source/mupen64plus-video-arachnoid/src/Combiner/AdvancedTexEnvCombiner.cpp

   1 /******************************************************************************
   2  * Arachnoid Graphics Plugin for Mupen64Plus
   3  * http://bitbucket.org/wahrhaft/mupen64plus-video-arachnoid/
   4  *
   5  * Copyright (C) 2007 Kristofer Karlsson, Rickard Niklasson
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License
   9  * as published by the Free Software Foundation; either version 2
  10  * of the License, or (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  20  *****************************************************************************/
  21
  22 #include <algorithm>
  23 using std::max;
  24 #include "AdvancedTexEnvCombiner.h"
  25 #include "CombinerStructs.h"
  26 #include "MultiTexturingExt.h"    //glActiveTextureARB
  27 #include "ExtensionChecker.h"
  28
  29 #ifndef GL_ATI_texture_env_combine3
  30 #define GL_ATI_texture_env_combine3
  31     #define GL_ATI_texture_env_combine3
  32     #define GL_MODULATE_ADD_ATI                             0x8744
  33     #define GL_MODULATE_SIGNED_ADD_ATI                      0x8745
  34     #define GL_MODULATE_SUBTRACT_ATI                        0x8746
  35 #endif //GL_ATI_texture_env_combine3
  36
  37 #ifndef GL_ATIX_texture_env_route
  38 #define GL_ATIX_texture_env_route 1
  39     #define GL_SECONDARY_COLOR_ATIX                 0x8747
  40     #define GL_TEXTURE_OUTPUT_RGB_ATIX              0x8748
  41     #define GL_TEXTURE_OUTPUT_ALPHA_ATIX            0x8749
  42 #endif // GL_ATIX_texture_env_route
  43
  44 static TexEnvCombinerArg TexEnvArgs[] =
  45 {
  46     // CMB
  47     { GL_PREVIOUS_ARB,       GL_SRC_COLOR },
  48     // T0
  49     { GL_TEXTURE,            GL_SRC_COLOR },
  50     // T1
  51     { GL_TEXTURE,            GL_SRC_COLOR },
  52     // PRIM
  53     { GL_CONSTANT_ARB,       GL_SRC_COLOR },
  54     // SHADE
  55     { GL_PRIMARY_COLOR_ARB,  GL_SRC_COLOR },
  56     // ENV
  57     { GL_CONSTANT_ARB,       GL_SRC_COLOR },
  58     // CENTER
  59     { GL_CONSTANT_ARB,       GL_SRC_COLOR },
  60     // SCALE
  61     { GL_CONSTANT_ARB,       GL_SRC_COLOR },
  62     // CMBALPHA
  63     { GL_PREVIOUS_ARB,       GL_SRC_ALPHA },
  64     // T0ALPHA
  65     { GL_TEXTURE,            GL_SRC_ALPHA },
  66     // T1ALPHA
  67     { GL_TEXTURE,            GL_SRC_ALPHA },
  68     // PRIMALPHA
  69     { GL_CONSTANT_ARB,       GL_SRC_ALPHA },
  70     // SHADEALPHA
  71     { GL_PRIMARY_COLOR_ARB,  GL_SRC_ALPHA },
  72     // ENVALPHA
  73     { GL_CONSTANT_ARB,       GL_SRC_COLOR },
  74     // LODFRAC
  75     { GL_CONSTANT_ARB,       GL_SRC_COLOR },
  76     // PRIMLODFRAC
  77     { GL_CONSTANT_ARB,       GL_SRC_COLOR },
  78     // NOISE
  79     { GL_TEXTURE,            GL_SRC_COLOR },
  80     // K4
  81     { GL_CONSTANT_ARB,       GL_SRC_COLOR },
  82     // K5
  83     { GL_CONSTANT_ARB,       GL_SRC_COLOR },
  84     // ONE
  85     { GL_CONSTANT_ARB,       GL_SRC_COLOR },
  86     // ZERO
  87     { GL_CONSTANT_ARB,       GL_SRC_COLOR }
  88 };
  89
  90 //-----------------------------------------------------------------------------
  91 //! Constructor
  92 //-----------------------------------------------------------------------------
  93 AdvancedTexEnvCombiner::AdvancedTexEnvCombiner()
  94 {
  95 }
  96
  97 //-----------------------------------------------------------------------------
  98 //! Destructor
  99 //-----------------------------------------------------------------------------
 100 AdvancedTexEnvCombiner::~AdvancedTexEnvCombiner()
 101 {
 102 }
 103
 104 //-----------------------------------------------------------------------------
 105 //* Initialize
 106 //! Checks if extensions are supported
 107 //-----------------------------------------------------------------------------
