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           fbo(0),
  25           finalized(false) {}
  26
  27 EffectChain::~EffectChain()
  28 {
  29         for (unsigned i = 0; i < nodes.size(); ++i) {
  30                 if (nodes[i]->output_texture != 0) {
  31                         glDeleteTextures(1, &nodes[i]->output_texture);
  32                 }
  33                 delete nodes[i]->effect;
  34                 delete nodes[i];
  35         }
  36         for (unsigned i = 0; i < phases.size(); ++i) {
  37                 glDeleteProgram(phases[i]->glsl_program_num);
  38                 glDeleteShader(phases[i]->vertex_shader);
  39                 glDeleteShader(phases[i]->fragment_shader);
  40                 delete phases[i];
  41         }
  42         if (fbo != 0) {
  43                 glDeleteFramebuffers(1, &fbo);
  44         }
  45 }
  46
  47 Input *EffectChain::add_input(Input *input)
  48 {
  49         inputs.push_back(input);
  50
  51         Node *node = add_node(input);
  52         node->output_color_space = input->get_color_space();
  53         node->output_gamma_curve = input->get_gamma_curve();
  54         return input;
  55 }
  56
  57 void EffectChain::add_output(const ImageFormat &format)
  58 {
  59         output_format = format;
  60 }
  61
  62 Node *EffectChain::add_node(Effect *effect)
  63 {
  64         char effect_id[256];
  65         sprintf(effect_id, "eff%u", (unsigned)nodes.size());
  66
  67         Node *node = new Node;
  68         node->effect = effect;
  69         node->disabled = false;
  70         node->effect_id = effect_id;
  71         node->output_color_space = COLORSPACE_INVALID;
  72         node->output_gamma_curve = GAMMA_INVALID;
  73         node->output_texture = 0;
  74
  75         nodes.push_back(node);
  76         node_map[effect] = node;
  77         return node;
  78 }
  79
  80 void EffectChain::connect_nodes(Node *sender, Node *receiver)
  81 {
  82         sender->outgoing_links.push_back(receiver);
  83         receiver->incoming_links.push_back(sender);
  84 }
  85
  86 void EffectChain::replace_receiver(Node *old_receiver, Node *new_receiver)
  87 {
  88         new_receiver->incoming_links = old_receiver->incoming_links;
  89         old_receiver->incoming_links.clear();
  90
  91         for (unsigned i = 0; i < new_receiver->incoming_links.size(); ++i) {
  92                 Node *sender = new_receiver->incoming_links[i];
  93                 for (unsigned j = 0; j < sender->outgoing_links.size(); ++j) {
  94                         if (sender->outgoing_links[j] == old_receiver) {
  95                                 sender->outgoing_links[j] = new_receiver;
  96                         }
  97                 }
  98         }
  99 }
 100
 101 void EffectChain::replace_sender(Node *old_sender, Node *new_sender)
 102 {
 103         new_sender->outgoing_links = old_sender->outgoing_links;
 104         old_sender->outgoing_links.clear();
 105
 106         for (unsigned i = 0; i < new_sender->outgoing_links.size(); ++i) {
 107                 Node *receiver = new_sender->outgoing_links[i];
 108                 for (unsigned j = 0; j < receiver->incoming_links.size(); ++j) {
 109                         if (receiver->incoming_links[j] == old_sender) {
 110                                 receiver->incoming_links[j] = new_sender;
 111                         }
 112                 }
 113         }
 114 }
 115
 116 void EffectChain::insert_node_between(Node *sender, Node *middle, Node *receiver)
 117 {
 118         for (unsigned i = 0; i < sender->outgoing_links.size(); ++i) {
 119                 if (sender->outgoing_links[i] == receiver) {
 120                         sender->outgoing_links[i] = middle;
 121                         middle->incoming_links.push_back(sender);
 122                 }
 123         }
 124         for (unsigned i = 0; i < receiver->incoming_links.size(); ++i) {
 125                 if (receiver->incoming_links[i] == sender) {
 126                         receiver->incoming_links[i] = middle;
 127                         middle->outgoing_links.push_back(receiver);
 128                 }
 129         }
 130
 131         assert(middle->incoming_links.size() == middle->effect->num_inputs());
 132 }
 133
 134 void EffectChain::find_all_nonlinear_inputs(Node *node, std::vector<Node *> *nonlinear_inputs)
 135 {
 136         if (node->output_gamma_curve == GAMMA_LINEAR &&
 137             node->effect->effect_type_id() != "GammaCompressionEffect") {
 138                 return;
 139         }
 140         if (node->effect->num_inputs() == 0) {
 141                 nonlinear_inputs->push_back(node);
 142         } else {
 143                 assert(node->effect->num_inputs() == node->incoming_links.size());
 144                 for (unsigned i = 0; i < node->incoming_links.size(); ++i) {
 145                         find_all_nonlinear_inputs(node->incoming_links[i], nonlinear_inputs);
 146                 }
 147         }
 148 }
 149
 150 Effect *EffectChain::add_effect(Effect *effect, const std::vector<Effect *> &inputs)
 151 {
 152         assert(inputs.size() == effect->num_inputs());
 153         Node *node = add_node(effect);
 154         for (unsigned i = 0; i < inputs.size(); ++i) {
 155                 assert(node_map.count(inputs[i]) != 0);
 156                 connect_nodes(node_map[inputs[i]], node);
 157         }
 158         return effect;
 159 }
 160
 161 // GLSL pre-1.30 doesn't support token pasting. Replace PREFIX(x) with <effect_id>_x.
 162 std::string replace_prefix(const std::string &text, const std::string &prefix)
 163 {
 164         std::string output;
 165         size_t start = 0;
 166
 167         while (start < text.size()) {
 168                 size_t pos = text.find("PREFIX(", start);
 169                 if (pos == std::string::npos) {
 170                         output.append(text.substr(start, std::string::npos));
 171                         break;
 172                 }
 173
 174                 output.append(text.substr(start, pos - start));
 175                 output.append(prefix);
 176                 output.append("_");
 177
 178                 pos += strlen("PREFIX(");
 179
 180                 // Output stuff until we find the matching ), which we then eat.
