source/programbuilder.cpp

   1 #include <algorithm>
   2 #include <msp/strings/format.h>
   3 #include "program.h"
   4 #include "programbuilder.h"
   5 #include "shader.h"
   6 #include "vertexformat.h"
   7
   8 using namespace std;
   9
  10 namespace Msp {
  11 namespace GL {
  12
  13 /*
  14 Naming conventions:
  15   n_*        Normalized vector
  16   l_*        Lighting component
  17
  18   obj_*      Object space
  19   eye_*      Eye space
  20   tbn_*      Tangent-Binormal-Normal space
  21   shd_*      Shadow space
  22   env_*      Environment space
  23   *_dir      Direction vector
  24
  25   zzz_*      Wildcard space, resolved by the builder
  26              All wildcard spaces within an expression must match
  27
  28   xxx_yyy_*  Matrix that transforms between yyy to xxx
  29              The vector is on the side of its designated space, result will be
  30              in the other space
  31   *_matrix   A matrix (duh)
  32   *_rmatrix  A mat4 that works with a row vector
  33
  34   rgb_*      Color with rgb components only
  35   color_*    Color with rgba components
  36 */
  37
  38 /* The array are stored in reverse order, so that variables always come after
  39 anything that might need them. */
  40 const ProgramBuilder::StandardVariable ProgramBuilder::standard_variables[] =
  41 {
  42         { FRAGMENT, "gl_FragColor", 0, "color_base", "!t" },
  43         { FRAGMENT, "gl_FragColor", 0, "tex_sample", "!l!s!mt" },
  44         { FRAGMENT, "gl_FragColor", 0, "tex_sample*color_base", "l|s|mt" },
  45         { FRAGMENT, "color_base", "vec4", "vec4(1.0)", "!l!s!m" },
  46         { FRAGMENT, "color_base", "vec4", "color", "!l!sm" },
  47         { FRAGMENT, "color_base", "vec4", "vec4(vec3(l_shadow), 1.0)", "!ls!m" },
  48         { FRAGMENT, "color_base", "vec4", "color*vec4(vec3(l_shadow), 1.0)", "!lsm" },
  49         { FRAGMENT, "color_base", "vec4", "vec4(rgb_light_env, 1.0)", "l!m" },
  50         { FRAGMENT, "color_base", "vec4", "vec4(rgb_light_env, gl_FrontMaterial.diffuse.a)", "lm" },
  51         { FRAGMENT, "rgb_light_env", "vec3", "rgb_light_full+reflect_sample.rgb*reflectivity", "e" },
  52         { FRAGMENT, "rgb_light_env", "vec3", "rgb_light_full", "!e" },
  53         { FRAGMENT, "rgb_light_full", "vec3", "rgb_light_shadow+gl_FrontLightModelProduct.sceneColor.rgb", "m" },
  54         { FRAGMENT, "rgb_light_full", "vec3", "rgb_light_shadow", "!m" },
  55         { FRAGMENT, "rgb_light_shadow", "vec3", "rgb_light*l_shadow", "s" },
  56         { FRAGMENT, "rgb_light_shadow", "vec3", "rgb_light", "!s" },
  57         { FRAGMENT, "rgb_light", "vec3", "vec3(l_diffuse)", "!m!p" },
  58         { FRAGMENT, "rgb_light", "vec3", "vec3(l_diffuse+l_specular)", "!mp" },
  59         { FRAGMENT, "rgb_light", "vec3", "l_diffuse*gl_FrontLightProduct[0].diffuse.rgb", "m!p" },
  60         { FRAGMENT, "rgb_light", "vec3", "l_diffuse*gl_FrontLightProduct[0].diffuse.rgb+l_specular*gl_FrontLightProduct[0].specular.rgb", "mp" },
  61         { FRAGMENT, "reflect_sample", "vec4", "textureCube(environment, env_reflect_dir)", 0 },
  62         { FRAGMENT, "env_reflect_dir", "vec3", "env_eye_matrix*eye_reflect_dir", 0 },
  63         { FRAGMENT, "eye_reflect_dir", "vec3", "eye_tbn_matrix*tbn_reflect_dir", "n" },
  64         { FRAGMENT, "zzz_reflect_dir", "vec3", "reflect(zzz_incident_dir, n_zzz_normal)", 0 },
  65         { FRAGMENT, "l_shadow", "float", "mix(1.0, shadow_sample, shadow_darkness)", 0 },
  66         { FRAGMENT, "shadow_sample", "float", "shadow2D(shadow, shd_vertex).r", 0 },
  67         { FRAGMENT, "l_diffuse", "float", "max(dot(n_zzz_normal, n_zzz_light_dir), 0.0)", 0 },
  68         { FRAGMENT, "l_specular", "float", "pow(max(dot(n_zzz_half_vec, n_zzz_normal), 0.0), gl_FrontMaterial.shininess)", 0 },
  69         { FRAGMENT, "n_zzz_half_vec", "vec3", "normalize(zzz_light_dir-zzz_incident_dir)", 0 },
  70         { FRAGMENT, "n_zzz_light_dir", "vec3", "normalize(zzz_light_dir)", 0 },
  71         { FRAGMENT, "n_tbn_normal", "vec3", "texture2D(normalmap, texture_coord).xyz*2.0-1.0", "n" },
  72         { FRAGMENT, "n_eye_normal", "vec3", "normalize(eye_normal)", "!n" },
  73         { FRAGMENT, "tex_sample", "vec4", "texture2D(texture, texture_coord)", 0 },
