git.sesse.net Git - movit/blob - effect_chain.cpp

   1 #define GL_GLEXT_PROTOTYPES 1
   2
   3 #include <stdio.h>
   4 #include <math.h>
   5 #include <string.h>
   6 #include <assert.h>
   7
   8 #include <algorithm>
   9 #include <set>
  10 #include <stack>
  11 #include <vector>
  12
  13 #include "util.h"
  14 #include "effect_chain.h"
  15 #include "gamma_expansion_effect.h"
  16 #include "gamma_compression_effect.h"
  17 #include "colorspace_conversion_effect.h"
  18 #include "input.h"
  19 #include "opengl.h"
  20
  21 EffectChain::EffectChain(float aspect_nom, float aspect_denom)
  22         : aspect_nom(aspect_nom),
  23           aspect_denom(aspect_denom),
  24           finalized(false) {}
  25
  26 Input *EffectChain::add_input(Input *input)
  27 {
  28         inputs.push_back(input);
  29
  30         Node *node = add_node(input);
  31         node->output_color_space = input->get_color_space();
  32         node->output_gamma_curve = input->get_gamma_curve();
  33         return input;
  34 }
  35
  36 void EffectChain::add_output(const ImageFormat &format)
  37 {
  38         output_format = format;
  39 }
  40
  41 Node *EffectChain::add_node(Effect *effect)
  42 {
  43         char effect_id[256];
  44         sprintf(effect_id, "eff%u", (unsigned)nodes.size());
  45
  46         Node *node = new Node;
  47         node->effect = effect;
  48         node->disabled = false;
  49         node->effect_id = effect_id;
  50         node->output_color_space = COLORSPACE_INVALID;
  51         node->output_gamma_curve = GAMMA_INVALID;
  52
  53         nodes.push_back(node);
  54         node_map[effect] = node;
  55         return node;
  56 }
  57
  58 void EffectChain::connect_nodes(Node *sender, Node *receiver)
  59 {
  60         sender->outgoing_links.push_back(receiver);
  61         receiver->incoming_links.push_back(sender);
  62 }
  63
  64 void EffectChain::replace_receiver(Node *old_receiver, Node *new_receiver)
  65 {
  66         new_receiver->incoming_links = old_receiver->incoming_links;
  67         old_receiver->incoming_links.clear();
  68
  69         for (unsigned i = 0; i < new_receiver->incoming_links.size(); ++i) {
  70                 Node *sender = new_receiver->incoming_links[i];
  71                 for (unsigned j = 0; j < sender->outgoing_links.size(); ++j) {
  72                         if (sender->outgoing_links[j] == old_receiver) {
  73                                 sender->outgoing_links[j] = new_receiver;
  74                         }
  75                 }
  76         }
  77 }
  78
  79 void EffectChain::replace_sender(Node *old_sender, Node *new_sender)
  80 {
  81         new_sender->outgoing_links = old_sender->outgoing_links;
  82         old_sender->outgoing_links.clear();
  83
  84         for (unsigned i = 0; i < new_sender->outgoing_links.size(); ++i) {
  85                 Node *receiver = new_sender->outgoing_links[i];
  86                 for (unsigned j = 0; j < receiver->incoming_links.size(); ++j) {
  87                         if (receiver->incoming_links[j] == old_sender) {
  88                                 receiver->incoming_links[j] = new_sender;
  89                         }
  90                 }
  91         }
  92 }
  93
  94 void EffectChain::insert_node_between(Node *sender, Node *middle, Node *receiver)
  95 {
  96         for (unsigned i = 0; i < sender->outgoing_links.size(); ++i) {
  97                 if (sender->outgoing_links[i] == receiver) {
  98                         sender->outgoing_links[i] = middle;
  99                         middle->incoming_links.push_back(sender);
 100                 }
 101         }
 102         for (unsigned i = 0; i < receiver->incoming_links.size(); ++i) {
 103                 if (receiver->incoming_links[i] == sender) {
 104                         receiver->incoming_links[i] = middle;
 105                         middle->outgoing_links.push_back(receiver);
 106                 }
 107         }
 108
 109         assert(middle->incoming_links.size() == middle->effect->num_inputs());
 110 }
 111
 112 void EffectChain::find_all_nonlinear_inputs(Node *node, std::vector<Node *> *nonlinear_inputs)
 113 {
 114         if (node->output_gamma_curve == GAMMA_LINEAR &&
 115             node->effect->effect_type_id() != "GammaCompressionEffect") {
 116                 return;
 117         }
 118         if (node->effect->num_inputs() == 0) {
 119                 nonlinear_inputs->push_back(node);
 120         } else {
 121                 assert(node->effect->num_inputs() == node->incoming_links.size());
 122                 for (unsigned i = 0; i < node->incoming_links.size(); ++i) {
 123                         find_all_nonlinear_inputs(node->incoming_links[i], nonlinear_inputs);
 124                 }
 125         }
 126 }
 127
 128 Effect *EffectChain::add_effect(Effect *effect, const std::vector<Effect *> &inputs)
 129 {
 130         assert(inputs.size() == effect->num_inputs());
 131         Node *node = add_node(effect);
 132         for (unsigned i = 0; i < inputs.size(); ++i) {
 133                 assert(node_map.count(inputs[i]) != 0);
 134                 connect_nodes(node_map[inputs[i]], node);
 135         }
 136         return effect;
 137 }
 138
 139 // GLSL pre-1.30 doesn't support token pasting. Replace PREFIX(x) with <effect_id>_x.
