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         //      or effects that change the output size).
 628         //   2. If all of your inputs have the same size, that will be your output size.
 629         //   3. Otherwise, your output size is 0x0.
 630         for (unsigned i = 0; i < phase->effects.size(); ++i) {
 631                 Node *node = phase->effects[i];
 632                 if (node->effect->num_inputs() == 0) {
 633                         continue;
 634                 }
 635                 unsigned this_output_width = 0;
 636                 unsigned this_output_height = 0;
 637                 for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
 638                         Node *input = node->incoming_links[j];
 639                         node->effect->inform_input_size(j, input->output_width, input->output_height);
 640                         if (j == 0) {
 641                                 this_output_width = input->output_width;
 642                                 this_output_height = input->output_height;
 643                         } else if (input->output_width != this_output_width || input->output_height != this_output_height) {
 644                                 // Inputs disagree.
 645                                 this_output_width = 0;
 646                                 this_output_height = 0;
 647                         }
 648                 }
 649                 if (node->effect->changes_output_size()) {
 650                         // We cannot call get_output_size() before we've done inform_input_size()
 651                         // on all inputs.
 652                         unsigned real_width_ignored, real_height_ignored;
 653                         node->effect->get_output_size(&real_width_ignored, &real_height_ignored,
 654                                                       &node->output_width, &node->output_height);
 655                 } else {
 656                         node->output_width = this_output_width;
 657                         node->output_height = this_output_height;
 658                 }
 659         }
 660 }
 661
 662 // Note: You should call inform_input_sizes() before this, as the last effect's
 663 // desired output size might change based on the inputs.
 664 void EffectChain::find_output_size(Phase *phase)
 665 {
 666         Node *output_node = phase->effects.back();
 667
 668         // If the last effect explicitly sets an output size, use that.
 669         if (output_node->effect->changes_output_size()) {
 670                 output_node->effect->get_output_size(&phase->output_width, &phase->output_height,
 671                                                      &phase->virtual_output_width, &phase->virtual_output_height);
 672                 return;
 673         }
 674
 675         // If all effects have the same size, use that.
 676         unsigned output_width = 0, output_height = 0;
 677         bool all_inputs_same_size = true;
 678
 679         for (unsigned i = 0; i < phase->inputs.size(); ++i) {
 680                 Phase *input = phase->inputs[i];
 681                 assert(input->output_width != 0);
 682                 assert(input->output_height != 0);
 683                 if (output_width == 0 && output_height == 0) {
 684                         output_width = input->virtual_output_width;
 685                         output_height = input->virtual_output_height;
 686                 } else if (output_width != input->virtual_output_width ||
 687                            output_height != input->virtual_output_height) {
 688                         all_inputs_same_size = false;
 689                 }
 690         }
 691         for (unsigned i = 0; i < phase->effects.size(); ++i) {
 692                 Effect *effect = phase->effects[i]->effect;
 693                 if (effect->num_inputs() != 0) {
 694                         continue;
 695                 }
 696
 697                 Input *input = static_cast<Input *>(effect);
 698                 if (output_width == 0 && output_height == 0) {
 699                         output_width = input->get_width();
 700                         output_height = input->get_height();
 701                 } else if (output_width != input->get_width() ||
 702                            output_height != input->get_height()) {
 703                         all_inputs_same_size = false;
 704                 }
 705         }
 706
 707         if (all_inputs_same_size) {
 708                 assert(output_width != 0);
 709                 assert(output_height != 0);
 710                 phase->virtual_output_width = phase->output_width = output_width;
 711                 phase->virtual_output_height = phase->output_height = output_height;
 712                 return;
 713         }
 714
 715         // If not, fit all the inputs into the current aspect, and select the largest one.
 716         output_width = 0;
 717         output_height = 0;
 718         for (unsigned i = 0; i < phase->inputs.size(); ++i) {
 719                 Phase *input = phase->inputs[i];
 720                 assert(input->output_width != 0);
 721                 assert(input->output_height != 0);
 722                 size_rectangle_to_fit(input->output_width, input->output_height, &output_width, &output_height);
 723         }
 724         for (unsigned i = 0; i < phase->effects.size(); ++i) {
 725                 Effect *effect = phase->effects[i]->effect;
 726                 if (effect->num_inputs() != 0) {
 727                         continue;
 728                 }
 729
 730                 Input *input = static_cast<Input *>(effect);
 731                 size_rectangle_to_fit(input->get_width(), input->get_height(), &output_width, &output_height);
 732         }
 733         assert(output_width != 0);
 734         assert(output_height != 0);
 735         phase->virtual_output_width = phase->output_width = output_width;
 736         phase->virtual_output_height = phase->output_height = output_height;
 737 }
 738
 739 void EffectChain::sort_all_nodes_topologically()
 740 {
 741         nodes = topological_sort(nodes);
 742 }
 743
 744 vector<Node *> EffectChain::topological_sort(const vector<Node *> &nodes)
 745 {
 746         set<Node *> nodes_left_to_visit(nodes.begin(), nodes.end());
 747         vector<Node *> sorted_list;
 748         for (unsigned i = 0; i < nodes.size(); ++i) {
 749                 topological_sort_visit_node(nodes[i], &nodes_left_to_visit, &sorted_list);
 750         }
 751         reverse(sorted_list.begin(), sorted_list.end());