 181                 int depth = 1;
 182                 size_t end_arg_pos = pos;
 183                 while (end_arg_pos < text.size()) {
 184                         if (text[end_arg_pos] == '(') {
 185                                 ++depth;
 186                         } else if (text[end_arg_pos] == ')') {
 187                                 --depth;
 188                                 if (depth == 0) {
 189                                         break;
 190                                 }
 191                         }
 192                         ++end_arg_pos;
 193                 }
 194                 output.append(text.substr(pos, end_arg_pos - pos));
 195                 ++end_arg_pos;
 196                 assert(depth == 0);
 197                 start = end_arg_pos;
 198         }
 199         return output;
 200 }
 201
 202 Phase *EffectChain::compile_glsl_program(
 203         const std::vector<Node *> &inputs,
 204         const std::vector<Node *> &effects)
 205 {
 206         assert(!effects.empty());
 207
 208         // Deduplicate the inputs.
 209         std::vector<Node *> true_inputs = inputs;
 210         std::sort(true_inputs.begin(), true_inputs.end());
 211         true_inputs.erase(std::unique(true_inputs.begin(), true_inputs.end()), true_inputs.end());
 212
 213         bool input_needs_mipmaps = false;
 214         std::string frag_shader = read_file("header.frag");
 215
 216         // Create functions for all the texture inputs that we need.
 217         for (unsigned i = 0; i < true_inputs.size(); ++i) {
 218                 Node *input = true_inputs[i];
 219
 220                 frag_shader += std::string("uniform sampler2D tex_") + input->effect_id + ";\n";
 221                 frag_shader += std::string("vec4 ") + input->effect_id + "(vec2 tc) {\n";
 222                 frag_shader += "\treturn texture2D(tex_" + input->effect_id + ", tc);\n";
 223                 frag_shader += "}\n";
 224                 frag_shader += "\n";
 225         }
 226
 227         for (unsigned i = 0; i < effects.size(); ++i) {
 228                 Node *node = effects[i];
 229
 230                 if (node->incoming_links.size() == 1) {
 231                         frag_shader += std::string("#define INPUT ") + node->incoming_links[0]->effect_id + "\n";
 232                 } else {
 233                         for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
 234                                 char buf[256];
 235                                 sprintf(buf, "#define INPUT%d %s\n", j + 1, node->incoming_links[j]->effect_id.c_str());
 236                                 frag_shader += buf;
 237                         }
 238                 }
 239
 240                 frag_shader += "\n";
 241                 frag_shader += std::string("#define FUNCNAME ") + node->effect_id + "\n";
 242                 frag_shader += replace_prefix(node->effect->output_convenience_uniforms(), node->effect_id);
 243                 frag_shader += replace_prefix(node->effect->output_fragment_shader(), node->effect_id);
 244                 frag_shader += "#undef PREFIX\n";
 245                 frag_shader += "#undef FUNCNAME\n";
 246                 if (node->incoming_links.size() == 1) {
 247                         frag_shader += "#undef INPUT\n";
 248                 } else {
 249                         for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
 250                                 char buf[256];
 251                                 sprintf(buf, "#undef INPUT%d\n", j + 1);
 252                                 frag_shader += buf;
 253                         }
 254                 }
 255                 frag_shader += "\n";
 256
 257                 input_needs_mipmaps |= node->effect->needs_mipmaps();
 258         }
 259         for (unsigned i = 0; i < effects.size(); ++i) {
 260                 Node *node = effects[i];
 261                 if (node->effect->num_inputs() == 0) {
 262                         node->effect->set_int("needs_mipmaps", input_needs_mipmaps);
 263                 }
 264         }
 265         frag_shader += std::string("#define INPUT ") + effects.back()->effect_id + "\n";
 266         frag_shader.append(read_file("footer.frag"));
 267
 268         // Output shader to a temporary file, for easier debugging.
 269         static int compiled_shader_num = 0;
 270         char filename[256];
 271         sprintf(filename, "chain-%03d.frag", compiled_shader_num++);
 272         FILE *fp = fopen(filename, "w");
 273         if (fp == NULL) {
 274                 perror(filename);
 275                 exit(1);
 276         }
 277         fprintf(fp, "%s\n", frag_shader.c_str());
 278         fclose(fp);
 279
 280         GLuint glsl_program_num = glCreateProgram();
 281         GLuint vs_obj = compile_shader(read_file("vs.vert"), GL_VERTEX_SHADER);
 282         GLuint fs_obj = compile_shader(frag_shader, GL_FRAGMENT_SHADER);
 283         glAttachShader(glsl_program_num, vs_obj);
 284         check_error();
 285         glAttachShader(glsl_program_num, fs_obj);
 286         check_error();
 287         glLinkProgram(glsl_program_num);
 288         check_error();
 289
 290         Phase *phase = new Phase;
 291         phase->glsl_program_num = glsl_program_num;
 292         phase->vertex_shader = vs_obj;
 293         phase->fragment_shader = fs_obj;
 294         phase->input_needs_mipmaps = input_needs_mipmaps;
 295         phase->inputs = true_inputs;
 296         phase->effects = effects;
 297
 298         return phase;
 299 }
 300
 301 // Construct GLSL programs, starting at the given effect and following
 302 // the chain from there. We end a program every time we come to an effect
 303 // marked as "needs texture bounce", one that is used by multiple other
 304 // effects, every time an effect wants to change the output size,
 305 // and of course at the end.
 306 //
 307 // We follow a quite simple depth-first search from the output, although
 308 // without any explicit recursion.
 309 void EffectChain::construct_glsl_programs(Node *output)
 310 {
 311         // Which effects have already been completed in this phase?
 312         // We need to keep track of it, as an effect with multiple outputs
 313         // could otherwise be calculate multiple times.