  74
  75         { VERTEX, "gl_Position", 0, "gl_ProjectionMatrix*eye_vertex", 0 },
  76         { VERTEX, "shd_vertex", "vec3", "(eye_vertex*eye_shd_rmatrix).xyz", 0 },
  77         { VERTEX, "eye_shd_rmatrix", "mat4", "mat4(gl_EyePlaneS[shadow_unit], gl_EyePlaneT[shadow_unit], gl_EyePlaneR[shadow_unit], vec4(0.0, 0.0, 0.0, 1.0))", 0 },
  78         { VERTEX, "tbn_light_dir", "vec3", "eye_light_dir*eye_tbn_matrix", 0 },
  79         { VERTEX, "eye_light_dir", "vec3", "normalize(gl_LightSource[0].position.xyz-eye_vertex.xyz*gl_LightSource[0].position.w)", 0 },
  80         { VERTEX, "tbn_incident_dir", "vec3", "eye_incident_dir*eye_tbn_matrix", 0 },
  81         { VERTEX, "eye_incident_dir", "vec3", "normalize(eye_vertex.xyz)", 0 },
  82         { VERTEX, "eye_tbn_matrix", "mat3", "mat3(eye_tangent, eye_binormal, eye_normal)", 0 },
  83         { VERTEX, "eye_vertex", "vec4", "gl_ModelViewMatrix*gl_Vertex", "!r" },
  84         { VERTEX, "eye_vertex", "vec4", "transform_vertex(gl_Vertex)", "r" },
  85         { VERTEX, "eye_normal", "vec3", "gl_NormalMatrix*gl_Normal", "!r" },
  86         { VERTEX, "eye_normal", "vec3", "transform_normal(gl_Normal)", "r" },
  87         { VERTEX, "eye_tangent", "vec3", "gl_NormalMatrix*tangent", "!r" },
  88         { VERTEX, "eye_tangent", "vec3", "transform_normal(tangent)", "r" },
  89         { VERTEX, "eye_binormal", "vec3", "gl_NormalMatrix*binormal", "!r" },
  90         { VERTEX, "eye_binormal", "vec3", "transform_normal(binormal)", "r" },
  91         { VERTEX, "color", "vec4", "gl_Color", 0 },
  92         { VERTEX, "texture_coord", "vec2", "gl_MultiTexCoord0.xy", 0 },
  93
  94         { ATTRIBUTE, "tangent", "vec3", 0, 0 },
  95         { ATTRIBUTE, "binormal", "vec3", 0, 0 },
  96
  97         { UNIFORM, "shadow_unit", "int", 0, 0 },
  98         { UNIFORM, "texture", "sampler2D", 0, 0 },
  99         { UNIFORM, "shadow", "sampler2DShadow", 0, 0 },
 100         { UNIFORM, "shadow_darkness", "float", 0, 0 },
 101         { UNIFORM, "normalmap", "sampler2D", 0, 0 },
 102         { UNIFORM, "environment", "samplerCube", 0, 0 },
 103         { UNIFORM, "env_eye_matrix", "mat3", 0, 0 },
 104         { UNIFORM, "reflectivity", "float", 0, 0 },
 105
 106         // Terminator entry
 107         { NO_SCOPE,  0, 0, 0, 0 }
 108 };
 109
 110 ProgramBuilder::ProgramBuilder(const StandardFeatures &f):
 111         features(f),
 112         feature_flags(features.create_flags()),
 113         optimize(true)
 114 { }
 115
 116 void ProgramBuilder::set_optimize(bool o)
 117 {
 118         optimize = o;
 119 }
 120
 121 Program *ProgramBuilder::create_program() const
 122 {
 123         Program *prog = new Program;
 124         add_shaders(*prog);
 125         return prog;
 126 }
 127
 128 void ProgramBuilder::add_shaders(Program &prog) const
 129 {
 130         list<ShaderVariable> variables;
 131         list<ShaderVariable *> resolved_vars;
 132
 133         variables.push_front(ShaderVariable("gl_Position"));
 134         variables.push_front(ShaderVariable("gl_FragColor"));
 135
 136         for(const StandardVariable *i=standard_variables; i->name; ++i)
 137         {
 138                 // Skip over anything that isn't used with the supplied flags
 139                 if(i->flags && !evaluate_flags(i->flags))
 140                         continue;
 141
 142                 // See if this variable can satisfy any unresolved variables
 143                 ShaderVariable *last_resolved = 0;
 144                 for(list<ShaderVariable>::iterator j=variables.begin(); j!=variables.end(); ++j)
 145                 {
 146                         if(j->variable)
 147                                 continue;
 148
 149                         if(!name_match(i->name, j->resolved_name.c_str()))
 150                                 continue;
 151
 152                         if(last_resolved)
 153                         {
 154                                 /* We've already resolved a non-fuzzy variable in this iteration.
 155                                 If there are multiple variables that can be resolved, they refer
 156                                 to the same variable. */