 752         return sorted_list;
 753 }
 754
 755 void EffectChain::topological_sort_visit_node(Node *node, set<Node *> *nodes_left_to_visit, vector<Node *> *sorted_list)
 756 {
 757         if (nodes_left_to_visit->count(node) == 0) {
 758                 return;
 759         }
 760         nodes_left_to_visit->erase(node);
 761         for (unsigned i = 0; i < node->outgoing_links.size(); ++i) {
 762                 topological_sort_visit_node(node->outgoing_links[i], nodes_left_to_visit, sorted_list);
 763         }
 764         sorted_list->push_back(node);
 765 }
 766
 767 void EffectChain::find_color_spaces_for_inputs()
 768 {
 769         for (unsigned i = 0; i < nodes.size(); ++i) {
 770                 Node *node = nodes[i];
 771                 if (node->disabled) {
 772                         continue;
 773                 }
 774                 if (node->incoming_links.size() == 0) {
 775                         Input *input = static_cast<Input *>(node->effect);
 776                         node->output_color_space = input->get_color_space();
 777                         node->output_gamma_curve = input->get_gamma_curve();
 778
 779                         Effect::AlphaHandling alpha_handling = input->alpha_handling();
 780                         switch (alpha_handling) {
 781                         case Effect::OUTPUT_BLANK_ALPHA:
 782                                 node->output_alpha_type = ALPHA_BLANK;
 783                                 break;
 784                         case Effect::INPUT_AND_OUTPUT_PREMULTIPLIED_ALPHA:
 785                                 node->output_alpha_type = ALPHA_PREMULTIPLIED;
 786                                 break;
 787                         case Effect::OUTPUT_POSTMULTIPLIED_ALPHA:
 788                                 node->output_alpha_type = ALPHA_POSTMULTIPLIED;
 789                                 break;
 790                         case Effect::INPUT_PREMULTIPLIED_ALPHA_KEEP_BLANK:
 791                         case Effect::DONT_CARE_ALPHA_TYPE:
 792                         default:
 793                                 assert(false);
 794                         }
 795
 796                         if (node->output_alpha_type == ALPHA_PREMULTIPLIED) {
 797                                 assert(node->output_gamma_curve == GAMMA_LINEAR);
 798                         }
 799                 }
 800         }
 801 }
 802
 803 // Propagate gamma and color space information as far as we can in the graph.
 804 // The rules are simple: Anything where all the inputs agree, get that as
 805 // output as well. Anything else keeps having *_INVALID.
 806 void EffectChain::propagate_gamma_and_color_space()
 807 {
 808         // We depend on going through the nodes in order.
 809         sort_all_nodes_topologically();
 810
 811         for (unsigned i = 0; i < nodes.size(); ++i) {
 812                 Node *node = nodes[i];
 813                 if (node->disabled) {
 814                         continue;
 815                 }
 816                 assert(node->incoming_links.size() == node->effect->num_inputs());
 817                 if (node->incoming_links.size() == 0) {
 818                         assert(node->output_color_space != COLORSPACE_INVALID);
 819                         assert(node->output_gamma_curve != GAMMA_INVALID);
 820                         continue;
 821                 }
 822
 823                 Colorspace color_space = node->incoming_links[0]->output_color_space;
 824                 GammaCurve gamma_curve = node->incoming_links[0]->output_gamma_curve;
 825                 for (unsigned j = 1; j < node->incoming_links.size(); ++j) {
 826                         if (node->incoming_links[j]->output_color_space != color_space) {
 827                                 color_space = COLORSPACE_INVALID;
 828                         }
 829                         if (node->incoming_links[j]->output_gamma_curve != gamma_curve) {
 830                                 gamma_curve = GAMMA_INVALID;
 831                         }
 832                 }
 833
 834                 // The conversion effects already have their outputs set correctly,
 835                 // so leave them alone.
 836                 if (node->effect->effect_type_id() != "ColorspaceConversionEffect") {
 837                         node->output_color_space = color_space;
 838                 }
 839                 if (node->effect->effect_type_id() != "GammaCompressionEffect" &&
 840                     node->effect->effect_type_id() != "GammaExpansionEffect") {
 841                         node->output_gamma_curve = gamma_curve;
 842                 }
 843         }
 844 }
 845
 846 // Propagate alpha information as far as we can in the graph.
 847 // Similar to propagate_gamma_and_color_space().
 848 void EffectChain::propagate_alpha()
 849 {
 850         // We depend on going through the nodes in order.
 851         sort_all_nodes_topologically();
 852
 853         for (unsigned i = 0; i < nodes.size(); ++i) {
 854                 Node *node = nodes[i];
 855                 if (node->disabled) {
 856                         continue;
 857                 }
 858                 assert(node->incoming_links.size() == node->effect->num_inputs());
 859                 if (node->incoming_links.size() == 0) {
 860                         assert(node->output_alpha_type != ALPHA_INVALID);
 861                         continue;
 862                 }
 863
 864                 // The alpha multiplication/division effects are special cases.
 865                 if (node->effect->effect_type_id() == "AlphaMultiplicationEffect") {
 866                         assert(node->incoming_links.size() == 1);
 867                         assert(node->incoming_links[0]->output_alpha_type == ALPHA_POSTMULTIPLIED);
 868                         node->output_alpha_type = ALPHA_PREMULTIPLIED;
 869                         continue;
 870                 }
 871                 if (node->effect->effect_type_id() == "AlphaDivisionEffect") {
 872                         assert(node->incoming_links.size() == 1);
 873                         assert(node->incoming_links[0]->output_alpha_type == ALPHA_PREMULTIPLIED);
 874                         node->output_alpha_type = ALPHA_POSTMULTIPLIED;
 875                         continue;
 876                 }
 877
 878                 // GammaCompressionEffect and GammaExpansionEffect are also a special case,
 879                 // because they are the only one that _need_ postmultiplied alpha.