 108 void AdvancedTexEnvCombiner::initialize()
 109 {
 110 #ifdef HAVE_GLES
 111     ARB_texture_env_combine  = true;
 112     ARB_texture_env_crossbar = true;
 113 #else
 114     ARB_texture_env_combine  = isExtensionSupported( "GL_ARB_texture_env_combine" );
 115     ARB_texture_env_crossbar = isExtensionSupported( "GL_ARB_texture_env_crossbar" );
 116 #endif
 117     ATI_texture_env_combine3 = isExtensionSupported( "GL_ATI_texture_env_combine3" );
 118     ATIX_texture_env_route   = isExtensionSupported( "GL_ATIX_texture_env_route" );
 119     NV_texture_env_combine4  = isExtensionSupported( "GL_NV_texture_env_combine4" );;
 120
 121     if ( ARB_texture_env_crossbar || NV_texture_env_combine4 || ATIX_texture_env_route )
 122     {
 123         TexEnvArgs[TEXEL0].source       = GL_TEXTURE0_ARB;
 124         TexEnvArgs[TEXEL0_ALPHA].source = GL_TEXTURE0_ARB;
 125         TexEnvArgs[TEXEL1].source       = GL_TEXTURE1_ARB;
 126         TexEnvArgs[TEXEL1_ALPHA].source = GL_TEXTURE1_ARB;
 127     }
 128
 129     if ( ATI_texture_env_combine3 )
 130     {
 131         TexEnvArgs[ONE].source  = GL_ONE;
 132         TexEnvArgs[ZERO].source = GL_ZERO;
 133     }
 134 }
 135
 136 //-----------------------------------------------------------------------------
 137 //* Begin Texture Update
 138 //! Disables all textures
 139 //-----------------------------------------------------------------------------
 140 void AdvancedTexEnvCombiner::beginTextureUpdate()
 141 {
 142     const int openGLMaxTextureUnits = 8;
 143
 144     //Disable all texture channels
 145     for (int i = 0; i <openGLMaxTextureUnits; i++)
 146     {
 147         glActiveTextureARB(GL_TEXTURE0_ARB + i);
 148         glDisable(GL_TEXTURE_2D );
 149     }
 150 }
 151
 152
 153 //-----------------------------------------------------------------------------
 154 //* End Texture Update
 155 //! Enables selected textures in a texture environment
 156 //! @param texEnv Texture environment with textures to be enabled
 157 //-----------------------------------------------------------------------------
 158 void AdvancedTexEnvCombiner::endTextureUpdate(TexEnvCombiner* texEnv)
 159 {
 160     //Enable texturing
 161     for (int i = 0; i <texEnv->usedUnits; i++)
 162     {
 163         glActiveTextureARB( GL_TEXTURE0_ARB + i );
 164         glEnable( GL_TEXTURE_2D );
 165     }
 166 }
 167
 168 //-----------------------------------------------------------------------------
 169 //* Set Texture Enviroment Colors
 170 //! Sets texture enviorment colors for all active textures
 171 //! @param texEnv Texture environment with textures that will be assigned colors
 172 //-----------------------------------------------------------------------------
 173 void AdvancedTexEnvCombiner::setTextureEnviromentColors(TexEnvCombiner* texEnv)
 174 {
 175     float color[4];
 176
 177     int openGLMaxTextureUnits = 8;
 178
 179     for (int i = 0; i < openGLMaxTextureUnits; i++)
 180     {
 181         this->getCombinerColor( color, texEnv->color[i].constant, texEnv->alpha[i].constant );
 182
 183         glActiveTextureARB(GL_TEXTURE0_ARB + i);
 184         glTexEnvfv(GL_TEXTURE_ENV, GL_TEXTURE_ENV_COLOR, &color[0]);
 185     }
 186 }
 187
 188 //-----------------------------------------------------------------------------
 189 //* Set Texture Enviroment
 190 //! Sets texture environment for all active textures
 191 //! @param texEnv Texture environment with input data which will be
 192 //!               sent to OpenGL using function "glTexEnvi" using ARB extensions
 193 //-----------------------------------------------------------------------------
 194 void AdvancedTexEnvCombiner::setTextureEnviroment(TexEnvCombiner* texEnv)
 195 {
 196     const int openGLMaxTextureUnits = 8;
 197
 198     for (int i=0; i<openGLMaxTextureUnits; ++i)
