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

   1 #define GL_GLEXT_PROTOTYPES 1
   2
   3 #include <epoxy/gl.h>
   4 #include <assert.h>
   5 #include <math.h>
   6 #include <stddef.h>
   7 #include <stdio.h>
   8 #include <stdlib.h>
   9 #include <string.h>
  10 #include <algorithm>
  11 #include <set>
  12 #include <stack>
  13 #include <utility>
  14 #include <vector>
  15
  16 #include "alpha_division_effect.h"
  17 #include "alpha_multiplication_effect.h"
  18 #include "colorspace_conversion_effect.h"
  19 #include "dither_effect.h"
  20 #include "effect.h"
  21 #include "effect_chain.h"
  22 #include "gamma_compression_effect.h"
  23 #include "gamma_expansion_effect.h"
  24 #include "init.h"
  25 #include "input.h"
  26 #include "resource_pool.h"
  27 #include "util.h"
  28
  29 using namespace std;
  30
  31 namespace movit {
  32
  33 EffectChain::EffectChain(float aspect_nom, float aspect_denom, ResourcePool *resource_pool)
  34         : aspect_nom(aspect_nom),
  35           aspect_denom(aspect_denom),
  36           dither_effect(NULL),
  37           num_dither_bits(0),
  38           finalized(false),
  39           resource_pool(resource_pool),
  40           do_phase_timing(false) {
  41         if (resource_pool == NULL) {
  42                 this->resource_pool = new ResourcePool();
  43                 owns_resource_pool = true;
  44         } else {
  45                 owns_resource_pool = false;
  46         }
  47 }
  48
  49 EffectChain::~EffectChain()
  50 {
  51         for (unsigned i = 0; i < nodes.size(); ++i) {
  52                 delete nodes[i]->effect;
  53                 delete nodes[i];
  54         }
  55         for (unsigned i = 0; i < phases.size(); ++i) {
  56                 resource_pool->release_glsl_program(phases[i]->glsl_program_num);
  57                 delete phases[i];
  58         }
  59         if (owns_resource_pool) {
  60                 delete resource_pool;
  61         }
  62 }
  63
  64 Input *EffectChain::add_input(Input *input)
  65 {
  66         assert(!finalized);
  67         inputs.push_back(input);
  68         add_node(input);
  69         return input;
  70 }
  71
  72 void EffectChain::add_output(const ImageFormat &format, OutputAlphaFormat alpha_format)
  73 {
  74         assert(!finalized);
  75         output_format = format;
  76         output_alpha_format = alpha_format;
  77 }
  78
  79 Node *EffectChain::add_node(Effect *effect)
  80 {
  81         for (unsigned i = 0; i < nodes.size(); ++i) {
  82                 assert(nodes[i]->effect != effect);
  83         }
  84
  85         Node *node = new Node;
  86         node->effect = effect;
  87         node->disabled = false;
  88         node->output_color_space = COLORSPACE_INVALID;
  89         node->output_gamma_curve = GAMMA_INVALID;
  90         node->output_alpha_type = ALPHA_INVALID;
  91         node->needs_mipmaps = false;
  92
  93         nodes.push_back(node);
  94         node_map[effect] = node;
  95         effect->inform_added(this);
  96         return node;
  97 }
  98
  99 void EffectChain::connect_nodes(Node *sender, Node *receiver)
 100 {
 101         sender->outgoing_links.push_back(receiver);
 102         receiver->incoming_links.push_back(sender);
 103 }
 104
 105 void EffectChain::replace_receiver(Node *old_receiver, Node *new_receiver)
 106 {
 107         new_receiver->incoming_links = old_receiver->incoming_links;
 108         old_receiver->incoming_links.clear();
 109
 110         for (unsigned i = 0; i < new_receiver->incoming_links.size(); ++i) {
 111                 Node *sender = new_receiver->incoming_links[i];
 112                 for (unsigned j = 0; j < sender->outgoing_links.size(); ++j) {
 113                         if (sender->outgoing_links[j] == old_receiver) {
 114                                 sender->outgoing_links[j] = new_receiver;
 115                         }
 116                 }
 117         }
 118 }
 119
 120 void EffectChain::replace_sender(Node *old_sender, Node *new_sender)
 121 {
 122         new_sender->outgoing_links = old_sender->outgoing_links;
 123         old_sender->outgoing_links.clear();
 124
 125         for (unsigned i = 0; i < new_sender->outgoing_links.size(); ++i) {
 126                 Node *receiver = new_sender->outgoing_links[i];
 127                 for (unsigned j = 0; j < receiver->incoming_links.size(); ++j) {
 128                         if (receiver->incoming_links[j] == old_sender) {
 129                                 receiver->incoming_links[j] = new_sender;
 130                         }
 131                 }
 132         }
 133 }
 134
 135 void EffectChain::insert_node_between(Node *sender, Node *middle, Node *receiver)
 136 {
 137         for (unsigned i = 0; i < sender->outgoing_links.size(); ++i) {
 138                 if (sender->outgoing_links[i] == receiver) {
 139                         sender->outgoing_links[i] = middle;
 140                         middle->incoming_links.push_back(sender);
 141                 }
 142         }
 143         for (unsigned i = 0; i < receiver->incoming_links.size(); ++i) {
 144                 if (receiver->incoming_links[i] == sender) {
 145                         receiver->incoming_links[i] = middle;
 146                         middle->outgoing_links.push_back(receiver);
 147                 }
 148         }
 149
 150         assert(middle->incoming_links.size() == middle->effect->num_inputs());
 151 }
 152
 153 GLenum EffectChain::get_input_sampler(Node *node, unsigned input_num) const
 154 {
 155         assert(node->effect->needs_texture_bounce());
 156         assert(input_num < node->incoming_links.size());
 157         assert(node->incoming_links[input_num]->bound_sampler_num >= 0);
 158         assert(node->incoming_links[input_num]->bound_sampler_num < 8);
 159         return GL_TEXTURE0 + node->incoming_links[input_num]->bound_sampler_num;
 160 }
 161
 162 void EffectChain::find_all_nonlinear_inputs(Node *node, vector<Node *> *nonlinear_inputs)
 163 {
 164         if (node->output_gamma_curve == GAMMA_LINEAR &&
 165             node->effect->effect_type_id() != "GammaCompressionEffect") {
 166                 return;
 167         }
 168         if (node->effect->num_inputs() == 0) {
 169                 nonlinear_inputs->push_back(node);
 170         } else {
 171                 assert(node->effect->num_inputs() == node->incoming_links.size());
 172                 for (unsigned i = 0; i < node->incoming_links.size(); ++i) {
 173                         find_all_nonlinear_inputs(node->incoming_links[i], nonlinear_inputs);
 174                 }
 175         }
 176 }
 177
 178 Effect *EffectChain::add_effect(Effect *effect, const vector<Effect *> &inputs)
 179 {
 180         assert(!finalized);
 181         assert(inputs.size() == effect->num_inputs());
 182         Node *node = add_node(effect);
 183         for (unsigned i = 0; i < inputs.size(); ++i) {
 184                 assert(node_map.count(inputs[i]) != 0);
 185                 connect_nodes(node_map[inputs[i]], node);
 186         }
 187         return effect;
 188 }
 189
 190 // GLSL pre-1.30 doesn't support token pasting. Replace PREFIX(x) with <effect_id>_x.
 191 string replace_prefix(const string &text, const string &prefix)
 192 {
 193         string output;
 194         size_t start = 0;
 195
 196         while (start < text.size()) {
 197                 size_t pos = text.find("PREFIX(", start);
 198                 if (pos == string::npos) {
 199                         output.append(text.substr(start, string::npos));
 200                         break;
 201                 }
 202
 203                 output.append(text.substr(start, pos - start));
 204                 output.append(prefix);
 205                 output.append("_");
 206
 207                 pos += strlen("PREFIX(");
 208
 209                 // Output stuff until we find the matching ), which we then eat.
 210                 int depth = 1;
 211                 size_t end_arg_pos = pos;
 212                 while (end_arg_pos < text.size()) {
 213                         if (text[end_arg_pos] == '(') {
 214                                 ++depth;
 215                         } else if (text[end_arg_pos] == ')') {
 216                                 --depth;
 217                                 if (depth == 0) {
 218                                         break;
 219                                 }
 220                         }
 221                         ++end_arg_pos;
 222                 }
 223                 output.append(text.substr(pos, end_arg_pos - pos));
 224                 ++end_arg_pos;
 225                 assert(depth == 0);
 226                 start = end_arg_pos;
 227         }
 228         return output;
 229 }
 230
 231 void EffectChain::compile_glsl_program(Phase *phase)
 232 {
 233         string frag_shader = read_version_dependent_file("header", "frag");
 234
 235         // Create functions for all the texture inputs that we need.