 314         std::set<Node *> completed_effects;
 315
 316         // Effects in the current phase, as well as inputs (outputs from other phases
 317         // that we depend on). Note that since we start iterating from the end,
 318         // the effect list will be in the reverse order.
 319         std::vector<Node *> this_phase_inputs;
 320         std::vector<Node *> this_phase_effects;
 321
 322         // Effects that we have yet to calculate, but that we know should
 323         // be in the current phase.
 324         std::stack<Node *> effects_todo_this_phase;
 325
 326         // Effects that we have yet to calculate, but that come from other phases.
 327         // We delay these until we have this phase done in its entirety,
 328         // at which point we pick any of them and start a new phase from that.
 329         std::stack<Node *> effects_todo_other_phases;
 330
 331         effects_todo_this_phase.push(output);
 332
 333         for ( ;; ) {  // Termination condition within loop.
 334                 if (!effects_todo_this_phase.empty()) {
 335                         // OK, we have more to do this phase.
 336                         Node *node = effects_todo_this_phase.top();
 337                         effects_todo_this_phase.pop();
 338
 339                         // This should currently only happen for effects that are phase outputs,
 340                         // and we throw those out separately below.
 341                         assert(completed_effects.count(node) == 0);
 342
 343                         this_phase_effects.push_back(node);
 344                         completed_effects.insert(node);
 345
 346                         // Find all the dependencies of this effect, and add them to the stack.
 347                         std::vector<Node *> deps = node->incoming_links;
 348                         assert(node->effect->num_inputs() == deps.size());
 349                         for (unsigned i = 0; i < deps.size(); ++i) {
 350                                 bool start_new_phase = false;
 351
 352                                 // FIXME: If we sample directly from a texture, we won't need this.
 353                                 if (node->effect->needs_texture_bounce()) {
 354                                         start_new_phase = true;
 355                                 }
 356
 357                                 if (deps[i]->outgoing_links.size() > 1) {
 358                                         if (deps[i]->effect->num_inputs() > 0) {
 359                                                 // More than one effect uses this as the input,
 360                                                 // and it is not a texture itself.
 361                                                 // The easiest thing to do (and probably also the safest
 362                                                 // performance-wise in most cases) is to bounce it to a texture
 363                                                 // and then let the next passes read from that.
 364                                                 start_new_phase = true;
 365                                         } else {
 366                                                 // For textures, we try to be slightly more clever;
 367                                                 // if none of our outputs need a bounce, we don't bounce
 368                                                 // but instead simply use the effect many times.
 369                                                 //
 370                                                 // Strictly speaking, we could bounce it for some outputs
 371                                                 // and use it directly for others, but the processing becomes
 372                                                 // somewhat simpler if the effect is only used in one such way.
 373                                                 for (unsigned j = 0; j < deps[i]->outgoing_links.size(); ++j) {
 374                                                         Node *rdep = deps[i]->outgoing_links[j];
 375                                                         start_new_phase |= rdep->effect->needs_texture_bounce();
 376                                                 }
 377                                         }
 378                                 }
 379
 380                                 if (deps[i]->effect->changes_output_size()) {
 381                                         start_new_phase = true;
 382                                 }
 383
 384                                 if (start_new_phase) {
 385                                         effects_todo_other_phases.push(deps[i]);
 386                                         this_phase_inputs.push_back(deps[i]);
 387                                 } else {
 388                                         effects_todo_this_phase.push(deps[i]);
 389                                 }
 390                         }
 391                         continue;
 392                 }
 393
 394                 // No more effects to do this phase. Take all the ones we have,
 395                 // and create a GLSL program for it.
 396                 if (!this_phase_effects.empty()) {
 397                         reverse(this_phase_effects.begin(), this_phase_effects.end());
 398                         phases.push_back(compile_glsl_program(this_phase_inputs, this_phase_effects));
 399                         this_phase_effects.back()->phase = phases.back();
 400                         this_phase_inputs.clear();
 401                         this_phase_effects.clear();
 402                 }
 403                 assert(this_phase_inputs.empty());
 404                 assert(this_phase_effects.empty());
 405
 406                 // If we have no effects left, exit.
 407                 if (effects_todo_other_phases.empty()) {
 408                         break;
 409                 }
 410
 411                 Node *node = effects_todo_other_phases.top();
 412                 effects_todo_other_phases.pop();
 413
 414                 if (completed_effects.count(node) == 0) {
 415                         // Start a new phase, calculating from this effect.
 416                         effects_todo_this_phase.push(node);
 417                 }
 418         }
 419
 420         // Finally, since the phases are found from the output but must be executed
 421         // from the input(s), reverse them, too.
 422         std::reverse(phases.begin(), phases.end());
 423 }
 424
 425 void EffectChain::output_dot(const char *filename)
 426 {
 427         FILE *fp = fopen(filename, "w");
 428         if (fp == NULL) {
 429                 perror(filename);
 430                 exit(1);
 431         }
 432
 433         fprintf(fp, "digraph G {\n");
 434         for (unsigned i = 0; i < nodes.size(); ++i) {
 435                 // Find out which phase this event belongs to.