 880                 if (node->effect->effect_type_id() == "GammaCompressionEffect" ||
 881                     node->effect->effect_type_id() == "GammaExpansionEffect") {
 882                         assert(node->incoming_links.size() == 1);
 883                         if (node->incoming_links[0]->output_alpha_type == ALPHA_BLANK) {
 884                                 node->output_alpha_type = ALPHA_BLANK;
 885                         } else if (node->incoming_links[0]->output_alpha_type == ALPHA_POSTMULTIPLIED) {
 886                                 node->output_alpha_type = ALPHA_POSTMULTIPLIED;
 887                         } else {
 888                                 node->output_alpha_type = ALPHA_INVALID;
 889                         }
 890                         continue;
 891                 }
 892
 893                 // Only inputs can have unconditional alpha output (OUTPUT_BLANK_ALPHA
 894                 // or OUTPUT_POSTMULTIPLIED_ALPHA), and they have already been
 895                 // taken care of above. Rationale: Even if you could imagine
 896                 // e.g. an effect that took in an image and set alpha=1.0
 897                 // unconditionally, it wouldn't make any sense to have it as
 898                 // e.g. OUTPUT_BLANK_ALPHA, since it wouldn't know whether it
 899                 // got its input pre- or postmultiplied, so it wouldn't know
 900                 // whether to divide away the old alpha or not.
 901                 Effect::AlphaHandling alpha_handling = node->effect->alpha_handling();
 902                 assert(alpha_handling == Effect::INPUT_AND_OUTPUT_PREMULTIPLIED_ALPHA ||
 903                        alpha_handling == Effect::INPUT_PREMULTIPLIED_ALPHA_KEEP_BLANK ||
 904                        alpha_handling == Effect::DONT_CARE_ALPHA_TYPE);
 905
 906                 // If the node has multiple inputs, check that they are all valid and
 907                 // the same.
 908                 bool any_invalid = false;
 909                 bool any_premultiplied = false;
 910                 bool any_postmultiplied = false;
 911
 912                 for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
 913                         switch (node->incoming_links[j]->output_alpha_type) {
 914                         case ALPHA_INVALID:
 915                                 any_invalid = true;
 916                                 break;
 917                         case ALPHA_BLANK:
 918                                 // Blank is good as both pre- and postmultiplied alpha,
 919                                 // so just ignore it.
 920                                 break;
 921                         case ALPHA_PREMULTIPLIED:
 922                                 any_premultiplied = true;
 923                                 break;
 924                         case ALPHA_POSTMULTIPLIED:
 925                                 any_postmultiplied = true;
 926                                 break;
 927                         default:
 928                                 assert(false);
 929                         }
 930                 }
 931
 932                 if (any_invalid) {
 933                         node->output_alpha_type = ALPHA_INVALID;
 934                         continue;
 935                 }
 936
 937                 // Inputs must be of the same type.
 938                 if (any_premultiplied && any_postmultiplied) {
 939                         node->output_alpha_type = ALPHA_INVALID;
 940                         continue;
 941                 }
 942
 943                 if (alpha_handling == Effect::INPUT_AND_OUTPUT_PREMULTIPLIED_ALPHA ||
 944                     alpha_handling == Effect::INPUT_PREMULTIPLIED_ALPHA_KEEP_BLANK) {
 945                         // If the effect has asked for premultiplied alpha, check that it has got it.
 946                         if (any_postmultiplied) {
 947                                 node->output_alpha_type = ALPHA_INVALID;
 948                         } else if (!any_premultiplied &&
 949                                    alpha_handling == Effect::INPUT_PREMULTIPLIED_ALPHA_KEEP_BLANK) {
 950                                 // Blank input alpha, and the effect preserves blank alpha.
 951                                 node->output_alpha_type = ALPHA_BLANK;
 952                         } else {
 953                                 node->output_alpha_type = ALPHA_PREMULTIPLIED;
 954                         }
 955                 } else {
 956                         // OK, all inputs are the same, and this effect is not going
 957                         // to change it.
 958                         assert(alpha_handling == Effect::DONT_CARE_ALPHA_TYPE);
 959                         if (any_premultiplied) {
 960                                 node->output_alpha_type = ALPHA_PREMULTIPLIED;
 961                         } else if (any_postmultiplied) {
 962                                 node->output_alpha_type = ALPHA_POSTMULTIPLIED;
 963                         } else {
 964                                 node->output_alpha_type = ALPHA_BLANK;
 965                         }
 966                 }
 967         }
 968 }
 969
 970 bool EffectChain::node_needs_colorspace_fix(Node *node)
 971 {
 972         if (node->disabled) {
 973                 return false;
 974         }
 975         if (node->effect->num_inputs() == 0) {
 976                 return false;
 977         }
 978
 979         // propagate_gamma_and_color_space() has already set our output
 980         // to COLORSPACE_INVALID if the inputs differ, so we can rely on that.
 981         if (node->output_color_space == COLORSPACE_INVALID) {
 982                 return true;
 983         }
 984         return (node->effect->needs_srgb_primaries() && node->output_color_space != COLORSPACE_sRGB);
 985 }
 986
 987 // Fix up color spaces so that there are no COLORSPACE_INVALID nodes left in
 988 // the graph. Our strategy is not always optimal, but quite simple:
 989 // Find an effect that's as early as possible where the inputs are of
 990 // unacceptable colorspaces (that is, either different, or, if the effect only
 991 // wants sRGB, not sRGB.) Add appropriate conversions on all its inputs,
 992 // propagate the information anew, and repeat until there are no more such
 993 // effects.