 236         for (unsigned i = 0; i < phase->inputs.size(); ++i) {
 237                 Node *input = phase->inputs[i]->output_node;
 238                 char effect_id[256];
 239                 sprintf(effect_id, "in%u", i);
 240                 phase->effect_ids.insert(make_pair(input, effect_id));
 241
 242                 frag_shader += string("uniform sampler2D tex_") + effect_id + ";\n";
 243                 frag_shader += string("vec4 ") + effect_id + "(vec2 tc) {\n";
 244                 frag_shader += "\treturn tex2D(tex_" + string(effect_id) + ", tc);\n";
 245                 frag_shader += "}\n";
 246                 frag_shader += "\n";
 247         }
 248
 249         for (unsigned i = 0; i < phase->effects.size(); ++i) {
 250                 Node *node = phase->effects[i];
 251                 char effect_id[256];
 252                 sprintf(effect_id, "eff%u", i);
 253                 phase->effect_ids.insert(make_pair(node, effect_id));
 254
 255                 if (node->incoming_links.size() == 1) {
 256                         frag_shader += string("#define INPUT ") + phase->effect_ids[node->incoming_links[0]] + "\n";
 257                 } else {
 258                         for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
 259                                 char buf[256];
 260                                 sprintf(buf, "#define INPUT%d %s\n", j + 1, phase->effect_ids[node->incoming_links[j]].c_str());
 261                                 frag_shader += buf;
 262                         }
 263                 }
 264
 265                 frag_shader += "\n";
 266                 frag_shader += string("#define FUNCNAME ") + effect_id + "\n";
 267                 frag_shader += replace_prefix(node->effect->output_convenience_uniforms(), effect_id);
 268                 frag_shader += replace_prefix(node->effect->output_fragment_shader(), effect_id);
 269                 frag_shader += "#undef PREFIX\n";
 270                 frag_shader += "#undef FUNCNAME\n";
 271                 if (node->incoming_links.size() == 1) {
 272                         frag_shader += "#undef INPUT\n";
 273                 } else {
 274                         for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
 275                                 char buf[256];
 276                                 sprintf(buf, "#undef INPUT%d\n", j + 1);
 277                                 frag_shader += buf;
 278                         }
 279                 }
 280                 frag_shader += "\n";
 281         }
 282         frag_shader += string("#define INPUT ") + phase->effect_ids[phase->effects.back()] + "\n";
 283         frag_shader.append(read_version_dependent_file("footer", "frag"));
 284
 285         string vert_shader = read_version_dependent_file("vs", "vert");
 286         phase->glsl_program_num = resource_pool->compile_glsl_program(vert_shader, frag_shader);
 287 }
 288
 289 // Construct GLSL programs, starting at the given effect and following
 290 // the chain from there. We end a program every time we come to an effect
 291 // marked as "needs texture bounce", one that is used by multiple other
 292 // effects, every time an effect wants to change the output size,
 293 // and of course at the end.
 294 //
 295 // We follow a quite simple depth-first search from the output, although
 296 // without recursing explicitly within each phase.
 297 Phase *EffectChain::construct_phase(Node *output, map<Node *, Phase *> *completed_effects)
 298 {
 299         if (completed_effects->count(output)) {
 300                 return (*completed_effects)[output];
 301         }
 302
 303         Phase *phase = new Phase;
 304         phase->output_node = output;
 305
 306         // Effects that we have yet to calculate, but that we know should
 307         // be in the current phase.
 308         stack<Node *> effects_todo_this_phase;
 309         effects_todo_this_phase.push(output);
 310
 311         while (!effects_todo_this_phase.empty()) {
 312                 Node *node = effects_todo_this_phase.top();
 313                 effects_todo_this_phase.pop();
 314
 315                 if (node->effect->needs_mipmaps()) {
 316                         node->needs_mipmaps = true;
 317                 }
 318
 319                 // This should currently only happen for effects that are inputs
 320                 // (either true inputs or phase outputs). We special-case inputs,
 321                 // and then deduplicate phase outputs below.
 322                 if (node->effect->num_inputs() == 0) {
 323                         if (find(phase->effects.begin(), phase->effects.end(), node) != phase->effects.end()) {
 324                                 continue;
 325                         }
 326                 } else {
 327                         assert(completed_effects->count(node) == 0);
 328                 }
 329
 330                 phase->effects.push_back(node);
 331
 332                 // Find all the dependencies of this effect, and add them to the stack.
 333                 vector<Node *> deps = node->incoming_links;
 334                 assert(node->effect->num_inputs() == deps.size());
 335                 for (unsigned i = 0; i < deps.size(); ++i) {
 336                         bool start_new_phase = false;
 337
 338                         if (node->effect->needs_texture_bounce() &&
 339                             !deps[i]->effect->is_single_texture()) {
 340                                 start_new_phase = true;
 341                         }
 342
 343                         // Propagate information about needing mipmaps down the chain,
 344                         // breaking the phase if we notice an incompatibility.
 345                         //
 346                         // Note that we cannot do this propagation as a normal pass,
 347                         // because it needs information about where the phases end
 348                         // (we should not propagate the flag across phases).
 349                         if (node->needs_mipmaps) {
 350                                 if (deps[i]->effect->num_inputs() == 0) {
 351                                         Input *input = static_cast<Input *>(deps[i]->effect);
 352                                         start_new_phase |= !input->can_supply_mipmaps();
 353                                 } else {
 354                                         deps[i]->needs_mipmaps = true;
 355                                 }
 356                         }
 357
 358                         if (deps[i]->outgoing_links.size() > 1) {
 359                                 if (!deps[i]->effect->is_single_texture()) {
 360                                         // More than one effect uses this as the input,
 361                                         // and it is not a texture itself.
 362                                         // The easiest thing to do (and probably also the safest
 363                                         // performance-wise in most cases) is to bounce it to a texture
 364                                         // and then let the next passes read from that.
 365                                         start_new_phase = true;
 366                                 } else {
 367                                         assert(deps[i]->effect->num_inputs() == 0);
 368
 369                                         // For textures, we try to be slightly more clever;
 370                                         // if none of our outputs need a bounce, we don't bounce
 371                                         // but instead simply use the effect many times.
 372                                         //
 373                                         // Strictly speaking, we could bounce it for some outputs
 374                                         // and use it directly for others, but the processing becomes
 375                                         // somewhat simpler if the effect is only used in one such way.
 376                                         for (unsigned j = 0; j < deps[i]->outgoing_links.size(); ++j) {
 377                                                 Node *rdep = deps[i]->outgoing_links[j];
 378                                                 start_new_phase |= rdep->effect->needs_texture_bounce();
 379                                         }
 380                                 }
 381                         }
 382
 383                         if (deps[i]->effect->changes_output_size()) {
 384                                 start_new_phase = true;
 385                         }
 386
 387                         if (start_new_phase) {
 388                                 phase->inputs.push_back(construct_phase(deps[i], completed_effects));
 389                         } else {
 390                                 effects_todo_this_phase.push(deps[i]);
 391                         }
 392                 }
 393         }
 394
 395         // No more effects to do this phase. Take all the ones we have,
 396         // and create a GLSL program for it.
 397         assert(!phase->effects.empty());
 398
 399         // Deduplicate the inputs.
 400         sort(phase->inputs.begin(), phase->inputs.end());
 401         phase->inputs.erase(unique(phase->inputs.begin(), phase->inputs.end()), phase->inputs.end());
 402
 403         // We added the effects from the output and back, but we need to output
 404         // them in topological sort order in the shader.
 405         phase->effects = topological_sort(phase->effects);
 406
 407         // Figure out if we need mipmaps or not, and if so, tell the inputs that.
 408         phase->input_needs_mipmaps = false;
 409         for (unsigned i = 0; i < phase->effects.size(); ++i) {
 410                 Node *node = phase->effects[i];
 411                 phase->input_needs_mipmaps |= node->effect->needs_mipmaps();
 412         }
 413         for (unsigned i = 0; i < phase->effects.size(); ++i) {
 414                 Node *node = phase->effects[i];
 415                 if (node->effect->num_inputs() == 0) {
 416                         Input *input = static_cast<Input *>(node->effect);
 417                         assert(!phase->input_needs_mipmaps || input->can_supply_mipmaps());
 418                         CHECK(input->set_int("needs_mipmaps", phase->input_needs_mipmaps));
 419                 }
 420         }
 421
 422         // Actually make the shader for this phase.
 423         compile_glsl_program(phase);
 424
 425         // Initialize timer objects.
