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 #include <GL/glew.h>
   8
   9 #include <algorithm>
  10 #include <set>
  11 #include <stack>
  12 #include <vector>
  13
  14 #include "util.h"
  15 #include "effect_chain.h"
  16 #include "gamma_expansion_effect.h"
  17 #include "gamma_compression_effect.h"
  18 #include "colorspace_conversion_effect.h"
  19 #include "dither_effect.h"
  20 #include "input.h"
  21
  22 EffectChain::EffectChain(float aspect_nom, float aspect_denom)
  23         : aspect_nom(aspect_nom),
  24           aspect_denom(aspect_denom),
  25           dither_effect(NULL),
  26           fbo(0),
  27           num_dither_bits(0),
  28           finalized(false) {}
  29
  30 EffectChain::~EffectChain()
  31 {
  32         for (unsigned i = 0; i < nodes.size(); ++i) {
  33                 if (nodes[i]->output_texture != 0) {
  34                         glDeleteTextures(1, &nodes[i]->output_texture);
  35                 }
  36                 delete nodes[i]->effect;
  37                 delete nodes[i];
  38         }
  39         for (unsigned i = 0; i < phases.size(); ++i) {
  40                 glDeleteProgram(phases[i]->glsl_program_num);
  41                 glDeleteShader(phases[i]->vertex_shader);
  42                 glDeleteShader(phases[i]->fragment_shader);
  43                 delete phases[i];
  44         }
  45         if (fbo != 0) {
  46                 glDeleteFramebuffers(1, &fbo);
  47         }
  48 }
  49
  50 Input *EffectChain::add_input(Input *input)
  51 {
  52         inputs.push_back(input);
  53
  54         Node *node = add_node(input);
  55         node->output_color_space = input->get_color_space();
  56         node->output_gamma_curve = input->get_gamma_curve();
  57         return input;
  58 }
  59
  60 void EffectChain::add_output(const ImageFormat &format)
  61 {
  62         output_format = format;
  63 }
  64
  65 Node *EffectChain::add_node(Effect *effect)
  66 {
  67         char effect_id[256];
  68         sprintf(effect_id, "eff%u", (unsigned)nodes.size());
  69
  70         Node *node = new Node;
  71         node->effect = effect;
  72         node->disabled = false;
  73         node->effect_id = effect_id;
  74         node->output_color_space = COLORSPACE_INVALID;
  75         node->output_gamma_curve = GAMMA_INVALID;
  76         node->output_texture = 0;
  77
  78         nodes.push_back(node);
  79         node_map[effect] = node;
  80         return node;
  81 }
  82
  83 void EffectChain::connect_nodes(Node *sender, Node *receiver)
  84 {
  85         sender->outgoing_links.push_back(receiver);
  86         receiver->incoming_links.push_back(sender);
  87 }
  88
  89 void EffectChain::replace_receiver(Node *old_receiver, Node *new_receiver)
  90 {
  91         new_receiver->incoming_links = old_receiver->incoming_links;
  92         old_receiver->incoming_links.clear();
  93
  94         for (unsigned i = 0; i < new_receiver->incoming_links.size(); ++i) {
  95                 Node *sender = new_receiver->incoming_links[i];
  96                 for (unsigned j = 0; j < sender->outgoing_links.size(); ++j) {
  97                         if (sender->outgoing_links[j] == old_receiver) {
  98                                 sender->outgoing_links[j] = new_receiver;
  99                         }
 100                 }
 101         }
 102 }
 103
 104 void EffectChain::replace_sender(Node *old_sender, Node *new_sender)
 105 {
 106         new_sender->outgoing_links = old_sender->outgoing_links;
 107         old_sender->outgoing_links.clear();
 108
 109         for (unsigned i = 0; i < new_sender->outgoing_links.size(); ++i) {
 110                 Node *receiver = new_sender->outgoing_links[i];
 111                 for (unsigned j = 0; j < receiver->incoming_links.size(); ++j) {
 112                         if (receiver->incoming_links[j] == old_sender) {
 113                                 receiver->incoming_links[j] = new_sender;
 114                         }
 115                 }
 116         }
 117 }
 118
 119 void EffectChain::insert_node_between(Node *sender, Node *middle, Node *receiver)
 120 {
 121         for (unsigned i = 0; i < sender->outgoing_links.size(); ++i) {
 122                 if (sender->outgoing_links[i] == receiver) {
 123                         sender->outgoing_links[i] = middle;
 124                         middle->incoming_links.push_back(sender);
 125                 }
 126         }
 127         for (unsigned i = 0; i < receiver->incoming_links.size(); ++i) {
 128                 if (receiver->incoming_links[i] == sender) {
 129                         receiver->incoming_links[i] = middle;
 130                         middle->outgoing_links.push_back(receiver);
 131                 }
 132         }
 133
 134         assert(middle->incoming_links.size() == middle->effect->num_inputs());
 135 }
 136
 137 void EffectChain::find_all_nonlinear_inputs(Node *node, std::vector<Node *> *nonlinear_inputs)
 138 {
 139         if (node->output_gamma_curve == GAMMA_LINEAR &&
 140             node->effect->effect_type_id() != "GammaCompressionEffect") {
 141                 return;
 142         }
 143         if (node->effect->num_inputs() == 0) {
 144                 nonlinear_inputs->push_back(node);
 145         } else {
 146                 assert(node->effect->num_inputs() == node->incoming_links.size());
 147                 for (unsigned i = 0; i < node->incoming_links.size(); ++i) {
 148                         find_all_nonlinear_inputs(node->incoming_links[i], nonlinear_inputs);
 149                 }
 150         }
 151 }
 152
 153 Effect *EffectChain::add_effect(Effect *effect, const std::vector<Effect *> &inputs)
 154 {
 155         assert(inputs.size() == effect->num_inputs());
 156         Node *node = add_node(effect);
 157         for (unsigned i = 0; i < inputs.size(); ++i) {
 158                 assert(node_map.count(inputs[i]) != 0);
 159                 connect_nodes(node_map[inputs[i]], node);
 160         }
 161         return effect;
 162 }
 163
 164 // GLSL pre-1.30 doesn't support token pasting. Replace PREFIX(x) with <effect_id>_x.