 199     {
 200         glActiveTextureARB(GL_TEXTURE0_ARB + i);
 201
 202         if ( (i < texEnv->usedUnits ) || (i < 2 && texEnv->usesT1) )
 203         {
 204             glEnable( GL_TEXTURE_2D );
 205             glTexEnvi( GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE,   GL_COMBINE_ARB );
 206             glTexEnvi( GL_TEXTURE_ENV, GL_COMBINE_RGB_ARB,    texEnv->color[i].combine );
 207             glTexEnvi( GL_TEXTURE_ENV, GL_SOURCE0_RGB_ARB,    texEnv->color[i].arg0.source );
 208             glTexEnvi( GL_TEXTURE_ENV, GL_OPERAND0_RGB_ARB,   texEnv->color[i].arg0.operand );
 209             glTexEnvi( GL_TEXTURE_ENV, GL_SOURCE1_RGB_ARB,    texEnv->color[i].arg1.source );
 210             glTexEnvi( GL_TEXTURE_ENV, GL_OPERAND1_RGB_ARB,   texEnv->color[i].arg1.operand );
 211             glTexEnvi( GL_TEXTURE_ENV, GL_SOURCE2_RGB_ARB,    texEnv->color[i].arg2.source );
 212             glTexEnvi( GL_TEXTURE_ENV, GL_OPERAND2_RGB_ARB,   texEnv->color[i].arg2.operand );
 213             glTexEnvi( GL_TEXTURE_ENV, GL_COMBINE_ALPHA_ARB,  texEnv->alpha[i].combine );
 214             glTexEnvi( GL_TEXTURE_ENV, GL_SOURCE0_ALPHA_ARB,  texEnv->alpha[i].arg0.source );
 215             glTexEnvi( GL_TEXTURE_ENV, GL_OPERAND0_ALPHA_ARB, texEnv->alpha[i].arg0.operand );
 216             glTexEnvi( GL_TEXTURE_ENV, GL_SOURCE1_ALPHA_ARB,  texEnv->alpha[i].arg1.source );
 217             glTexEnvi( GL_TEXTURE_ENV, GL_OPERAND1_ALPHA_ARB, texEnv->alpha[i].arg1.operand );
 218             glTexEnvi( GL_TEXTURE_ENV, GL_SOURCE2_ALPHA_ARB,  texEnv->alpha[i].arg2.source );
 219             glTexEnvi( GL_TEXTURE_ENV, GL_OPERAND2_ALPHA_ARB, texEnv->alpha[i].arg2.operand );
 220         }
 221         else
 222         {
 223             glDisable(GL_TEXTURE_2D);
 224         }
 225     }
 226 }
 227
 228 //-----------------------------------------------------------------------------
 229 //* Create New Texture Enviornment
 230 //! Allocates a new texture enviroment
 231 //! @param[in] colorCombiner How to combine and get a color
 232 //! @param[in] alphaCombiner How to combine and get an alpha value
 233 //! @return The texture enviroment that was created
 234 //-----------------------------------------------------------------------------
 235 TexEnvCombiner* AdvancedTexEnvCombiner::createNewTextureEnviroment(Combiner* colorCombiner, Combiner *alphaCombiner)
 236 {
 237     TexEnvCombiner* envCombiner = new TexEnvCombiner();
 238
 239     int curUnit;
 240
 241     const int openGLMaxTextureUnits = 8;
 242
 243     //For each texture unit
 244     for (int i = 0; i < openGLMaxTextureUnits; i++)
 245     {
 246         envCombiner->color[i].combine = GL_REPLACE;
 247         envCombiner->alpha[i].combine = GL_REPLACE;
 248
 249         SetColorCombinerValues( i, arg0, GL_PREVIOUS_ARB, GL_SRC_COLOR );
 250         SetColorCombinerValues( i, arg1, GL_PREVIOUS_ARB, GL_SRC_COLOR );
 251         SetColorCombinerValues( i, arg2, GL_PREVIOUS_ARB, GL_SRC_COLOR );
 252         envCombiner->color[i].constant = COMBINED;
 253         envCombiner->color[i].outputTexture = GL_TEXTURE0_ARB + i;
 254
 255         SetAlphaCombinerValues( i, arg0, GL_PREVIOUS_ARB, GL_SRC_ALPHA );
 256         SetAlphaCombinerValues( i, arg1, GL_PREVIOUS_ARB, GL_SRC_ALPHA );
 257         SetAlphaCombinerValues( i, arg2, GL_PREVIOUS_ARB, GL_SRC_ALPHA );
 258         envCombiner->alpha[i].constant = COMBINED;
 259         envCombiner->alpha[i].outputTexture = GL_TEXTURE0_ARB + i;
 260     }
 261
 262     envCombiner->usesT0 = false;
 263     envCombiner->usesT1 = false;
 264
 265     envCombiner->vertex.color = COMBINED;
 266     envCombiner->vertex.secondaryColor = COMBINED;
 267     envCombiner->vertex.alpha = COMBINED;
 268
 269     curUnit = 0;
 270
 271     for (int i=0; i<alphaCombiner->numStages; i++)