 426         if (movit_timer_queries_supported) {
 427                 glGenQueries(1, &phase->timer_query_object);
 428                 phase->time_elapsed_ns = 0;
 429                 phase->num_measured_iterations = 0;
 430         }
 431
 432         assert(completed_effects->count(output) == 0);
 433         completed_effects->insert(make_pair(output, phase));
 434         phases.push_back(phase);
 435         return phase;
 436 }
 437
 438 void EffectChain::output_dot(const char *filename)
 439 {
 440         if (movit_debug_level != MOVIT_DEBUG_ON) {
 441                 return;
 442         }
 443
 444         FILE *fp = fopen(filename, "w");
 445         if (fp == NULL) {
 446                 perror(filename);
 447                 exit(1);
 448         }
 449
 450         fprintf(fp, "digraph G {\n");
 451         fprintf(fp, "  output [shape=box label=\"(output)\"];\n");
 452         for (unsigned i = 0; i < nodes.size(); ++i) {
 453                 // Find out which phase this event belongs to.
 454                 vector<int> in_phases;
 455                 for (unsigned j = 0; j < phases.size(); ++j) {
 456                         const Phase* p = phases[j];
 457                         if (find(p->effects.begin(), p->effects.end(), nodes[i]) != p->effects.end()) {
 458                                 in_phases.push_back(j);
 459                         }
 460                 }
 461
 462                 if (in_phases.empty()) {
 463                         fprintf(fp, "  n%ld [label=\"%s\"];\n", (long)nodes[i], nodes[i]->effect->effect_type_id().c_str());
 464                 } else if (in_phases.size() == 1) {
 465                         fprintf(fp, "  n%ld [label=\"%s\" style=\"filled\" fillcolor=\"/accent8/%d\"];\n",
 466                                 (long)nodes[i], nodes[i]->effect->effect_type_id().c_str(),
 467                                 (in_phases[0] % 8) + 1);
 468                 } else {
 469                         // If we had new enough Graphviz, style="wedged" would probably be ideal here.
 470                         // But alas.
 471                         fprintf(fp, "  n%ld [label=\"%s [in multiple phases]\" style=\"filled\" fillcolor=\"/accent8/%d\"];\n",
 472                                 (long)nodes[i], nodes[i]->effect->effect_type_id().c_str(),
 473                                 (in_phases[0] % 8) + 1);
 474                 }
 475
 476                 char from_node_id[256];
 477                 snprintf(from_node_id, 256, "n%ld", (long)nodes[i]);
 478
 479                 for (unsigned j = 0; j < nodes[i]->outgoing_links.size(); ++j) {
 480                         char to_node_id[256];
 481                         snprintf(to_node_id, 256, "n%ld", (long)nodes[i]->outgoing_links[j]);
 482
 483                         vector<string> labels = get_labels_for_edge(nodes[i], nodes[i]->outgoing_links[j]);
 484                         output_dot_edge(fp, from_node_id, to_node_id, labels);
 485                 }
 486
 487                 if (nodes[i]->outgoing_links.empty() && !nodes[i]->disabled) {
 488                         // Output node.
 489                         vector<string> labels = get_labels_for_edge(nodes[i], NULL);
 490                         output_dot_edge(fp, from_node_id, "output", labels);
 491                 }
 492         }
 493         fprintf(fp, "}\n");
 494
 495         fclose(fp);
 496 }
 497
 498 vector<string> EffectChain::get_labels_for_edge(const Node *from, const Node *to)
 499 {
 500         vector<string> labels;
 501
 502         if (to != NULL && to->effect->needs_texture_bounce()) {
 503                 labels.push_back("needs_bounce");
 504         }
 505         if (from->effect->changes_output_size()) {
 506                 labels.push_back("resize");
 507         }
 508
 509         switch (from->output_color_space) {
 510         case COLORSPACE_INVALID:
 511                 labels.push_back("spc[invalid]");
 512                 break;
 513         case COLORSPACE_REC_601_525:
 514                 labels.push_back("spc[rec601-525]");
 515                 break;
 516         case COLORSPACE_REC_601_625:
 517                 labels.push_back("spc[rec601-625]");
 518                 break;
 519         default:
 520                 break;
 521         }
 522
 523         switch (from->output_gamma_curve) {
 524         case GAMMA_INVALID:
 525                 labels.push_back("gamma[invalid]");
 526                 break;
 527         case GAMMA_sRGB:
 528                 labels.push_back("gamma[sRGB]");
 529                 break;
 530         case GAMMA_REC_601:  // and GAMMA_REC_709
 531                 labels.push_back("gamma[rec601/709]");
 532                 break;
 533         default:
 534                 break;
 535         }
 536
 537         switch (from->output_alpha_type) {
 538         case ALPHA_INVALID:
 539                 labels.push_back("alpha[invalid]");
 540                 break;
 541         case ALPHA_BLANK:
 542                 labels.push_back("alpha[blank]");
 543                 break;
 544         case ALPHA_POSTMULTIPLIED:
 545                 labels.push_back("alpha[postmult]");
 546                 break;
 547         default:
 548                 break;
 549         }
 550
 551         return labels;
 552 }
 553
 554 void EffectChain::output_dot_edge(FILE *fp,
 555                                   const string &from_node_id,
 556                                   const string &to_node_id,
 557                                   const vector<string> &labels)
 558 {
 559         if (labels.empty()) {
 560                 fprintf(fp, "  %s -> %s;\n", from_node_id.c_str(), to_node_id.c_str());
 561         } else {
 562                 string label = labels[0];
 563                 for (unsigned k = 1; k < labels.size(); ++k) {
 564                         label += ", " + labels[k];
 565                 }
 566                 fprintf(fp, "  %s -> %s [label=\"%s\"];\n", from_node_id.c_str(), to_node_id.c_str(), label.c_str());
 567         }
 568 }
 569
 570 void EffectChain::size_rectangle_to_fit(unsigned width, unsigned height, unsigned *output_width, unsigned *output_height)
 571 {
 572         unsigned scaled_width, scaled_height;
 573
 574         if (float(width) * aspect_denom >= float(height) * aspect_nom) {
 575                 // Same aspect, or W/H > aspect (image is wider than the frame).
 576                 // In either case, keep width, and adjust height.
 577                 scaled_width = width;
 578                 scaled_height = lrintf(width * aspect_denom / aspect_nom);
 579         } else {
 580                 // W/H < aspect (image is taller than the frame), so keep height,
 581                 // and adjust width.
 582                 scaled_width = lrintf(height * aspect_nom / aspect_denom);
 583                 scaled_height = height;
 584         }
 585
 586         // We should be consistently larger or smaller then the existing choice,
 587         // since we have the same aspect.
 588         assert(!(scaled_width < *output_width && scaled_height > *output_height));
 589         assert(!(scaled_height < *output_height && scaled_width > *output_width));
 590
 591         if (scaled_width >= *output_width && scaled_height >= *output_height) {
 592                 *output_width = scaled_width;
 593                 *output_height = scaled_height;
 594         }
 595 }
 596
 597 // Propagate input texture sizes throughout, and inform effects downstream.
 598 // (Like a lot of other code, we depend on effects being in topological order.)
 599 void EffectChain::inform_input_sizes(Phase *phase)
 600 {
 601         // All effects that have a defined size (inputs and RTT inputs)
 602         // get that. Reset all others.
 603         for (unsigned i = 0; i < phase->effects.size(); ++i) {
 604                 Node *node = phase->effects[i];
 605                 if (node->effect->num_inputs() == 0) {
 606                         Input *input = static_cast<Input *>(node->effect);
 607                         node->output_width = input->get_width();
 608                         node->output_height = input->get_height();
 609                         assert(node->output_width != 0);
 610                         assert(node->output_height != 0);
 611                 } else {
 612                         node->output_width = node->output_height = 0;
 613                 }
 614         }
 615         for (unsigned i = 0; i < phase->inputs.size(); ++i) {
 616                 Phase *input = phase->inputs[i];
 617                 input->output_node->output_width = input->virtual_output_width;
 618                 input->output_node->output_height = input->virtual_output_height;
 619                 assert(input->output_node->output_width != 0);
 620                 assert(input->output_node->output_height != 0);
 621         }
 622
 623         // Now propagate from the inputs towards the end, and inform as we go.
 624         // The rules are simple:
 625         //
 626         //   1. Don't touch effects that already have given sizes (ie., inputs).
 627         //   2. If all of your inputs have the same size, that will be your output size.
 628         //   3. Otherwise, your output size is 0x0.