 157                                 j->resolve(*last_resolved);
 158                                 continue;
 159                         }
 160
 161                         j->resolve(*i);
 162                         resolved_vars.push_front(&*j);
 163                         if(!j->fuzzy_space)
 164                                 last_resolved = &*j;
 165
 166                         if(!i->expression)
 167                                 continue;
 168
 169                         vector<string> identifiers = extract_identifiers(i->expression);
 170                         for(vector<string>::const_iterator k=identifiers.begin(); k!=identifiers.end(); ++k)
 171                         {
 172                                 // Use an existing variable if possible, but only if it's not fuzzy
 173                                 ShaderVariable *var = 0;
 174                                 for(list<ShaderVariable>::iterator l=variables.begin(); (!var && l!=variables.end()); ++l)
 175                                         if(!l->fuzzy_space && l->resolved_name==*k)
 176                                                 var = &*l;
 177
 178                                 if(!var)
 179                                 {
 180                                         variables.push_back(ShaderVariable(*k));
 181                                         var = &variables.back();
 182                                 }
 183                                 j->add_reference(*var);
 184                         }
 185                 }
 186         }
 187
 188         if(optimize)
 189         {
 190                 for(list<ShaderVariable *>::const_iterator i=resolved_vars.begin(); i!=resolved_vars.end(); ++i)
 191                         (*i)->check_inline();
 192         }
 193
 194         prog.attach_shader_owned(new VertexShader(create_source(resolved_vars, VERTEX)));
 195         prog.attach_shader_owned(new FragmentShader(create_source(resolved_vars, FRAGMENT)));
 196
 197         if(features.normalmap)
 198         {
 199                 prog.bind_attribute(get_component_type(TANGENT3), "tangent");
 200                 prog.bind_attribute(get_component_type(BINORMAL3), "binormal");
 201         }
 202 }
 203
 204 string ProgramBuilder::create_source(const list<ShaderVariable *> &variables, VariableScope scope) const
 205 {
 206         string source;
 207
 208         for(list<ShaderVariable *>::const_iterator i=variables.begin(); i!=variables.end(); ++i)
 209                 if((*i)->variable->scope==UNIFORM && (*i)->is_referenced_from(scope))
 210                         source += format("uniform %s %s;\n", (*i)->variable->type, (*i)->resolved_name);
 211
 212         if(scope==VERTEX)
 213         {
 214                 for(list<ShaderVariable *>::const_iterator i=variables.begin(); i!=variables.end(); ++i)
 215                         if((*i)->variable->scope==ATTRIBUTE)
 216                                 source += format("attribute %s %s;\n", (*i)->variable->type, (*i)->resolved_name);
 217         }
 218
 219         /* Any variables defined in vertex scope but referenced from fragment scope
 220         should be exported as varyings over the interface. */
 221         list<ShaderVariable *> varyings;
 222         for(list<ShaderVariable *>::const_iterator i=variables.begin(); i!=variables.end(); ++i)
 223                 if((*i)->variable->scope==VERTEX && (*i)->is_referenced_from(FRAGMENT))
 224                 {
 225                         varyings.push_back(*i);
 226                         source += format("varying %s v_%s;\n", (*i)->variable->type, (*i)->resolved_name);
 227                 }
 228
 229         if(scope==VERTEX && features.transform)
 230         {
 231                 // Add the prototypes here, until I come up with something better
 232                 source += "vec4 transform_vertex(vec4);\n";
 233                 source += "vec3 transform_normal(vec3);\n";
 234         }
 235
 236         source += "void main()\n{\n";
 237
 238         for(list<ShaderVariable *>::const_iterator i=variables.begin(); i!=variables.end(); ++i)
 239                 if((*i)->variable->scope==scope && !(*i)->inlined)
 240                 {
 241                         source += '\t';