 165 std::string replace_prefix(const std::string &text, const std::string &prefix)
 166 {
 167         std::string output;
 168         size_t start = 0;
 169
 170         while (start < text.size()) {
 171                 size_t pos = text.find("PREFIX(", start);
 172                 if (pos == std::string::npos) {
 173                         output.append(text.substr(start, std::string::npos));
 174                         break;
 175                 }
 176
 177                 output.append(text.substr(start, pos - start));
 178                 output.append(prefix);
 179                 output.append("_");
 180
 181                 pos += strlen("PREFIX(");
 182
 183                 // Output stuff until we find the matching ), which we then eat.
 184                 int depth = 1;
 185                 size_t end_arg_pos = pos;
 186                 while (end_arg_pos < text.size()) {
 187                         if (text[end_arg_pos] == '(') {
 188                                 ++depth;
 189                         } else if (text[end_arg_pos] == ')') {
 190                                 --depth;
 191                                 if (depth == 0) {
 192                                         break;
 193                                 }
 194                         }
 195                         ++end_arg_pos;
 196                 }
 197                 output.append(text.substr(pos, end_arg_pos - pos));
 198                 ++end_arg_pos;
 199                 assert(depth == 0);
 200                 start = end_arg_pos;
 201         }
 202         return output;
 203 }
 204
 205 Phase *EffectChain::compile_glsl_program(
 206         const std::vector<Node *> &inputs,
 207         const std::vector<Node *> &effects)
 208 {
 209         assert(!effects.empty());
 210
 211         // Deduplicate the inputs.
 212         std::vector<Node *> true_inputs = inputs;
 213         std::sort(true_inputs.begin(), true_inputs.end());
 214         true_inputs.erase(std::unique(true_inputs.begin(), true_inputs.end()), true_inputs.end());
 215
 216         bool input_needs_mipmaps = false;
 217         std::string frag_shader = read_file("header.frag");
 218
 219         // Create functions for all the texture inputs that we need.
 220         for (unsigned i = 0; i < true_inputs.size(); ++i) {
 221                 Node *input = true_inputs[i];
 222
 223                 frag_shader += std::string("uniform sampler2D tex_") + input->effect_id + ";\n";
 224                 frag_shader += std::string("vec4 ") + input->effect_id + "(vec2 tc) {\n";
 225                 frag_shader += "\treturn texture2D(tex_" + input->effect_id + ", tc);\n";
 226                 frag_shader += "}\n";
 227                 frag_shader += "\n";
 228         }
 229
 230         for (unsigned i = 0; i < effects.size(); ++i) {
 231                 Node *node = effects[i];
 232
 233                 if (node->incoming_links.size() == 1) {
 234                         frag_shader += std::string("#define INPUT ") + node->incoming_links[0]->effect_id + "\n";
 235                 } else {
 236                         for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
 237                                 char buf[256];
 238                                 sprintf(buf, "#define INPUT%d %s\n", j + 1, node->incoming_links[j]->effect_id.c_str());
 239                                 frag_shader += buf;
 240                         }
 241                 }
 242
 243                 frag_shader += "\n";
 244                 frag_shader += std::string("#define FUNCNAME ") + node->effect_id + "\n";
 245                 frag_shader += replace_prefix(node->effect->output_convenience_uniforms(), node->effect_id);
 246                 frag_shader += replace_prefix(node->effect->output_fragment_shader(), node->effect_id);
 247                 frag_shader += "#undef PREFIX\n";
 248                 frag_shader += "#undef FUNCNAME\n";
 249                 if (node->incoming_links.size() == 1) {
 250                         frag_shader += "#undef INPUT\n";
 251                 } else {
 252                         for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
 253                                 char buf[256];
 254                                 sprintf(buf, "#undef INPUT%d\n", j + 1);
 255                                 frag_shader += buf;
 256                         }
 257                 }
 258                 frag_shader += "\n";
 259
 260                 input_needs_mipmaps |= node->effect->needs_mipmaps();
 261         }
 262         for (unsigned i = 0; i < effects.size(); ++i) {
 263                 Node *node = effects[i];
 264                 if (node->effect->num_inputs() == 0) {
 265                         CHECK(node->effect->set_int("needs_mipmaps", input_needs_mipmaps));
 266                 }
 267         }
 268         frag_shader += std::string("#define INPUT ") + effects.back()->effect_id + "\n";
 269         frag_shader.append(read_file("footer.frag"));
 270
 271 #ifndef NDEBUG
 272         // Output shader to a temporary file, for easier debugging.
 273         static int compiled_shader_num = 0;
 274         char filename[256];
 275         sprintf(filename, "chain-%03d.frag", compiled_shader_num++);
 276         FILE *fp = fopen(filename, "w");
 277         if (fp == NULL) {
 278                 perror(filename);
 279                 exit(1);
 280         }
 281         fprintf(fp, "%s\n", frag_shader.c_str());
 282         fclose(fp);
 283 #endif
 284
 285         GLuint glsl_program_num = glCreateProgram();
 286         GLuint vs_obj = compile_shader(read_file("vs.vert"), GL_VERTEX_SHADER);
 287         GLuint fs_obj = compile_shader(frag_shader, GL_FRAGMENT_SHADER);
 288         glAttachShader(glsl_program_num, vs_obj);
 289         check_error();
 290         glAttachShader(glsl_program_num, fs_obj);
 291         check_error();
 292         glLinkProgram(glsl_program_num);
 293         check_error();
 294
 295         Phase *phase = new Phase;
 296         phase->glsl_program_num = glsl_program_num;
 297         phase->vertex_shader = vs_obj;
 298         phase->fragment_shader = fs_obj;
 299         phase->input_needs_mipmaps = input_needs_mipmaps;
 300         phase->inputs = true_inputs;
 301         phase->effects = effects;
 302
 303         return phase;
 304 }
 305
 306 // Construct GLSL programs, starting at the given effect and following
 307 // the chain from there. We end a program every time we come to an effect
 308 // marked as "needs texture bounce", one that is used by multiple other
 309 // effects, every time an effect wants to change the output size,
 310 // and of course at the end.
 311 //
 312 // We follow a quite simple depth-first search from the output, although
 313 // without any explicit recursion.