 629         for (unsigned i = 0; i < phase->effects.size(); ++i) {
 630                 Node *node = phase->effects[i];
 631                 if (node->effect->num_inputs() == 0) {
 632                         continue;
 633                 }
 634                 unsigned this_output_width = 0;
 635                 unsigned this_output_height = 0;
 636                 for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
 637                         Node *input = node->incoming_links[j];
 638                         node->effect->inform_input_size(j, input->output_width, input->output_height);
 639                         if (j == 0) {
 640                                 this_output_width = input->output_width;
 641                                 this_output_height = input->output_height;
 642                         } else if (input->output_width != this_output_width || input->output_height != this_output_height) {
 643                                 // Inputs disagree.
 644                                 this_output_width = 0;
 645                                 this_output_height = 0;
 646                         }
 647                 }
 648                 node->output_width = this_output_width;
 649                 node->output_height = this_output_height;
 650         }
 651 }
 652
 653 // Note: You should call inform_input_sizes() before this, as the last effect's
 654 // desired output size might change based on the inputs.
 655 void EffectChain::find_output_size(Phase *phase)
 656 {
 657         Node *output_node = phase->effects.back();
 658
 659         // If the last effect explicitly sets an output size, use that.
 660         if (output_node->effect->changes_output_size()) {
 661                 output_node->effect->get_output_size(&phase->output_width, &phase->output_height,
 662                                                      &phase->virtual_output_width, &phase->virtual_output_height);
 663                 return;
 664         }
 665
 666         // If all effects have the same size, use that.
 667         unsigned output_width = 0, output_height = 0;
 668         bool all_inputs_same_size = true;
 669
 670         for (unsigned i = 0; i < phase->inputs.size(); ++i) {
 671                 Phase *input = phase->inputs[i];
 672                 assert(input->output_width != 0);
 673                 assert(input->output_height != 0);
 674                 if (output_width == 0 && output_height == 0) {
 675                         output_width = input->virtual_output_width;
 676                         output_height = input->virtual_output_height;
 677                 } else if (output_width != input->virtual_output_width ||
 678                            output_height != input->virtual_output_height) {
 679                         all_inputs_same_size = false;
 680                 }
 681         }
 682         for (unsigned i = 0; i < phase->effects.size(); ++i) {
 683                 Effect *effect = phase->effects[i]->effect;
 684                 if (effect->num_inputs() != 0) {
 685                         continue;
 686                 }
 687
 688                 Input *input = static_cast<Input *>(effect);
 689                 if (output_width == 0 && output_height == 0) {
 690                         output_width = input->get_width();
 691                         output_height = input->get_height();
 692                 } else if (output_width != input->get_width() ||
 693                            output_height != input->get_height()) {
 694                         all_inputs_same_size = false;
 695                 }
 696         }
 697
 698         if (all_inputs_same_size) {
 699                 assert(output_width != 0);
 700                 assert(output_height != 0);
 701                 phase->virtual_output_width = phase->output_width = output_width;
 702                 phase->virtual_output_height = phase->output_height = output_height;
 703                 return;
 704         }
 705
 706         // If not, fit all the inputs into the current aspect, and select the largest one.
 707         output_width = 0;
 708         output_height = 0;
 709         for (unsigned i = 0; i < phase->inputs.size(); ++i) {
 710                 Phase *input = phase->inputs[i];
 711                 assert(input->output_width != 0);
 712                 assert(input->output_height != 0);
 713                 size_rectangle_to_fit(input->output_width, input->output_height, &output_width, &output_height);
 714         }
 715         for (unsigned i = 0; i < phase->effects.size(); ++i) {
 716                 Effect *effect = phase->effects[i]->effect;
 717                 if (effect->num_inputs() != 0) {
 718                         continue;
 719                 }
 720
 721                 Input *input = static_cast<Input *>(effect);
 722                 size_rectangle_to_fit(input->get_width(), input->get_height(), &output_width, &output_height);
 723         }
 724         assert(output_width != 0);
 725         assert(output_height != 0);
 726         phase->virtual_output_width = phase->output_width = output_width;
 727         phase->virtual_output_height = phase->output_height = output_height;
 728 }
 729
 730 void EffectChain::sort_all_nodes_topologically()
 731 {
 732         nodes = topological_sort(nodes);
 733 }
 734
 735 vector<Node *> EffectChain::topological_sort(const vector<Node *> &nodes)
 736 {
 737         set<Node *> nodes_left_to_visit(nodes.begin(), nodes.end());
 738         vector<Node *> sorted_list;
 739         for (unsigned i = 0; i < nodes.size(); ++i) {
 740                 topological_sort_visit_node(nodes[i], &nodes_left_to_visit, &sorted_list);
 741         }
 742         reverse(sorted_list.begin(), sorted_list.end());
 743         return sorted_list;
 744 }
 745
 746 void EffectChain::topological_sort_visit_node(Node *node, set<Node *> *nodes_left_to_visit, vector<Node *> *sorted_list)
 747 {
 748         if (nodes_left_to_visit->count(node) == 0) {
 749                 return;
 750         }
 751         nodes_left_to_visit->erase(node);
 752         for (unsigned i = 0; i < node->outgoing_links.size(); ++i) {
 753                 topological_sort_visit_node(node->outgoing_links[i], nodes_left_to_visit, sorted_list);
 754         }
 755         sorted_list->push_back(node);
 756 }
 757
 758 void EffectChain::find_color_spaces_for_inputs()
 759 {
 760         for (unsigned i = 0; i < nodes.size(); ++i) {
 761                 Node *node = nodes[i];
 762                 if (node->disabled) {
 763                         continue;
 764                 }
 765                 if (node->incoming_links.size() == 0) {
 766                         Input *input = static_cast<Input *>(node->effect);
 767                         node->output_color_space = input->get_color_space();
 768                         node->output_gamma_curve = input->get_gamma_curve();
 769
 770                         Effect::AlphaHandling alpha_handling = input->alpha_handling();
 771                         switch (alpha_handling) {
 772                         case Effect::OUTPUT_BLANK_ALPHA:
 773                                 node->output_alpha_type = ALPHA_BLANK;
 774                                 break;
 775                         case Effect::INPUT_AND_OUTPUT_PREMULTIPLIED_ALPHA:
 776                                 node->output_alpha_type = ALPHA_PREMULTIPLIED;
 777                                 break;
 778                         case Effect::OUTPUT_POSTMULTIPLIED_ALPHA:
 779                                 node->output_alpha_type = ALPHA_POSTMULTIPLIED;
 780                                 break;
 781                         case Effect::INPUT_PREMULTIPLIED_ALPHA_KEEP_BLANK:
 782                         case Effect::DONT_CARE_ALPHA_TYPE:
 783                         default:
 784                                 assert(false);
 785                         }
 786
 787                         if (node->output_alpha_type == ALPHA_PREMULTIPLIED) {
 788                                 assert(node->output_gamma_curve == GAMMA_LINEAR);
 789                         }
 790                 }
 791         }
 792 }
 793
 794 // Propagate gamma and color space information as far as we can in the graph.
 795 // The rules are simple: Anything where all the inputs agree, get that as
 796 // output as well. Anything else keeps having *_INVALID.
 797 void EffectChain::propagate_gamma_and_color_space()
 798 {
 799         // We depend on going through the nodes in order.
 800         sort_all_nodes_topologically();
 801
 802         for (unsigned i = 0; i < nodes.size(); ++i) {
 803                 Node *node = nodes[i];
 804                 if (node->disabled) {
 805                         continue;
 806                 }
 807                 assert(node->incoming_links.size() == node->effect->num_inputs());
 808                 if (node->incoming_links.size() == 0) {
 809                         assert(node->output_color_space != COLORSPACE_INVALID);
 810                         assert(node->output_gamma_curve != GAMMA_INVALID);
 811                         continue;
 812                 }
 813
 814                 Colorspace color_space = node->incoming_links[0]->output_color_space;
 815                 GammaCurve gamma_curve = node->incoming_links[0]->output_gamma_curve;
 816                 for (unsigned j = 1; j < node->incoming_links.size(); ++j) {
 817                         if (node->incoming_links[j]->output_color_space != color_space) {
 818                                 color_space = COLORSPACE_INVALID;
 819                         }
 820                         if (node->incoming_links[j]->output_gamma_curve != gamma_curve) {
 821                                 gamma_curve = GAMMA_INVALID;
 822                         }
 823                 }
 824
 825                 // The conversion effects already have their outputs set correctly,
 826                 // so leave them alone.
 827                 if (node->effect->effect_type_id() != "ColorspaceConversionEffect") {
 828                         node->output_color_space = color_space;
 829                 }
 830                 if (node->effect->effect_type_id() != "GammaCompressionEffect" &&
 831                     node->effect->effect_type_id() != "GammaExpansionEffect") {
 832                         node->output_gamma_curve = gamma_curve;
 833                 }
 834         }
 835 }
 836
 837 // Propagate alpha information as far as we can in the graph.
 838 // Similar to propagate_gamma_and_color_space().
