparse.c's parse_state_single_item().
  73           */
  74          /* state[2] is the material attribute */
  75          switch (state[2]) {
  76          case STATE_AMBIENT:
  77             COPY_4V(value, mat->Attrib[MAT_ATTRIB_FRONT_AMBIENT + face]);
  78             return;
  79          case STATE_DIFFUSE:
  80             COPY_4V(value, mat->Attrib[MAT_ATTRIB_FRONT_DIFFUSE + face]);
  81             return;
  82          case STATE_SPECULAR:
  83             COPY_4V(value, mat->Attrib[MAT_ATTRIB_FRONT_SPECULAR + face]);
  84             return;
  85          case STATE_EMISSION:
  86             COPY_4V(value, mat->Attrib[MAT_ATTRIB_FRONT_EMISSION + face]);
  87             return;
  88          case STATE_SHININESS:
  89             value[0] = mat->Attrib[MAT_ATTRIB_FRONT_SHININESS + face][0];
  90             value[1] = 0.0F;
  91             value[2] = 0.0F;
  92             value[3] = 1.0F;
  93             return;
  94          default:
  95             _mesa_problem(ctx, "Invalid material state in fetch_state");
  96             return;
  97          }
  98       }
  99    case STATE_LIGHT:
 100       {
 101          /* state[1] is the light number */
 102          const GLuint ln = (GLuint) state[1];
 103          /* state[2] is the light attribute */
 104          switch (state[2]) {
 105          case STATE_AMBIENT:
 106             COPY_4V(value, ctx->Light.Light[ln].Ambient);
 107             return;
 108          case STATE_DIFFUSE:
 109             COPY_4V(value, ctx->Light.Light[ln].Diffuse);
 110             return;
 111          case STATE_SPECULAR:
 112             COPY_4V(value, ctx->Light.Light[ln].Specular);
 113             return;
 114          case STATE_POSITION:
 115             COPY_4V(value, ctx->Light.Light[ln].EyePosition);
 116             return;
 117          case STATE_ATTENUATION:
 118             value[0] = ctx->Light.Light[ln].ConstantAttenuation;
 119             value[1] = ctx->Light.Light[ln].LinearAttenuation;
 120             value[2] = ctx->Light.Light[ln].QuadraticAttenuation;
 121             value[3] = ctx->Light.Light[ln].SpotExponent;
 122             return;
 123          case STATE_SPOT_DIRECTION:
 124             COPY_3V(value, ctx->Light.Light[ln].SpotDirection);
 125             value[3] = ctx->Light.Light[ln]._CosCutoff;
 126             return;
 127          case STATE_SPOT_CUTOFF:
 128             value[0] = ctx->Light.Light[ln].SpotCutoff;
 129             return;
 130          case STATE_HALF_VECTOR:
 131             {
 132                static const GLfloat eye_z[] = {0, 0, 1};
 133                GLfloat p[3];
 134                /* Compute infinite half angle vector:
 135                 *   halfVector = normalize(normalize(lightPos) + (0, 0, 1))
 136                 * light.EyePosition.w should be 0 for infinite lights.
 137                 */
 138                COPY_3V(p, ctx->Light.Light[ln].EyePosition);
 139                NORMALIZE_3FV(p);
 140                ADD_3V(value, p, eye_z);
 141                NORMALIZE_3FV(value);
 142                value[3] = 1.0;
 143             }
 144             return;
 145          default:
 146             _mesa_problem(ctx, "Invalid light state in fetch_state");
 147             return;
 148          }
 149       }
 150    case STATE_LIGHTMODEL_AMBIENT:
 151       COPY_4V(value, ctx->Light.Model.Ambient);
 152       return;
 153    case STATE_LIGHTMODEL_SCENECOLOR:
 154       if (state[1] == 0) {
 155          /* front */
 156          GLint i;
 157          for (i = 0; i < 3; i++) {
 158             value[i] = ctx->Light.Model.Ambient[i]
 159                * ctx->Light.Material.Attrib[MAT_ATTRIB_FRONT_AMBIENT][i]
 160                + ctx->Light.Material.Attrib[MAT_ATTRIB_FRONT_EMISSION][i];
 161          }
 162          value[3] = ctx->Light.Material.Attrib[MAT_ATTRIB_FRONT_DIFFUSE][3];
 163       }
 164       else {
 165          /* back */
 166          GLint i;
 167          for (i = 0; i < 3; i++) {
 168             value[i] = ctx->Light.Model.Ambient[i]
 169                * ctx->Light.Material.Attrib[MAT_ATTRIB_BACK_AMBIENT][i]
 170                + ctx->Light.Material.Attrib[MAT_ATTRIB_BACK_EMISSION][i];
 171          }
 172          value[3] = ctx->Light.Material.Attrib[MAT_ATTRIB_BACK_DIFFUSE][3];
 173       }
 174       return;
 175    case STATE_LIGHTPROD:
 176       {
 177          const GLuint ln = (GLuint) state[1];
 178          const GLuint face = (GLuint) state[2];
 179          GLint i;
 180          assert(face == 0 || face == 1);
 181          switch (state[3]) {
 182             case STATE_AMBIENT:
 183                for (i = 0; i < 3; i++) {
 184                   value[i] = ctx->Light.Light[ln].Ambient[i] *
 185                      ctx->Light.Material.Attrib[MAT_ATTRIB_FRONT_AMBIENT+face][i];
 186                }
 187                /* [3] = material alpha */
 188                value[3] = ctx->Light.Material.Attrib[MAT_ATTRIB_FRONT_AMBIENT+face][3];
 189                return;
 190             case STATE_DIFFUSE:
 191                for (i = 0; i < 3; i++) {