 140 std::string replace_prefix(const std::string &text, const std::string &prefix)
 141 {
 142         std::string output;
 143         size_t start = 0;
 144
 145         while (start < text.size()) {
 146                 size_t pos = text.find("PREFIX(", start);
 147                 if (pos == std::string::npos) {
 148                         output.append(text.substr(start, std::string::npos));
 149                         break;
 150                 }
 151
 152                 output.append(text.substr(start, pos - start));
 153                 output.append(prefix);
 154                 output.append("_");
 155
 156                 pos += strlen("PREFIX(");
 157
 158                 // Output stuff until we find the matching ), which we then eat.
 159                 int depth = 1;
 160                 size_t end_arg_pos = pos;
 161                 while (end_arg_pos < text.size()) {
 162                         if (text[end_arg_pos] == '(') {
 163                                 ++depth;
 164                         } else if (text[end_arg_pos] == ')') {
 165                                 --depth;
 166                                 if (depth == 0) {
 167                                         break;
 168                                 }
 169                         }
 170                         ++end_arg_pos;
 171                 }
 172                 output.append(text.substr(pos, end_arg_pos - pos));
 173                 ++end_arg_pos;
 174                 assert(depth == 0);
 175                 start = end_arg_pos;
 176         }
 177         return output;
 178 }
 179
 180 Phase *EffectChain::compile_glsl_program(
 181         const std::vector<Node *> &inputs,
 182         const std::vector<Node *> &effects)
 183 {
 184         assert(!effects.empty());
 185
 186         // Deduplicate the inputs.
 187         std::vector<Node *> true_inputs = inputs;
 188         std::sort(true_inputs.begin(), true_inputs.end());
 189         true_inputs.erase(std::unique(true_inputs.begin(), true_inputs.end()), true_inputs.end());
 190
 191         bool input_needs_mipmaps = false;
 192         std::string frag_shader = read_file("header.frag");
 193
 194         // Create functions for all the texture inputs that we need.
 195         for (unsigned i = 0; i < true_inputs.size(); ++i) {
 196                 Node *input = true_inputs[i];
 197
 198                 frag_shader += std::string("uniform sampler2D tex_") + input->effect_id + ";\n";
 199                 frag_shader += std::string("vec4 ") + input->effect_id + "(vec2 tc) {\n";
 200                 frag_shader += "\treturn texture2D(tex_" + input->effect_id + ", tc);\n";
 201                 frag_shader += "}\n";
 202                 frag_shader += "\n";
 203         }
 204
 205         for (unsigned i = 0; i < effects.size(); ++i) {
 206                 Node *node = effects[i];
 207
 208                 if (node->incoming_links.size() == 1) {
 209                         frag_shader += std::string("#define INPUT ") + node->incoming_links[0]->effect_id + "\n";
 210                 } else {
 211                         for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
 212                                 char buf[256];
 213                                 sprintf(buf, "#define INPUT%d %s\n", j + 1, node->incoming_links[j]->effect_id.c_str());
 214                                 frag_shader += buf;
 215                         }
 216                 }
 217
 218                 frag_shader += "\n";
 219                 frag_shader += std::string("#define FUNCNAME ") + node->effect_id + "\n";
 220                 frag_shader += replace_prefix(node->effect->output_convenience_uniforms(), node->effect_id);
 221                 frag_shader += replace_prefix(node->effect->output_fragment_shader(), node->effect_id);
 222                 frag_shader += "#undef PREFIX\n";
 223                 frag_shader += "#undef FUNCNAME\n";
 224                 if (node->incoming_links.size() == 1) {
 225                         frag_shader += "#undef INPUT\n";
 226                 } else {
 227                         for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
 228                                 char buf[256];
 229                                 sprintf(buf, "#undef INPUT%d\n", j + 1);
 230                                 frag_shader += buf;
 231                         }
 232                 }
 233                 frag_shader += "\n";
 234
 235                 input_needs_mipmaps |= node->effect->needs_mipmaps();
 236         }
 237         for (unsigned i = 0; i < effects.size(); ++i) {
 238                 Node *node = effects[i];
 239                 if (node->effect->num_inputs() == 0) {
 240                         node->effect->set_int("needs_mipmaps", input_needs_mipmaps);
 241                 }
 242         }
 243         frag_shader += std::string("#define INPUT ") + effects.back()->effect_id + "\n";
 244         frag_shader.append(read_file("footer.frag"));
 245
 246         // Output shader to a temporary file, for easier debugging.
 247         static int compiled_shader_num = 0;
 248         char filename[256];
 249         sprintf(filename, "chain-%03d.frag", compiled_shader_num++);
 250         FILE *fp = fopen(filename, "w");
 251         if (fp == NULL) {
 252                 perror(filename);
 253                 exit(1);
 254         }
 255         fprintf(fp, "%s\n", frag_shader.c_str());
 256         fclose(fp);
 257
 258         GLuint glsl_program_num = glCreateProgram();
 259         GLuint vs_obj = compile_shader(read_file("vs.vert"), GL_VERTEX_SHADER);
 260         GLuint fs_obj = compile_shader(frag_shader, GL_FRAGMENT_SHADER);
 261         glAttachShader(glsl_program_num, vs_obj);
 262         check_error();
 263         glAttachShader(glsl_program_num, fs_obj);
 264         check_error();
 265         glLinkProgram(glsl_program_num);
 266         check_error();
 267
 268         Phase *phase = new Phase;
 269         phase->glsl_program_num = glsl_program_num;
 270         phase->input_needs_mipmaps = input_needs_mipmaps;
 271         phase->inputs = true_inputs;
 272         phase->effects = effects;
 273
 274         return phase;
 275 }
 276
 277 // Construct GLSL programs, starting at the given effect and following
 278 // the chain from there. We end a program every time we come to an effect
 279 // marked as "needs texture bounce", one that is used by multiple other
 280 // effects, every time an effect wants to change the output size,
 281 // and of course at the end.
 282 //
 283 // We follow a quite simple depth-first search from the output, although
 284 // without any explicit recursion.