 839 void EffectChain::propagate_alpha()
 840 {
 841         // We depend on going through the nodes in order.
 842         sort_all_nodes_topologically();
 843
 844         for (unsigned i = 0; i < nodes.size(); ++i) {
 845                 Node *node = nodes[i];
 846                 if (node->disabled) {
 847                         continue;
 848                 }
 849                 assert(node->incoming_links.size() == node->effect->num_inputs());
 850                 if (node->incoming_links.size() == 0) {
 851                         assert(node->output_alpha_type != ALPHA_INVALID);
 852                         continue;
 853                 }
 854
 855                 // The alpha multiplication/division effects are special cases.
 856                 if (node->effect->effect_type_id() == "AlphaMultiplicationEffect") {
 857                         assert(node->incoming_links.size() == 1);
 858                         assert(node->incoming_links[0]->output_alpha_type == ALPHA_POSTMULTIPLIED);
 859                         node->output_alpha_type = ALPHA_PREMULTIPLIED;
 860                         continue;
 861                 }
 862                 if (node->effect->effect_type_id() == "AlphaDivisionEffect") {
 863                         assert(node->incoming_links.size() == 1);
 864                         assert(node->incoming_links[0]->output_alpha_type == ALPHA_PREMULTIPLIED);
 865                         node->output_alpha_type = ALPHA_POSTMULTIPLIED;
 866                         continue;
 867                 }
 868
 869                 // GammaCompressionEffect and GammaExpansionEffect are also a special case,
 870                 // because they are the only one that _need_ postmultiplied alpha.
 871                 if (node->effect->effect_type_id() == "GammaCompressionEffect" ||
 872                     node->effect->effect_type_id() == "GammaExpansionEffect") {
 873                         assert(node->incoming_links.size() == 1);
 874                         if (node->incoming_links[0]->output_alpha_type == ALPHA_BLANK) {
 875                                 node->output_alpha_type = ALPHA_BLANK;
 876                         } else if (node->incoming_links[0]->output_alpha_type == ALPHA_POSTMULTIPLIED) {
 877                                 node->output_alpha_type = ALPHA_POSTMULTIPLIED;
 878                         } else {
 879                                 node->output_alpha_type = ALPHA_INVALID;
 880                         }
 881                         continue;
 882                 }
 883
 884                 // Only inputs can have unconditional alpha output (OUTPUT_BLANK_ALPHA
 885                 // or OUTPUT_POSTMULTIPLIED_ALPHA), and they have already been
 886                 // taken care of above. Rationale: Even if you could imagine
 887                 // e.g. an effect that took in an image and set alpha=1.0
 888                 // unconditionally, it wouldn't make any sense to have it as
 889                 // e.g. OUTPUT_BLANK_ALPHA, since it wouldn't know whether it
 890                 // got its input pre- or postmultiplied, so it wouldn't know
 891                 // whether to divide away the old alpha or not.
 892                 Effect::AlphaHandling alpha_handling = node->effect->alpha_handling();
 893                 assert(alpha_handling == Effect::INPUT_AND_OUTPUT_PREMULTIPLIED_ALPHA ||
 894                        alpha_handling == Effect::INPUT_PREMULTIPLIED_ALPHA_KEEP_BLANK ||
 895                        alpha_handling == Effect::DONT_CARE_ALPHA_TYPE);
 896
 897                 // If the node has multiple inputs, check that they are all valid and
 898                 // the same.
 899                 bool any_invalid = false;
 900                 bool any_premultiplied = false;
 901                 bool any_postmultiplied = false;
 902
 903                 for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
 904                         switch (node->incoming_links[j]->output_alpha_type) {
 905                         case ALPHA_INVALID:
 906                                 any_invalid = true;
 907                                 break;
 908                         case ALPHA_BLANK:
 909                                 // Blank is good as both pre- and postmultiplied alpha,
 910                                 // so just ignore it.
 911                                 break;
 912                         case ALPHA_PREMULTIPLIED:
 913                                 any_premultiplied = true;
 914                                 break;
 915                         case ALPHA_POSTMULTIPLIED:
 916                                 any_postmultiplied = true;
 917                                 break;
 918                         default:
 919                                 assert(false);
 920                         }
 921                 }
 922
 923                 if (any_invalid) {
 924                         node->output_alpha_type = ALPHA_INVALID;
 925                         continue;
 926                 }
 927
 928                 // Inputs must be of the same type.
 929                 if (any_premultiplied && any_postmultiplied) {
 930                         node->output_alpha_type = ALPHA_INVALID;
 931                         continue;
 932                 }
 933
 934                 if (alpha_handling == Effect::INPUT_AND_OUTPUT_PREMULTIPLIED_ALPHA ||
 935                     alpha_handling == Effect::INPUT_PREMULTIPLIED_ALPHA_KEEP_BLANK) {
 936                         // If the effect has asked for premultiplied alpha, check that it has got it.
 937                         if (any_postmultiplied) {
 938                                 node->output_alpha_type = ALPHA_INVALID;
 939                         } else if (!any_premultiplied &&
 940                                    alpha_handling == Effect::INPUT_PREMULTIPLIED_ALPHA_KEEP_BLANK) {
 941                                 // Blank input alpha, and the effect preserves blank alpha.
 942                                 node->output_alpha_type = ALPHA_BLANK;
 943                         } else {
 944                                 node->output_alpha_type = ALPHA_PREMULTIPLIED;
 945                         }
 946                 } else {
 947                         // OK, all inputs are the same, and this effect is not going
 948                         // to change it.
 949                         assert(alpha_handling == Effect::DONT_CARE_ALPHA_TYPE);
 950                         if (any_premultiplied) {
 951                                 node->output_alpha_type = ALPHA_PREMULTIPLIED;
 952                         } else if (any_postmultiplied) {
 953                                 node->output_alpha_type = ALPHA_POSTMULTIPLIED;
 954                         } else {
 955                                 node->output_alpha_type = ALPHA_BLANK;
 956                         }
 957                 }
 958         }
 959 }
 960
 961 bool EffectChain::node_needs_colorspace_fix(Node *node)
 962 {
 963         if (node->disabled) {
 964                 return false;
 965         }
 966         if (node->effect->num_inputs() == 0) {
 967                 return false;
 968         }
 969
 970         // propagate_gamma_and_color_space() has already set our output
 971         // to COLORSPACE_INVALID if the inputs differ, so we can rely on that.
 972         if (node->output_color_space == COLORSPACE_INVALID) {
 973                 return true;
 974         }
 975         return (node->effect->needs_srgb_primaries() && node->output_color_space != COLORSPACE_sRGB);
 976 }
 977
 978 // Fix up color spaces so that there are no COLORSPACE_INVALID nodes left in
 979 // the graph. Our strategy is not always optimal, but quite simple:
 980 // Find an effect that's as early as possible where the inputs are of
 981 // unacceptable colorspaces (that is, either different, or, if the effect only
 982 // wants sRGB, not sRGB.) Add appropriate conversions on all its inputs,
 983 // propagate the information anew, and repeat until there are no more such
 984 // effects.
 985 void EffectChain::fix_internal_color_spaces()
 986 {
 987         unsigned colorspace_propagation_pass = 0;
 988         bool found_any;
 989         do {
 990                 found_any = false;
 991                 for (unsigned i = 0; i < nodes.size(); ++i) {
 992                         Node *node = nodes[i];
 993                         if (!node_needs_colorspace_fix(node)) {
 994                                 continue;
 995                         }
 996
 997                         // Go through each input that is not sRGB, and insert
 998                         // a colorspace conversion after it.
 999                         for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
1000                                 Node *input = node->incoming_links[j];
1001                                 assert(input->output_color_space != COLORSPACE_INVALID);
1002                                 if (input->output_color_space == COLORSPACE_sRGB) {
1003                                         continue;
1004                                 }
1005                                 Node *conversion = add_node(new ColorspaceConversionEffect());
1006                                 CHECK(conversion->effect->set_int("source_space", input->output_color_space));
1007                                 CHECK(conversion->effect->set_int("destination_space", COLORSPACE_sRGB));
1008                                 conversion->output_color_space = COLORSPACE_sRGB;
1009                                 replace_sender(input, conversion);
1010                                 connect_nodes(input, conversion);
1011                         }
1012
1013                         // Re-sort topologically, and propagate the new information.