 436                 int in_phase = -1;
 437                 for (unsigned j = 0; j < phases.size(); ++j) {
 438                         const Phase* p = phases[j];
 439                         if (std::find(p->effects.begin(), p->effects.end(), nodes[i]) != p->effects.end()) {
 440                                 assert(in_phase == -1);
 441                                 in_phase = j;
 442                         }
 443                 }
 444
 445                 if (in_phase == -1) {
 446                         fprintf(fp, "  n%ld [label=\"%s\"];\n", (long)nodes[i], nodes[i]->effect->effect_type_id().c_str());
 447                 } else {
 448                         fprintf(fp, "  n%ld [label=\"%s\" style=\"filled\" fillcolor=\"/accent8/%d\"];\n",
 449                                 (long)nodes[i], nodes[i]->effect->effect_type_id().c_str(),
 450                                 (in_phase % 8) + 1);
 451                 }
 452                 for (unsigned j = 0; j < nodes[i]->outgoing_links.size(); ++j) {
 453                         std::vector<std::string> labels;
 454
 455                         if (nodes[i]->outgoing_links[j]->effect->needs_texture_bounce()) {
 456                                 labels.push_back("needs_bounce");
 457                         }
 458                         if (nodes[i]->effect->changes_output_size()) {
 459                                 labels.push_back("resize");
 460                         }
 461
 462                         switch (nodes[i]->output_color_space) {
 463                         case COLORSPACE_INVALID:
 464                                 labels.push_back("spc[invalid]");
 465                                 break;
 466                         case COLORSPACE_REC_601_525:
 467                                 labels.push_back("spc[rec601-525]");
 468                                 break;
 469                         case COLORSPACE_REC_601_625:
 470                                 labels.push_back("spc[rec601-625]");
 471                                 break;
 472                         default:
 473                                 break;
 474                         }
 475
 476                         switch (nodes[i]->output_gamma_curve) {
 477                         case GAMMA_INVALID:
 478                                 labels.push_back("gamma[invalid]");
 479                                 break;
 480                         case GAMMA_sRGB:
 481                                 labels.push_back("gamma[sRGB]");
 482                                 break;
 483                         case GAMMA_REC_601:  // and GAMMA_REC_709
 484                                 labels.push_back("gamma[rec601/709]");
 485                                 break;
 486                         default:
 487                                 break;
 488                         }
 489
 490                         if (labels.empty()) {
 491                                 fprintf(fp, "  n%ld -> n%ld;\n", (long)nodes[i], (long)nodes[i]->outgoing_links[j]);
 492                         } else {
 493                                 std::string label = labels[0];
 494                                 for (unsigned k = 1; k < labels.size(); ++k) {
 495                                         label += ", " + labels[k];
 496                                 }
 497                                 fprintf(fp, "  n%ld -> n%ld [label=\"%s\"];\n", (long)nodes[i], (long)nodes[i]->outgoing_links[j], label.c_str());
 498                         }
 499                 }
 500         }
 501         fprintf(fp, "}\n");
 502
 503         fclose(fp);
 504 }
 505
 506 unsigned EffectChain::fit_rectangle_to_aspect(unsigned width, unsigned height)
 507 {
 508         if (float(width) * aspect_denom >= float(height) * aspect_nom) {
 509                 // Same aspect, or W/H > aspect (image is wider than the frame).
 510                 // In either case, keep width.
 511                 return width;
 512         } else {
 513                 // W/H < aspect (image is taller than the frame), so keep height,
 514                 // and adjust width correspondingly.
 515                 return lrintf(height * aspect_nom / aspect_denom);
 516         }
 517 }
 518
 519 // Propagate input texture sizes throughout, and inform effects downstream.
 520 // (Like a lot of other code, we depend on effects being in topological order.)
 521 void EffectChain::inform_input_sizes(Phase *phase)
 522 {
 523         // All effects that have a defined size (inputs and RTT inputs)
 524         // get that. Reset all others.
 525         for (unsigned i = 0; i < phase->effects.size(); ++i) {
 526                 Node *node = phase->effects[i];
 527                 if (node->effect->num_inputs() == 0) {
 528                         Input *input = static_cast<Input *>(node->effect);
 529                         node->output_width = input->get_width();
 530                         node->output_height = input->get_height();
 531                         assert(node->output_width != 0);
 532                         assert(node->output_height != 0);
 533                 } else {
 534                         node->output_width = node->output_height = 0;
 535                 }
 536         }
 537         for (unsigned i = 0; i < phase->inputs.size(); ++i) {
 538                 Node *input = phase->inputs[i];
 539                 input->output_width = input->phase->output_width;
 540                 input->output_height = input->phase->output_height;
 541                 assert(input->output_width != 0);
 542                 assert(input->output_height != 0);
 543         }
 544
 545         // Now propagate from the inputs towards the end, and inform as we go.
 546         // The rules are simple:
 547         //
 548         //   1. Don't touch effects that already have given sizes (ie., inputs).
 549         //   2. If all of your inputs have the same size, that will be your output size.
 550         //   3. Otherwise, your output size is 0x0.
 551         for (unsigned i = 0; i < phase->effects.size(); ++i) {
 552                 Node *node = phase->effects[i];
 553                 if (node->effect->num_inputs() == 0) {
 554                         continue;
 555                 }
 556                 unsigned this_output_width = 0;
 557                 unsigned this_output_height = 0;
 558                 for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
 559                         Node *input = node->incoming_links[j];
 560                         node->effect->inform_input_size(j, input->output_width, input->output_height);
 561                         if (j == 0) {
 562                                 this_output_width = input->output_width;
 563                                 this_output_height = input->output_height;
 564                         } else if (input->output_width != this_output_width || input->output_height != this_output_height) {
 565                                 // Inputs disagree.
 566                                 this_output_width = 0;
 567                                 this_output_height = 0;
 568                         }
 569                 }
 570                 node->output_width = this_output_width;
 571                 node->output_height = this_output_height;
 572         }
 573 }
 574
 575 // Note: You should call inform_input_sizes() before this, as the last effect's
 576 // desired output size might change based on the inputs.
 577 void EffectChain::find_output_size(Phase *phase)
 578 {
 579         Node *output_node = phase->effects.back();
 580
 581         // If the last effect explicitly sets an output size, use that.
 582         if (output_node->effect->changes_output_size()) {
 583                 output_node->effect->get_output_size(&phase->output_width, &phase->output_height);
 584                 return;
 585         }
 586
 587         // If not, look at the input phases and textures.
 588         // We select the largest one (by fit into the current aspect).