 285 void EffectChain::construct_glsl_programs(Node *output)
 286 {
 287         // Which effects have already been completed in this phase?
 288         // We need to keep track of it, as an effect with multiple outputs
 289         // could otherwise be calculate multiple times.
 290         std::set<Node *> completed_effects;
 291
 292         // Effects in the current phase, as well as inputs (outputs from other phases
 293         // that we depend on). Note that since we start iterating from the end,
 294         // the effect list will be in the reverse order.
 295         std::vector<Node *> this_phase_inputs;
 296         std::vector<Node *> this_phase_effects;
 297
 298         // Effects that we have yet to calculate, but that we know should
 299         // be in the current phase.
 300         std::stack<Node *> effects_todo_this_phase;
 301
 302         // Effects that we have yet to calculate, but that come from other phases.
 303         // We delay these until we have this phase done in its entirety,
 304         // at which point we pick any of them and start a new phase from that.
 305         std::stack<Node *> effects_todo_other_phases;
 306
 307         effects_todo_this_phase.push(output);
 308
 309         for ( ;; ) {  // Termination condition within loop.
 310                 if (!effects_todo_this_phase.empty()) {
 311                         // OK, we have more to do this phase.
 312                         Node *node = effects_todo_this_phase.top();
 313                         effects_todo_this_phase.pop();
 314
 315                         // This should currently only happen for effects that are phase outputs,
 316                         // and we throw those out separately below.
 317                         assert(completed_effects.count(node) == 0);
 318
 319                         this_phase_effects.push_back(node);
 320                         completed_effects.insert(node);
 321
 322                         // Find all the dependencies of this effect, and add them to the stack.
 323                         std::vector<Node *> deps = node->incoming_links;
 324                         assert(node->effect->num_inputs() == deps.size());
 325                         for (unsigned i = 0; i < deps.size(); ++i) {
 326                                 bool start_new_phase = false;
 327
 328                                 // FIXME: If we sample directly from a texture, we won't need this.
 329                                 if (node->effect->needs_texture_bounce()) {
 330                                         start_new_phase = true;
 331                                 }
 332
 333                                 if (deps[i]->outgoing_links.size() > 1 && deps[i]->effect->num_inputs() > 0) {
 334                                         // More than one effect uses this as the input,
 335                                         // and it is not a texture itself.
 336                                         // The easiest thing to do (and probably also the safest
 337                                         // performance-wise in most cases) is to bounce it to a texture
 338                                         // and then let the next passes read from that.
 339                                         start_new_phase = true;
 340                                 }
 341
 342                                 if (deps[i]->effect->changes_output_size()) {
 343                                         start_new_phase = true;
 344                                 }
 345
 346                                 if (start_new_phase) {
 347                                         effects_todo_other_phases.push(deps[i]);
 348                                         this_phase_inputs.push_back(deps[i]);
 349                                 } else {
 350                                         effects_todo_this_phase.push(deps[i]);
 351                                 }
 352                         }
 353                         continue;
 354                 }
 355
 356                 // No more effects to do this phase. Take all the ones we have,
 357                 // and create a GLSL program for it.
 358                 if (!this_phase_effects.empty()) {
 359                         reverse(this_phase_effects.begin(), this_phase_effects.end());
 360                         phases.push_back(compile_glsl_program(this_phase_inputs, this_phase_effects));
 361                         this_phase_effects.back()->phase = phases.back();
 362                         this_phase_inputs.clear();
 363                         this_phase_effects.clear();
 364                 }
 365                 assert(this_phase_inputs.empty());
 366                 assert(this_phase_effects.empty());
 367
 368                 // If we have no effects left, exit.
 369                 if (effects_todo_other_phases.empty()) {
 370                         break;
 371                 }
 372
 373                 Node *node = effects_todo_other_phases.top();
 374                 effects_todo_other_phases.pop();
 375
 376                 if (completed_effects.count(node) == 0) {
 377                         // Start a new phase, calculating from this effect.
 378                         effects_todo_this_phase.push(node);
 379                 }
 380         }
 381
 382         // Finally, since the phases are found from the output but must be executed
 383         // from the input(s), reverse them, too.
 384         std::reverse(phases.begin(), phases.end());
 385 }
 386
 387 void EffectChain::output_dot(const char *filename)
 388 {
 389         FILE *fp = fopen(filename, "w");
 390         if (fp == NULL) {
 391                 perror(filename);
 392                 exit(1);
 393         }
 394
 395         fprintf(fp, "digraph G {\n");
 396         for (unsigned i = 0; i < nodes.size(); ++i) {
 397                 fprintf(fp, "  n%ld [label=\"%s\"];\n", (long)nodes[i], nodes[i]->effect->effect_type_id().c_str());
 398                 for (unsigned j = 0; j < nodes[i]->outgoing_links.size(); ++j) {
 399                         std::vector<std::string> labels;
 400
 401                         if (nodes[i]->outgoing_links[j]->effect->needs_texture_bounce()) {
 402                                 labels.push_back("needs_bounce");
 403                         }
 404                         if (nodes[i]->effect->changes_output_size()) {
 405                                 labels.push_back("resize");
 406                         }
 407
 408                         switch (nodes[i]->output_color_space) {
 409                         case COLORSPACE_INVALID:
 410                                 labels.push_back("spc[invalid]");
 411                                 break;
 412                         case COLORSPACE_REC_601_525:
 413                                 labels.push_back("spc[rec601-525]");
 414                                 break;
 415                         case COLORSPACE_REC_601_625:
 416                                 labels.push_back("spc[rec601-625]");
 417                                 break;
 418                         default:
 419                                 break;
 420                         }
 421
 422                         switch (nodes[i]->output_gamma_curve) {
 423                         case GAMMA_INVALID:
 424                                 labels.push_back("gamma[invalid]");
 425                                 break;
 426                         case GAMMA_sRGB:
 427                                 labels.push_back("gamma[sRGB]");
 428                                 break;
 429                         case GAMMA_REC_601:  // and GAMMA_REC_709
 430                                 labels.push_back("gamma[rec601/709]");
 431                                 break;
 432                         default:
 433                                 break;
 434                         }
 435
 436                         if (labels.empty()) {
 437                                 fprintf(fp, "  n%ld -> n%ld;\n", (long)nodes[i], (long)nodes[i]->outgoing_links[j]);
 438                         } else {
 439                                 std::string label = labels[0];
 440                                 for (unsigned k = 1; k < labels.size(); ++k) {
 441                                         label += ", " + labels[k];
 442                                 }
 443                                 fprintf(fp, "  n%ld -> n%ld [label=\"%s\"];\n", (long)nodes[i], (long)nodes[i]->outgoing_links[j], label.c_str());
 444                         }
 445                 }
 446         }
 447         fprintf(fp, "}\n");
 448
 449         fclose(fp);
 450 }
 451
 452 unsigned EffectChain::fit_rectangle_to_aspect(unsigned width, unsigned height)
 453 {
 454         if (float(width) * aspect_denom >= float(height) * aspect_nom) {
 455                 // Same aspect, or W/H > aspect (image is wider than the frame).