 192                   value[i] = ctx->Light.Light[ln].Diffuse[i] *
 193                      ctx->Light.Material.Attrib[MAT_ATTRIB_FRONT_DIFFUSE+face][i];
 194                }
 195                /* [3] = material alpha */
 196                value[3] = ctx->Light.Material.Attrib[MAT_ATTRIB_FRONT_DIFFUSE+face][3];
 197                return;
 198             case STATE_SPECULAR:
 199                for (i = 0; i < 3; i++) {
 200                   value[i] = ctx->Light.Light[ln].Specular[i] *
 201                      ctx->Light.Material.Attrib[MAT_ATTRIB_FRONT_SPECULAR+face][i];
 202                }
 203                /* [3] = material alpha */
 204                value[3] = ctx->Light.Material.Attrib[MAT_ATTRIB_FRONT_SPECULAR+face][3];
 205                return;
 206             default:
 207                _mesa_problem(ctx, "Invalid lightprod state in fetch_state");
 208                return;
 209          }
 210       }
 211    case STATE_TEXGEN:
 212       {
 213          /* state[1] is the texture unit */
 214          const GLuint unit = (GLuint) state[1];
 215          /* state[2] is the texgen attribute */
 216          switch (state[2]) {
 217          case STATE_TEXGEN_EYE_S:
 218             COPY_4V(value, ctx->Texture.FixedFuncUnit[unit].GenS.EyePlane);
 219             return;
 220          case STATE_TEXGEN_EYE_T:
 221             COPY_4V(value, ctx->Texture.FixedFuncUnit[unit].GenT.EyePlane);
 222             return;
 223          case STATE_TEXGEN_EYE_R:
 224             COPY_4V(value, ctx->Texture.FixedFuncUnit[unit].GenR.EyePlane);
 225             return;
 226          case STATE_TEXGEN_EYE_Q:
 227             COPY_4V(value, ctx->Texture.FixedFuncUnit[unit].GenQ.EyePlane);
 228             return;
 229          case STATE_TEXGEN_OBJECT_S:
 230             COPY_4V(value, ctx->Texture.FixedFuncUnit[unit].GenS.ObjectPlane);
 231             return;
 232          case STATE_TEXGEN_OBJECT_T:
 233             COPY_4V(value, ctx->Texture.FixedFuncUnit[unit].GenT.ObjectPlane);
 234             return;
 235          case STATE_TEXGEN_OBJECT_R:
 236             COPY_4V(value, ctx->Texture.FixedFuncUnit[unit].GenR.ObjectPlane);
 237             return;
 238          case STATE_TEXGEN_OBJECT_Q:
 239             COPY_4V(value, ctx->Texture.FixedFuncUnit[unit].GenQ.ObjectPlane);
 240             return;
 241          default:
 242             _mesa_problem(ctx, "Invalid texgen state in fetch_state");
 243             return;
 244          }
 245       }
 246    case STATE_TEXENV_COLOR:
 247       {
 248          /* state[1] is the texture unit */
 249          const GLuint unit = (GLuint) state[1];
 250          if (_mesa_get_clamp_fragment_color(ctx, ctx->DrawBuffer))
 251             COPY_4V(value, ctx->Texture.FixedFuncUnit[unit].EnvColor);
 252          else
 253             COPY_4V(value, ctx->Texture.FixedFuncUnit[unit].EnvColorUnclamped);
 254       }
 255       return;
 256    case STATE_FOG_COLOR:
 257       if (_mesa_get_clamp_fragment_color(ctx, ctx->DrawBuffer))
 258          COPY_4V(value, ctx->Fog.Color);
 259       else
 260          COPY_4V(value, ctx->Fog.ColorUnclamped);
 261       return;
 262    case STATE_FOG_PARAMS:
 263       value[0] = ctx->Fog.Density;
 264       value[1] = ctx->Fog.Start;
 265       value[2] = ctx->Fog.End;
 266       value[3] = 1.0f / (ctx->Fog.End - ctx->Fog.Start);
 267       return;
 268    case STATE_CLIPPLANE:
 269       {
 270          const GLuint plane = (GLuint) state[1];
 271          COPY_4V(value, ctx->Transform.EyeUserPlane[plane]);
 272       }
 273       return;
 274    case STATE_POINT_SIZE:
 275       value[0] = ctx->Point.Size;
 276       value[1] = ctx->Point.MinSize;
 277       value[2] = ctx->Point.MaxSize;
 278       value[3] = ctx->Point.Threshold;
 279       return;
 280    case STATE_POINT_ATTENUATION:
 281       value[0] = ctx->Point.Params[0];
 282       value[1] = ctx->Point.Params[1];
 283       value[2] = ctx->Point.Params[2];
 284       value[3] = 1.0F;
 285       return;
 286    case STATE_MODELVIEW_MATRIX:
 287    case STATE_PROJECTION_MATRIX:
 288    case STATE_MVP_MATRIX:
 289    case STATE_TEXTURE_MATRIX:
 290    case STATE_PROGRAM_MATRIX:
 291       {
 292          /* state[0] = modelview, projection, texture, etc. */
 293          /* state[1] = which texture matrix or program matrix */
 294          /* state[2] = first row to fetch */
 295          /* state[3] = last row to fetch */
 296          /* state[4] = transpose, inverse or invtrans */
 297          const GLmatrix *matrix;
 298          const gl_state_index mat = state[0];
 299          const GLuint index = (GLuint) state[1];
 300          const GLuint firstRow = (GLuint) state[2];
 301          const GLuint lastRow = (GLuint) state[3];
 302          const gl_state_index modifier = state[4];
 303          const GLfloat *m;
 304          GLuint row, i;
 305          assert(firstRow < 4);
 306          assert(lastRow < 4);
 307          if (mat == STATE_MODELVIEW_MATRIX) {
 308             matrix = ctx->ModelviewMatrixStack.Top;