 994 void EffectChain::fix_internal_color_spaces()
 995 {
 996         unsigned colorspace_propagation_pass = 0;
 997         bool found_any;
 998         do {
 999                 found_any = false;
1000                 for (unsigned i = 0; i < nodes.size(); ++i) {
1001                         Node *node = nodes[i];
1002                         if (!node_needs_colorspace_fix(node)) {
1003                                 continue;
1004                         }
1005
1006                         // Go through each input that is not sRGB, and insert
1007                         // a colorspace conversion after it.
1008                         for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
1009                                 Node *input = node->incoming_links[j];
1010                                 assert(input->output_color_space != COLORSPACE_INVALID);
1011                                 if (input->output_color_space == COLORSPACE_sRGB) {
1012                                         continue;
1013                                 }
1014                                 Node *conversion = add_node(new ColorspaceConversionEffect());
1015                                 CHECK(conversion->effect->set_int("source_space", input->output_color_space));
1016                                 CHECK(conversion->effect->set_int("destination_space", COLORSPACE_sRGB));
1017                                 conversion->output_color_space = COLORSPACE_sRGB;
1018                                 replace_sender(input, conversion);
1019                                 connect_nodes(input, conversion);
1020                         }
1021
1022                         // Re-sort topologically, and propagate the new information.
1023                         propagate_gamma_and_color_space();
1024
1025                         found_any = true;
1026                         break;
1027                 }
1028
1029                 char filename[256];
1030                 sprintf(filename, "step5-colorspacefix-iter%u.dot", ++colorspace_propagation_pass);
1031                 output_dot(filename);
1032                 assert(colorspace_propagation_pass < 100);
1033         } while (found_any);
1034
1035         for (unsigned i = 0; i < nodes.size(); ++i) {
1036                 Node *node = nodes[i];
1037                 if (node->disabled) {
1038                         continue;
1039                 }
1040                 assert(node->output_color_space != COLORSPACE_INVALID);
1041         }
1042 }
1043
1044 bool EffectChain::node_needs_alpha_fix(Node *node)
1045 {
1046         if (node->disabled) {
1047                 return false;
1048         }
1049
1050         // propagate_alpha() has already set our output to ALPHA_INVALID if the
1051         // inputs differ or we are otherwise in mismatch, so we can rely on that.
1052         return (node->output_alpha_type == ALPHA_INVALID);
1053 }
1054
1055 // Fix up alpha so that there are no ALPHA_INVALID nodes left in
1056 // the graph. Similar to fix_internal_color_spaces().
1057 void EffectChain::fix_internal_alpha(unsigned step)
1058 {
1059         unsigned alpha_propagation_pass = 0;
1060         bool found_any;
1061         do {
1062                 found_any = false;
1063                 for (unsigned i = 0; i < nodes.size(); ++i) {
1064                         Node *node = nodes[i];
1065                         if (!node_needs_alpha_fix(node)) {
1066                                 continue;
1067                         }
1068
1069                         // If we need to fix up GammaExpansionEffect, then clearly something
1070                         // is wrong, since the combination of premultiplied alpha and nonlinear inputs
1071                         // is meaningless.
1072                         assert(node->effect->effect_type_id() != "GammaExpansionEffect");
1073
1074                         AlphaType desired_type = ALPHA_PREMULTIPLIED;
1075
1076                         // GammaCompressionEffect is special; it needs postmultiplied alpha.
1077                         if (node->effect->effect_type_id() == "GammaCompressionEffect") {
1078                                 assert(node->incoming_links.size() == 1);
1079                                 assert(node->incoming_links[0]->output_alpha_type == ALPHA_PREMULTIPLIED);
1080                                 desired_type = ALPHA_POSTMULTIPLIED;
1081                         }
1082
1083                         // Go through each input that is not premultiplied alpha, and insert
1084                         // a conversion before it.
1085                         for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
1086                                 Node *input = node->incoming_links[j];
1087                                 assert(input->output_alpha_type != ALPHA_INVALID);
1088                                 if (input->output_alpha_type == desired_type ||
1089                                     input->output_alpha_type == ALPHA_BLANK) {
1090                                         continue;
1091                                 }
1092                                 Node *conversion;
1093                                 if (desired_type == ALPHA_PREMULTIPLIED) {
1094                                         conversion = add_node(new AlphaMultiplicationEffect());
1095                                 } else {
1096                                         conversion = add_node(new AlphaDivisionEffect());
1097                                 }
1098                                 conversion->output_alpha_type = desired_type;
1099                                 replace_sender(input, conversion);
1100                                 connect_nodes(input, conversion);
1101                         }
1102
1103                         // Re-sort topologically, and propagate the new information.
1104                         propagate_gamma_and_color_space();
1105                         propagate_alpha();
1106
1107                         found_any = true;
1108                         break;
1109                 }
1110
1111                 char filename[256];
1112                 sprintf(filename, "step%u-alphafix-iter%u.dot", step, ++alpha_propagation_pass);
1113                 output_dot(filename);
1114                 assert(alpha_propagation_pass < 100);
1115         } while (found_any);
1116
1117         for (unsigned i = 0; i < nodes.size(); ++i) {
1118                 Node *node = nodes[i];
1119                 if (node->disabled) {
1120                         continue;
1121                 }
1122                 assert(node->output_alpha_type != ALPHA_INVALID);
1123         }
1124 }
1125
1126 // Make so that the output is in the desired color space.