 272     {
 273         for (int j = 0; j < alphaCombiner->stage[i].numOps; j++)
 274         {
 275             float sb = 0.0f;
 276
 277             if (alphaCombiner->stage[i].op[j].param1 == PRIMITIVE_ALPHA)
 278                 sb = m_primColor[3];
 279             else if (alphaCombiner->stage[i].op[j].param1 == ENV_ALPHA)
 280                 sb = m_envColor[3];
 281             else if (alphaCombiner->stage[i].op[j].param1 == ONE)
 282                 sb = 1.0f;
 283
 284             if (((alphaCombiner->stage[i].numOps - j) >= 3) &&
 285                 (alphaCombiner->stage[i].op[j].op == SUB) &&
 286                 (alphaCombiner->stage[i].op[j+1].op == MUL) &&
 287                 (alphaCombiner->stage[i].op[j+2].op == ADD) &&
 288                 (sb > 0.5f) &&
 289                 (ARB_texture_env_combine))
 290             {
 291                 envCombiner->usesT0 |= alphaCombiner->stage[i].op[j].param1 == TEXEL0_ALPHA;
 292                 envCombiner->usesT1 |= alphaCombiner->stage[i].op[j].param1 == TEXEL1_ALPHA;
 293
 294                 if (alphaCombiner->stage[i].op[j].param1 == ONE)
 295                 {
 296                     SetAlphaCombinerValues( curUnit, arg0, envCombiner->alpha[curUnit].arg0.source, GL_ONE_MINUS_SRC_ALPHA );
 297                 }
 298                 else
 299                 {
 300                     envCombiner->alpha[curUnit].combine = GL_SUBTRACT_ARB;
 301                     SetAlphaCombinerValues( curUnit, arg1, envCombiner->alpha[curUnit].arg0.source, GL_SRC_ALPHA );
 302                     SetAlphaCombinerArg( curUnit, arg0, alphaCombiner->stage[i].op[j].param1 );
 303
 304                     curUnit++;
 305                 }
 306
 307                 j++;
 308
 309                 envCombiner->usesT0 |= alphaCombiner->stage[i].op[j].param1 == TEXEL0_ALPHA;
 310                 envCombiner->usesT1 |= alphaCombiner->stage[i].op[j].param1 == TEXEL1_ALPHA;
 311
 312                 envCombiner->alpha[curUnit].combine = GL_MODULATE;
 313                 SetAlphaCombinerArg( curUnit, arg1, alphaCombiner->stage[i].op[j].param1 );
 314
 315                 curUnit++;
 316                 j++;
 317
 318                 envCombiner->usesT0 |= alphaCombiner->stage[i].op[j].param1 == TEXEL0_ALPHA;
 319                 envCombiner->usesT1 |= alphaCombiner->stage[i].op[j].param1 == TEXEL1_ALPHA;
 320
 321                 envCombiner->alpha[curUnit].combine = GL_SUBTRACT_ARB;
 322                 SetAlphaCombinerArg( curUnit, arg0, alphaCombiner->stage[i].op[j].param1 );
 323
 324                 curUnit++;
 325             }
 326             else
 327             {
 328                 envCombiner->usesT0 |= alphaCombiner->stage[i].op[j].param1 == TEXEL0_ALPHA;
 329                 envCombiner->usesT1 |= alphaCombiner->stage[i].op[j].param1 == TEXEL1_ALPHA;
 330
 331                 switch (alphaCombiner->stage[i].op[j].op)
 332                 {
 333                     case LOAD:
 334                         if (!(ARB_texture_env_crossbar || NV_texture_env_combine4) &&
 335                             (alphaCombiner->stage[i].op[j].param1 == TEXEL1_ALPHA) && (curUnit == 0))
 336                             curUnit++;
 337
 338                         envCombiner->alpha[curUnit].combine = GL_REPLACE;
 339
 340                         SetAlphaCombinerArg( curUnit, arg0, alphaCombiner->stage[i].op[j].param1 );
 341                         break;
 342                     case SUB:
 343                         if (!ARB_texture_env_combine)
 344                             break;
 345
 346                         if (!(ARB_texture_env_crossbar || NV_texture_env_combine4) &&
 347                             (alphaCombiner->stage[i].op[j].param1 == TEXEL1_ALPHA) && (curUnit == 0))
 348                             curUnit++;