 309          }
 310          else if (mat == STATE_PROJECTION_MATRIX) {
 311             matrix = ctx->ProjectionMatrixStack.Top;
 312          }
 313          else if (mat == STATE_MVP_MATRIX) {
 314             matrix = &ctx->_ModelProjectMatrix;
 315          }
 316          else if (mat == STATE_TEXTURE_MATRIX) {
 317             assert(index < ARRAY_SIZE(ctx->TextureMatrixStack));
 318             matrix = ctx->TextureMatrixStack[index].Top;
 319          }
 320          else if (mat == STATE_PROGRAM_MATRIX) {
 321             assert(index < ARRAY_SIZE(ctx->ProgramMatrixStack));
 322             matrix = ctx->ProgramMatrixStack[index].Top;
 323          }
 324          else {
 325             _mesa_problem(ctx, "Bad matrix name in _mesa_fetch_state()");
 326             return;
 327          }
 328          if (modifier == STATE_MATRIX_INVERSE ||
 329              modifier == STATE_MATRIX_INVTRANS) {
 330             /* Be sure inverse is up to date:
 331              */
 332             _math_matrix_analyse( (GLmatrix*) matrix );
 333             m = matrix->inv;
 334          }
 335          else {
 336             m = matrix->m;
 337          }
 338          if (modifier == STATE_MATRIX_TRANSPOSE ||
 339              modifier == STATE_MATRIX_INVTRANS) {
 340             for (i = 0, row = firstRow; row <= lastRow; row++) {
 341                value[i++] = m[row * 4 + 0];
 342                value[i++] = m[row * 4 + 1];
 343                value[i++] = m[row * 4 + 2];
 344                value[i++] = m[row * 4 + 3];
 345             }
 346          }
 347          else {
 348             for (i = 0, row = firstRow; row <= lastRow; row++) {
 349                value[i++] = m[row + 0];
 350                value[i++] = m[row + 4];
 351                value[i++] = m[row + 8];
 352                value[i++] = m[row + 12];
 353             }
 354          }
 355       }
 356       return;
 357    case STATE_NUM_SAMPLES:
 358       val[0].i = MAX2(1, _mesa_geometric_samples(ctx->DrawBuffer));
 359       return;
 360    case STATE_DEPTH_RANGE:
 361       value[0] = ctx->ViewportArray[0].Near;                /* near       */
 362       value[1] = ctx->ViewportArray[0].Far;                 /* far        */
 363       value[2] = ctx->ViewportArray[0].Far - ctx->ViewportArray[0].Near; /* far - near */
 364       value[3] = 1.0;
 365       return;
 366    case STATE_FRAGMENT_PROGRAM:
 367       {
 368          /* state[1] = {STATE_ENV, STATE_LOCAL} */
 369          /* state[2] = parameter index          */
 370          const int idx = (int) state[2];
 371          switch (state[1]) {
 372             case STATE_ENV:
 373                COPY_4V(value, ctx->FragmentProgram.Parameters[idx]);
 374                return;
 375             case STATE_LOCAL:
 376                if (!ctx->FragmentProgram.Current->arb.LocalParams) {
 377                   ctx->FragmentProgram.Current->arb.LocalParams =
 378                      rzalloc_array_size(ctx->FragmentProgram.Current,
 379                                         sizeof(float[4]),
 380                                         MAX_PROGRAM_LOCAL_PARAMS);
 381                   if (!ctx->FragmentProgram.Current->arb.LocalParams)
 382                      return;
 383                }
 384
 385                COPY_4V(value,
 386                        ctx->FragmentProgram.Current->arb.LocalParams[idx]);
 387                return;
 388             default:
 389                _mesa_problem(ctx, "Bad state switch in _mesa_fetch_state()");
 390                return;
 391          }
 392       }
 393       return;
 394
 395    case STATE_VERTEX_PROGRAM:
 396       {
 397          /* state[1] = {STATE_ENV, STATE_LOCAL} */
 398          /* state[2] = parameter index          */
 399          const int idx = (int) state[2];
 400          switch (state[1]) {
 401             case STATE_ENV:
 402                COPY_4V(value, ctx->VertexProgram.Parameters[idx]);
 403                return;
 404             case STATE_LOCAL:
 405                if (!ctx->VertexProgram.Current->arb.LocalParams) {
 406                   ctx->VertexProgram.Current->arb.LocalParams =
 407                      rzalloc_array_size(ctx->VertexProgram.Current,
 408                                         sizeof(float[4]),
 409                                         MAX_PROGRAM_LOCAL_PARAMS);
 410                   if (!ctx->VertexProgram.Current->arb.LocalParams)
 411                      return;
 412                }
 413
 414                COPY_4V(value,
 415                        ctx->VertexProgram.Current->arb.LocalParams[idx]);
 416                return;
 417             default:
 418                _mesa_problem(ctx, "Bad state switch in _mesa_fetch_state()");
 419                return;
 420          }
 421       }
 422       return;
 423
 424    case STATE_NORMAL_SCALE:
 425       ASSIGN_4V(value, ctx->_ModelViewInvScaleEyespace, 0, 0, 1);
 426       return;
 427
 428    case STATE_INTERNAL:
 429       switch (state[1]) {
 430       case STATE_CURRENT_ATTRIB:
 431          {
 432             const GLuint idx = (GLuint) state[2];
 433             COPY_4V(value, ctx->Current.Attrib[idx]);
 434          }
 435          return;
 436
 437       case STATE_CURRENT_ATTRIB_MAYBE_VP_CLAMPED:
 438          {
 439             const GLuint idx = (GLuint) state[2];
 440             if(ctx->Light._ClampVertexColor &&
 441                (idx == VERT_ATTRIB_COLOR0 ||
 442                 idx == VERT_ATTRIB_COLOR1)) {
 443                value[0] = CLAMP(ctx->Current.Attrib[idx][0], 0.0f, 1.0f);
 444                value[1] = CLAMP(ctx->Current.Attrib[idx][1], 0.0f, 1.0f);
 445                value[2] = CLAMP(ctx->Current.Attrib[idx][2], 0.0f, 1.0f);
 446                value[3] = CLAMP(ctx->Current.Attrib[idx][3], 0.0f, 1.0f);
 447             }
 448             else
 449                COPY_4V(value, ctx->Current.Attrib[idx]);
 450          }
 451          return;
 452
 453       case STATE_NORMAL_SCALE:
 454          ASSIGN_4V(value,
 455                    ctx->_ModelViewInvScale,
 456                    ctx->_ModelViewInvScale,
 457                    ctx->_ModelViewInvScale,
 458                    1);
 459          return;
 460
 461       case STATE_FOG_PARAMS_OPTIMIZED:
 462          /* for simpler per-vertex/pixel fog calcs. POW (for EXP/EXP2 fog)
 463           * might be more expensive than EX2 on some hw, plus it needs
 464           * another constant (e) anyway. Linear fog can now be done with a
 465           * single MAD.
 466           * linear: fogcoord * -1/(end-start) + end/(end-start)
 467           * exp: 2^-(density/ln(2) * fogcoord)
 468           * exp2: 2^-((density/(sqrt(ln(2))) * fogcoord)^2)
 469           */
 470          value[0] = (ctx->Fog.End == ctx->Fog.Start)
 471             ? 1.0f : (GLfloat)(-1.0F / (ctx->Fog.End - ctx->Fog.Start));
 472          value[1] = ctx->Fog.End * -value[0];
 473          value[2] = (GLfloat)(ctx->Fog.Density * M_LOG2E); /* M_LOG2E == 1/ln(2) */
 474          value[3] = (GLfloat)(ctx->Fog.Density * ONE_DIV_SQRT_LN2);
 475          return;
 476
 477       case STATE_POINT_SIZE_CLAMPED:
 478          {
 479            /* this includes implementation dependent limits, to avoid
 480             * another potentially necessary clamp.
 481             * Note: for sprites, point smooth (point AA) is ignored
 482             * and we'll clamp to MinPointSizeAA and MaxPointSize, because we
 483             * expect drivers will want to say their minimum for AA size is 0.0
 484             * but for non-AA it's 1.0 (because normal points with size below 1.0
 485             * need to get rounded up to 1.0, hence never disappear). GL does
 486             * not specify max clamp size for sprites, other than it needs to be
 487             * at least as large as max AA size, hence use non-AA size there.
 488             */
 489             GLfloat minImplSize;
 490             GLfloat maxImplSize;
 491             if (ctx->Point.PointSprite) {
 492                minImplSize = ctx->Const.MinPointSizeAA;
 493                maxImplSize = ctx->Const.MaxPointSize;
 494             }
 495             else if (ctx->Point.SmoothFlag || _mesa_is_multisample_enabled(ctx)) {
 496                minImplSize = ctx->Const.MinPointSizeAA;
 497                maxImplSize = ctx->Const.MaxPointSizeAA;
 498             }
 499             else {
 500                minImplSize = ctx->Const.MinPointSize;
 501                maxImplSize = ctx->Const.MaxPointSize;
 502             }
 503             value[0] = ctx->Point.Size;
 504             value[1] = ctx->Point.MinSize >= minImplSize ? ctx->Point.MinSize : minImplSize;
 505             value[2] = ctx->Point.MaxSize <= maxImplSize ? ctx->Point.MaxSize : maxImplSize;
 506             value[3] = ctx->Point.Threshold;
 507          }
 508          return;
 509       case STATE_LIGHT_SPOT_DIR_NORMALIZED:
 510          {
 511             /* here, state[2] is the light number */
 512             /* pre-normalize spot dir */
 513             const GLuint ln = (GLuint) state[2];
 514             COPY_3V(value, ctx->Light.Light[ln]._NormSpotDirection);
 515             value[3] = ctx->Light.Light[ln]._CosCutoff;
 516          }
 517          return;
 518
 519       case STATE_LIGHT_POSITION:
 520          {
 521             const GLuint ln = (GLuint) state[2];
 522             COPY_4V(value, ctx->Light.Light[ln]._Position);
 523          }
 524          return;
 525
 526       case STATE_LIGHT_POSITION_NORMALIZED:
 527          {
 528             const GLuint ln = (GLuint) state[2];
 529             COPY_4V(value, ctx->Light.Light[ln]._Position);
 530             NORMALIZE_3FV( value );
 531          }
 532          return;
 533
 534       case STATE_LIGHT_HALF_VECTOR:
 535          {
 536             const GLuint ln = (GLuint) state[2];
 537             GLfloat p[3];
 538             /* Compute infinite half angle vector:
 539              *   halfVector = normalize(normalize(lightPos) + (0, 0, 1))
 540              * light.EyePosition.w should be 0 for infinite lights.