1127 void EffectChain::fix_output_color_space()
1128 {
1129         Node *output = find_output_node();
1130         if (output->output_color_space != output_format.color_space) {
1131                 Node *conversion = add_node(new ColorspaceConversionEffect());
1132                 CHECK(conversion->effect->set_int("source_space", output->output_color_space));
1133                 CHECK(conversion->effect->set_int("destination_space", output_format.color_space));
1134                 conversion->output_color_space = output_format.color_space;
1135                 connect_nodes(output, conversion);
1136                 propagate_alpha();
1137                 propagate_gamma_and_color_space();
1138         }
1139 }
1140
1141 // Make so that the output is in the desired pre-/postmultiplication alpha state.
1142 void EffectChain::fix_output_alpha()
1143 {
1144         Node *output = find_output_node();
1145         assert(output->output_alpha_type != ALPHA_INVALID);
1146         if (output->output_alpha_type == ALPHA_BLANK) {
1147                 // No alpha output, so we don't care.
1148                 return;
1149         }
1150         if (output->output_alpha_type == ALPHA_PREMULTIPLIED &&
1151             output_alpha_format == OUTPUT_ALPHA_FORMAT_POSTMULTIPLIED) {
1152                 Node *conversion = add_node(new AlphaDivisionEffect());
1153                 connect_nodes(output, conversion);
1154                 propagate_alpha();
1155                 propagate_gamma_and_color_space();
1156         }
1157         if (output->output_alpha_type == ALPHA_POSTMULTIPLIED &&
1158             output_alpha_format == OUTPUT_ALPHA_FORMAT_PREMULTIPLIED) {
1159                 Node *conversion = add_node(new AlphaMultiplicationEffect());
1160                 connect_nodes(output, conversion);
1161                 propagate_alpha();
1162                 propagate_gamma_and_color_space();
1163         }
1164 }
1165
1166 bool EffectChain::node_needs_gamma_fix(Node *node)
1167 {
1168         if (node->disabled) {
1169                 return false;
1170         }
1171
1172         // Small hack since the output is not an explicit node:
1173         // If we are the last node and our output is in the wrong
1174         // space compared to EffectChain's output, we need to fix it.
1175         // This will only take us to linear, but fix_output_gamma()
1176         // will come and take us to the desired output gamma
1177         // if it is needed.
1178         //
1179         // This needs to be before everything else, since it could
1180         // even apply to inputs (if they are the only effect).
1181         if (node->outgoing_links.empty() &&
1182             node->output_gamma_curve != output_format.gamma_curve &&
1183             node->output_gamma_curve != GAMMA_LINEAR) {
1184                 return true;
1185         }
1186
1187         if (node->effect->num_inputs() == 0) {
1188                 return false;
1189         }
1190
1191         // propagate_gamma_and_color_space() has already set our output
1192         // to GAMMA_INVALID if the inputs differ, so we can rely on that,
1193         // except for GammaCompressionEffect.
1194         if (node->output_gamma_curve == GAMMA_INVALID) {
1195                 return true;
1196         }
1197         if (node->effect->effect_type_id() == "GammaCompressionEffect") {
1198                 assert(node->incoming_links.size() == 1);
1199                 return node->incoming_links[0]->output_gamma_curve != GAMMA_LINEAR;
1200         }
1201
1202         return (node->effect->needs_linear_light() && node->output_gamma_curve != GAMMA_LINEAR);
1203 }
1204
1205 // Very similar to fix_internal_color_spaces(), but for gamma.
1206 // There is one difference, though; before we start adding conversion nodes,
1207 // we see if we can get anything out of asking the sources to deliver
1208 // linear gamma directly. fix_internal_gamma_by_asking_inputs()
1209 // does that part, while fix_internal_gamma_by_inserting_nodes()
1210 // inserts nodes as needed afterwards.
1211 void EffectChain::fix_internal_gamma_by_asking_inputs(unsigned step)
1212 {
1213         unsigned gamma_propagation_pass = 0;
1214         bool found_any;
1215         do {
1216                 found_any = false;
1217                 for (unsigned i = 0; i < nodes.size(); ++i) {
1218                         Node *node = nodes[i];
1219                         if (!node_needs_gamma_fix(node)) {
1220                                 continue;
1221                         }
1222
1223                         // See if all inputs can give us linear gamma. If not, leave it.
1224                         vector<Node *> nonlinear_inputs;
1225                         find_all_nonlinear_inputs(node, &nonlinear_inputs);
1226                         assert(!nonlinear_inputs.empty());
1227
1228                         bool all_ok = true;
1229                         for (unsigned i = 0; i < nonlinear_inputs.size(); ++i) {
1230                                 Input *input = static_cast<Input *>(nonlinear_inputs[i]->effect);
1231                                 all_ok &= input->can_output_linear_gamma();
1232                         }
1233
1234                         if (!all_ok) {
1235                                 continue;
1236                         }
1237
1238                         for (unsigned i = 0; i < nonlinear_inputs.size(); ++i) {
1239                                 CHECK(nonlinear_inputs[i]->effect->set_int("output_linear_gamma", 1));
1240                                 nonlinear_inputs[i]->output_gamma_curve = GAMMA_LINEAR;
1241                         }
1242
1243                         // Re-sort topologically, and propagate the new information.