 589         unsigned best_width = 0;
 590         for (unsigned i = 0; i < phase->inputs.size(); ++i) {
 591                 Node *input = phase->inputs[i];
 592                 assert(input->phase->output_width != 0);
 593                 assert(input->phase->output_height != 0);
 594                 unsigned width = fit_rectangle_to_aspect(input->phase->output_width, input->phase->output_height);
 595                 if (width > best_width) {
 596                         best_width = width;
 597                 }
 598         }
 599         for (unsigned i = 0; i < phase->effects.size(); ++i) {
 600                 Effect *effect = phase->effects[i]->effect;
 601                 if (effect->num_inputs() != 0) {
 602                         continue;
 603                 }
 604
 605                 Input *input = static_cast<Input *>(effect);
 606                 unsigned width = fit_rectangle_to_aspect(input->get_width(), input->get_height());
 607                 if (width > best_width) {
 608                         best_width = width;
 609                 }
 610         }
 611         assert(best_width != 0);
 612         phase->output_width = best_width;
 613         phase->output_height = best_width * aspect_denom / aspect_nom;
 614 }
 615
 616 void EffectChain::sort_nodes_topologically()
 617 {
 618         std::set<Node *> visited_nodes;
 619         std::vector<Node *> sorted_list;
 620         for (unsigned i = 0; i < nodes.size(); ++i) {
 621                 if (nodes[i]->incoming_links.size() == 0) {
 622                         topological_sort_visit_node(nodes[i], &visited_nodes, &sorted_list);
 623                 }
 624         }
 625         reverse(sorted_list.begin(), sorted_list.end());
 626         nodes = sorted_list;
 627 }
 628
 629 void EffectChain::topological_sort_visit_node(Node *node, std::set<Node *> *visited_nodes, std::vector<Node *> *sorted_list)
 630 {
 631         if (visited_nodes->count(node) != 0) {
 632                 return;
 633         }
 634         visited_nodes->insert(node);
 635         for (unsigned i = 0; i < node->outgoing_links.size(); ++i) {
 636                 topological_sort_visit_node(node->outgoing_links[i], visited_nodes, sorted_list);
 637         }
 638         sorted_list->push_back(node);
 639 }
 640
 641 // Propagate gamma and color space information as far as we can in the graph.
 642 // The rules are simple: Anything where all the inputs agree, get that as
 643 // output as well. Anything else keeps having *_INVALID.
 644 void EffectChain::propagate_gamma_and_color_space()
 645 {
 646         // We depend on going through the nodes in order.
 647         sort_nodes_topologically();
 648
 649         for (unsigned i = 0; i < nodes.size(); ++i) {
 650                 Node *node = nodes[i];
 651                 if (node->disabled) {
 652                         continue;
 653                 }
 654                 assert(node->incoming_links.size() == node->effect->num_inputs());
 655                 if (node->incoming_links.size() == 0) {
 656                         assert(node->output_color_space != COLORSPACE_INVALID);
 657                         assert(node->output_gamma_curve != GAMMA_INVALID);
 658                         continue;
 659                 }
 660
 661                 Colorspace color_space = node->incoming_links[0]->output_color_space;
 662                 GammaCurve gamma_curve = node->incoming_links[0]->output_gamma_curve;
 663                 for (unsigned j = 1; j < node->incoming_links.size(); ++j) {
 664                         if (node->incoming_links[j]->output_color_space != color_space) {
 665                                 color_space = COLORSPACE_INVALID;
 666                         }
 667                         if (node->incoming_links[j]->output_gamma_curve != gamma_curve) {
 668                                 gamma_curve = GAMMA_INVALID;
 669                         }
 670                 }
 671
 672                 // The conversion effects already have their outputs set correctly,
 673                 // so leave them alone.
 674                 if (node->effect->effect_type_id() != "ColorspaceConversionEffect") {
 675                         node->output_color_space = color_space;
 676                 }
 677                 if (node->effect->effect_type_id() != "GammaCompressionEffect" &&
 678                     node->effect->effect_type_id() != "GammaExpansionEffect") {
 679                         node->output_gamma_curve = gamma_curve;
 680                 }
 681         }
 682 }
 683
 684 bool EffectChain::node_needs_colorspace_fix(Node *node)
 685 {
 686         if (node->disabled) {
 687                 return false;
 688         }
 689         if (node->effect->num_inputs() == 0) {
 690                 return false;
 691         }
 692
 693         // propagate_gamma_and_color_space() has already set our output
 694         // to COLORSPACE_INVALID if the inputs differ, so we can rely on that.
 695         if (node->output_color_space == COLORSPACE_INVALID) {
 696                 return true;
 697         }
 698         return (node->effect->needs_srgb_primaries() && node->output_color_space != COLORSPACE_sRGB);
 699 }
 700
 701 // Fix up color spaces so that there are no COLORSPACE_INVALID nodes left in
 702 // the graph. Our strategy is not always optimal, but quite simple:
 703 // Find an effect that's as early as possible where the inputs are of
 704 // unacceptable colorspaces (that is, either different, or, if the effect only
 705 // wants sRGB, not sRGB.) Add appropriate conversions on all its inputs,
 706 // propagate the information anew, and repeat until there are no more such
 707 // effects.
 708 void EffectChain::fix_internal_color_spaces()
 709 {
 710         unsigned colorspace_propagation_pass = 0;
 711         bool found_any;
 712         do {
 713                 found_any = false;
 714                 for (unsigned i = 0; i < nodes.size(); ++i) {
 715                         Node *node = nodes[i];
 716                         if (!node_needs_colorspace_fix(node)) {
 717                                 continue;
 718                         }
 719
 720                         // Go through each input that is not sRGB, and insert
 721                         // a colorspace conversion before it.
 722                         for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
 723                                 Node *input = node->incoming_links[j];
 724                                 assert(input->output_color_space != COLORSPACE_INVALID);
 725                                 if (input->output_color_space == COLORSPACE_sRGB) {
 726                                         continue;
 727                                 }
 728                                 Node *conversion = add_node(new ColorspaceConversionEffect());
 729                                 conversion->effect->set_int("source_space", input->output_color_space);
 730                                 conversion->effect->set_int("destination_space", COLORSPACE_sRGB);
 731                                 conversion->output_color_space = COLORSPACE_sRGB;
 732                                 insert_node_between(input, conversion, node);
 733                         }
 734
 735                         // Re-sort topologically, and propagate the new information.