 541              */
 542             COPY_3V(p, ctx->Light.Light[ln]._Position);
 543             NORMALIZE_3FV(p);
 544             ADD_3V(value, p, ctx->_EyeZDir);
 545             NORMALIZE_3FV(value);
 546             value[3] = 1.0;
 547          }
 548          return;
 549
 550       case STATE_PT_SCALE:
 551          value[0] = ctx->Pixel.RedScale;
 552          value[1] = ctx->Pixel.GreenScale;
 553          value[2] = ctx->Pixel.BlueScale;
 554          value[3] = ctx->Pixel.AlphaScale;
 555          return;
 556
 557       case STATE_PT_BIAS:
 558          value[0] = ctx->Pixel.RedBias;
 559          value[1] = ctx->Pixel.GreenBias;
 560          value[2] = ctx->Pixel.BlueBias;
 561          value[3] = ctx->Pixel.AlphaBias;
 562          return;
 563
 564       case STATE_FB_SIZE:
 565          value[0] = (GLfloat) (ctx->DrawBuffer->Width - 1);
 566          value[1] = (GLfloat) (ctx->DrawBuffer->Height - 1);
 567          value[2] = 0.0F;
 568          value[3] = 0.0F;
 569          return;
 570
 571       case STATE_FB_WPOS_Y_TRANSFORM:
 572          /* A driver may negate this conditional by using ZW swizzle
 573           * instead of XY (based on e.g. some other state). */
 574          if (!ctx->DrawBuffer->FlipY) {
 575             /* Identity (XY) followed by flipping Y upside down (ZW). */
 576             value[0] = 1.0F;
 577             value[1] = 0.0F;
 578             value[2] = -1.0F;
 579             value[3] = _mesa_geometric_height(ctx->DrawBuffer);
 580          } else {
 581             /* Flipping Y upside down (XY) followed by identity (ZW). */
 582             value[0] = -1.0F;
 583             value[1] = _mesa_geometric_height(ctx->DrawBuffer);
 584             value[2] = 1.0F;
 585             value[3] = 0.0F;
 586          }
 587          return;
 588
 589       case STATE_TCS_PATCH_VERTICES_IN:
 590          val[0].i = ctx->TessCtrlProgram.patch_vertices;
 591          return;
 592
 593       case STATE_TES_PATCH_VERTICES_IN:
 594          if (ctx->TessCtrlProgram._Current)
 595             val[0].i = ctx->TessCtrlProgram._Current->info.tess.tcs_vertices_out;
 596          else
 597             val[0].i = ctx->TessCtrlProgram.patch_vertices;
 598          return;
 599
 600       case STATE_ADVANCED_BLENDING_MODE:
 601          val[0].i = _mesa_get_advanced_blend_sh_constant(
 602                       ctx->Color.BlendEnabled, ctx->Color._AdvancedBlendMode);
 603          return;
 604
 605       case STATE_ALPHA_REF:
 606          value[0] = ctx->Color.AlphaRefUnclamped;
 607          return;
 608
 609       /* XXX: make sure new tokens added here are also handled in the
 610        * _mesa_program_state_flags() switch, below.
 611        */
 612       default:
 613          /* Unknown state indexes are silently ignored here.
 614           * Drivers may do something special.
 615           */
 616          return;
 617       }
 618       return;
 619
 620    default:
 621       _mesa_problem(ctx, "Invalid state in _mesa_fetch_state");
 622       return;
 623    }
 624 }
 625
 626
 627 /**
 628  * Return a bitmask of the Mesa state flags (_NEW_* values) which would
 629  * indicate that the given context state may have changed.
 630  * The bitmask is used during validation to determine if we need to update
 631  * vertex/fragment program parameters (like "state.material.color") when
 632  * some GL state has changed.