 456                 // In either case, keep width.
 457                 return width;
 458         } else {
 459                 // W/H < aspect (image is taller than the frame), so keep height,
 460                 // and adjust width correspondingly.
 461                 return lrintf(height * aspect_nom / aspect_denom);
 462         }
 463 }
 464
 465 // Propagate input texture sizes throughout, and inform effects downstream.
 466 // (Like a lot of other code, we depend on effects being in topological order.)
 467 void EffectChain::inform_input_sizes(Phase *phase)
 468 {
 469         // All effects that have a defined size (inputs and RTT inputs)
 470         // get that. Reset all others.
 471         for (unsigned i = 0; i < phase->effects.size(); ++i) {
 472                 Node *node = phase->effects[i];
 473                 if (node->effect->num_inputs() == 0) {
 474                         Input *input = static_cast<Input *>(node->effect);
 475                         node->output_width = input->get_width();
 476                         node->output_height = input->get_height();
 477                         assert(node->output_width != 0);
 478                         assert(node->output_height != 0);
 479                 } else {
 480                         node->output_width = node->output_height = 0;
 481                 }
 482         }
 483         for (unsigned i = 0; i < phase->inputs.size(); ++i) {
 484                 Node *input = phase->inputs[i];
 485                 input->output_width = input->phase->output_width;
 486                 input->output_height = input->phase->output_height;
 487                 assert(input->output_width != 0);
 488                 assert(input->output_height != 0);
 489         }
 490
 491         // Now propagate from the inputs towards the end, and inform as we go.
 492         // The rules are simple:
 493         //
 494         //   1. Don't touch effects that already have given sizes (ie., inputs).
 495         //   2. If all of your inputs have the same size, that will be your output size.
 496         //   3. Otherwise, your output size is 0x0.
 497         for (unsigned i = 0; i < phase->effects.size(); ++i) {
 498                 Node *node = phase->effects[i];
 499                 if (node->effect->num_inputs() == 0) {
 500                         continue;
 501                 }
 502                 unsigned this_output_width = 0;
 503                 unsigned this_output_height = 0;
 504                 for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
 505                         Node *input = node->incoming_links[j];
 506                         node->effect->inform_input_size(j, input->output_width, input->output_height);
 507                         if (j == 0) {
 508                                 this_output_width = input->output_width;
 509                                 this_output_height = input->output_height;
 510                         } else if (input->output_width != this_output_width || input->output_height != this_output_height) {
 511                                 // Inputs disagree.
 512                                 this_output_width = 0;
 513                                 this_output_height = 0;
 514                         }
 515                 }
 516                 node->output_width = this_output_width;
 517                 node->output_height = this_output_height;
 518         }
 519 }
 520
 521 // Note: You should call inform_input_sizes() before this, as the last effect's
 522 // desired output size might change based on the inputs.
 523 void EffectChain::find_output_size(Phase *phase)
 524 {
 525         Node *output_node = phase->effects.back();
 526
 527         // If the last effect explicitly sets an output size, use that.
 528         if (output_node->effect->changes_output_size()) {
 529                 output_node->effect->get_output_size(&phase->output_width, &phase->output_height);
 530                 return;
 531         }
 532
 533         // If not, look at the input phases and textures.
 534         // We select the largest one (by fit into the current aspect).