 736                         propagate_gamma_and_color_space();
 737
 738                         found_any = true;
 739                         break;
 740                 }
 741
 742                 char filename[256];
 743                 sprintf(filename, "step3-colorspacefix-iter%u.dot", ++colorspace_propagation_pass);
 744                 output_dot(filename);
 745                 assert(colorspace_propagation_pass < 100);
 746         } while (found_any);
 747
 748         for (unsigned i = 0; i < nodes.size(); ++i) {
 749                 Node *node = nodes[i];
 750                 if (node->disabled) {
 751                         continue;
 752                 }
 753                 assert(node->output_color_space != COLORSPACE_INVALID);
 754         }
 755 }
 756
 757 // Make so that the output is in the desired color space.
 758 void EffectChain::fix_output_color_space()
 759 {
 760         Node *output = find_output_node();
 761         if (output->output_color_space != output_format.color_space) {
 762                 Node *conversion = add_node(new ColorspaceConversionEffect());
 763                 conversion->effect->set_int("source_space", output->output_color_space);
 764                 conversion->effect->set_int("destination_space", output_format.color_space);
 765                 conversion->output_color_space = output_format.color_space;
 766                 connect_nodes(output, conversion);
 767                 propagate_gamma_and_color_space();
 768         }
 769 }
 770
 771 bool EffectChain::node_needs_gamma_fix(Node *node)
 772 {
 773         if (node->disabled) {
 774                 return false;
 775         }
 776
 777         // Small hack since the output is not an explicit node:
 778         // If we are the last node and our output is in the wrong
 779         // space compared to EffectChain's output, we need to fix it.
 780         // This will only take us to linear, but fix_output_gamma()
 781         // will come and take us to the desired output gamma
 782         // if it is needed.
 783         //
 784         // This needs to be before everything else, since it could
 785         // even apply to inputs (if they are the only effect).
 786         if (node->outgoing_links.empty() &&
 787             node->output_gamma_curve != output_format.gamma_curve &&
 788             node->output_gamma_curve != GAMMA_LINEAR) {
 789                 return true;
 790         }
 791
 792         if (node->effect->num_inputs() == 0) {
 793                 return false;
 794         }
 795
 796         // propagate_gamma_and_color_space() has already set our output
 797         // to GAMMA_INVALID if the inputs differ, so we can rely on that,
 798         // except for GammaCompressionEffect.
 799         if (node->output_gamma_curve == GAMMA_INVALID) {
 800                 return true;
 801         }
 802         if (node->effect->effect_type_id() == "GammaCompressionEffect") {
 803                 assert(node->incoming_links.size() == 1);
 804                 return node->incoming_links[0]->output_gamma_curve != GAMMA_LINEAR;
 805         }
 806
 807         return (node->effect->needs_linear_light() && node->output_gamma_curve != GAMMA_LINEAR);
 808 }
 809
 810 // Very similar to fix_internal_color_spaces(), but for gamma.
 811 // There is one difference, though; before we start adding conversion nodes,
 812 // we see if we can get anything out of asking the sources to deliver
 813 // linear gamma directly. fix_internal_gamma_by_asking_inputs()
 814 // does that part, while fix_internal_gamma_by_inserting_nodes()
 815 // inserts nodes as needed afterwards.
 816 void EffectChain::fix_internal_gamma_by_asking_inputs(unsigned step)
 817 {
 818         unsigned gamma_propagation_pass = 0;
 819         bool found_any;
 820         do {
 821                 found_any = false;
 822                 for (unsigned i = 0; i < nodes.size(); ++i) {
 823                         Node *node = nodes[i];
 824                         if (!node_needs_gamma_fix(node)) {
 825                                 continue;
 826                         }
 827
 828                         // See if all inputs can give us linear gamma. If not, leave it.
 829                         std::vector<Node *> nonlinear_inputs;
 830                         find_all_nonlinear_inputs(node, &nonlinear_inputs);
 831                         assert(!nonlinear_inputs.empty());
 832
 833                         bool all_ok = true;
 834                         for (unsigned i = 0; i < nonlinear_inputs.size(); ++i) {
 835                                 Input *input = static_cast<Input *>(nonlinear_inputs[i]->effect);
 836                                 all_ok &= input->can_output_linear_gamma();
 837                         }
 838
 839                         if (!all_ok) {
 840                                 continue;
 841                         }
 842
 843                         for (unsigned i = 0; i < nonlinear_inputs.size(); ++i) {
 844                                 nonlinear_inputs[i]->effect->set_int("output_linear_gamma", 1);
 845                                 nonlinear_inputs[i]->output_gamma_curve = GAMMA_LINEAR;
 846                         }
 847
 848                         // Re-sort topologically, and propagate the new information.
 849                         propagate_gamma_and_color_space();
 850
 851                         found_any = true;
 852                         break;
 853                 }
 854
 855                 char filename[256];
 856                 sprintf(filename, "step%u-gammafix-iter%u.dot", step, ++gamma_propagation_pass);
 857                 output_dot(filename);
 858                 assert(gamma_propagation_pass < 100);
 859         } while (found_any);
 860 }
 861
 862 void EffectChain::fix_internal_gamma_by_inserting_nodes(unsigned step)
 863 {
 864         unsigned gamma_propagation_pass = 0;
 865         bool found_any;
 866         do {
 867                 found_any = false;
 868                 for (unsigned i = 0; i < nodes.size(); ++i) {
 869                         Node *node = nodes[i];
 870                         if (!node_needs_gamma_fix(node)) {
 871                                 continue;
 872                         }
 873
 874                         // Special case: We could be an input and still be asked to
 875                         // fix our gamma; if so, we should be the only node
 876                         // (as node_needs_gamma_fix() would only return true in
 877                         // for an input in that case). That means we should insert
 878                         // a conversion node _after_ ourselves.