 633  */
 634 GLbitfield
 635 _mesa_program_state_flags(const gl_state_index16 state[STATE_LENGTH])
 636 {
 637    switch (state[0]) {
 638    case STATE_MATERIAL:
 639    case STATE_LIGHTPROD:
 640    case STATE_LIGHTMODEL_SCENECOLOR:
 641       /* these can be effected by glColor when colormaterial mode is used */
 642       return _NEW_LIGHT | _NEW_CURRENT_ATTRIB;
 643
 644    case STATE_LIGHT:
 645    case STATE_LIGHTMODEL_AMBIENT:
 646       return _NEW_LIGHT;
 647
 648    case STATE_TEXGEN:
 649       return _NEW_TEXTURE_STATE;
 650    case STATE_TEXENV_COLOR:
 651       return _NEW_TEXTURE_STATE | _NEW_BUFFERS | _NEW_FRAG_CLAMP;
 652
 653    case STATE_FOG_COLOR:
 654       return _NEW_FOG | _NEW_BUFFERS | _NEW_FRAG_CLAMP;
 655    case STATE_FOG_PARAMS:
 656       return _NEW_FOG;
 657
 658    case STATE_CLIPPLANE:
 659       return _NEW_TRANSFORM;
 660
 661    case STATE_POINT_SIZE:
 662    case STATE_POINT_ATTENUATION:
 663       return _NEW_POINT;
 664
 665    case STATE_MODELVIEW_MATRIX:
 666       return _NEW_MODELVIEW;
 667    case STATE_PROJECTION_MATRIX:
 668       return _NEW_PROJECTION;
 669    case STATE_MVP_MATRIX:
 670       return _NEW_MODELVIEW | _NEW_PROJECTION;
 671    case STATE_TEXTURE_MATRIX:
 672       return _NEW_TEXTURE_MATRIX;
 673    case STATE_PROGRAM_MATRIX:
 674       return _NEW_TRACK_MATRIX;
 675
 676    case STATE_NUM_SAMPLES:
 677       return _NEW_BUFFERS;
 678
 679    case STATE_DEPTH_RANGE:
 680       return _NEW_VIEWPORT;
 681
 682    case STATE_FRAGMENT_PROGRAM:
 683    case STATE_VERTEX_PROGRAM:
 684       return _NEW_PROGRAM;
 685
 686    case STATE_NORMAL_SCALE:
 687       return _NEW_MODELVIEW;
 688
 689    case STATE_INTERNAL:
 690       switch (state[1]) {
 691       case STATE_CURRENT_ATTRIB:
 692          return _NEW_CURRENT_ATTRIB;
 693       case STATE_CURRENT_ATTRIB_MAYBE_VP_CLAMPED:
 694          return _NEW_CURRENT_ATTRIB | _NEW_LIGHT | _NEW_BUFFERS;
 695
 696       case STATE_NORMAL_SCALE:
 697          return _NEW_MODELVIEW;
 698
 699       case STATE_FOG_PARAMS_OPTIMIZED:
 700          return _NEW_FOG;
 701       case STATE_POINT_SIZE_CLAMPED:
 702          return _NEW_POINT | _NEW_MULTISAMPLE;
 703       case STATE_LIGHT_SPOT_DIR_NORMALIZED:
 704       case STATE_LIGHT_POSITION:
 705       case STATE_LIGHT_POSITION_NORMALIZED:
 706       case STATE_LIGHT_HALF_VECTOR:
 707          return _NEW_LIGHT;
 708
 709       case STATE_PT_SCALE:
 710       case STATE_PT_BIAS:
 711          return _NEW_PIXEL;
 712
 713       case STATE_FB_SIZE:
 714       case STATE_FB_WPOS_Y_TRANSFORM:
 715          return _NEW_BUFFERS;
 716
 717       case STATE_ADVANCED_BLENDING_MODE:
 718          return _NEW_COLOR;
 719
 720       case STATE_ALPHA_REF:
 721          return _NEW_COLOR;
 722
 723       default:
 724          /* unknown state indexes are silently ignored and
 725          *  no flag set, since it is handled by the driver.
 726          */
 727          return 0;
 728       }
 729
 730    default:
 731       _mesa_problem(NULL, "unexpected state[0] in make_state_flags()");
 732       return 0;
 733    }
 734 }
 735
 736
 737 static void
 738 append(char *dst, const char *src)
 739 {
 740    while (*dst)
 741       dst++;
 742    while (*src)
 743      *dst++ = *src++;
 744    *dst = 0;
 745 }
 746
 747
 748 /**
 749  * Convert token 'k' to a string, append it onto 'dst' string.