 314 void EffectChain::construct_glsl_programs(Node *output)
 315 {
 316         // Which effects have already been completed in this phase?
 317         // We need to keep track of it, as an effect with multiple outputs
 318         // could otherwise be calculate multiple times.
 319         std::set<Node *> completed_effects;
 320
 321         // Effects in the current phase, as well as inputs (outputs from other phases
 322         // that we depend on). Note that since we start iterating from the end,
 323         // the effect list will be in the reverse order.
 324         std::vector<Node *> this_phase_inputs;
 325         std::vector<Node *> this_phase_effects;
 326
 327         // Effects that we have yet to calculate, but that we know should
 328         // be in the current phase.
 329         std::stack<Node *> effects_todo_this_phase;
 330
 331         // Effects that we have yet to calculate, but that come from other phases.
 332         // We delay these until we have this phase done in its entirety,
 333         // at which point we pick any of them and start a new phase from that.
 334         std::stack<Node *> effects_todo_other_phases;
 335
 336         effects_todo_this_phase.push(output);
 337
 338         for ( ;; ) {  // Termination condition within loop.
 339                 if (!effects_todo_this_phase.empty()) {
 340                         // OK, we have more to do this phase.
 341                         Node *node = effects_todo_this_phase.top();
 342                         effects_todo_this_phase.pop();
 343
 344                         // This should currently only happen for effects that are phase outputs,
 345                         // and we throw those out separately below.
 346                         assert(completed_effects.count(node) == 0);
 347
 348                         this_phase_effects.push_back(node);
 349                         completed_effects.insert(node);
 350
 351                         // Find all the dependencies of this effect, and add them to the stack.
 352                         std::vector<Node *> deps = node->incoming_links;
 353                         assert(node->effect->num_inputs() == deps.size());
 354                         for (unsigned i = 0; i < deps.size(); ++i) {
 355                                 bool start_new_phase = false;
 356
 357                                 // FIXME: If we sample directly from a texture, we won't need this.
 358                                 if (node->effect->needs_texture_bounce()) {
 359                                         start_new_phase = true;
 360                                 }
 361
 362                                 if (deps[i]->outgoing_links.size() > 1) {
 363                                         if (deps[i]->effect->num_inputs() > 0) {
 364                                                 // More than one effect uses this as the input,
 365                                                 // and it is not a texture itself.
 366                                                 // The easiest thing to do (and probably also the safest
 367                                                 // performance-wise in most cases) is to bounce it to a texture
 368                                                 // and then let the next passes read from that.
 369                                                 start_new_phase = true;
 370                                         } else {
 371                                                 // For textures, we try to be slightly more clever;
 372                                                 // if none of our outputs need a bounce, we don't bounce
 373                                                 // but instead simply use the effect many times.
 374                                                 //
 375                                                 // Strictly speaking, we could bounce it for some outputs
 376                                                 // and use it directly for others, but the processing becomes
 377                                                 // somewhat simpler if the effect is only used in one such way.
 378                                                 for (unsigned j = 0; j < deps[i]->outgoing_links.size(); ++j) {
 379                                                         Node *rdep = deps[i]->outgoing_links[j];
 380                                                         start_new_phase |= rdep->effect->needs_texture_bounce();
 381                                                 }
 382                                         }
 383                                 }
 384
 385                                 if (deps[i]->effect->changes_output_size()) {
 386                                         start_new_phase = true;
 387                                 }
 388
 389                                 if (start_new_phase) {
 390                                         effects_todo_other_phases.push(deps[i]);
 391                                         this_phase_inputs.push_back(deps[i]);
 392                                 } else {
 393                                         effects_todo_this_phase.push(deps[i]);
 394                                 }
 395                         }
 396                         continue;
 397                 }
 398
 399                 // No more effects to do this phase. Take all the ones we have,
 400                 // and create a GLSL program for it.
 401                 if (!this_phase_effects.empty()) {
 402                         reverse(this_phase_effects.begin(), this_phase_effects.end());
 403                         phases.push_back(compile_glsl_program(this_phase_inputs, this_phase_effects));
 404                         this_phase_effects.back()->phase = phases.back();
 405                         this_phase_inputs.clear();
 406                         this_phase_effects.clear();
 407                 }
 408                 assert(this_phase_inputs.empty());
 409                 assert(this_phase_effects.empty());
 410
 411                 // If we have no effects left, exit.
 412                 if (effects_todo_other_phases.empty()) {
 413                         break;
 414                 }
 415
 416                 Node *node = effects_todo_other_phases.top();
 417                 effects_todo_other_phases.pop();
 418
 419                 if (completed_effects.count(node) == 0) {
 420                         // Start a new phase, calculating from this effect.
 421                         effects_todo_this_phase.push(node);
 422                 }
 423         }
 424
 425         // Finally, since the phases are found from the output but must be executed
 426         // from the input(s), reverse them, too.
 427         std::reverse(phases.begin(), phases.end());
 428 }
 429
 430 void EffectChain::output_dot(const char *filename)
 431 {
 432 #ifdef NDEBUG
 433         return;
 434 #endif
 435
 436         FILE *fp = fopen(filename, "w");
 437         if (fp == NULL) {
 438                 perror(filename);
 439                 exit(1);
 440         }
 441
 442         fprintf(fp, "digraph G {\n");
 443         for (unsigned i = 0; i < nodes.size(); ++i) {
 444                 // Find out which phase this event belongs to.