1244                         propagate_gamma_and_color_space();
1245
1246                         found_any = true;
1247                         break;
1248                 }
1249
1250                 char filename[256];
1251                 sprintf(filename, "step%u-gammafix-iter%u.dot", step, ++gamma_propagation_pass);
1252                 output_dot(filename);
1253                 assert(gamma_propagation_pass < 100);
1254         } while (found_any);
1255 }
1256
1257 void EffectChain::fix_internal_gamma_by_inserting_nodes(unsigned step)
1258 {
1259         unsigned gamma_propagation_pass = 0;
1260         bool found_any;
1261         do {
1262                 found_any = false;
1263                 for (unsigned i = 0; i < nodes.size(); ++i) {
1264                         Node *node = nodes[i];
1265                         if (!node_needs_gamma_fix(node)) {
1266                                 continue;
1267                         }
1268
1269                         // Special case: We could be an input and still be asked to
1270                         // fix our gamma; if so, we should be the only node
1271                         // (as node_needs_gamma_fix() would only return true in
1272                         // for an input in that case). That means we should insert
1273                         // a conversion node _after_ ourselves.
1274                         if (node->incoming_links.empty()) {
1275                                 assert(node->outgoing_links.empty());
1276                                 Node *conversion = add_node(new GammaExpansionEffect());
1277                                 CHECK(conversion->effect->set_int("source_curve", node->output_gamma_curve));
1278                                 conversion->output_gamma_curve = GAMMA_LINEAR;
1279                                 connect_nodes(node, conversion);
1280                         }
1281
1282                         // If not, go through each input that is not linear gamma,
1283                         // and insert a gamma conversion after it.
1284                         for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
1285                                 Node *input = node->incoming_links[j];
1286                                 assert(input->output_gamma_curve != GAMMA_INVALID);
1287                                 if (input->output_gamma_curve == GAMMA_LINEAR) {
1288                                         continue;
1289                                 }
1290                                 Node *conversion = add_node(new GammaExpansionEffect());
1291                                 CHECK(conversion->effect->set_int("source_curve", input->output_gamma_curve));
1292                                 conversion->output_gamma_curve = GAMMA_LINEAR;
1293                                 replace_sender(input, conversion);
1294                                 connect_nodes(input, conversion);
1295                         }
1296
1297                         // Re-sort topologically, and propagate the new information.
1298                         propagate_alpha();
1299                         propagate_gamma_and_color_space();
1300
1301                         found_any = true;
1302                         break;
1303                 }
1304
1305                 char filename[256];
1306                 sprintf(filename, "step%u-gammafix-iter%u.dot", step, ++gamma_propagation_pass);
1307                 output_dot(filename);
1308                 assert(gamma_propagation_pass < 100);
1309         } while (found_any);
1310
1311         for (unsigned i = 0; i < nodes.size(); ++i) {
1312                 Node *node = nodes[i];
1313                 if (node->disabled) {
1314                         continue;
1315                 }
1316                 assert(node->output_gamma_curve != GAMMA_INVALID);
1317         }
1318 }
1319
1320 // Make so that the output is in the desired gamma.
1321 // Note that this assumes linear input gamma, so it might create the need
1322 // for another pass of fix_internal_gamma().
1323 void EffectChain::fix_output_gamma()
1324 {
1325         Node *output = find_output_node();
1326         if (output->output_gamma_curve != output_format.gamma_curve) {
1327                 Node *conversion = add_node(new GammaCompressionEffect());
1328                 CHECK(conversion->effect->set_int("destination_curve", output_format.gamma_curve));
1329                 conversion->output_gamma_curve = output_format.gamma_curve;
1330                 connect_nodes(output, conversion);
1331         }
1332 }
1333
1334 // If the user has requested dither, add a DitherEffect right at the end
1335 // (after GammaCompressionEffect etc.). This needs to be done after everything else,
1336 // since dither is about the only effect that can _not_ be done in linear space.
1337 void EffectChain::add_dither_if_needed()
1338 {
1339         if (num_dither_bits == 0) {
1340                 return;
1341         }
1342         Node *output = find_output_node();
1343         Node *dither = add_node(new DitherEffect());
1344         CHECK(dither->effect->set_int("num_bits", num_dither_bits));
1345         connect_nodes(output, dither);
1346
1347         dither_effect = dither->effect;
1348 }
1349
1350 // Find the output node. This is, simply, one that has no outgoing links.
1351 // If there are multiple ones, the graph is malformed (we do not support
1352 // multiple outputs right now).
1353 Node *EffectChain::find_output_node()
1354 {
1355         vector<Node *> output_nodes;
1356         for (unsigned i = 0; i < nodes.size(); ++i) {
1357                 Node *node = nodes[i];
1358                 if (node->disabled) {
1359                         continue;
1360                 }
1361                 if (node->outgoing_links.empty()) {
1362                         output_nodes.push_back(node);
1363                 }
1364         }
1365         assert(output_nodes.size() == 1);
1366         return output_nodes[0];
1367 }
1368
1369 void EffectChain::finalize()
1370 {
1371         // Output the graph as it is before we do any conversions on it.
1372         output_dot("step0-start.dot");
1373
1374         // Give each effect in turn a chance to rewrite its own part of the graph.
1375         // Note that if more effects are added as part of this, they will be
1376         // picked up as part of the same for loop, since they are added at the end.
1377         for (unsigned i = 0; i < nodes.size(); ++i) {
1378                 nodes[i]->effect->rewrite_graph(this, nodes[i]);
1379         }
1380         output_dot("step1-rewritten.dot");
1381
1382         find_color_spaces_for_inputs();
1383         output_dot("step2-input-colorspace.dot");
1384
1385         propagate_alpha();
1386         output_dot("step3-propagated-alpha.dot");
1387
1388         propagate_gamma_and_color_space();
1389         output_dot("step4-propagated-all.dot");
1390
1391         fix_internal_color_spaces();
1392         fix_internal_alpha(6);
1393         fix_output_color_space();
1394         output_dot("step7-output-colorspacefix.dot");
1395         fix_output_alpha();
1396         output_dot("step8-output-alphafix.dot");
1397
1398         // Note that we need to fix gamma after colorspace conversion,
1399         // because colorspace conversions might create needs for gamma conversions.