 750  */
 751 static void
 752 append_token(char *dst, gl_state_index k)
 753 {
 754    switch (k) {
 755    case STATE_MATERIAL:
 756       append(dst, "material");
 757       break;
 758    case STATE_LIGHT:
 759       append(dst, "light");
 760       break;
 761    case STATE_LIGHTMODEL_AMBIENT:
 762       append(dst, "lightmodel.ambient");
 763       break;
 764    case STATE_LIGHTMODEL_SCENECOLOR:
 765       break;
 766    case STATE_LIGHTPROD:
 767       append(dst, "lightprod");
 768       break;
 769    case STATE_TEXGEN:
 770       append(dst, "texgen");
 771       break;
 772    case STATE_FOG_COLOR:
 773       append(dst, "fog.color");
 774       break;
 775    case STATE_FOG_PARAMS:
 776       append(dst, "fog.params");
 777       break;
 778    case STATE_CLIPPLANE:
 779       append(dst, "clip");
 780       break;
 781    case STATE_POINT_SIZE:
 782       append(dst, "point.size");
 783       break;
 784    case STATE_POINT_ATTENUATION:
 785       append(dst, "point.attenuation");
 786       break;
 787    case STATE_MODELVIEW_MATRIX:
 788       append(dst, "matrix.modelview");
 789       break;
 790    case STATE_PROJECTION_MATRIX:
 791       append(dst, "matrix.projection");
 792       break;
 793    case STATE_MVP_MATRIX:
 794       append(dst, "matrix.mvp");
 795       break;
 796    case STATE_TEXTURE_MATRIX:
 797       append(dst, "matrix.texture");
 798       break;
 799    case STATE_PROGRAM_MATRIX:
 800       append(dst, "matrix.program");
 801       break;
 802    case STATE_MATRIX_INVERSE:
 803       append(dst, ".inverse");
 804       break;
 805    case STATE_MATRIX_TRANSPOSE:
 806       append(dst, ".transpose");
 807       break;
 808    case STATE_MATRIX_INVTRANS:
 809       append(dst, ".invtrans");
 810       break;
 811    case STATE_AMBIENT:
 812       append(dst, ".ambient");
 813       break;
 814    case STATE_DIFFUSE:
 815       append(dst, ".diffuse");
 816       break;
 817    case STATE_SPECULAR:
 818       append(dst, ".specular");
 819       break;
 820    case STATE_EMISSION:
 821       append(dst, ".emission");
 822       break;
 823    case STATE_SHININESS:
 824       append(dst, "lshininess");
 825       break;
 826    case STATE_HALF_VECTOR:
 827       append(dst, ".half");
 828       break;
 829    case STATE_POSITION:
 830       append(dst, ".position");
 831       break;
 832    case STATE_ATTENUATION:
 833       append(dst, ".attenuation");
 834       break;
 835    case STATE_SPOT_DIRECTION:
 836       append(dst, ".spot.direction");
 837       break;
 838    case STATE_SPOT_CUTOFF:
 839       append(dst, ".spot.cutoff");
 840       break;
 841    case STATE_TEXGEN_EYE_S:
 842       append(dst, ".eye.s");
 843       break;
 844    case STATE_TEXGEN_EYE_T:
 845       append(dst, ".eye.t");
 846       break;
 847    case STATE_TEXGEN_EYE_R:
 848       append(dst, ".eye.r");
 849       break;
 850    case STATE_TEXGEN_EYE_Q:
 851       append(dst, ".eye.q");
 852       break;
 853    case STATE_TEXGEN_OBJECT_S:
 854       append(dst, ".object.s");
 855       break;
 856    case STATE_TEXGEN_OBJECT_T:
 857       append(dst, ".object.t");
 858       break;
 859    case STATE_TEXGEN_OBJECT_R:
 860       append(dst, ".object.r");
 861       break;
 862    case STATE_TEXGEN_OBJECT_Q:
 863       append(dst, ".object.q");
 864       break;
 865    case STATE_TEXENV_COLOR:
 866       append(dst, "texenv");
 867       break;
 868    case STATE_NUM_SAMPLES:
 869       append(dst, "numsamples");
 870       break;
 871    case STATE_DEPTH_RANGE:
 872       append(dst, "depth.range");
 873       break;
 874    case STATE_VERTEX_PROGRAM:
 875    case STATE_FRAGMENT_PROGRAM:
 876       break;
 877    case STATE_ENV:
 878       append(dst, "env");
 879       break;
 880    case STATE_LOCAL:
 881       append(dst, "local");
 882       break;
 883    /* BEGIN internal state vars */
 884    case STATE_INTERNAL:
 885       append(dst, ".internal.");
 886       break;
 887    case STATE_CURRENT_ATTRIB:
 888       append(dst, "current");
 889       break;
 890    case STATE_CURRENT_ATTRIB_MAYBE_VP_CLAMPED:
 891       append(dst, "currentAttribMaybeVPClamped");
 892       break;
 893    case STATE_NORMAL_SCALE:
 894       append(dst, "normalScale");
 895       break;
 896    case STATE_FOG_PARAMS_OPTIMIZED:
 897       append(dst, "fogParamsOptimized");
 898       break;
 899    case STATE_POINT_SIZE_CLAMPED:
 900       append(dst, "pointSizeClamped");
 901       break;
 902    case STATE_LIGHT_SPOT_DIR_NORMALIZED:
 903       append(dst, "lightSpotDirNormalized");
 904       break;
 905    case STATE_LIGHT_POSITION:
 906       append(dst, "lightPosition");
 907       break;
 908    case STATE_LIGHT_POSITION_NORMALIZED:
 909       append(dst, "light.position.normalized");
 910       break;
 911    case STATE_LIGHT_HALF_VECTOR:
 912       append(dst, "lightHalfVector");
 913       break;
 914    case STATE_PT_SCALE:
 915       append(dst, "PTscale");
 916       break;
 917    case STATE_PT_BIAS:
 918       append(dst, "PTbias");
 919       break;
 920    case STATE_FB_SIZE:
 921       append(dst, "FbSize");
 922       break;
 923    case STATE_FB_WPOS_Y_TRANSFORM:
 924       append(dst, "FbWposYTransform");
 925       break;
 926    case STATE_ADVANCED_BLENDING_MODE:
 927       append(dst, "AdvancedBlendingMode");
 928       break;
 929    case STATE_ALPHA_REF:
 930       append(dst, "alphaRef");
 931       break;
 932    default:
 933       /* probably STATE_INTERNAL_DRIVER+i (driver private state) */
 934       append(dst, "driverState");
 935    }
 936 }
 937
 938 static void
 939 append_face(char *dst, GLint face)
 940 {
 941    if (face == 0)
 942       append(dst, "front.");
 943    else
 944       append(dst, "back.");
 945 }
 946
 947 static void
 948 append_index(char *dst, GLint index)
 949 {
 950    char s[20];
 951    sprintf(s, "[%d]", index);
 952    append(dst, s);
 953 }
 954
 955 /**
 956  * Make a string from the given state vector.