1014                         propagate_gamma_and_color_space();
1015
1016                         found_any = true;
1017                         break;
1018                 }
1019
1020                 char filename[256];
1021                 sprintf(filename, "step5-colorspacefix-iter%u.dot", ++colorspace_propagation_pass);
1022                 output_dot(filename);
1023                 assert(colorspace_propagation_pass < 100);
1024         } while (found_any);
1025
1026         for (unsigned i = 0; i < nodes.size(); ++i) {
1027                 Node *node = nodes[i];
1028                 if (node->disabled) {
1029                         continue;
1030                 }
1031                 assert(node->output_color_space != COLORSPACE_INVALID);
1032         }
1033 }
1034
1035 bool EffectChain::node_needs_alpha_fix(Node *node)
1036 {
1037         if (node->disabled) {
1038                 return false;
1039         }
1040
1041         // propagate_alpha() has already set our output to ALPHA_INVALID if the
1042         // inputs differ or we are otherwise in mismatch, so we can rely on that.
1043         return (node->output_alpha_type == ALPHA_INVALID);
1044 }
1045
1046 // Fix up alpha so that there are no ALPHA_INVALID nodes left in
1047 // the graph. Similar to fix_internal_color_spaces().
1048 void EffectChain::fix_internal_alpha(unsigned step)
1049 {
1050         unsigned alpha_propagation_pass = 0;
1051         bool found_any;
1052         do {
1053                 found_any = false;
1054                 for (unsigned i = 0; i < nodes.size(); ++i) {
1055                         Node *node = nodes[i];
1056                         if (!node_needs_alpha_fix(node)) {
1057                                 continue;
1058                         }
1059
1060                         // If we need to fix up GammaExpansionEffect, then clearly something
1061                         // is wrong, since the combination of premultiplied alpha and nonlinear inputs
1062                         // is meaningless.
1063                         assert(node->effect->effect_type_id() != "GammaExpansionEffect");
1064
1065                         AlphaType desired_type = ALPHA_PREMULTIPLIED;
1066
1067                         // GammaCompressionEffect is special; it needs postmultiplied alpha.
1068                         if (node->effect->effect_type_id() == "GammaCompressionEffect") {
1069                                 assert(node->incoming_links.size() == 1);
1070                                 assert(node->incoming_links[0]->output_alpha_type == ALPHA_PREMULTIPLIED);
1071                                 desired_type = ALPHA_POSTMULTIPLIED;
1072                         }
1073
1074                         // Go through each input that is not premultiplied alpha, and insert
1075                         // a conversion before it.
1076                         for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
1077                                 Node *input = node->incoming_links[j];
1078                                 assert(input->output_alpha_type != ALPHA_INVALID);
1079                                 if (input->output_alpha_type == desired_type ||
1080                                     input->output_alpha_type == ALPHA_BLANK) {
1081                                         continue;
1082                                 }
1083                                 Node *conversion;
1084                                 if (desired_type == ALPHA_PREMULTIPLIED) {
1085                                         conversion = add_node(new AlphaMultiplicationEffect());
1086                                 } else {
1087                                         conversion = add_node(new AlphaDivisionEffect());
1088                                 }
1089                                 conversion->output_alpha_type = desired_type;
1090                                 replace_sender(input, conversion);
1091                                 connect_nodes(input, conversion);
1092                         }
1093
1094                         // Re-sort topologically, and propagate the new information.
1095                         propagate_gamma_and_color_space();
1096                         propagate_alpha();
1097
1098                         found_any = true;
1099                         break;
1100                 }
1101
1102                 char filename[256];
1103                 sprintf(filename, "step%u-alphafix-iter%u.dot", step, ++alpha_propagation_pass);
1104                 output_dot(filename);
1105                 assert(alpha_propagation_pass < 100);
1106         } while (found_any);
1107
1108         for (unsigned i = 0; i < nodes.size(); ++i) {
1109                 Node *node = nodes[i];
1110                 if (node->disabled) {
1111                         continue;
1112                 }
1113                 assert(node->output_alpha_type != ALPHA_INVALID);
1114         }
1115 }
1116
1117 // Make so that the output is in the desired color space.
1118 void EffectChain::fix_output_color_space()
1119 {
1120         Node *output = find_output_node();
1121         if (output->output_color_space != output_format.color_space) {
1122                 Node *conversion = add_node(new ColorspaceConversionEffect());
1123                 CHECK(conversion->effect->set_int("source_space", output->output_color_space));
1124                 CHECK(conversion->effect->set_int("destination_space", output_format.color_space));
1125                 conversion->output_color_space = output_format.color_space;
1126                 connect_nodes(output, conversion);
1127                 propagate_alpha();
1128                 propagate_gamma_and_color_space();
1129         }
1130 }
1131
1132 // Make so that the output is in the desired pre-/postmultiplication alpha state.
1133 void EffectChain::fix_output_alpha()
1134 {
1135         Node *output = find_output_node();
1136         assert(output->output_alpha_type != ALPHA_INVALID);
1137         if (output->output_alpha_type == ALPHA_BLANK) {
1138                 // No alpha output, so we don't care.
1139                 return;
1140         }
1141         if (output->output_alpha_type == ALPHA_PREMULTIPLIED &&
1142             output_alpha_format == OUTPUT_ALPHA_FORMAT_POSTMULTIPLIED) {
1143                 Node *conversion = add_node(new AlphaDivisionEffect());
1144                 connect_nodes(output, conversion);
1145                 propagate_alpha();
1146                 propagate_gamma_and_color_space();
1147         }
1148         if (output->output_alpha_type == ALPHA_POSTMULTIPLIED &&
1149             output_alpha_format == OUTPUT_ALPHA_FORMAT_PREMULTIPLIED) {
1150                 Node *conversion = add_node(new AlphaMultiplicationEffect());
1151                 connect_nodes(output, conversion);
1152                 propagate_alpha();
1153                 propagate_gamma_and_color_space();
1154         }
1155 }
1156
1157 bool EffectChain::node_needs_gamma_fix(Node *node)
1158 {
1159         if (node->disabled) {
1160                 return false;
1161         }
1162
1163         // Small hack since the output is not an explicit node:
1164         // If we are the last node and our output is in the wrong
1165         // space compared to EffectChain's output, we need to fix it.
1166         // This will only take us to linear, but fix_output_gamma()
1167         // will come and take us to the desired output gamma
1168         // if it is needed.
1169         //
1170         // This needs to be before everything else, since it could
1171         // even apply to inputs (if they are the only effect).
1172         if (node->outgoing_links.empty() &&
1173             node->output_gamma_curve != output_format.gamma_curve &&
1174             node->output_gamma_curve != GAMMA_LINEAR) {
1175                 return true;
1176         }
1177
1178         if (node->effect->num_inputs() == 0) {
1179                 return false;
1180         }
1181
1182         // propagate_gamma_and_color_space() has already set our output
1183         // to GAMMA_INVALID if the inputs differ, so we can rely on that,
1184         // except for GammaCompressionEffect.
1185         if (node->output_gamma_curve == GAMMA_INVALID) {
1186                 return true;
1187         }
1188         if (node->effect->effect_type_id() == "GammaCompressionEffect") {
1189                 assert(node->incoming_links.size() == 1);
1190                 return node->incoming_links[0]->output_gamma_curve != GAMMA_LINEAR;
1191         }
1192
1193         return (node->effect->needs_linear_light() && node->output_gamma_curve != GAMMA_LINEAR);
1194 }
1195
1196 // Very similar to fix_internal_color_spaces(), but for gamma.
1197 // There is one difference, though; before we start adding conversion nodes,
1198 // we see if we can get anything out of asking the sources to deliver
1199 // linear gamma directly. fix_internal_gamma_by_asking_inputs()
1200 // does that part, while fix_internal_gamma_by_inserting_nodes()
1201 // inserts nodes as needed afterwards.
1202 void EffectChain::fix_internal_gamma_by_asking_inputs(unsigned step)
1203 {
1204         unsigned gamma_propagation_pass = 0;
1205         bool found_any;
1206         do {
1207                 found_any = false;
1208                 for (unsigned i = 0; i < nodes.size(); ++i) {
1209                         Node *node = nodes[i];
1210                         if (!node_needs_gamma_fix(node)) {
1211                                 continue;
1212                         }
1213
1214                         // See if all inputs can give us linear gamma. If not, leave it.
1215                         vector<Node *> nonlinear_inputs;
1216                         find_all_nonlinear_inputs(node, &nonlinear_inputs);
1217                         assert(!nonlinear_inputs.empty());
1218
1219                         bool all_ok = true;
1220                         for (unsigned i = 0; i < nonlinear_inputs.size(); ++i) {
1221                                 Input *input = static_cast<Input *>(nonlinear_inputs[i]->effect);
1222                                 all_ok &= input->can_output_linear_gamma();
1223                         }
1224
1225                         if (!all_ok) {
1226                                 continue;
1227                         }
1228
1229                         for (unsigned i = 0; i < nonlinear_inputs.size(); ++i) {
1230                                 CHECK(nonlinear_inputs[i]->effect->set_int("output_linear_gamma", 1));
1231                                 nonlinear_inputs[i]->output_gamma_curve = GAMMA_LINEAR;
1232                         }
1233
1234                         // Re-sort topologically, and propagate the new information.