 445                 int in_phase = -1;
 446                 for (unsigned j = 0; j < phases.size(); ++j) {
 447                         const Phase* p = phases[j];
 448                         if (std::find(p->effects.begin(), p->effects.end(), nodes[i]) != p->effects.end()) {
 449                                 assert(in_phase == -1);
 450                                 in_phase = j;
 451                         }
 452                 }
 453
 454                 if (in_phase == -1) {
 455                         fprintf(fp, "  n%ld [label=\"%s\"];\n", (long)nodes[i], nodes[i]->effect->effect_type_id().c_str());
 456                 } else {
 457                         fprintf(fp, "  n%ld [label=\"%s\" style=\"filled\" fillcolor=\"/accent8/%d\"];\n",
 458                                 (long)nodes[i], nodes[i]->effect->effect_type_id().c_str(),
 459                                 (in_phase % 8) + 1);
 460                 }
 461                 for (unsigned j = 0; j < nodes[i]->outgoing_links.size(); ++j) {
 462                         std::vector<std::string> labels;
 463
 464                         if (nodes[i]->outgoing_links[j]->effect->needs_texture_bounce()) {
 465                                 labels.push_back("needs_bounce");
 466                         }
 467                         if (nodes[i]->effect->changes_output_size()) {
 468                                 labels.push_back("resize");
 469                         }
 470
 471                         switch (nodes[i]->output_color_space) {
 472                         case COLORSPACE_INVALID:
 473                                 labels.push_back("spc[invalid]");
 474                                 break;
 475                         case COLORSPACE_REC_601_525:
 476                                 labels.push_back("spc[rec601-525]");
 477                                 break;
 478                         case COLORSPACE_REC_601_625:
 479                                 labels.push_back("spc[rec601-625]");
 480                                 break;
 481                         default:
 482                                 break;
 483                         }
 484
 485                         switch (nodes[i]->output_gamma_curve) {
 486                         case GAMMA_INVALID:
 487                                 labels.push_back("gamma[invalid]");
 488                                 break;
 489                         case GAMMA_sRGB:
 490                                 labels.push_back("gamma[sRGB]");
 491                                 break;
 492                         case GAMMA_REC_601:  // and GAMMA_REC_709
 493                                 labels.push_back("gamma[rec601/709]");
 494                                 break;
 495                         default:
 496                                 break;
 497                         }
 498
 499                         if (labels.empty()) {
 500                                 fprintf(fp, "  n%ld -> n%ld;\n", (long)nodes[i], (long)nodes[i]->outgoing_links[j]);
 501                         } else {
 502                                 std::string label = labels[0];
 503                                 for (unsigned k = 1; k < labels.size(); ++k) {
 504                                         label += ", " + labels[k];
 505                                 }
 506                                 fprintf(fp, "  n%ld -> n%ld [label=\"%s\"];\n", (long)nodes[i], (long)nodes[i]->outgoing_links[j], label.c_str());
 507                         }
 508                 }
 509         }
 510         fprintf(fp, "}\n");
 511
 512         fclose(fp);
 513 }
 514
 515 unsigned EffectChain::fit_rectangle_to_aspect(unsigned width, unsigned height)
 516 {
 517         if (float(width) * aspect_denom >= float(height) * aspect_nom) {
 518                 // Same aspect, or W/H > aspect (image is wider than the frame).
 519                 // In either case, keep width.
 520                 return width;
 521         } else {
 522                 // W/H < aspect (image is taller than the frame), so keep height,
 523                 // and adjust width correspondingly.
 524                 return lrintf(height * aspect_nom / aspect_denom);
 525         }
 526 }
 527
 528 // Propagate input texture sizes throughout, and inform effects downstream.
 529 // (Like a lot of other code, we depend on effects being in topological order.)
 530 void EffectChain::inform_input_sizes(Phase *phase)
 531 {
 532         // All effects that have a defined size (inputs and RTT inputs)
 533         // get that. Reset all others.
 534         for (unsigned i = 0; i < phase->effects.size(); ++i) {
 535                 Node *node = phase->effects[i];
 536                 if (node->effect->num_inputs() == 0) {
 537                         Input *input = static_cast<Input *>(node->effect);
 538                         node->output_width = input->get_width();
 539                         node->output_height = input->get_height();
 540                         assert(node->output_width != 0);
 541                         assert(node->output_height != 0);
 542                 } else {
 543                         node->output_width = node->output_height = 0;
 544                 }
 545         }
 546         for (unsigned i = 0; i < phase->inputs.size(); ++i) {
 547                 Node *input = phase->inputs[i];
 548                 input->output_width = input->phase->output_width;
 549                 input->output_height = input->phase->output_height;
 550                 assert(input->output_width != 0);
 551                 assert(input->output_height != 0);
 552         }
 553
 554         // Now propagate from the inputs towards the end, and inform as we go.
 555         // The rules are simple:
 556         //
 557         //   1. Don't touch effects that already have given sizes (ie., inputs).
 558         //   2. If all of your inputs have the same size, that will be your output size.
 559         //   3. Otherwise, your output size is 0x0.
 560         for (unsigned i = 0; i < phase->effects.size(); ++i) {
 561                 Node *node = phase->effects[i];
 562                 if (node->effect->num_inputs() == 0) {
 563                         continue;
 564                 }
 565                 unsigned this_output_width = 0;
 566                 unsigned this_output_height = 0;
 567                 for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
 568                         Node *input = node->incoming_links[j];
 569                         node->effect->inform_input_size(j, input->output_width, input->output_height);
 570                         if (j == 0) {
 571                                 this_output_width = input->output_width;
 572                                 this_output_height = input->output_height;
 573                         } else if (input->output_width != this_output_width || input->output_height != this_output_height) {
 574                                 // Inputs disagree.
 575                                 this_output_width = 0;
 576                                 this_output_height = 0;
 577                         }
 578                 }
 579                 node->output_width = this_output_width;
 580                 node->output_height = this_output_height;
 581         }
 582 }
 583
 584 // Note: You should call inform_input_sizes() before this, as the last effect's
 585 // desired output size might change based on the inputs.
 586 void EffectChain::find_output_size(Phase *phase)
 587 {
 588         Node *output_node = phase->effects.back();
 589
 590         // If the last effect explicitly sets an output size, use that.
 591         if (output_node->effect->changes_output_size()) {
 592                 output_node->effect->get_output_size(&phase->output_width, &phase->output_height);
 593                 return;
 594         }
 595
 596         // If not, look at the input phases and textures.
 597         // We select the largest one (by fit into the current aspect).