 242                         if((*i)->variable->type)
 243                         {
 244                                 source += (*i)->variable->type;
 245                                 source += ' ';
 246                         }
 247                         source += format("%s = %s;\n", (*i)->resolved_name, (*i)->get_expression());
 248                 }
 249
 250         if(scope==VERTEX)
 251         {
 252                 for(list<ShaderVariable *>::const_iterator i=varyings.begin(); i!=varyings.end(); ++i)
 253                 {
 254                         if((*i)->inlined)
 255                                 source += format("\tv_%s = %s;\n", (*i)->resolved_name, (*i)->get_expression());
 256                         else
 257                                 source += format("\tv_%s = %s;\n", (*i)->resolved_name, (*i)->resolved_name);
 258                 }
 259         }
 260
 261         source += '}';
 262
 263         return source;
 264 }
 265
 266 bool ProgramBuilder::evaluate_flags(const char *flags) const
 267 {
 268         if(!flags)
 269                 return true;
 270
 271         bool cond = true;
 272         char oper = '&';
 273         for(const char *i=flags; *i; ++i)
 274         {
 275                 if(*i>='a' && *i<='z')
 276                 {
 277                         bool found = (feature_flags.find(*i)!=string::npos);
 278                         if(oper=='|')
 279                                 cond = (cond || found);
 280                         else if(oper=='!')
 281                                 cond = (cond && !found);
 282                         else if(oper=='&')
 283                                 cond = (cond && found);
 284                         oper = '&';
 285                 }
 286                 else
 287                         oper = *i;
 288         }
 289
 290         return cond;
 291 }
 292
 293 ProgramBuilder::MatchLevel ProgramBuilder::name_match(const char *n1, const char *n2, const char **space)
 294 {
 295         int i = 0;
 296         int zzz = -1;
 297         int zside = 0;
 298         while(*n1 && *n2)
 299         {
 300                 if(*n1==*n2 || *n1=='z' || *n2=='z')
 301                 {
 302                         if(*n1!=*n2)
 303                         {
 304                                 int side = (*n1=='z' ? 1 : 2);
 305                                 if(zzz<0)
 306                                 {
 307                                         zzz = i;
 308                                         zside = side;
 309                                         if(space)
 310                                         {
 311                                                 if(*n1=='z')
 312                                                         *space = n2;
 313                                                 else
 314                                                         *space = n1;
 315                                         }
 316                                 }
 317                                 else if(i>=zzz+3 || side!=zside)
 318                                         return NO_MATCH;
 319                         }
 320                 }
 321                 else
 322                         return NO_MATCH;
 323                 ++n1;
 324                 ++n2;
 325                 ++i;
 326         }
 327         return (!*n1 && !*n2) ? zzz>=0 ? FUZZY : EXACT : NO_MATCH;
 328 }
 329
 330 bool ProgramBuilder::parse_identifier(const char *ptr, unsigned &start, unsigned &length)
 331 {
 332         bool found = false;
 333         bool member = false;
 334         for(const char *i=ptr;; ++i)
 335         {
 336                 if(!found)
 337                 {
 338                         if(!*i)
 339                                 return false;
 340                         if(isalpha(*i) || *i=='_')
 341                         {
 342                                 if(!member)
 343                                 {
 344                                         start = i-ptr;
 345                                         found = true;
 346                                 }
 347                         }
 348                         else if(*i=='.')
