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

   1 #define GL_GLEXT_PROTOTYPES 1
   2
   3 #include <GL/glew.h>
   4 #include <assert.h>
   5 #include <locale.h>
   6 #include <math.h>
   7 #include <stddef.h>
   8 #include <stdio.h>
   9 #include <stdlib.h>
  10 #include <string.h>
  11 #include <algorithm>
  12 #include <set>
  13 #include <stack>
  14 #include <utility>
  15 #include <vector>
  16
  17 #include "alpha_division_effect.h"
  18 #include "alpha_multiplication_effect.h"
  19 #include "colorspace_conversion_effect.h"
  20 #include "dither_effect.h"
  21 #include "effect.h"
  22 #include "effect_chain.h"
  23 #include "gamma_compression_effect.h"
  24 #include "gamma_expansion_effect.h"
  25 #include "init.h"
  26 #include "input.h"
  27 #include "resource_pool.h"
  28 #include "util.h"
  29
  30 using namespace std;
  31
  32 namespace movit {
  33
  34 EffectChain::EffectChain(float aspect_nom, float aspect_denom, ResourcePool *resource_pool)
  35         : aspect_nom(aspect_nom),
  36           aspect_denom(aspect_denom),
  37           dither_effect(NULL),
  38           num_dither_bits(0),
  39           finalized(false),
  40           resource_pool(resource_pool) {
  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         for (map<void *, GLuint>::const_iterator fbo_it = fbos.begin();
  63              fbo_it != fbos.end(); ++fbo_it) {
  64                 glDeleteFramebuffers(1, &fbo_it->second);
  65                 check_error();
  66         }
  67 }
  68
  69 Input *EffectChain::add_input(Input *input)
  70 {
  71         assert(!finalized);
  72         inputs.push_back(input);
  73         add_node(input);
  74         return input;
  75 }
  76
  77 void EffectChain::add_output(const ImageFormat &format, OutputAlphaFormat alpha_format)
  78 {
  79         assert(!finalized);
  80         output_format = format;
  81         output_alpha_format = alpha_format;
  82 }
  83
  84 Node *EffectChain::add_node(Effect *effect)
  85 {
  86         for (unsigned i = 0; i < nodes.size(); ++i) {
  87                 assert(nodes[i]->effect != effect);
  88         }
  89
  90         Node *node = new Node;
  91         node->effect = effect;
  92         node->disabled = false;
  93         node->output_color_space = COLORSPACE_INVALID;
  94         node->output_gamma_curve = GAMMA_INVALID;
  95         node->output_alpha_type = ALPHA_INVALID;
  96
  97         nodes.push_back(node);
  98         node_map[effect] = node;
  99         effect->inform_added(this);
 100         return node;
 101 }
 102
 103 void EffectChain::connect_nodes(Node *sender, Node *receiver)
 104 {
 105         sender->outgoing_links.push_back(receiver);
 106         receiver->incoming_links.push_back(sender);
 107 }
 108
 109 void EffectChain::replace_receiver(Node *old_receiver, Node *new_receiver)
 110 {
 111         new_receiver->incoming_links = old_receiver->incoming_links;
 112         old_receiver->incoming_links.clear();
 113
 114         for (unsigned i = 0; i < new_receiver->incoming_links.size(); ++i) {
 115                 Node *sender = new_receiver->incoming_links[i];
 116                 for (unsigned j = 0; j < sender->outgoing_links.size(); ++j) {
 117                         if (sender->outgoing_links[j] == old_receiver) {
 118                                 sender->outgoing_links[j] = new_receiver;
 119                         }
 120                 }
 121         }
 122 }
 123
 124 void EffectChain::replace_sender(Node *old_sender, Node *new_sender)
 125 {
 126         new_sender->outgoing_links = old_sender->outgoing_links;
 127         old_sender->outgoing_links.clear();
 128
 129         for (unsigned i = 0; i < new_sender->outgoing_links.size(); ++i) {
 130                 Node *receiver = new_sender->outgoing_links[i];
 131                 for (unsigned j = 0; j < receiver->incoming_links.size(); ++j) {
 132                         if (receiver->incoming_links[j] == old_sender) {
 133                                 receiver->incoming_links[j] = new_sender;
 134                         }
 135                 }
 136         }
 137 }
 138
 139 void EffectChain::insert_node_between(Node *sender, Node *middle, Node *receiver)
 140 {
 141         for (unsigned i = 0; i < sender->outgoing_links.size(); ++i) {
 142                 if (sender->outgoing_links[i] == receiver) {
 143                         sender->outgoing_links[i] = middle;
 144                         middle->incoming_links.push_back(sender);
 145                 }
 146         }
 147         for (unsigned i = 0; i < receiver->incoming_links.size(); ++i) {
 148                 if (receiver->incoming_links[i] == sender) {