 598         unsigned best_width = 0;
 599         for (unsigned i = 0; i < phase->inputs.size(); ++i) {
 600                 Node *input = phase->inputs[i];
 601                 assert(input->phase->output_width != 0);
 602                 assert(input->phase->output_height != 0);
 603                 unsigned width = fit_rectangle_to_aspect(input->phase->output_width, input->phase->output_height);
 604                 if (width > best_width) {
 605                         best_width = width;
 606                 }
 607         }
 608         for (unsigned i = 0; i < phase->effects.size(); ++i) {
 609                 Effect *effect = phase->effects[i]->effect;
 610                 if (effect->num_inputs() != 0) {
 611                         continue;
 612                 }
 613
 614                 Input *input = static_cast<Input *>(effect);
 615                 unsigned width = fit_rectangle_to_aspect(input->get_width(), input->get_height());
 616                 if (width > best_width) {
 617                         best_width = width;
 618                 }
 619         }
 620         assert(best_width != 0);
 621         phase->output_width = best_width;
 622         phase->output_height = best_width * aspect_denom / aspect_nom;
 623 }
 624
 625 void EffectChain::sort_nodes_topologically()
 626 {
 627         std::set<Node *> visited_nodes;
 628         std::vector<Node *> sorted_list;
 629         for (unsigned i = 0; i < nodes.size(); ++i) {
 630                 if (nodes[i]->incoming_links.size() == 0) {
 631                         topological_sort_visit_node(nodes[i], &visited_nodes, &sorted_list);
 632                 }
 633         }
 634         reverse(sorted_list.begin(), sorted_list.end());
 635         nodes = sorted_list;
 636 }
 637
 638 void EffectChain::topological_sort_visit_node(Node *node, std::set<Node *> *visited_nodes, std::vector<Node *> *sorted_list)
 639 {
 640         if (visited_nodes->count(node) != 0) {
 641                 return;
 642         }
 643         visited_nodes->insert(node);
 644         for (unsigned i = 0; i < node->outgoing_links.size(); ++i) {
 645                 topological_sort_visit_node(node->outgoing_links[i], visited_nodes, sorted_list);
 646         }
 647         sorted_list->push_back(node);
 648 }
 649
 650 // Propagate gamma and color space information as far as we can in the graph.
 651 // The rules are simple: Anything where all the inputs agree, get that as
 652 // output as well. Anything else keeps having *_INVALID.
 653 void EffectChain::propagate_gamma_and_color_space()
 654 {
 655         // We depend on going through the nodes in order.
 656         sort_nodes_topologically();
 657
 658         for (unsigned i = 0; i < nodes.size(); ++i) {
 659                 Node *node = nodes[i];
 660                 if (node->disabled) {
 661                         continue;
 662                 }
 663                 assert(node->incoming_links.size() == node->effect->num_inputs());
 664                 if (node->incoming_links.size() == 0) {
 665                         assert(node->output_color_space != COLORSPACE_INVALID);
 666                         assert(node->output_gamma_curve != GAMMA_INVALID);
 667                         continue;
 668                 }
 669
 670                 Colorspace color_space = node->incoming_links[0]->output_color_space;
 671                 GammaCurve gamma_curve = node->incoming_links[0]->output_gamma_curve;
 672                 for (unsigned j = 1; j < node->incoming_links.size(); ++j) {
 673                         if (node->incoming_links[j]->output_color_space != color_space) {
 674                                 color_space = COLORSPACE_INVALID;
 675                         }
 676                         if (node->incoming_links[j]->output_gamma_curve != gamma_curve) {
 677                                 gamma_curve = GAMMA_INVALID;
 678                         }
 679                 }
 680
 681                 // The conversion effects already have their outputs set correctly,
 682                 // so leave them alone.
 683                 if (node->effect->effect_type_id() != "ColorspaceConversionEffect") {
 684                         node->output_color_space = color_space;
 685                 }
 686                 if (node->effect->effect_type_id() != "GammaCompressionEffect" &&
 687                     node->effect->effect_type_id() != "GammaExpansionEffect") {
 688                         node->output_gamma_curve = gamma_curve;
 689                 }
 690         }
 691 }
 692
 693 bool EffectChain::node_needs_colorspace_fix(Node *node)
 694 {
 695         if (node->disabled) {
 696                 return false;
 697         }
 698         if (node->effect->num_inputs() == 0) {
 699                 return false;
 700         }
 701
 702         // propagate_gamma_and_color_space() has already set our output
 703         // to COLORSPACE_INVALID if the inputs differ, so we can rely on that.
 704         if (node->output_color_space == COLORSPACE_INVALID) {
 705                 return true;
 706         }
 707         return (node->effect->needs_srgb_primaries() && node->output_color_space != COLORSPACE_sRGB);
 708 }
 709
 710 // Fix up color spaces so that there are no COLORSPACE_INVALID nodes left in
 711 // the graph. Our strategy is not always optimal, but quite simple:
 712 // Find an effect that's as early as possible where the inputs are of
 713 // unacceptable colorspaces (that is, either different, or, if the effect only
 714 // wants sRGB, not sRGB.) Add appropriate conversions on all its inputs,
 715 // propagate the information anew, and repeat until there are no more such
 716 // effects.
 717 void EffectChain::fix_internal_color_spaces()
 718 {
 719         unsigned colorspace_propagation_pass = 0;
 720         bool found_any;
 721         do {
 722                 found_any = false;
 723                 for (unsigned i = 0; i < nodes.size(); ++i) {
 724                         Node *node = nodes[i];
 725                         if (!node_needs_colorspace_fix(node)) {
 726                                 continue;
 727                         }
 728
 729                         // Go through each input that is not sRGB, and insert
 730                         // a colorspace conversion before it.
 731                         for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
 732                                 Node *input = node->incoming_links[j];
 733                                 assert(input->output_color_space != COLORSPACE_INVALID);
 734                                 if (input->output_color_space == COLORSPACE_sRGB) {
 735                                         continue;
 736                                 }
 737                                 Node *conversion = add_node(new ColorspaceConversionEffect());
 738                                 CHECK(conversion->effect->set_int("source_space", input->output_color_space));
 739                                 CHECK(conversion->effect->set_int("destination_space", COLORSPACE_sRGB));
 740                                 conversion->output_color_space = COLORSPACE_sRGB;
 741                                 insert_node_between(input, conversion, node);
 742                         }
 743
 744                         // Re-sort topologically, and propagate the new information.