 349
 350                         if ((j > 0) && (alphaCombiner->stage[i].op[j-1].op == LOAD) && (alphaCombiner->stage[i].op[j-1].param1 == ONE))
 351                         {
 352                             SetAlphaCombinerArg( curUnit, arg0, alphaCombiner->stage[i].op[j].param1 );
 353                             envCombiner->alpha[curUnit].arg0.operand = GL_ONE_MINUS_SRC_ALPHA;
 354                         }
 355                         else if ((ATI_texture_env_combine3) && (curUnit > 0) && (envCombiner->alpha[curUnit - 1].combine == GL_MODULATE))
 356                         {
 357                             curUnit--;
 358                             SetAlphaCombinerValues( curUnit, arg2, envCombiner->alpha[curUnit].arg1.source, envCombiner->alpha[curUnit].arg1.operand );
 359                             envCombiner->alpha[curUnit].combine = GL_MODULATE_SUBTRACT_ATI;
 360                             SetAlphaCombinerArg( curUnit, arg1, alphaCombiner->stage[i].op[j].param1 );
 361                             curUnit++;
 362                         }
 363                         else
 364                         {
 365                             envCombiner->alpha[curUnit].combine = GL_SUBTRACT_ARB;
 366                             SetAlphaCombinerArg( curUnit, arg1, alphaCombiner->stage[i].op[j].param1 );
 367                             curUnit++;
 368                         }
 369                         break;
 370                     case MUL:
 371                         if (!( ARB_texture_env_crossbar ||  NV_texture_env_combine4) &&
 372                             (alphaCombiner->stage[i].op[j].param1 == TEXEL1_ALPHA) && (curUnit == 0))
 373                             curUnit++;
 374
 375                         envCombiner->alpha[curUnit].combine = GL_MODULATE;
 376
 377                         SetAlphaCombinerArg( curUnit, arg1, alphaCombiner->stage[i].op[j].param1 );
 378                         curUnit++;
 379                         break;
 380                     case ADD:
 381                         if (!(ARB_texture_env_crossbar || NV_texture_env_combine4) &&
 382                             (alphaCombiner->stage[i].op[j].param1 == TEXEL1_ALPHA) && (curUnit == 0))
 383                             curUnit++;
 384
 385                         if ((ATI_texture_env_combine3) && (curUnit > 0) && (envCombiner->alpha[curUnit - 1].combine == GL_MODULATE))
 386                         {
 387                             curUnit--;
 388                             SetAlphaCombinerValues( curUnit, arg2, envCombiner->alpha[curUnit].arg1.source, envCombiner->alpha[curUnit].arg1.operand );
 389                             envCombiner->alpha[curUnit].combine = GL_MODULATE_ADD_ATI;
 390                             SetAlphaCombinerArg( curUnit, arg1, alphaCombiner->stage[i].op[j].param1 );
 391                         }
 392                         else
 393                         {
 394                             envCombiner->alpha[curUnit].combine = GL_ADD;
 395                             SetAlphaCombinerArg( curUnit, arg1, alphaCombiner->stage[i].op[j].param1 );
 396                         }
 397                         curUnit++;
 398                         break;
 399                     case INTERPOLATE:
 400                         envCombiner->usesT0 |= (alphaCombiner->stage[i].op[j].param2 == TEXEL0_ALPHA) || (alphaCombiner->stage[i].op[j].param3 == TEXEL0_ALPHA);
 401                         envCombiner->usesT1 |= (alphaCombiner->stage[i].op[j].param2 == TEXEL1_ALPHA) || (alphaCombiner->stage[i].op[j].param3 == TEXEL1_ALPHA);
 402
 403                         envCombiner->alpha[curUnit].combine = GL_INTERPOLATE_ARB;
 404
 405                         SetAlphaCombinerArg( curUnit, arg0, alphaCombiner->stage[i].op[j].param1 );