1235                         propagate_gamma_and_color_space();
1236
1237                         found_any = true;
1238                         break;
1239                 }
1240
1241                 char filename[256];
1242                 sprintf(filename, "step%u-gammafix-iter%u.dot", step, ++gamma_propagation_pass);
1243                 output_dot(filename);
1244                 assert(gamma_propagation_pass < 100);
1245         } while (found_any);
1246 }
1247
1248 void EffectChain::fix_internal_gamma_by_inserting_nodes(unsigned step)
1249 {
1250         unsigned gamma_propagation_pass = 0;
1251         bool found_any;
1252         do {
1253                 found_any = false;
1254                 for (unsigned i = 0; i < nodes.size(); ++i) {
1255                         Node *node = nodes[i];
1256                         if (!node_needs_gamma_fix(node)) {
1257                                 continue;
1258                         }
1259
1260                         // Special case: We could be an input and still be asked to
1261                         // fix our gamma; if so, we should be the only node
1262                         // (as node_needs_gamma_fix() would only return true in
1263                         // for an input in that case). That means we should insert
1264                         // a conversion node _after_ ourselves.
1265                         if (node->incoming_links.empty()) {
1266                                 assert(node->outgoing_links.empty());
1267                                 Node *conversion = add_node(new GammaExpansionEffect());
1268                                 CHECK(conversion->effect->set_int("source_curve", node->output_gamma_curve));
1269                                 conversion->output_gamma_curve = GAMMA_LINEAR;
1270                                 connect_nodes(node, conversion);
1271                         }
1272
1273                         // If not, go through each input that is not linear gamma,
1274                         // and insert a gamma conversion after it.
1275                         for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
1276                                 Node *input = node->incoming_links[j];
1277                                 assert(input->output_gamma_curve != GAMMA_INVALID);
1278                                 if (input->output_gamma_curve == GAMMA_LINEAR) {
1279                                         continue;
1280                                 }
1281                                 Node *conversion = add_node(new GammaExpansionEffect());
1282                                 CHECK(conversion->effect->set_int("source_curve", input->output_gamma_curve));
1283                                 conversion->output_gamma_curve = GAMMA_LINEAR;
1284                                 replace_sender(input, conversion);
1285                                 connect_nodes(input, conversion);
1286                         }
1287
1288                         // Re-sort topologically, and propagate the new information.
1289                         propagate_alpha();
1290                         propagate_gamma_and_color_space();
1291
1292                         found_any = true;
1293                         break;
1294                 }
1295
1296                 char filename[256];
1297                 sprintf(filename, "step%u-gammafix-iter%u.dot", step, ++gamma_propagation_pass);
1298                 output_dot(filename);
1299                 assert(gamma_propagation_pass < 100);
1300         } while (found_any);
1301
1302         for (unsigned i = 0; i < nodes.size(); ++i) {
1303                 Node *node = nodes[i];
1304                 if (node->disabled) {
1305                         continue;
1306                 }
1307                 assert(node->output_gamma_curve != GAMMA_INVALID);
1308         }
1309 }
1310
1311 // Make so that the output is in the desired gamma.
1312 // Note that this assumes linear input gamma, so it might create the need
1313 // for another pass of fix_internal_gamma().
1314 void EffectChain::fix_output_gamma()
1315 {
1316         Node *output = find_output_node();
1317         if (output->output_gamma_curve != output_format.gamma_curve) {
1318                 Node *conversion = add_node(new GammaCompressionEffect());
1319                 CHECK(conversion->effect->set_int("destination_curve", output_format.gamma_curve));
1320                 conversion->output_gamma_curve = output_format.gamma_curve;
1321                 connect_nodes(output, conversion);
1322         }
1323 }
1324
1325 // If the user has requested dither, add a DitherEffect right at the end
1326 // (after GammaCompressionEffect etc.). This needs to be done after everything else,
1327 // since dither is about the only effect that can _not_ be done in linear space.
1328 void EffectChain::add_dither_if_needed()
1329 {
1330         if (num_dither_bits == 0) {
1331                 return;
1332         }
1333         Node *output = find_output_node();
1334         Node *dither = add_node(new DitherEffect());
1335         CHECK(dither->effect->set_int("num_bits", num_dither_bits));
1336         connect_nodes(output, dither);
1337
1338         dither_effect = dither->effect;
1339 }
1340
1341 // Find the output node. This is, simply, one that has no outgoing links.
1342 // If there are multiple ones, the graph is malformed (we do not support
1343 // multiple outputs right now).
1344 Node *EffectChain::find_output_node()
1345 {
1346         vector<Node *> output_nodes;
1347         for (unsigned i = 0; i < nodes.size(); ++i) {
1348                 Node *node = nodes[i];
1349                 if (node->disabled) {
1350                         continue;
1351                 }
1352                 if (node->outgoing_links.empty()) {
1353                         output_nodes.push_back(node);
1354                 }
1355         }
1356         assert(output_nodes.size() == 1);
1357         return output_nodes[0];
1358 }
1359
1360 void EffectChain::finalize()
1361 {
1362         // Output the graph as it is before we do any conversions on it.
1363         output_dot("step0-start.dot");
1364
1365         // Give each effect in turn a chance to rewrite its own part of the graph.
1366         // Note that if more effects are added as part of this, they will be
1367         // picked up as part of the same for loop, since they are added at the end.
1368         for (unsigned i = 0; i < nodes.size(); ++i) {
1369                 nodes[i]->effect->rewrite_graph(this, nodes[i]);
1370         }
1371         output_dot("step1-rewritten.dot");
1372
1373         find_color_spaces_for_inputs();
1374         output_dot("step2-input-colorspace.dot");
1375
1376         propagate_alpha();
1377         output_dot("step3-propagated-alpha.dot");
1378
1379         propagate_gamma_and_color_space();
1380         output_dot("step4-propagated-all.dot");
1381
1382         fix_internal_color_spaces();
1383         fix_internal_alpha(6);
1384         fix_output_color_space();
1385         output_dot("step7-output-colorspacefix.dot");
1386         fix_output_alpha();
1387         output_dot("step8-output-alphafix.dot");
1388
1389         // Note that we need to fix gamma after colorspace conversion,
1390         // because colorspace conversions might create needs for gamma conversions.
1391         // Also, we need to run an extra pass of fix_internal_gamma() after
1392         // fixing the output gamma, as we only have conversions to/from linear,
1393         // and fix_internal_alpha() since GammaCompressionEffect needs
1394         // postmultiplied input.
1395         fix_internal_gamma_by_asking_inputs(9);
1396         fix_internal_gamma_by_inserting_nodes(10);
1397         fix_output_gamma();
1398         output_dot("step11-output-gammafix.dot");
1399         propagate_alpha();
1400         output_dot("step12-output-alpha-propagated.dot");
1401         fix_internal_alpha(13);
1402         output_dot("step14-output-alpha-fixed.dot");
1403         fix_internal_gamma_by_asking_inputs(15);
1404         fix_internal_gamma_by_inserting_nodes(16);
1405
1406         output_dot("step17-before-dither.dot");
1407
1408         add_dither_if_needed();
1409
1410         output_dot("step18-final.dot");
1411
1412         // Construct all needed GLSL programs, starting at the output.
1413         // We need to keep track of which effects have already been computed,
1414         // as an effect with multiple users could otherwise be calculated
1415         // multiple times.
1416         map<Node *, Phase *> completed_effects;
1417         construct_phase(find_output_node(), &completed_effects);
1418
1419         output_dot("step19-split-to-phases.dot");
1420
1421         assert(phases[0]->inputs.empty());
1422
1423         finalized = true;
1424 }
1425
1426 void EffectChain::render_to_fbo(GLuint dest_fbo, unsigned width, unsigned height)
1427 {
1428         assert(finalized);
1429
1430         // Save original viewport.
1431         GLuint x = 0, y = 0;
1432
1433         if (width == 0 && height == 0) {
1434                 GLint viewport[4];
1435                 glGetIntegerv(GL_VIEWPORT, viewport);
1436                 x = viewport[0];
1437                 y = viewport[1];
1438                 width = viewport[2];
1439                 height = viewport[3];
1440         }
1441
1442         // Basic state.
1443         glDisable(GL_BLEND);
1444         check_error();
1445         glDisable(GL_DEPTH_TEST);
1446         check_error();
1447         glDepthMask(GL_FALSE);
1448         check_error();
1449
1450         set<Phase *> generated_mipmaps;
1451
1452         // We choose the simplest option of having one texture per output,
1453         // since otherwise this turns into an (albeit simple) register allocation problem.