 745                         propagate_gamma_and_color_space();
 746
 747                         found_any = true;
 748                         break;
 749                 }
 750
 751                 char filename[256];
 752                 sprintf(filename, "step3-colorspacefix-iter%u.dot", ++colorspace_propagation_pass);
 753                 output_dot(filename);
 754                 assert(colorspace_propagation_pass < 100);
 755         } while (found_any);
 756
 757         for (unsigned i = 0; i < nodes.size(); ++i) {
 758                 Node *node = nodes[i];
 759                 if (node->disabled) {
 760                         continue;
 761                 }
 762                 assert(node->output_color_space != COLORSPACE_INVALID);
 763         }
 764 }
 765
 766 // Make so that the output is in the desired color space.
 767 void EffectChain::fix_output_color_space()
 768 {
 769         Node *output = find_output_node();
 770         if (output->output_color_space != output_format.color_space) {
 771                 Node *conversion = add_node(new ColorspaceConversionEffect());
 772                 CHECK(conversion->effect->set_int("source_space", output->output_color_space));
 773                 CHECK(conversion->effect->set_int("destination_space", output_format.color_space));
 774                 conversion->output_color_space = output_format.color_space;
 775                 connect_nodes(output, conversion);
 776                 propagate_gamma_and_color_space();
 777         }
 778 }
 779
 780 bool EffectChain::node_needs_gamma_fix(Node *node)
 781 {
 782         if (node->disabled) {
 783                 return false;
 784         }
 785
 786         // Small hack since the output is not an explicit node:
 787         // If we are the last node and our output is in the wrong
 788         // space compared to EffectChain's output, we need to fix it.
 789         // This will only take us to linear, but fix_output_gamma()
 790         // will come and take us to the desired output gamma
 791         // if it is needed.
 792         //
 793         // This needs to be before everything else, since it could
 794         // even apply to inputs (if they are the only effect).
 795         if (node->outgoing_links.empty() &&
 796             node->output_gamma_curve != output_format.gamma_curve &&
 797             node->output_gamma_curve != GAMMA_LINEAR) {
 798                 return true;
 799         }
 800
 801         if (node->effect->num_inputs() == 0) {
 802                 return false;
 803         }
 804
 805         // propagate_gamma_and_color_space() has already set our output
 806         // to GAMMA_INVALID if the inputs differ, so we can rely on that,
 807         // except for GammaCompressionEffect.
 808         if (node->output_gamma_curve == GAMMA_INVALID) {
 809                 return true;
 810         }
 811         if (node->effect->effect_type_id() == "GammaCompressionEffect") {
 812                 assert(node->incoming_links.size() == 1);
 813                 return node->incoming_links[0]->output_gamma_curve != GAMMA_LINEAR;
 814         }
 815
 816         return (node->effect->needs_linear_light() && node->output_gamma_curve != GAMMA_LINEAR);
 817 }
 818
 819 // Very similar to fix_internal_color_spaces(), but for gamma.
 820 // There is one difference, though; before we start adding conversion nodes,
 821 // we see if we can get anything out of asking the sources to deliver
 822 // linear gamma directly. fix_internal_gamma_by_asking_inputs()
 823 // does that part, while fix_internal_gamma_by_inserting_nodes()
 824 // inserts nodes as needed afterwards.
 825 void EffectChain::fix_internal_gamma_by_asking_inputs(unsigned step)
 826 {
 827         unsigned gamma_propagation_pass = 0;
 828         bool found_any;
 829         do {
 830                 found_any = false;
 831                 for (unsigned i = 0; i < nodes.size(); ++i) {
 832                         Node *node = nodes[i];
 833                         if (!node_needs_gamma_fix(node)) {
 834                                 continue;
 835                         }
 836
 837                         // See if all inputs can give us linear gamma. If not, leave it.
 838                         std::vector<Node *> nonlinear_inputs;
 839                         find_all_nonlinear_inputs(node, &nonlinear_inputs);
 840                         assert(!nonlinear_inputs.empty());
 841
 842                         bool all_ok = true;
 843                         for (unsigned i = 0; i < nonlinear_inputs.size(); ++i) {
 844                                 Input *input = static_cast<Input *>(nonlinear_inputs[i]->effect);
 845                                 all_ok &= input->can_output_linear_gamma();
 846                         }
 847
 848                         if (!all_ok) {
 849                                 continue;
 850                         }
 851
 852                         for (unsigned i = 0; i < nonlinear_inputs.size(); ++i) {
 853                                 CHECK(nonlinear_inputs[i]->effect->set_int("output_linear_gamma", 1));
 854                                 nonlinear_inputs[i]->output_gamma_curve = GAMMA_LINEAR;
 855                         }
 856
 857                         // Re-sort topologically, and propagate the new information.
 858                         propagate_gamma_and_color_space();
 859
 860                         found_any = true;
 861                         break;
 862                 }
 863
 864                 char filename[256];
 865                 sprintf(filename, "step%u-gammafix-iter%u.dot", step, ++gamma_propagation_pass);
 866                 output_dot(filename);
 867                 assert(gamma_propagation_pass < 100);
 868         } while (found_any);
 869 }
 870
 871 void EffectChain::fix_internal_gamma_by_inserting_nodes(unsigned step)
 872 {
 873         unsigned gamma_propagation_pass = 0;
 874         bool found_any;
 875         do {
 876                 found_any = false;
 877                 for (unsigned i = 0; i < nodes.size(); ++i) {
 878                         Node *node = nodes[i];
 879                         if (!node_needs_gamma_fix(node)) {
 880                                 continue;
 881                         }
 882
 883                         // Special case: We could be an input and still be asked to
 884                         // fix our gamma; if so, we should be the only node
 885                         // (as node_needs_gamma_fix() would only return true in
 886                         // for an input in that case). That means we should insert
 887                         // a conversion node _after_ ourselves.
 888                         if (node->incoming_links.empty()) {
 889                                 assert(node->outgoing_links.empty());
 890                                 Node *conversion = add_node(new GammaExpansionEffect());
 891                                 CHECK(conversion->effect->set_int("source_curve", node->output_gamma_curve));
 892                                 conversion->output_gamma_curve = GAMMA_LINEAR;
 893                                 connect_nodes(node, conversion);
 894                         }
 895
 896                         // If not, go through each input that is not linear gamma,
 897                         // and insert a gamma conversion before it.