 879                         if (node->incoming_links.empty()) {
 880                                 assert(node->outgoing_links.empty());
 881                                 Node *conversion = add_node(new GammaExpansionEffect());
 882                                 conversion->effect->set_int("source_curve", node->output_gamma_curve);
 883                                 conversion->output_gamma_curve = GAMMA_LINEAR;
 884                                 connect_nodes(node, conversion);
 885                         }
 886
 887                         // If not, go through each input that is not linear gamma,
 888                         // and insert a gamma conversion before it.
 889                         for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
 890                                 Node *input = node->incoming_links[j];
 891                                 assert(input->output_gamma_curve != GAMMA_INVALID);
 892                                 if (input->output_gamma_curve == GAMMA_LINEAR) {
 893                                         continue;
 894                                 }
 895                                 Node *conversion = add_node(new GammaExpansionEffect());
 896                                 conversion->effect->set_int("source_curve", input->output_gamma_curve);
 897                                 conversion->output_gamma_curve = GAMMA_LINEAR;
 898                                 insert_node_between(input, conversion, node);
 899                         }
 900
 901                         // Re-sort topologically, and propagate the new information.
 902                         propagate_gamma_and_color_space();
 903
 904                         found_any = true;
 905                         break;
 906                 }
 907
 908                 char filename[256];
 909                 sprintf(filename, "step%u-gammafix-iter%u.dot", step, ++gamma_propagation_pass);
 910                 output_dot(filename);
 911                 assert(gamma_propagation_pass < 100);
 912         } while (found_any);
 913
 914         for (unsigned i = 0; i < nodes.size(); ++i) {
 915                 Node *node = nodes[i];
 916                 if (node->disabled) {
 917                         continue;
 918                 }
 919                 assert(node->output_gamma_curve != GAMMA_INVALID);
 920         }
 921 }
 922
 923 // Make so that the output is in the desired gamma.
 924 // Note that this assumes linear input gamma, so it might create the need
 925 // for another pass of fix_internal_gamma().
 926 void EffectChain::fix_output_gamma()
 927 {
 928         Node *output = find_output_node();
 929         if (output->output_gamma_curve != output_format.gamma_curve) {
 930                 Node *conversion = add_node(new GammaCompressionEffect());
 931                 conversion->effect->set_int("destination_curve", output_format.gamma_curve);
 932                 conversion->output_gamma_curve = output_format.gamma_curve;
 933                 connect_nodes(output, conversion);
 934         }
 935 }
 936
 937 // Find the output node. This is, simply, one that has no outgoing links.
 938 // If there are multiple ones, the graph is malformed (we do not support
 939 // multiple outputs right now).
 940 Node *EffectChain::find_output_node()
 941 {
 942         std::vector<Node *> output_nodes;
 943         for (unsigned i = 0; i < nodes.size(); ++i) {
 944                 Node *node = nodes[i];
 945                 if (node->disabled) {
 946                         continue;
 947                 }
 948                 if (node->outgoing_links.empty()) {
 949                         output_nodes.push_back(node);
 950                 }
 951         }
 952         assert(output_nodes.size() == 1);
 953         return output_nodes[0];
 954 }
 955
 956 void EffectChain::finalize()
 957 {
 958         // Output the graph as it is before we do any conversions on it.
 959         output_dot("step0-start.dot");
 960
 961         // Give each effect in turn a chance to rewrite its own part of the graph.
 962         // Note that if more effects are added as part of this, they will be
 963         // picked up as part of the same for loop, since they are added at the end.
 964         for (unsigned i = 0; i < nodes.size(); ++i) {
 965                 nodes[i]->effect->rewrite_graph(this, nodes[i]);
 966         }
 967         output_dot("step1-rewritten.dot");
 968
 969         propagate_gamma_and_color_space();
 970         output_dot("step2-propagated.dot");
 971
 972         fix_internal_color_spaces();
 973         fix_output_color_space();
 974         output_dot("step4-output-colorspacefix.dot");
 975
 976         // Note that we need to fix gamma after colorspace conversion,
 977         // because colorspace conversions might create needs for gamma conversions.
 978         // Also, we need to run an extra pass of fix_internal_gamma() after
 979         // fixing the output gamma, as we only have conversions to/from linear.
 980         fix_internal_gamma_by_asking_inputs(5);
 981         fix_internal_gamma_by_inserting_nodes(6);
 982         fix_output_gamma();
 983         output_dot("step7-output-gammafix.dot");
 984         fix_internal_gamma_by_asking_inputs(8);
 985         fix_internal_gamma_by_inserting_nodes(9);
 986
 987         output_dot("step10-final.dot");
 988
 989         // Construct all needed GLSL programs, starting at the output.
 990         construct_glsl_programs(find_output_node());
 991
 992         output_dot("step11-split-to-phases.dot");
 993
 994         // If we have more than one phase, we need intermediate render-to-texture.
 995         // Construct an FBO, and then as many textures as we need.
 996         // We choose the simplest option of having one texture per output,
 997         // since otherwise this turns into an (albeit simple)
 998         // register allocation problem.
 999         if (phases.size() > 1) {
1000                 glGenFramebuffers(1, &fbo);
1001
1002                 for (unsigned i = 0; i < phases.size() - 1; ++i) {
1003                         inform_input_sizes(phases[i]);
1004                         find_output_size(phases[i]);
1005
1006                         Node *output_node = phases[i]->effects.back();
1007                         glGenTextures(1, &output_node->output_texture);
1008                         check_error();
1009                         glBindTexture(GL_TEXTURE_2D, output_node->output_texture);
1010                         check_error();
1011                         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
1012                         check_error();
1013                         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
1014                         check_error();
1015                         glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA16F_ARB, phases[i]->output_width, phases[i]->output_height, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
1016                         check_error();
1017
1018                         output_node->output_texture_width = phases[i]->output_width;
1019                         output_node->output_texture_height = phases[i]->output_height;
1020                 }
1021                 inform_input_sizes(phases.back());
1022         }
1023
1024         for (unsigned i = 0; i < inputs.size(); ++i) {
1025                 inputs[i]->finalize();
1026         }
1027
1028         assert(phases[0]->inputs.empty());
1029
1030         finalized = true;
1031 }
1032
1033 void EffectChain::render_to_fbo(GLuint dest_fbo, unsigned width, unsigned height)
1034 {
1035         assert(finalized);
1036
1037         // Save original viewport.