 957  * For example, return "state.matrix.texture[2].inverse".
 958  * Use free() to deallocate the string.
 959  */
 960 char *
 961 _mesa_program_state_string(const gl_state_index16 state[STATE_LENGTH])
 962 {
 963    char str[1000] = "";
 964    char tmp[30];
 965
 966    append(str, "state.");
 967    append_token(str, state[0]);
 968
 969    switch (state[0]) {
 970    case STATE_MATERIAL:
 971       append_face(str, state[1]);
 972       append_token(str, state[2]);
 973       break;
 974    case STATE_LIGHT:
 975       append_index(str, state[1]); /* light number [i]. */
 976       append_token(str, state[2]); /* coefficients */
 977       break;
 978    case STATE_LIGHTMODEL_AMBIENT:
 979       append(str, "lightmodel.ambient");
 980       break;
 981    case STATE_LIGHTMODEL_SCENECOLOR:
 982       if (state[1] == 0) {
 983          append(str, "lightmodel.front.scenecolor");
 984       }
 985       else {
 986          append(str, "lightmodel.back.scenecolor");
 987       }
 988       break;
 989    case STATE_LIGHTPROD:
 990       append_index(str, state[1]); /* light number [i]. */
 991       append_face(str, state[2]);
 992       append_token(str, state[3]);
 993       break;
 994    case STATE_TEXGEN:
 995       append_index(str, state[1]); /* tex unit [i] */
 996       append_token(str, state[2]); /* plane coef */
 997       break;
 998    case STATE_TEXENV_COLOR:
 999       append_index(str, state[1]); /* tex unit [i] */
1000       append(str, "color");
1001       break;
1002    case STATE_CLIPPLANE:
1003       append_index(str, state[1]); /* plane [i] */
1004       append(str, ".plane");
1005       break;
1006    case STATE_MODELVIEW_MATRIX:
1007    case STATE_PROJECTION_MATRIX:
1008    case STATE_MVP_MATRIX:
1009    case STATE_TEXTURE_MATRIX:
1010    case STATE_PROGRAM_MATRIX:
1011       {
1012          /* state[0] = modelview, projection, texture, etc. */
1013          /* state[1] = which texture matrix or program matrix */
1014          /* state[2] = first row to fetch */
1015          /* state[3] = last row to fetch */
1016          /* state[4] = transpose, inverse or invtrans */
1017          const gl_state_index mat = state[0];
1018          const GLuint index = (GLuint) state[1];
1019          const GLuint firstRow = (GLuint) state[2];
1020          const GLuint lastRow = (GLuint) state[3];
1021          const gl_state_index modifier = state[4];
1022          if (index ||
1023              mat == STATE_TEXTURE_MATRIX ||
1024              mat == STATE_PROGRAM_MATRIX)
1025             append_index(str, index);
1026          if (modifier)
1027             append_token(str, modifier);
1028          if (firstRow == lastRow)
1029             sprintf(tmp, ".row[%d]", firstRow);
1030          else
1031             sprintf(tmp, ".row[%d..%d]", firstRow, lastRow);
1032          append(str, tmp);
1033       }
1034       break;
1035    case STATE_POINT_SIZE:
1036       break;
1037    case STATE_POINT_ATTENUATION:
1038       break;
1039    case STATE_FOG_PARAMS:
1040       break;
1041    case STATE_FOG_COLOR:
1042       break;
1043    case STATE_NUM_SAMPLES:
1044       break;
1045    case STATE_DEPTH_RANGE:
1046       break;
1047    case STATE_FRAGMENT_PROGRAM:
1048    case STATE_VERTEX_PROGRAM:
1049       /* state[1] = {STATE_ENV, STATE_LOCAL} */
1050       /* state[2] = parameter index          */
1051       append_token(str, state[1]);
1052       append_index(str, state[2]);
1053       break;
1054    case STATE_NORMAL_SCALE:
1055       break;
1056    case STATE_INTERNAL:
1057       append_token(str, state[1]);
1058       if (state[1] == STATE_CURRENT_ATTRIB)
1059          append_index(str, state[2]);
1060        break;
1061    default:
1062       _mesa_problem(NULL, "Invalid state in _mesa_program_state_string");
1063       break;
1064    }
1065
1066    return strdup(str);
1067 }
1068
1069
1070 /**
1071  * Loop over all the parameters in a parameter list.  If the parameter
1072  * is a GL state reference, look up the current value of that state
1073  * variable and put it into the parameter's Value[4] array.
1074  * Other parameter types never change or are explicitly set by the user
1075  * with glUniform() or glProgramParameter(), etc.
1076  * This would be called at glBegin time.
1077  */
1078 void
1079 _mesa_load_state_parameters(struct gl_context *ctx,
1080                             struct gl_program_parameter_list *paramList)
1081 {
1082    GLuint i;
1083
1084    if (!paramList)
1085       return;
1086
1087    for (i = 0; i < paramList->NumParameters; i++) {
1088       if (paramList->Parameters[i].Type == PROGRAM_STATE_VAR) {
1089          unsigned pvo = paramList->ParameterValueOffset[i];
1090          _mesa_fetch_state(ctx,
1091                            paramList->Parameters[i].StateIndexes,
1092                            paramList->ParameterValues + pvo);
1093       }
1094    }
1095 }