 349                                 member = true;
 350                         else
 351                                 member = false;
 352                 }
 353                 else
 354                 {
 355                         if(!isalnum(*i) && *i!='_')
 356                         {
 357                                 length = i-(ptr+start);
 358                                 return true;
 359                         }
 360                 }
 361         }
 362 }
 363
 364 vector<string> ProgramBuilder::extract_identifiers(const char *expression)
 365 {
 366         vector<string> result;
 367         const char *ptr = expression;
 368         unsigned start, length;
 369         while(parse_identifier(ptr, start, length))
 370         {
 371                 result.push_back(string(ptr+start, length));
 372                 ptr += start+length;
 373         }
 374         return result;
 375 }
 376
 377 string ProgramBuilder::replace_identifiers(const char *expression, const map<string, string> &replace_map)
 378 {
 379         string result;
 380         const char *ptr = expression;
 381         unsigned start, length;
 382         while(parse_identifier(ptr, start, length))
 383         {
 384                 result.append(ptr, start);
 385                 string identifier(ptr+start, length);
 386                 map<string, string>::const_iterator i = replace_map.find(identifier);
 387                 if(i!=replace_map.end())
 388                         result += i->second;
 389                 else
 390                         result += identifier;
 391                 ptr += start+length;
 392         }
 393         result += ptr;
 394         return result;
 395 }
 396
 397
 398 ProgramBuilder::StandardFeatures::StandardFeatures():
 399         texture(false),
 400         material(false),
 401         lighting(false),
 402         specular(false),
 403         normalmap(false),
 404         shadow(false),
 405         reflection(false),
 406         transform(false)
 407 { }
 408
 409 string ProgramBuilder::StandardFeatures::create_flags() const
 410 {
 411         string flags;
 412         if(texture)
 413                 flags += 't';
 414         if(material)
 415                 flags += 'm';
 416         if(lighting)
 417         {
 418                 flags += 'l';
 419                 if(specular)
 420                         flags += 'p';
 421                 if(normalmap)
 422                         flags += 'n';
 423         }
 424         if(shadow)
 425                 flags += 's';
 426         if(reflection)
 427                 flags += 'e';
 428         if(transform)
 429                 flags += 'r';
 430
 431         return flags;
 432 }
 433
 434
 435 ProgramBuilder::ShaderVariable::ShaderVariable(const std::string &n):
 436         name(n),
 437         variable(0),
 438         resolved_name(n),
 439         fuzzy_space(name.find("zzz")!=string::npos),
 440         inlined(false),
 441         inline_parens(false)
 442 { }
 443
 444 void ProgramBuilder::ShaderVariable::resolve(const StandardVariable &var)
 445 {
 446         variable = &var;
 447         const char *space = 0;
 448         if(name_match(var.name, resolved_name.c_str(), &space)==FUZZY)
 449                 resolve_space(string(space, 3));
 450 }
 451
 452 void ProgramBuilder::ShaderVariable::resolve(ShaderVariable &var)
 453 {
 454         for(list<ShaderVariable *>::iterator i=referenced_by.begin(); i!=referenced_by.end(); ++i)
 455                 (*i)->update_reference(*this, var);
 456         var.referenced_by.insert(var.referenced_by.end(), referenced_by.begin(), referenced_by.end());
 457 }
 458
 459 void ProgramBuilder::ShaderVariable::resolve_space(const string &space)
 460 {
 461         if(fuzzy_space)
 462         {
 463                 resolved_space = space;
 464
 465                 string::size_type zzz = resolved_name.find("zzz");
 466                 resolved_name.replace(zzz, 3, resolved_space);
 467                 fuzzy_space = false;
 468
 469                 // Resolving the space could have affected other variables that use this one
 470                 for(list<ShaderVariable *>::iterator i=referenced_by.begin(); i!=referenced_by.end(); ++i)
 471                         (*i)->resolve_space(space);
 472         }
 473