1400         // Also, we need to run an extra pass of fix_internal_gamma() after
1401         // fixing the output gamma, as we only have conversions to/from linear,
1402         // and fix_internal_alpha() since GammaCompressionEffect needs
1403         // postmultiplied input.
1404         fix_internal_gamma_by_asking_inputs(9);
1405         fix_internal_gamma_by_inserting_nodes(10);
1406         fix_output_gamma();
1407         output_dot("step11-output-gammafix.dot");
1408         propagate_alpha();
1409         output_dot("step12-output-alpha-propagated.dot");
1410         fix_internal_alpha(13);
1411         output_dot("step14-output-alpha-fixed.dot");
1412         fix_internal_gamma_by_asking_inputs(15);
1413         fix_internal_gamma_by_inserting_nodes(16);
1414
1415         output_dot("step17-before-dither.dot");
1416
1417         add_dither_if_needed();
1418
1419         output_dot("step18-final.dot");
1420
1421         // Construct all needed GLSL programs, starting at the output.
1422         // We need to keep track of which effects have already been computed,
1423         // as an effect with multiple users could otherwise be calculated
1424         // multiple times.
1425         map<Node *, Phase *> completed_effects;
1426         construct_phase(find_output_node(), &completed_effects);
1427
1428         output_dot("step19-split-to-phases.dot");
1429
1430         assert(phases[0]->inputs.empty());
1431
1432         finalized = true;
1433 }
1434
1435 void EffectChain::render_to_fbo(GLuint dest_fbo, unsigned width, unsigned height)
1436 {
1437         assert(finalized);
1438
1439         // Save original viewport.
1440         GLuint x = 0, y = 0;
1441
1442         if (width == 0 && height == 0) {
1443                 GLint viewport[4];
1444                 glGetIntegerv(GL_VIEWPORT, viewport);
1445                 x = viewport[0];
1446                 y = viewport[1];
1447                 width = viewport[2];
1448                 height = viewport[3];
1449         }
1450
1451         // Basic state.
1452         glDisable(GL_BLEND);
1453         check_error();
1454         glDisable(GL_DEPTH_TEST);
1455         check_error();
1456         glDepthMask(GL_FALSE);
1457         check_error();
1458
1459         set<Phase *> generated_mipmaps;
1460
1461         // We choose the simplest option of having one texture per output,
1462         // since otherwise this turns into an (albeit simple) register allocation problem.
1463         map<Phase *, GLuint> output_textures;
1464
1465         for (unsigned phase_num = 0; phase_num < phases.size(); ++phase_num) {
1466                 Phase *phase = phases[phase_num];
1467
1468                 if (do_phase_timing) {
1469                         glBeginQuery(GL_TIME_ELAPSED, phase->timer_query_object);
1470                 }
1471                 if (phase_num == phases.size() - 1) {
1472                         // Last phase goes to the output the user specified.
1473                         glBindFramebuffer(GL_FRAMEBUFFER, dest_fbo);
1474                         check_error();
1475                         GLenum status = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);
1476                         assert(status == GL_FRAMEBUFFER_COMPLETE);
1477                         glViewport(x, y, width, height);
1478                         if (dither_effect != NULL) {
1479                                 CHECK(dither_effect->set_int("output_width", width));
1480                                 CHECK(dither_effect->set_int("output_height", height));
1481                         }
1482                 }
1483                 execute_phase(phase, phase_num == phases.size() - 1, &output_textures, &generated_mipmaps);
1484                 if (do_phase_timing) {
1485                         glEndQuery(GL_TIME_ELAPSED);
1486                 }
1487         }
1488
1489         for (map<Phase *, GLuint>::const_iterator texture_it = output_textures.begin();
1490              texture_it != output_textures.end();
1491              ++texture_it) {
1492                 resource_pool->release_2d_texture(texture_it->second);
1493         }
1494
1495         glBindFramebuffer(GL_FRAMEBUFFER, 0);
1496         check_error();
1497         glUseProgram(0);
1498         check_error();
1499
1500         if (do_phase_timing) {
1501                 // Get back the timer queries.
1502                 for (unsigned phase_num = 0; phase_num < phases.size(); ++phase_num) {
1503                         Phase *phase = phases[phase_num];
1504                         GLint available = 0;
1505                         while (!available) {
1506                                 glGetQueryObjectiv(phase->timer_query_object, GL_QUERY_RESULT_AVAILABLE, &available);
1507                         }
1508                         GLuint64 time_elapsed;
1509                         glGetQueryObjectui64v(phase->timer_query_object, GL_QUERY_RESULT, &time_elapsed);
1510                         phase->time_elapsed_ns += time_elapsed;
1511                         ++phase->num_measured_iterations;
1512                 }
1513         }
1514 }
1515
1516 void EffectChain::enable_phase_timing(bool enable)
1517 {
1518         if (enable) {
1519                 assert(movit_timer_queries_supported);
1520         }
1521         this->do_phase_timing = enable;
1522 }
1523
1524 void EffectChain::reset_phase_timing()
1525 {
1526         for (unsigned phase_num = 0; phase_num < phases.size(); ++phase_num) {
1527                 Phase *phase = phases[phase_num];
1528                 phase->time_elapsed_ns = 0;
1529                 phase->num_measured_iterations = 0;
1530         }
1531 }
1532
1533 void EffectChain::print_phase_timing()
1534 {
1535         double total_time_ms = 0.0;
1536         for (unsigned phase_num = 0; phase_num < phases.size(); ++phase_num) {
1537                 Phase *phase = phases[phase_num];
1538                 double avg_time_ms = phase->time_elapsed_ns * 1e-6 / phase->num_measured_iterations;
1539                 printf("Phase %d: %5.1f ms  [", phase_num, avg_time_ms);
1540                 for (unsigned effect_num = 0; effect_num < phase->effects.size(); ++effect_num) {
1541                         if (effect_num != 0) {
1542                                 printf(", ");
1543                         }
1544                         printf("%s", phase->effects[effect_num]->effect->effect_type_id().c_str());
1545                 }
1546                 printf("]\n");
1547                 total_time_ms += avg_time_ms;
1548         }
1549         printf("Total:   %5.1f ms\n", total_time_ms);
1550 }
1551
1552 void EffectChain::execute_phase(Phase *phase, bool last_phase, map<Phase *, GLuint> *output_textures, set<Phase *> *generated_mipmaps)
1553 {
1554         GLuint fbo = 0;
1555
1556         // Find a texture for this phase.