 406                         SetAlphaCombinerArg( curUnit, arg1, alphaCombiner->stage[i].op[j].param2 );
 407                         SetAlphaCombinerArg( curUnit, arg2, alphaCombiner->stage[i].op[j].param3 );
 408
 409                         curUnit++;
 410                         break;
 411                 }
 412             }
 413         }
 414     }
 415
 416     envCombiner->usedUnits = max( curUnit, 1 );
 417
 418     curUnit = 0;
 419     for (int i = 0; i < colorCombiner->numStages; i++)
 420     {
 421         for (int j = 0; j < colorCombiner->stage[i].numOps; j++)
 422         {
 423             float sb = 0.0f;
 424
 425             if (colorCombiner->stage[i].op[j].param1 == PRIMITIVE)
 426                 sb = (m_primColor[0] + m_primColor[2] + m_primColor[1]) / 3.0f;
 427             else if (colorCombiner->stage[i].op[j].param1 == ENVIRONMENT)
 428                 sb = (m_envColor[0] + m_envColor[2] + m_envColor[1]) / 3.0f;
 429
 430             // This helps with problems caused by not using signed values between texture units
 431             if (((colorCombiner->stage[i].numOps - j) >= 3) &&
 432                 (colorCombiner->stage[i].op[j].op == SUB) &&
 433                 (colorCombiner->stage[i].op[j+1].op == MUL) &&
 434                 (colorCombiner->stage[i].op[j+2].op == ADD) &&
 435                 (sb > 0.5f) &&
 436                 (ARB_texture_env_combine))
 437             {
 438                 envCombiner->usesT0 |= ((colorCombiner->stage[i].op[j].param1 == TEXEL0) || (colorCombiner->stage[i].op[j].param1 == TEXEL0_ALPHA));
 439                 envCombiner->usesT1 |= ((colorCombiner->stage[i].op[j].param1 == TEXEL1) || (colorCombiner->stage[i].op[j].param1 == TEXEL1_ALPHA));
 440
 441                 envCombiner->color[curUnit].combine = GL_SUBTRACT_ARB;
 442                 SetColorCombinerValues( curUnit, arg1, envCombiner->color[curUnit].arg0.source, envCombiner->color[curUnit].arg0.operand );
 443                 SetColorCombinerArg( curUnit, arg0, colorCombiner->stage[i].op[j].param1 );
 444
 445                 curUnit++;
 446                 j++;
 447
 448                 envCombiner->usesT0 |= ((colorCombiner->stage[i].op[j].param1 == TEXEL0) || (colorCombiner->stage[i].op[j].param1 == TEXEL0_ALPHA));
 449                 envCombiner->usesT1 |= ((colorCombiner->stage[i].op[j].param1 == TEXEL1) || (colorCombiner->stage[i].op[j].param1 == TEXEL1_ALPHA));
 450
 451                 envCombiner->color[curUnit].combine = GL_MODULATE;
 452                 SetColorCombinerArg( curUnit, arg1, colorCombiner->stage[i].op[j].param1 );
 453
 454                 curUnit++;
 455                 j++;
 456
 457                 envCombiner->usesT0 |= ((colorCombiner->stage[i].op[j].param1 == TEXEL0) || (colorCombiner->stage[i].op[j].param1 == TEXEL0_ALPHA));
 458                 envCombiner->usesT1 |= ((colorCombiner->stage[i].op[j].param1 == TEXEL1) || (colorCombiner->stage[i].op[j].param1 == TEXEL1_ALPHA));
 459
 460                 envCombiner->color[curUnit].combine = GL_SUBTRACT_ARB;
 461                 SetColorCombinerArg( curUnit, arg0, colorCombiner->stage[i].op[j].param1 );
 462
 463                 curUnit++;
 464             }
 465             else
 466             {
 467                 envCombiner->usesT0 |= ((colorCombiner->stage[i].op[j].param1 == TEXEL0) || (colorCombiner->stage[i].op[j].param1 == TEXEL0_ALPHA));
 468                 envCombiner->usesT1 |= ((colorCombiner->stage[i].op[j].param1 == TEXEL1) || (colorCombiner->stage[i].op[j].param1 == TEXEL1_ALPHA));
 469
 470                 switch (colorCombiner->stage[i].op[j].op)
 471                 {
 472                     case LOAD:
 473                         if (!( ARB_texture_env_crossbar ||  NV_texture_env_combine4) &&