 898                         for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
 899                                 Node *input = node->incoming_links[j];
 900                                 assert(input->output_gamma_curve != GAMMA_INVALID);
 901                                 if (input->output_gamma_curve == GAMMA_LINEAR) {
 902                                         continue;
 903                                 }
 904                                 Node *conversion = add_node(new GammaExpansionEffect());
 905                                 CHECK(conversion->effect->set_int("source_curve", input->output_gamma_curve));
 906                                 conversion->output_gamma_curve = GAMMA_LINEAR;
 907                                 insert_node_between(input, conversion, node);
 908                         }
 909
 910                         // Re-sort topologically, and propagate the new information.
 911                         propagate_gamma_and_color_space();
 912
 913                         found_any = true;
 914                         break;
 915                 }
 916
 917                 char filename[256];
 918                 sprintf(filename, "step%u-gammafix-iter%u.dot", step, ++gamma_propagation_pass);
 919                 output_dot(filename);
 920                 assert(gamma_propagation_pass < 100);
 921         } while (found_any);
 922
 923         for (unsigned i = 0; i < nodes.size(); ++i) {
 924                 Node *node = nodes[i];
 925                 if (node->disabled) {
 926                         continue;
 927                 }
 928                 assert(node->output_gamma_curve != GAMMA_INVALID);
 929         }
 930 }
 931
 932 // Make so that the output is in the desired gamma.
 933 // Note that this assumes linear input gamma, so it might create the need
 934 // for another pass of fix_internal_gamma().
 935 void EffectChain::fix_output_gamma()
 936 {
 937         Node *output = find_output_node();
 938         if (output->output_gamma_curve != output_format.gamma_curve) {
 939                 Node *conversion = add_node(new GammaCompressionEffect());
 940                 CHECK(conversion->effect->set_int("destination_curve", output_format.gamma_curve));
 941                 conversion->output_gamma_curve = output_format.gamma_curve;
 942                 connect_nodes(output, conversion);
 943         }
 944 }
 945
 946 // If the user has requested dither, add a DitherEffect right at the end
 947 // (after GammaCompressionEffect etc.). This needs to be done after everything else,
 948 // since dither is about the only effect that can _not_ be done in linear space.
 949 void EffectChain::add_dither_if_needed()
 950 {
 951         if (num_dither_bits == 0) {
 952                 return;
 953         }
 954         Node *output = find_output_node();
 955         Node *dither = add_node(new DitherEffect());
 956         CHECK(dither->effect->set_int("num_bits", num_dither_bits));
 957         connect_nodes(output, dither);
 958
 959         dither_effect = dither->effect;
 960 }
 961
 962 // Find the output node. This is, simply, one that has no outgoing links.
 963 // If there are multiple ones, the graph is malformed (we do not support
 964 // multiple outputs right now).
 965 Node *EffectChain::find_output_node()
 966 {
 967         std::vector<Node *> output_nodes;
 968         for (unsigned i = 0; i < nodes.size(); ++i) {
 969                 Node *node = nodes[i];
 970                 if (node->disabled) {
 971                         continue;
 972                 }
 973                 if (node->outgoing_links.empty()) {
 974                         output_nodes.push_back(node);
 975                 }
 976         }
 977         assert(output_nodes.size() == 1);
 978         return output_nodes[0];
 979 }
 980
 981 void EffectChain::finalize()
 982 {
 983         // Output the graph as it is before we do any conversions on it.
 984         output_dot("step0-start.dot");
 985
 986         // Give each effect in turn a chance to rewrite its own part of the graph.
 987         // Note that if more effects are added as part of this, they will be
 988         // picked up as part of the same for loop, since they are added at the end.
 989         for (unsigned i = 0; i < nodes.size(); ++i) {
 990                 nodes[i]->effect->rewrite_graph(this, nodes[i]);
 991         }
 992         output_dot("step1-rewritten.dot");
 993
 994         propagate_gamma_and_color_space();
 995         output_dot("step2-propagated.dot");
 996
 997         fix_internal_color_spaces();
 998         fix_output_color_space();
 999         output_dot("step4-output-colorspacefix.dot");
1000
1001         // Note that we need to fix gamma after colorspace conversion,
1002         // because colorspace conversions might create needs for gamma conversions.
1003         // Also, we need to run an extra pass of fix_internal_gamma() after
1004         // fixing the output gamma, as we only have conversions to/from linear.
1005         fix_internal_gamma_by_asking_inputs(5);
1006         fix_internal_gamma_by_inserting_nodes(6);
1007         fix_output_gamma();
1008         output_dot("step7-output-gammafix.dot");
1009         fix_internal_gamma_by_asking_inputs(8);
1010         fix_internal_gamma_by_inserting_nodes(9);
1011
1012         output_dot("step10-before-dither.dot");
1013
1014         add_dither_if_needed();
1015
1016         output_dot("step11-final.dot");
1017
1018         // Construct all needed GLSL programs, starting at the output.
1019         construct_glsl_programs(find_output_node());
1020
1021         output_dot("step12-split-to-phases.dot");
1022
1023         // If we have more than one phase, we need intermediate render-to-texture.
1024         // Construct an FBO, and then as many textures as we need.
1025         // We choose the simplest option of having one texture per output,
1026         // since otherwise this turns into an (albeit simple)
1027         // register allocation problem.
1028         if (phases.size() > 1) {
1029                 glGenFramebuffers(1, &fbo);
1030
1031                 for (unsigned i = 0; i < phases.size() - 1; ++i) {
1032                         inform_input_sizes(phases[i]);
1033                         find_output_size(phases[i]);
1034
1035                         Node *output_node = phases[i]->effects.back();
1036                         glGenTextures(1, &output_node->output_texture);
1037                         check_error();
1038                         glBindTexture(GL_TEXTURE_2D, output_node->output_texture);
1039                         check_error();
1040                         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
1041                         check_error();
1042                         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
1043                         check_error();
1044                         glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA16F_ARB, phases[i]->output_width, phases[i]->output_height, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
1045                         check_error();
1046
1047                         output_node->output_texture_width = phases[i]->output_width;
1048                         output_node->output_texture_height = phases[i]->output_height;
1049                 }
1050                 inform_input_sizes(phases.back());
1051         }
1052
1053         for (unsigned i = 0; i < inputs.size(); ++i) {
1054                 inputs[i]->finalize();
1055         }
1056
1057         assert(phases[0]->inputs.empty());
1058
1059         finalized = true;
1060 }
1061
1062 void EffectChain::render_to_fbo(GLuint dest_fbo, unsigned width, unsigned height)
1063 {
1064         assert(finalized);
1065
1066         // Save original viewport.