1454         map<Phase *, GLuint> output_textures;
1455
1456         for (unsigned phase_num = 0; phase_num < phases.size(); ++phase_num) {
1457                 Phase *phase = phases[phase_num];
1458
1459                 if (do_phase_timing) {
1460                         glBeginQuery(GL_TIME_ELAPSED, phase->timer_query_object);
1461                 }
1462                 if (phase_num == phases.size() - 1) {
1463                         // Last phase goes to the output the user specified.
1464                         glBindFramebuffer(GL_FRAMEBUFFER, dest_fbo);
1465                         check_error();
1466                         GLenum status = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);
1467                         assert(status == GL_FRAMEBUFFER_COMPLETE);
1468                         glViewport(x, y, width, height);
1469                         if (dither_effect != NULL) {
1470                                 CHECK(dither_effect->set_int("output_width", width));
1471                                 CHECK(dither_effect->set_int("output_height", height));
1472                         }
1473                 }
1474                 execute_phase(phase, phase_num == phases.size() - 1, &output_textures, &generated_mipmaps);
1475                 if (do_phase_timing) {
1476                         glEndQuery(GL_TIME_ELAPSED);
1477                 }
1478         }
1479
1480         for (map<Phase *, GLuint>::const_iterator texture_it = output_textures.begin();
1481              texture_it != output_textures.end();
1482              ++texture_it) {
1483                 resource_pool->release_2d_texture(texture_it->second);
1484         }
1485
1486         glBindFramebuffer(GL_FRAMEBUFFER, 0);
1487         check_error();
1488         glUseProgram(0);
1489         check_error();
1490
1491         if (do_phase_timing) {
1492                 // Get back the timer queries.
1493                 for (unsigned phase_num = 0; phase_num < phases.size(); ++phase_num) {
1494                         Phase *phase = phases[phase_num];
1495                         GLint available = 0;
1496                         while (!available) {
1497                                 glGetQueryObjectiv(phase->timer_query_object, GL_QUERY_RESULT_AVAILABLE, &available);
1498                         }
1499                         GLuint64 time_elapsed;
1500                         glGetQueryObjectui64v(phase->timer_query_object, GL_QUERY_RESULT, &time_elapsed);
1501                         phase->time_elapsed_ns += time_elapsed;
1502                         ++phase->num_measured_iterations;
1503                 }
1504         }
1505 }
1506
1507 void EffectChain::enable_phase_timing(bool enable)
1508 {
1509         if (enable) {
1510                 assert(movit_timer_queries_supported);
1511         }
1512         this->do_phase_timing = enable;
1513 }
1514
1515 void EffectChain::reset_phase_timing()
1516 {
1517         for (unsigned phase_num = 0; phase_num < phases.size(); ++phase_num) {
1518                 Phase *phase = phases[phase_num];
1519                 phase->time_elapsed_ns = 0;
1520                 phase->num_measured_iterations = 0;
1521         }
1522 }
1523
1524 void EffectChain::print_phase_timing()
1525 {
1526         double total_time_ms = 0.0;
1527         for (unsigned phase_num = 0; phase_num < phases.size(); ++phase_num) {
1528                 Phase *phase = phases[phase_num];
1529                 double avg_time_ms = phase->time_elapsed_ns * 1e-6 / phase->num_measured_iterations;
1530                 printf("Phase %d: %5.1f ms  [", phase_num, avg_time_ms);
1531                 for (unsigned effect_num = 0; effect_num < phase->effects.size(); ++effect_num) {
1532                         if (effect_num != 0) {
1533                                 printf(", ");
1534                         }
1535                         printf("%s", phase->effects[effect_num]->effect->effect_type_id().c_str());
1536                 }
1537                 printf("]\n");
1538                 total_time_ms += avg_time_ms;
1539         }
1540         printf("Total:   %5.1f ms\n", total_time_ms);
1541 }
1542
1543 void EffectChain::execute_phase(Phase *phase, bool last_phase, map<Phase *, GLuint> *output_textures, set<Phase *> *generated_mipmaps)
1544 {
1545         GLuint fbo = 0;
1546
1547         // Find a texture for this phase.
1548         inform_input_sizes(phase);
1549         if (!last_phase) {
1550                 find_output_size(phase);
1551
1552                 GLuint tex_num = resource_pool->create_2d_texture(GL_RGBA16F, phase->output_width, phase->output_height);
1553                 output_textures->insert(make_pair(phase, tex_num));
1554         }
1555
1556         const GLuint glsl_program_num = phase->glsl_program_num;
1557         check_error();
1558         glUseProgram(glsl_program_num);
1559         check_error();
1560
1561         // Set up RTT inputs for this phase.
1562         for (unsigned sampler = 0; sampler < phase->inputs.size(); ++sampler) {
1563                 glActiveTexture(GL_TEXTURE0 + sampler);
1564                 Phase *input = phase->inputs[sampler];
1565                 input->output_node->bound_sampler_num = sampler;
1566                 glBindTexture(GL_TEXTURE_2D, (*output_textures)[input]);
1567                 check_error();
1568                 if (phase->input_needs_mipmaps && generated_mipmaps->count(input) == 0) {
1569                         glGenerateMipmap(GL_TEXTURE_2D);
1570                         check_error();
1571                         generated_mipmaps->insert(input);
1572                 }
1573                 setup_rtt_sampler(glsl_program_num, sampler, phase->effect_ids[input->output_node], phase->input_needs_mipmaps);
1574         }
1575
1576         // And now the output. (Already set up for us if it is the last phase.)
1577         if (!last_phase) {
1578                 fbo = resource_pool->create_fbo((*output_textures)[phase]);
1579                 glBindFramebuffer(GL_FRAMEBUFFER, fbo);
1580                 glViewport(0, 0, phase->output_width, phase->output_height);
1581         }
1582
1583         // Give the required parameters to all the effects.
1584         unsigned sampler_num = phase->inputs.size();
1585         for (unsigned i = 0; i < phase->effects.size(); ++i) {
1586                 Node *node = phase->effects[i];
1587                 unsigned old_sampler_num = sampler_num;
1588                 node->effect->set_gl_state(glsl_program_num, phase->effect_ids[node], &sampler_num);
1589                 check_error();
1590
1591                 if (node->effect->is_single_texture()) {
1592                         assert(sampler_num - old_sampler_num == 1);
1593                         node->bound_sampler_num = old_sampler_num;
1594                 } else {
1595                         node->bound_sampler_num = -1;
1596                 }
1597         }
1598
1599         // Now draw!
1600         float vertices[] = {
1601                 0.0f, 1.0f,
1602                 0.0f, 0.0f,
1603                 1.0f, 1.0f,
1604                 1.0f, 0.0f
1605         };
1606
1607         GLuint vao;
1608         glGenVertexArrays(1, &vao);
1609         check_error();
1610         glBindVertexArray(vao);
1611         check_error();
1612
1613         GLuint position_vbo = fill_vertex_attribute(glsl_program_num, "position", 2, GL_FLOAT, sizeof(vertices), vertices);
1614         GLuint texcoord_vbo = fill_vertex_attribute(glsl_program_num, "texcoord", 2, GL_FLOAT, sizeof(vertices), vertices);  // Same as vertices.
1615
1616         glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
1617         check_error();
1618
1619         cleanup_vertex_attribute(glsl_program_num, "position", position_vbo);
1620         cleanup_vertex_attribute(glsl_program_num, "texcoord", texcoord_vbo);
1621
1622         glUseProgram(0);
1623         check_error();
1624
1625         for (unsigned i = 0; i < phase->effects.size(); ++i) {
1626                 Node *node = phase->effects[i];
1627                 node->effect->clear_gl_state();
1628         }
1629
1630         if (!last_phase) {
1631                 resource_pool->release_fbo(fbo);
1632         }
1633
1634         glDeleteVertexArrays(1, &vao);
1635         check_error();
1636 }
1637
1638 void EffectChain::setup_rtt_sampler(GLuint glsl_program_num, int sampler_num, const string &effect_id, bool use_mipmaps)
1639 {
1640         glActiveTexture(GL_TEXTURE0 + sampler_num);
1641         check_error();
1642         if (use_mipmaps) {
1643                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_NEAREST);
1644                 check_error();
1645         } else {
1646                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
1647                 check_error();
1648         }
1649         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
1650         check_error();
1651         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
1652         check_error();
1653
1654         string texture_name = string("tex_") + effect_id;
1655         glUniform1i(glGetUniformLocation(glsl_program_num, texture_name.c_str()), sampler_num);
1656         check_error();
1657 }
1658
1659 }  // namespace movit