 535         unsigned best_width = 0;
 536         for (unsigned i = 0; i < phase->inputs.size(); ++i) {
 537                 Node *input = phase->inputs[i];
 538                 assert(input->phase->output_width != 0);
 539                 assert(input->phase->output_height != 0);
 540                 unsigned width = fit_rectangle_to_aspect(input->phase->output_width, input->phase->output_height);
 541                 if (width > best_width) {
 542                         best_width = width;
 543                 }
 544         }
 545         for (unsigned i = 0; i < phase->effects.size(); ++i) {
 546                 Effect *effect = phase->effects[i]->effect;
 547                 if (effect->num_inputs() != 0) {
 548                         continue;
 549                 }
 550
 551                 Input *input = static_cast<Input *>(effect);
 552                 unsigned width = fit_rectangle_to_aspect(input->get_width(), input->get_height());
 553                 if (width > best_width) {
 554                         best_width = width;
 555                 }
 556         }
 557         assert(best_width != 0);
 558         phase->output_width = best_width;
 559         phase->output_height = best_width * aspect_denom / aspect_nom;
 560 }
 561
 562 void EffectChain::sort_nodes_topologically()
 563 {
 564         std::set<Node *> visited_nodes;
 565         std::vector<Node *> sorted_list;
 566         for (unsigned i = 0; i < nodes.size(); ++i) {
 567                 if (nodes[i]->incoming_links.size() == 0) {
 568                         topological_sort_visit_node(nodes[i], &visited_nodes, &sorted_list);
 569                 }
 570         }
 571         reverse(sorted_list.begin(), sorted_list.end());
 572         nodes = sorted_list;
 573 }
 574
 575 void EffectChain::topological_sort_visit_node(Node *node, std::set<Node *> *visited_nodes, std::vector<Node *> *sorted_list)
 576 {
 577         if (visited_nodes->count(node) != 0) {
 578                 return;
 579         }
 580         visited_nodes->insert(node);
 581         for (unsigned i = 0; i < node->outgoing_links.size(); ++i) {
 582                 topological_sort_visit_node(node->outgoing_links[i], visited_nodes, sorted_list);
 583         }
 584         sorted_list->push_back(node);
 585 }
 586
 587 // Propagate gamma and color space information as far as we can in the graph.
 588 // The rules are simple: Anything where all the inputs agree, get that as
 589 // output as well. Anything else keeps having *_INVALID.
 590 void EffectChain::propagate_gamma_and_color_space()
 591 {
 592         // We depend on going through the nodes in order.
 593         sort_nodes_topologically();
 594
 595         for (unsigned i = 0; i < nodes.size(); ++i) {
 596                 Node *node = nodes[i];
 597                 if (node->disabled) {
 598                         continue;
 599                 }
 600                 assert(node->incoming_links.size() == node->effect->num_inputs());
 601                 if (node->incoming_links.size() == 0) {
 602                         assert(node->output_color_space != COLORSPACE_INVALID);
 603                         assert(node->output_gamma_curve != GAMMA_INVALID);
 604                         continue;
 605                 }
 606
 607                 ColorSpace color_space = node->incoming_links[0]->output_color_space;
 608                 GammaCurve gamma_curve = node->incoming_links[0]->output_gamma_curve;
 609                 for (unsigned j = 1; j < node->incoming_links.size(); ++j) {
 610                         if (node->incoming_links[j]->output_color_space != color_space) {
 611                                 color_space = COLORSPACE_INVALID;
 612                         }
 613                         if (node->incoming_links[j]->output_gamma_curve != gamma_curve) {
 614                                 gamma_curve = GAMMA_INVALID;
 615                         }
 616                 }
 617
 618                 // The conversion effects already have their outputs set correctly,
 619                 // so leave them alone.
 620                 if (node->effect->effect_type_id() != "ColorSpaceConversionEffect") {
 621                         node->output_color_space = color_space;
 622                 }
 623                 if (node->effect->effect_type_id() != "GammaCompressionEffect" &&
 624                     node->effect->effect_type_id() != "GammaExpansionEffect") {
 625                         node->output_gamma_curve = gamma_curve;
 626                 }
 627         }
 628 }
 629
 630 bool EffectChain::node_needs_colorspace_fix(Node *node)
 631 {
 632         if (node->disabled) {
 633                 return false;
 634         }
 635         if (node->effect->num_inputs() == 0) {
 636                 return false;
 637         }
 638
 639         // propagate_gamma_and_color_space() has already set our output
 640         // to COLORSPACE_INVALID if the inputs differ, so we can rely on that.
 641         if (node->output_color_space == COLORSPACE_INVALID) {
 642                 return true;
 643         }
 644         return (node->effect->needs_srgb_primaries() && node->output_color_space != COLORSPACE_sRGB);
 645 }
 646
 647 // Fix up color spaces so that there are no COLORSPACE_INVALID nodes left in
 648 // the graph. Our strategy is not always optimal, but quite simple:
 649 // Find an effect that's as early as possible where the inputs are of
 650 // unacceptable colorspaces (that is, either different, or, if the effect only
 651 // wants sRGB, not sRGB.) Add appropriate conversions on all its inputs,
 652 // propagate the information anew, and repeat until there are no more such
 653 // effects.
 654 void EffectChain::fix_internal_color_spaces()
 655 {
 656         unsigned colorspace_propagation_pass = 0;
 657         bool found_any;
 658         do {
 659                 found_any = false;
 660                 for (unsigned i = 0; i < nodes.size(); ++i) {
 661                         Node *node = nodes[i];
 662                         if (!node_needs_colorspace_fix(node)) {
 663                                 continue;
 664                         }
 665
 666                         // Go through each input that is not sRGB, and insert
 667                         // a colorspace conversion before it.
 668                         for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
 669                                 Node *input = node->incoming_links[j];
 670                                 assert(input->output_color_space != COLORSPACE_INVALID);
 671                                 if (input->output_color_space == COLORSPACE_sRGB) {
 672                                         continue;
 673                                 }
 674                                 Node *conversion = add_node(new ColorSpaceConversionEffect());
 675                                 conversion->effect->set_int("source_space", input->output_color_space);
 676                                 conversion->effect->set_int("destination_space", COLORSPACE_sRGB);
 677                                 conversion->output_color_space = COLORSPACE_sRGB;
 678                                 insert_node_between(input, conversion, node);
 679                         }
 680
 681                         // Re-sort topologically, and propagate the new information.
 682                         propagate_gamma_and_color_space();
 683
 684                         found_any = true;
 685                         break;
 686                 }
 687
 688                 char filename[256];
 689                 sprintf(filename, "step3-colorspacefix-iter%u.dot", ++colorspace_propagation_pass);
 690                 output_dot(filename);
 691                 assert(colorspace_propagation_pass < 100);
 692         } while (found_any);
 693
 694         for (unsigned i = 0; i < nodes.size(); ++i) {
 695                 Node *node = nodes[i];
 696                 if (node->disabled) {
 697                         continue;
 698                 }
 699                 assert(node->output_color_space != COLORSPACE_INVALID);
 700         }
 701 }
 702
 703 // Make so that the output is in the desired color space.
