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