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