 704 void EffectChain::fix_output_color_space()
 705 {
 706         Node *output = find_output_node();
 707         if (output->output_color_space != output_format.color_space) {
 708                 Node *conversion = add_node(new ColorSpaceConversionEffect());
 709                 conversion->effect->set_int("source_space", output->output_color_space);
 710                 conversion->effect->set_int("destination_space", output_format.color_space);
 711                 conversion->output_color_space = output_format.color_space;
 712                 connect_nodes(output, conversion);
 713         }
 714 }
 715
 716 bool EffectChain::node_needs_gamma_fix(Node *node)
 717 {
 718         if (node->disabled) {
 719                 return false;
 720         }
 721
 722         // Small hack since the output is not an explicit node:
 723         // If we are the last node and our output is in the wrong
 724         // space compared to EffectChain's output, we need to fix it.
 725         // This will only take us to linear, but fix_output_gamma()
 726         // will come and take us to the desired output gamma
 727         // if it is needed.
 728         //
 729         // This needs to be before everything else, since it could
 730         // even apply to inputs (if they are the only effect).
 731         if (node->outgoing_links.empty() &&
 732             node->output_gamma_curve != output_format.gamma_curve &&
 733             node->output_gamma_curve != GAMMA_LINEAR) {
 734                 return true;
 735         }
 736
 737         if (node->effect->num_inputs() == 0) {
 738                 return false;
 739         }
 740
 741         // propagate_gamma_and_color_space() has already set our output
 742         // to GAMMA_INVALID if the inputs differ, so we can rely on that,
 743         // except for GammaCompressionEffect.
 744         if (node->output_gamma_curve == GAMMA_INVALID) {
 745                 return true;
 746         }
 747         if (node->effect->effect_type_id() == "GammaCompressionEffect") {
 748                 assert(node->incoming_links.size() == 1);
 749                 return node->incoming_links[0]->output_gamma_curve != GAMMA_LINEAR;
 750         }
 751
 752         return (node->effect->needs_linear_light() && node->output_gamma_curve != GAMMA_LINEAR);
 753 }
 754
 755 // Very similar to fix_internal_color_spaces(), but for gamma.
 756 // There is one difference, though; before we start adding conversion nodes,
 757 // we see if we can get anything out of asking the sources to deliver
 758 // linear gamma directly. fix_internal_gamma_by_asking_inputs()
 759 // does that part, while fix_internal_gamma_by_inserting_nodes()
 760 // inserts nodes as needed afterwards.
 761 void EffectChain::fix_internal_gamma_by_asking_inputs(unsigned step)
 762 {
 763         unsigned gamma_propagation_pass = 0;
 764         bool found_any;
 765         do {
 766                 found_any = false;
 767                 for (unsigned i = 0; i < nodes.size(); ++i) {
 768                         Node *node = nodes[i];
 769                         if (!node_needs_gamma_fix(node)) {
 770                                 continue;
 771                         }
 772
 773                         // See if all inputs can give us linear gamma. If not, leave it.
 774                         std::vector<Node *> nonlinear_inputs;
 775                         find_all_nonlinear_inputs(node, &nonlinear_inputs);
 776                         assert(!nonlinear_inputs.empty());
 777
 778                         bool all_ok = true;
 779                         for (unsigned i = 0; i < nonlinear_inputs.size(); ++i) {
 780                                 Input *input = static_cast<Input *>(nonlinear_inputs[i]->effect);
 781                                 all_ok &= input->can_output_linear_gamma();
 782                         }
 783
 784                         if (!all_ok) {
 785                                 continue;
 786                         }
 787
 788                         for (unsigned i = 0; i < nonlinear_inputs.size(); ++i) {
 789                                 nonlinear_inputs[i]->effect->set_int("output_linear_gamma", 1);
 790                                 nonlinear_inputs[i]->output_gamma_curve = GAMMA_LINEAR;
 791                         }
 792
 793                         // Re-sort topologically, and propagate the new information.
 794                         propagate_gamma_and_color_space();
 795
 796                         found_any = true;
 797                         break;
 798                 }
 799
 800                 char filename[256];
 801                 sprintf(filename, "step%u-gammafix-iter%u.dot", step, ++gamma_propagation_pass);
 802                 output_dot(filename);
 803                 assert(gamma_propagation_pass < 100);
 804         } while (found_any);
 805 }
 806
 807 void EffectChain::fix_internal_gamma_by_inserting_nodes(unsigned step)
 808 {
 809         unsigned gamma_propagation_pass = 0;
 810         bool found_any;
 811         do {
 812                 found_any = false;
 813                 for (unsigned i = 0; i < nodes.size(); ++i) {
 814                         Node *node = nodes[i];
 815                         if (!node_needs_gamma_fix(node)) {
 816                                 continue;
 817                         }
 818
 819                         // Special case: We could be an input and still be asked to
 820                         // fix our gamma; if so, we should be the only node
 821                         // (as node_needs_gamma_fix() would only return true in
 822                         // for an input in that case). That means we should insert
 823                         // a conversion node _after_ ourselves.
 824                         if (node->incoming_links.empty()) {
 825                                 assert(node->outgoing_links.empty());
 826                                 Node *conversion = add_node(new GammaExpansionEffect());
 827                                 conversion->effect->set_int("source_curve", node->output_gamma_curve);
 828                                 conversion->output_gamma_curve = GAMMA_LINEAR;
 829                                 connect_nodes(node, conversion);
 830                         }
 831
 832                         // If not, go through each input that is not linear gamma,
 833                         // and insert a gamma conversion before it.