1038         GLuint x = 0, y = 0;
1039
1040         if (width == 0 && height == 0) {
1041                 GLint viewport[4];
1042                 glGetIntegerv(GL_VIEWPORT, viewport);
1043                 x = viewport[0];
1044                 y = viewport[1];
1045                 width = viewport[2];
1046                 height = viewport[3];
1047         }
1048
1049         // Basic state.
1050         glDisable(GL_BLEND);
1051         check_error();
1052         glDisable(GL_DEPTH_TEST);
1053         check_error();
1054         glDepthMask(GL_FALSE);
1055         check_error();
1056
1057         glMatrixMode(GL_PROJECTION);
1058         glLoadIdentity();
1059         glOrtho(0.0, 1.0, 0.0, 1.0, 0.0, 1.0);
1060
1061         glMatrixMode(GL_MODELVIEW);
1062         glLoadIdentity();
1063
1064         if (phases.size() > 1) {
1065                 glBindFramebuffer(GL_FRAMEBUFFER, fbo);
1066                 check_error();
1067         }
1068
1069         std::set<Node *> generated_mipmaps;
1070
1071         for (unsigned phase = 0; phase < phases.size(); ++phase) {
1072                 // See if the requested output size has changed. If so, we need to recreate
1073                 // the texture (and before we start setting up inputs).
1074                 inform_input_sizes(phases[phase]);
1075                 if (phase != phases.size() - 1) {
1076                         find_output_size(phases[phase]);
1077
1078                         Node *output_node = phases[phase]->effects.back();
1079
1080                         if (output_node->output_texture_width != phases[phase]->output_width ||
1081                             output_node->output_texture_height != phases[phase]->output_height) {
1082                                 glActiveTexture(GL_TEXTURE0);
1083                                 check_error();
1084                                 glBindTexture(GL_TEXTURE_2D, output_node->output_texture);
1085                                 check_error();
1086                                 glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA16F_ARB, phases[phase]->output_width, phases[phase]->output_height, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
1087                                 check_error();
1088                                 glBindTexture(GL_TEXTURE_2D, 0);
1089                                 check_error();
1090
1091                                 output_node->output_texture_width = phases[phase]->output_width;
1092                                 output_node->output_texture_height = phases[phase]->output_height;
1093                         }
1094                 }
1095
1096                 glUseProgram(phases[phase]->glsl_program_num);
1097                 check_error();
1098
1099                 // Set up RTT inputs for this phase.
1100                 for (unsigned sampler = 0; sampler < phases[phase]->inputs.size(); ++sampler) {
1101                         glActiveTexture(GL_TEXTURE0 + sampler);
1102                         Node *input = phases[phase]->inputs[sampler];
1103                         glBindTexture(GL_TEXTURE_2D, input->output_texture);
1104                         check_error();
1105                         if (phases[phase]->input_needs_mipmaps) {
1106                                 if (generated_mipmaps.count(input) == 0) {
1107                                         glGenerateMipmap(GL_TEXTURE_2D);
1108                                         check_error();
1109                                         generated_mipmaps.insert(input);
1110                                 }
1111                                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_NEAREST);
1112                                 check_error();
1113                         } else {
1114                                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
1115                                 check_error();
1116                         }
1117
1118                         std::string texture_name = std::string("tex_") + input->effect_id;
1119                         glUniform1i(glGetUniformLocation(phases[phase]->glsl_program_num, texture_name.c_str()), sampler);
1120                         check_error();
1121                 }
1122
1123                 // And now the output.
1124                 if (phase == phases.size() - 1) {
1125                         // Last phase goes to the output the user specified.
1126                         glBindFramebuffer(GL_FRAMEBUFFER, dest_fbo);
1127                         check_error();
1128                         glViewport(x, y, width, height);
1129                 } else {
1130                         Node *output_node = phases[phase]->effects.back();
1131                         glFramebufferTexture2D(
1132                                 GL_FRAMEBUFFER,
1133                                 GL_COLOR_ATTACHMENT0,
1134                                 GL_TEXTURE_2D,
1135                                 output_node->output_texture,
1136                                 0);
1137                         check_error();
1138                         glViewport(0, 0, phases[phase]->output_width, phases[phase]->output_height);
1139                 }
1140
1141                 // Give the required parameters to all the effects.
1142                 unsigned sampler_num = phases[phase]->inputs.size();
1143                 for (unsigned i = 0; i < phases[phase]->effects.size(); ++i) {
1144                         Node *node = phases[phase]->effects[i];
1145                         node->effect->set_gl_state(phases[phase]->glsl_program_num, node->effect_id, &sampler_num);
1146                         check_error();
1147                 }
1148
1149                 // Now draw!
1150                 glBegin(GL_QUADS);
1151
1152                 glTexCoord2f(0.0f, 0.0f);
1153                 glVertex2f(0.0f, 0.0f);
1154
1155                 glTexCoord2f(1.0f, 0.0f);
1156                 glVertex2f(1.0f, 0.0f);
1157
1158                 glTexCoord2f(1.0f, 1.0f);
1159                 glVertex2f(1.0f, 1.0f);
1160
1161                 glTexCoord2f(0.0f, 1.0f);
1162                 glVertex2f(0.0f, 1.0f);
1163
1164                 glEnd();
1165                 check_error();
1166
1167                 for (unsigned i = 0; i < phases[phase]->effects.size(); ++i) {
1168                         Node *node = phases[phase]->effects[i];
1169                         node->effect->clear_gl_state();
1170                 }
1171         }
1172 }