1067         GLuint x = 0, y = 0;
1068
1069         if (width == 0 && height == 0) {
1070                 GLint viewport[4];
1071                 glGetIntegerv(GL_VIEWPORT, viewport);
1072                 x = viewport[0];
1073                 y = viewport[1];
1074                 width = viewport[2];
1075                 height = viewport[3];
1076         }
1077
1078         // Basic state.
1079         glDisable(GL_BLEND);
1080         check_error();
1081         glDisable(GL_DEPTH_TEST);
1082         check_error();
1083         glDepthMask(GL_FALSE);
1084         check_error();
1085
1086         glMatrixMode(GL_PROJECTION);
1087         glLoadIdentity();
1088         glOrtho(0.0, 1.0, 0.0, 1.0, 0.0, 1.0);
1089
1090         glMatrixMode(GL_MODELVIEW);
1091         glLoadIdentity();
1092
1093         if (phases.size() > 1) {
1094                 glBindFramebuffer(GL_FRAMEBUFFER, fbo);
1095                 check_error();
1096         }
1097
1098         std::set<Node *> generated_mipmaps;
1099
1100         for (unsigned phase = 0; phase < phases.size(); ++phase) {
1101                 // See if the requested output size has changed. If so, we need to recreate
1102                 // the texture (and before we start setting up inputs).
1103                 inform_input_sizes(phases[phase]);
1104                 if (phase != phases.size() - 1) {
1105                         find_output_size(phases[phase]);
1106
1107                         Node *output_node = phases[phase]->effects.back();
1108
1109                         if (output_node->output_texture_width != phases[phase]->output_width ||
1110                             output_node->output_texture_height != phases[phase]->output_height) {
1111                                 glActiveTexture(GL_TEXTURE0);
1112                                 check_error();
1113                                 glBindTexture(GL_TEXTURE_2D, output_node->output_texture);
1114                                 check_error();
1115                                 glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA16F_ARB, phases[phase]->output_width, phases[phase]->output_height, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
1116                                 check_error();
1117                                 glBindTexture(GL_TEXTURE_2D, 0);
1118                                 check_error();
1119
1120                                 output_node->output_texture_width = phases[phase]->output_width;
1121                                 output_node->output_texture_height = phases[phase]->output_height;
1122                         }
1123                 }
1124
1125                 glUseProgram(phases[phase]->glsl_program_num);
1126                 check_error();
1127
1128                 // Set up RTT inputs for this phase.
1129                 for (unsigned sampler = 0; sampler < phases[phase]->inputs.size(); ++sampler) {
1130                         glActiveTexture(GL_TEXTURE0 + sampler);
1131                         Node *input = phases[phase]->inputs[sampler];
1132                         glBindTexture(GL_TEXTURE_2D, input->output_texture);
1133                         check_error();
1134                         if (phases[phase]->input_needs_mipmaps) {
1135                                 if (generated_mipmaps.count(input) == 0) {
1136                                         glGenerateMipmap(GL_TEXTURE_2D);
1137                                         check_error();
1138                                         generated_mipmaps.insert(input);
1139                                 }
1140                                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_NEAREST);
1141                                 check_error();
1142                         } else {
1143                                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
1144                                 check_error();
1145                         }
1146
1147                         std::string texture_name = std::string("tex_") + input->effect_id;
1148                         glUniform1i(glGetUniformLocation(phases[phase]->glsl_program_num, texture_name.c_str()), sampler);
1149                         check_error();
1150                 }
1151
1152                 // And now the output.
1153                 if (phase == phases.size() - 1) {
1154                         // Last phase goes to the output the user specified.
1155                         glBindFramebuffer(GL_FRAMEBUFFER, dest_fbo);
1156                         check_error();
1157                         glViewport(x, y, width, height);
1158                         if (dither_effect != NULL) {
1159                                 CHECK(dither_effect->set_int("output_width", width));
1160                                 CHECK(dither_effect->set_int("output_height", height));
1161                         }
1162                 } else {
1163                         Node *output_node = phases[phase]->effects.back();
1164                         glFramebufferTexture2D(
1165                                 GL_FRAMEBUFFER,
1166                                 GL_COLOR_ATTACHMENT0,
1167                                 GL_TEXTURE_2D,
1168                                 output_node->output_texture,
1169                                 0);
1170                         check_error();
1171                         glViewport(0, 0, phases[phase]->output_width, phases[phase]->output_height);
1172                 }
1173
1174                 // Give the required parameters to all the effects.
1175                 unsigned sampler_num = phases[phase]->inputs.size();
1176                 for (unsigned i = 0; i < phases[phase]->effects.size(); ++i) {
1177                         Node *node = phases[phase]->effects[i];
1178                         node->effect->set_gl_state(phases[phase]->glsl_program_num, node->effect_id, &sampler_num);
1179                         check_error();
1180                 }
1181
1182                 // Now draw!
1183                 glBegin(GL_QUADS);
1184
1185                 glTexCoord2f(0.0f, 0.0f);
1186                 glVertex2f(0.0f, 0.0f);
1187
1188                 glTexCoord2f(1.0f, 0.0f);
1189                 glVertex2f(1.0f, 0.0f);
1190
1191                 glTexCoord2f(1.0f, 1.0f);
1192                 glVertex2f(1.0f, 1.0f);
1193
1194                 glTexCoord2f(0.0f, 1.0f);
1195                 glVertex2f(0.0f, 1.0f);
1196
1197                 glEnd();
1198                 check_error();
1199
1200                 for (unsigned i = 0; i < phases[phase]->effects.size(); ++i) {
1201                         Node *node = phases[phase]->effects[i];
1202                         node->effect->clear_gl_state();
1203                 }
1204         }
1205 }