 474         for(list<ShaderVariable *>::iterator i=referenced_vars.begin(); i!=referenced_vars.end(); ++i)
 475                 if((*i)->fuzzy_space)
 476                         (*i)->resolve_space(space);
 477 }
 478
 479 void ProgramBuilder::ShaderVariable::add_reference(ShaderVariable &var)
 480 {
 481         referenced_vars.push_back(&var);
 482         var.referenced_by.push_back(this);
 483         if(var.fuzzy_space && !resolved_space.empty())
 484                 var.resolve_space(resolved_space);
 485 }
 486
 487 void ProgramBuilder::ShaderVariable::update_reference(ShaderVariable &from, ShaderVariable &to)
 488 {
 489         replace(referenced_vars.begin(), referenced_vars.end(), &from, &to);
 490         replace(referenced_by.begin(), referenced_by.end(), &from, &to);
 491         if(from.fuzzy_space && !to.fuzzy_space && !to.resolved_space.empty())
 492                 resolve_space(to.resolved_space);
 493 }
 494
 495 void ProgramBuilder::ShaderVariable::check_inline()
 496 {
 497         if(variable->expression)
 498         {
 499                 unsigned total_refs = referenced_by.size();
 500                 unsigned in_scope_refs = 0;
 501                 for(list<ShaderVariable *>::const_iterator i=referenced_by.begin(); i!=referenced_by.end(); ++i)
 502                         if((*i)->variable->scope==variable->scope)
 503                                 ++in_scope_refs;
 504                 if(total_refs==1 || (total_refs>0 && in_scope_refs==0))
 505                 {
 506                         inlined = true;
 507                         unsigned level = 0;
 508                         for(const char *c=variable->expression; (!inline_parens && *c); ++c)
 509                         {
 510                                 if(*c=='(')
 511                                         ++level;
 512                                 else if(*c==')')
 513                                         --level;
 514                                 else if(level==0 && !isalnum(*c) && *c!='_' && *c!='.')
 515                                         inline_parens = true;
 516                         }
 517                 }
 518         }
 519 }
 520
 521 bool ProgramBuilder::ShaderVariable::is_referenced_from(VariableScope scope) const
 522 {
 523         for(list<ShaderVariable *>::const_iterator i=referenced_by.begin(); i!=referenced_by.end(); ++i)
 524                 if((*i)->variable->scope==scope)
 525                         return true;
 526         return false;
 527 }
 528
 529 string ProgramBuilder::ShaderVariable::get_expression() const
 530 {
 531         map<string, string> replace_map;
 532         for(list<ShaderVariable *>::const_iterator i=referenced_vars.begin(); i!=referenced_vars.end(); ++i)
 533                 if((*i)->variable)
 534                 {
 535                         string replacement = (*i)->resolved_name;
 536                         if(variable->scope==FRAGMENT && (*i)->variable->scope==VERTEX)
 537                                 replacement = "v_"+replacement;
 538                         else if((*i)->inlined)
 539                         {
 540                                 replacement = (*i)->get_expression();
 541                                 if((*i)->inline_parens)
 542                                         replacement = "("+replacement+")";
 543                         }
 544                         if(replacement!=(*i)->name)
 545                                 replace_map[(*i)->name] = replacement;
 546                 }
 547
 548         if(replace_map.empty())
 549                 return variable->expression;
 550         else
 551                 return replace_identifiers(variable->expression, replace_map);
 552 }
 553
 554
 555 ProgramBuilder::StandardFeatures::Loader::Loader(StandardFeatures &f):
 556         DataFile::ObjectLoader<StandardFeatures>(f)
 557 {
 558         add("lighting",  &StandardFeatures::lighting);
 559         add("material",  &StandardFeatures::material);
 560         add("normalmap", &StandardFeatures::normalmap);
 561         add("reflection", &StandardFeatures::reflection);
 562         add("shadow",    &StandardFeatures::shadow);
 563         add("specular",  &StandardFeatures::specular);
 564         add("texture",   &StandardFeatures::texture);
 565         add("transform", &StandardFeatures::transform);
 566 }
 567
 568 } // namespace GL
 569 } // namespace Msp