 474                             ((colorCombiner->stage[i].op[j].param1 == TEXEL1) || (colorCombiner->stage[i].op[j].param1 == TEXEL1_ALPHA)) && (curUnit == 0))
 475                             curUnit++;
 476
 477                         envCombiner->color[curUnit].combine = GL_REPLACE;
 478
 479                         SetColorCombinerArg( curUnit, arg0, colorCombiner->stage[i].op[j].param1 );
 480                         break;
 481                     case SUB:
 482                         if (!ARB_texture_env_combine)
 483                             break;
 484
 485                         if (!(ARB_texture_env_crossbar ||  NV_texture_env_combine4) &&
 486                             ((colorCombiner->stage[i].op[j].param1 == TEXEL1) || (colorCombiner->stage[i].op[j].param1 == TEXEL1_ALPHA)) && (curUnit == 0))
 487                             curUnit++;
 488
 489                         if ((j > 0) && (colorCombiner->stage[i].op[j-1].op == LOAD) && (colorCombiner->stage[i].op[j-1].param1 == ONE))
 490                         {
 491                             SetColorCombinerArg( curUnit, arg0, colorCombiner->stage[i].op[j].param1 );
 492                             envCombiner->color[curUnit].arg0.operand = GL_ONE_MINUS_SRC_COLOR;
 493                         }
 494                         else if (( ATI_texture_env_combine3) && (curUnit > 0) && (envCombiner->color[curUnit - 1].combine == GL_MODULATE))
 495                         {
 496                             curUnit--;
 497                             SetColorCombinerValues( curUnit, arg2, envCombiner->color[curUnit].arg1.source, envCombiner->color[curUnit].arg1.operand );
 498                             envCombiner->color[curUnit].combine = GL_MODULATE_SUBTRACT_ATI;
 499                             SetColorCombinerArg( curUnit, arg1, colorCombiner->stage[i].op[j].param1 );
 500                             curUnit++;
 501                         }
 502                         else
 503                         {
 504                             envCombiner->color[curUnit].combine = GL_SUBTRACT_ARB;
 505                             SetColorCombinerArg( curUnit, arg1, colorCombiner->stage[i].op[j].param1 );
 506                             curUnit++;
 507                         }
 508                         break;
 509                     case MUL:
 510                         if (!( ARB_texture_env_crossbar ||  NV_texture_env_combine4) &&
 511                             ((colorCombiner->stage[i].op[j].param1 == TEXEL1) || (colorCombiner->stage[i].op[j].param1 == TEXEL1_ALPHA)) && (curUnit == 0))
 512                             curUnit++;
 513
 514                         envCombiner->color[curUnit].combine = GL_MODULATE;
 515
 516                         SetColorCombinerArg( curUnit, arg1, colorCombiner->stage[i].op[j].param1 );
 517                         curUnit++;
 518                         break;
 519                     case ADD:
 520                         if (!( ARB_texture_env_crossbar ||  NV_texture_env_combine4) &&
 521                             ((colorCombiner->stage[i].op[j].param1 == TEXEL1) || (colorCombiner->stage[i].op[j].param1 == TEXEL1_ALPHA)) && (curUnit == 0))
 522                             curUnit++;
 523
 524                         // ATI_texture_env_combine3 adds GL_MODULATE_ADD_ATI; saves texture units
 525                         if (( ATI_texture_env_combine3) && (curUnit > 0) && (envCombiner->color[curUnit - 1].combine == GL_MODULATE))
 526                         {
 527                             curUnit--;
 528                             SetColorCombinerValues( curUnit, arg2, envCombiner->color[curUnit].arg1.source, envCombiner->color[curUnit].arg1.operand );
 529                             envCombiner->color[curUnit].combine = GL_MODULATE_ADD_ATI;
 530                             SetColorCombinerArg( curUnit, arg1, colorCombiner->stage[i].op[j].param1 );