 834                         for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
 835                                 Node *input = node->incoming_links[j];
 836                                 assert(input->output_gamma_curve != GAMMA_INVALID);
 837                                 if (input->output_gamma_curve == GAMMA_LINEAR) {
 838                                         continue;
 839                                 }
 840                                 Node *conversion = add_node(new GammaExpansionEffect());
 841                                 conversion->effect->set_int("source_curve", input->output_gamma_curve);
 842                                 conversion->output_gamma_curve = GAMMA_LINEAR;
 843                                 insert_node_between(input, conversion, node);
 844                         }
 845
 846                         // Re-sort topologically, and propagate the new information.
 847                         propagate_gamma_and_color_space();
 848
 849                         found_any = true;
 850                         break;
 851                 }
 852
 853                 char filename[256];
 854                 sprintf(filename, "step%u-gammafix-iter%u.dot", step, ++gamma_propagation_pass);
 855                 output_dot(filename);
 856                 assert(gamma_propagation_pass < 100);
 857         } while (found_any);
 858
 859         for (unsigned i = 0; i < nodes.size(); ++i) {
 860                 Node *node = nodes[i];
 861                 if (node->disabled) {
 862                         continue;
 863                 }
 864                 assert(node->output_gamma_curve != GAMMA_INVALID);
 865         }
 866 }
 867
 868 // Make so that the output is in the desired gamma.
 869 // Note that this assumes linear input gamma, so it might create the need
 870 // for another pass of fix_internal_gamma().
 871 void EffectChain::fix_output_gamma()
 872 {
 873         Node *output = find_output_node();
 874         if (output->output_gamma_curve != output_format.gamma_curve) {
 875                 Node *conversion = add_node(new GammaCompressionEffect());
 876                 conversion->effect->set_int("destination_curve", output_format.gamma_curve);
 877                 conversion->output_gamma_curve = output_format.gamma_curve;
 878                 connect_nodes(output, conversion);
 879         }
 880 }
 881
 882 // Find the output node. This is, simply, one that has no outgoing links.
 883 // If there are multiple ones, the graph is malformed (we do not support
 884 // multiple outputs right now).
 885 Node *EffectChain::find_output_node()
 886 {
 887         std::vector<Node *> output_nodes;
 888         for (unsigned i = 0; i < nodes.size(); ++i) {
 889                 Node *node = nodes[i];
 890                 if (node->disabled) {
 891                         continue;
 892                 }
 893                 if (node->outgoing_links.empty()) {
 894                         output_nodes.push_back(node);
 895                 }
 896         }
 897         assert(output_nodes.size() == 1);
 898         return output_nodes[0];
 899 }
 900
 901 void EffectChain::finalize()
 902 {
 903         // Output the graph as it is before we do any conversions on it.
 904         output_dot("step0-start.dot");
 905
 906         // Give each effect in turn a chance to rewrite its own part of the graph.
 907         // Note that if more effects are added as part of this, they will be
 908         // picked up as part of the same for loop, since they are added at the end.
 909         for (unsigned i = 0; i < nodes.size(); ++i) {
 910                 nodes[i]->effect->rewrite_graph(this, nodes[i]);
 911         }
 912         output_dot("step1-rewritten.dot");
 913
 914         propagate_gamma_and_color_space();
 915         output_dot("step2-propagated.dot");
 916
 917         fix_internal_color_spaces();
 918         fix_output_color_space();
 919         output_dot("step4-output-colorspacefix.dot");
 920
 921         // Note that we need to fix gamma after colorspace conversion,
 922         // because colorspace conversions might create needs for gamma conversions.
 923         // Also, we need to run an extra pass of fix_internal_gamma() after
 924         // fixing the output gamma, as we only have conversions to/from linear.
 925         fix_internal_gamma_by_asking_inputs(5);
 926         fix_internal_gamma_by_inserting_nodes(6);
 927         fix_output_gamma();
 928         output_dot("step7-output-gammafix.dot");
 929         fix_internal_gamma_by_asking_inputs(8);
 930         fix_internal_gamma_by_inserting_nodes(9);
 931
 932         output_dot("step10-final.dot");
 933
 934         // Construct all needed GLSL programs, starting at the output.
 935         construct_glsl_programs(find_output_node());
 936
 937         // If we have more than one phase, we need intermediate render-to-texture.
 938         // Construct an FBO, and then as many textures as we need.
 939         // We choose the simplest option of having one texture per output,
 940         // since otherwise this turns into an (albeit simple)
 941         // register allocation problem.
 942         if (phases.size() > 1) {
 943                 glGenFramebuffers(1, &fbo);
 944
 945                 for (unsigned i = 0; i < phases.size() - 1; ++i) {
 946                         inform_input_sizes(phases[i]);
 947                         find_output_size(phases[i]);
 948
 949                         Node *output_node = phases[i]->effects.back();
 950                         glGenTextures(1, &output_node->output_texture);
 951                         check_error();
 952                         glBindTexture(GL_TEXTURE_2D, output_node->output_texture);
 953                         check_error();
 954                         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
 955                         check_error();
 956                         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
 957                         check_error();
 958                         glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA16F_ARB, phases[i]->output_width, phases[i]->output_height, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
 959                         check_error();
 960
 961                         output_node->output_texture_width = phases[i]->output_width;
 962                         output_node->output_texture_height = phases[i]->output_height;
 963                 }
 964                 inform_input_sizes(phases.back());
 965         }
 966
 967         for (unsigned i = 0; i < inputs.size(); ++i) {
 968                 inputs[i]->finalize();
 969         }
 970
 971         assert(phases[0]->inputs.empty());
 972
 973         finalized = true;
 974 }
 975
 976 void EffectChain::render_to_fbo(GLuint fbo, unsigned width, unsigned height)
 977 {
 978         assert(finalized);
 979
 980         // Save original viewport.
