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