 531                         }
 532                         else
 533                         {
 534                             envCombiner->color[curUnit].combine = GL_ADD;
 535                             SetColorCombinerArg( curUnit, arg1, colorCombiner->stage[i].op[j].param1 );
 536                         }
 537                         curUnit++;
 538                         break;
 539                     case INTERPOLATE:
 540                         envCombiner->usesT0 |= (colorCombiner->stage[i].op[j].param2 == TEXEL0) || (colorCombiner->stage[i].op[j].param3 == TEXEL0) || (colorCombiner->stage[i].op[j].param3 == TEXEL0_ALPHA);
 541                         envCombiner->usesT1 |= (colorCombiner->stage[i].op[j].param2 == TEXEL1) || (colorCombiner->stage[i].op[j].param3 == TEXEL1) || (colorCombiner->stage[i].op[j].param3 == TEXEL1_ALPHA);
 542
 543                         if (!( ARB_texture_env_crossbar ||  NV_texture_env_combine4) &&
 544                             ((colorCombiner->stage[i].op[j].param1 == TEXEL1) || (colorCombiner->stage[i].op[j].param2 == TEXEL1) || (colorCombiner->stage[i].op[j].param3 == TEXEL1) || (colorCombiner->stage[i].op[j].param3 == TEXEL1_ALPHA)) && (curUnit == 0))
 545                         {
 546                             if (colorCombiner->stage[i].op[j].param1 == TEXEL0)
 547                             {
 548                                 envCombiner->color[curUnit].combine = GL_REPLACE;
 549                                 SetColorCombinerArg( curUnit, arg0, colorCombiner->stage[i].op[j].param1 );
 550                                 colorCombiner->stage[i].op[j].param1 = COMBINED;
 551                             }
 552                             if (colorCombiner->stage[i].op[j].param2 == TEXEL0)
 553                             {
 554                                 envCombiner->color[curUnit].combine = GL_REPLACE;
 555                                 SetColorCombinerArg( curUnit, arg0, colorCombiner->stage[i].op[j].param2 )
 556
 557                                 colorCombiner->stage[i].op[j].param2 = COMBINED;
 558                             }
 559                             if (colorCombiner->stage[i].op[j].param3 == TEXEL0)
 560                             {
 561                                 envCombiner->color[curUnit].combine = GL_REPLACE;
 562                                 SetColorCombinerArg( curUnit, arg0, colorCombiner->stage[i].op[j].param3 );
 563                                 colorCombiner->stage[i].op[j].param3 = COMBINED;
 564                             }
 565                             if (colorCombiner->stage[i].op[j].param3 == TEXEL0_ALPHA)
 566                             {
 567                                 envCombiner->color[curUnit].combine = GL_REPLACE;
 568                                 SetColorCombinerArg( curUnit, arg0, colorCombiner->stage[i].op[j].param3 );
 569                                 colorCombiner->stage[i].op[j].param3 = COMBINED_ALPHA;
 570                             }
 571
 572                             curUnit++;
 573                         }
 574
 575                         envCombiner->color[curUnit].combine = GL_INTERPOLATE_ARB;
 576
 577                         SetColorCombinerArg( curUnit, arg0, colorCombiner->stage[i].op[j].param1 );
 578                         SetColorCombinerArg( curUnit, arg1, colorCombiner->stage[i].op[j].param2 );
 579                         SetColorCombinerArg( curUnit, arg2, colorCombiner->stage[i].op[j].param3 );
 580
 581                         curUnit++;
 582                         break;
 583                 }
 584             }
 585         }
 586     }
 587
 588     envCombiner->usedUnits = max( (unsigned short)curUnit, envCombiner->usedUnits );
 589     return envCombiner;
 590 }