 981         GLuint x = 0, y = 0;
 982
 983         if (width == 0 && height == 0) {
 984                 GLint viewport[4];
 985                 glGetIntegerv(GL_VIEWPORT, viewport);
 986                 x = viewport[0];
 987                 y = viewport[1];
 988                 width = viewport[2];
 989                 height = viewport[3];
 990         }
 991
 992         // Basic state.
 993         glDisable(GL_BLEND);
 994         check_error();
 995         glDisable(GL_DEPTH_TEST);
 996         check_error();
 997         glDepthMask(GL_FALSE);
 998         check_error();
 999
1000         glMatrixMode(GL_PROJECTION);
1001         glLoadIdentity();
1002         glOrtho(0.0, 1.0, 0.0, 1.0, 0.0, 1.0);
1003
1004         glMatrixMode(GL_MODELVIEW);
1005         glLoadIdentity();
1006
1007         if (phases.size() > 1) {
1008                 glBindFramebuffer(GL_FRAMEBUFFER, fbo);
1009                 check_error();
1010         }
1011
1012         std::set<Node *> generated_mipmaps;
1013
1014         for (unsigned phase = 0; phase < phases.size(); ++phase) {
1015                 // See if the requested output size has changed. If so, we need to recreate
1016                 // the texture (and before we start setting up inputs).
1017                 inform_input_sizes(phases[phase]);
1018                 if (phase != phases.size() - 1) {
1019                         find_output_size(phases[phase]);
1020
1021                         Node *output_node = phases[phase]->effects.back();
1022
1023                         if (output_node->output_texture_width != phases[phase]->output_width ||
1024                             output_node->output_texture_height != phases[phase]->output_height) {
1025                                 glActiveTexture(GL_TEXTURE0);
1026                                 check_error();
1027                                 glBindTexture(GL_TEXTURE_2D, output_node->output_texture);
1028                                 check_error();
1029                                 glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA16F_ARB, phases[phase]->output_width, phases[phase]->output_height, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
1030                                 check_error();
1031                                 glBindTexture(GL_TEXTURE_2D, 0);
1032                                 check_error();
1033
1034                                 output_node->output_texture_width = phases[phase]->output_width;
1035                                 output_node->output_texture_height = phases[phase]->output_height;
1036                         }
1037                 }
1038
1039                 glUseProgram(phases[phase]->glsl_program_num);
1040                 check_error();
1041
1042                 // Set up RTT inputs for this phase.
1043                 for (unsigned sampler = 0; sampler < phases[phase]->inputs.size(); ++sampler) {
1044                         glActiveTexture(GL_TEXTURE0 + sampler);
1045                         Node *input = phases[phase]->inputs[sampler];
1046                         glBindTexture(GL_TEXTURE_2D, input->output_texture);
1047                         check_error();
1048                         if (phases[phase]->input_needs_mipmaps) {
1049                                 if (generated_mipmaps.count(input) == 0) {
1050                                         glGenerateMipmap(GL_TEXTURE_2D);
1051                                         check_error();
1052                                         generated_mipmaps.insert(input);
1053                                 }
1054                                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_NEAREST);
1055                                 check_error();
1056                         } else {
1057                                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
1058                                 check_error();
1059                         }
1060
1061                         std::string texture_name = std::string("tex_") + input->effect_id;
1062                         glUniform1i(glGetUniformLocation(phases[phase]->glsl_program_num, texture_name.c_str()), sampler);
1063                         check_error();
1064                 }
1065
1066                 // And now the output.
1067                 if (phase == phases.size() - 1) {
1068                         // Last phase goes to the output the user specified.
1069                         glBindFramebuffer(GL_FRAMEBUFFER, fbo);
1070                         check_error();
1071                         glViewport(x, y, width, height);
1072                 } else {
1073                         Node *output_node = phases[phase]->effects.back();
1074                         glFramebufferTexture2D(
1075                                 GL_FRAMEBUFFER,
1076                                 GL_COLOR_ATTACHMENT0,
1077                                 GL_TEXTURE_2D,
1078                                 output_node->output_texture,
1079                                 0);
1080                         check_error();
1081                         glViewport(0, 0, phases[phase]->output_width, phases[phase]->output_height);
1082                 }
1083
1084                 // Give the required parameters to all the effects.
1085                 unsigned sampler_num = phases[phase]->inputs.size();
1086                 for (unsigned i = 0; i < phases[phase]->effects.size(); ++i) {
1087                         Node *node = phases[phase]->effects[i];
1088                         node->effect->set_gl_state(phases[phase]->glsl_program_num, node->effect_id, &sampler_num);
1089                         check_error();
1090                 }
1091
1092                 // Now draw!
1093                 glBegin(GL_QUADS);
1094
1095                 glTexCoord2f(0.0f, 0.0f);
1096                 glVertex2f(0.0f, 0.0f);
1097
1098                 glTexCoord2f(1.0f, 0.0f);
1099                 glVertex2f(1.0f, 0.0f);
1100
1101                 glTexCoord2f(1.0f, 1.0f);
1102                 glVertex2f(1.0f, 1.0f);
1103
1104                 glTexCoord2f(0.0f, 1.0f);
1105                 glVertex2f(0.0f, 1.0f);
1106
1107                 glEnd();
1108                 check_error();
1109
1110                 for (unsigned i = 0; i < phases[phase]->effects.size(); ++i) {
1111                         Node *node = phases[phase]->effects[i];
1112                         node->effect->clear_gl_state();
1113                 }
1114         }
1115 }