1557         inform_input_sizes(phase);
1558         if (!last_phase) {
1559                 find_output_size(phase);
1560
1561                 GLuint tex_num = resource_pool->create_2d_texture(GL_RGBA16F, phase->output_width, phase->output_height);
1562                 output_textures->insert(make_pair(phase, tex_num));
1563         }
1564
1565         const GLuint glsl_program_num = phase->glsl_program_num;
1566         check_error();
1567         glUseProgram(glsl_program_num);
1568         check_error();
1569
1570         // Set up RTT inputs for this phase.
1571         for (unsigned sampler = 0; sampler < phase->inputs.size(); ++sampler) {
1572                 glActiveTexture(GL_TEXTURE0 + sampler);
1573                 Phase *input = phase->inputs[sampler];
1574                 input->output_node->bound_sampler_num = sampler;
1575                 glBindTexture(GL_TEXTURE_2D, (*output_textures)[input]);
1576                 check_error();
1577                 if (phase->input_needs_mipmaps && generated_mipmaps->count(input) == 0) {
1578                         glGenerateMipmap(GL_TEXTURE_2D);
1579                         check_error();
1580                         generated_mipmaps->insert(input);
1581                 }
1582                 setup_rtt_sampler(glsl_program_num, sampler, phase->effect_ids[input->output_node], phase->input_needs_mipmaps);
1583         }
1584
1585         // And now the output. (Already set up for us if it is the last phase.)
1586         if (!last_phase) {
1587                 fbo = resource_pool->create_fbo((*output_textures)[phase]);
1588                 glBindFramebuffer(GL_FRAMEBUFFER, fbo);
1589                 glViewport(0, 0, phase->output_width, phase->output_height);
1590         }
1591
1592         // Give the required parameters to all the effects.
1593         unsigned sampler_num = phase->inputs.size();
1594         for (unsigned i = 0; i < phase->effects.size(); ++i) {
1595                 Node *node = phase->effects[i];
1596                 unsigned old_sampler_num = sampler_num;
1597                 node->effect->set_gl_state(glsl_program_num, phase->effect_ids[node], &sampler_num);
1598                 check_error();
1599
1600                 if (node->effect->is_single_texture()) {
1601                         assert(sampler_num - old_sampler_num == 1);
1602                         node->bound_sampler_num = old_sampler_num;
1603                 } else {
1604                         node->bound_sampler_num = -1;
1605                 }
1606         }
1607
1608         // Now draw!
1609         float vertices[] = {
1610                 0.0f, 1.0f,
1611                 0.0f, 0.0f,
1612                 1.0f, 1.0f,
1613                 1.0f, 0.0f
1614         };
1615
1616         GLuint vao;
1617         glGenVertexArrays(1, &vao);
1618         check_error();
1619         glBindVertexArray(vao);
1620         check_error();
1621
1622         GLuint position_vbo = fill_vertex_attribute(glsl_program_num, "position", 2, GL_FLOAT, sizeof(vertices), vertices);
1623         GLuint texcoord_vbo = fill_vertex_attribute(glsl_program_num, "texcoord", 2, GL_FLOAT, sizeof(vertices), vertices);  // Same as vertices.
1624
1625         glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
1626         check_error();
1627
1628         cleanup_vertex_attribute(glsl_program_num, "position", position_vbo);
1629         cleanup_vertex_attribute(glsl_program_num, "texcoord", texcoord_vbo);
1630
1631         glUseProgram(0);
1632         check_error();
1633
1634         for (unsigned i = 0; i < phase->effects.size(); ++i) {
1635                 Node *node = phase->effects[i];
1636                 node->effect->clear_gl_state();
1637         }
1638
1639         if (!last_phase) {
1640                 resource_pool->release_fbo(fbo);
1641         }
1642
1643         glDeleteVertexArrays(1, &vao);
1644         check_error();
1645 }
1646
1647 void EffectChain::setup_rtt_sampler(GLuint glsl_program_num, int sampler_num, const string &effect_id, bool use_mipmaps)
1648 {
1649         glActiveTexture(GL_TEXTURE0 + sampler_num);
1650         check_error();
1651         if (use_mipmaps) {
1652                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_NEAREST);
1653                 check_error();
1654         } else {
1655                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
1656                 check_error();
1657         }
1658         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
1659         check_error();
1660         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
1661         check_error();
1662
1663         string texture_name = string("tex_") + effect_id;
1664         glUniform1i(glGetUniformLocation(glsl_program_num, texture_name.c_str()), sampler_num);
1665         check_error();
1666 }
1667
1668 }  // namespace movit