 149                         receiver->incoming_links[i] = middle;
 150                         middle->outgoing_links.push_back(receiver);
 151                 }
 152         }
 153
 154         assert(middle->incoming_links.size() == middle->effect->num_inputs());
 155 }
 156
 157 GLenum EffectChain::get_input_sampler(Node *node, unsigned input_num) const
 158 {
 159         assert(node->effect->needs_texture_bounce());
 160         assert(input_num < node->incoming_links.size());
 161         assert(node->incoming_links[input_num]->bound_sampler_num >= 0);
 162         assert(node->incoming_links[input_num]->bound_sampler_num < 8);
 163         return GL_TEXTURE0 + node->incoming_links[input_num]->bound_sampler_num;
 164 }
 165
 166 void EffectChain::find_all_nonlinear_inputs(Node *node, vector<Node *> *nonlinear_inputs)
 167 {
 168         if (node->output_gamma_curve == GAMMA_LINEAR &&
 169             node->effect->effect_type_id() != "GammaCompressionEffect") {
 170                 return;
 171         }
 172         if (node->effect->num_inputs() == 0) {
 173                 nonlinear_inputs->push_back(node);
 174         } else {
 175                 assert(node->effect->num_inputs() == node->incoming_links.size());
 176                 for (unsigned i = 0; i < node->incoming_links.size(); ++i) {
 177                         find_all_nonlinear_inputs(node->incoming_links[i], nonlinear_inputs);
 178                 }
 179         }
 180 }
 181
 182 Effect *EffectChain::add_effect(Effect *effect, const vector<Effect *> &inputs)
 183 {
 184         assert(!finalized);
 185         assert(inputs.size() == effect->num_inputs());
 186         Node *node = add_node(effect);
 187         for (unsigned i = 0; i < inputs.size(); ++i) {
 188                 assert(node_map.count(inputs[i]) != 0);
 189                 connect_nodes(node_map[inputs[i]], node);
 190         }
 191         return effect;
 192 }
 193
 194 // GLSL pre-1.30 doesn't support token pasting. Replace PREFIX(x) with <effect_id>_x.
 195 string replace_prefix(const string &text, const string &prefix)
 196 {
 197         string output;
 198         size_t start = 0;
 199
 200         while (start < text.size()) {
 201                 size_t pos = text.find("PREFIX(", start);
 202                 if (pos == string::npos) {
 203                         output.append(text.substr(start, string::npos));
 204                         break;
 205                 }
 206
 207                 output.append(text.substr(start, pos - start));
 208                 output.append(prefix);
 209                 output.append("_");
 210
 211                 pos += strlen("PREFIX(");
 212
 213                 // Output stuff until we find the matching ), which we then eat.
 214                 int depth = 1;
 215                 size_t end_arg_pos = pos;
 216                 while (end_arg_pos < text.size()) {
 217                         if (text[end_arg_pos] == '(') {
 218                                 ++depth;
 219                         } else if (text[end_arg_pos] == ')') {
 220                                 --depth;
 221                                 if (depth == 0) {
 222                                         break;
 223                                 }
 224                         }
 225                         ++end_arg_pos;
 226                 }
 227                 output.append(text.substr(pos, end_arg_pos - pos));
 228                 ++end_arg_pos;
 229                 assert(depth == 0);
 230                 start = end_arg_pos;
 231         }
 232         return output;
 233 }
 234
 235 void EffectChain::compile_glsl_program(Phase *phase)
 236 {
 237         string frag_shader = read_file("header.frag");
 238
 239         // Create functions for all the texture inputs that we need.
 240         for (unsigned i = 0; i < phase->inputs.size(); ++i) {
 241                 Node *input = phase->inputs[i]->output_node;
 242                 char effect_id[256];
 243                 sprintf(effect_id, "in%u", i);
 244                 phase->effect_ids.insert(make_pair(input, effect_id));
 245
 246                 frag_shader += string("uniform sampler2D tex_") + effect_id + ";\n";
 247                 frag_shader += string("vec4 ") + effect_id + "(vec2 tc) {\n";
 248                 frag_shader += "\treturn texture2D(tex_" + string(effect_id) + ", tc);\n";
 249                 frag_shader += "}\n";
 250                 frag_shader += "\n";
 251         }
 252
 253         for (unsigned i = 0; i < phase->effects.size(); ++i) {
 254                 Node *node = phase->effects[i];
 255                 char effect_id[256];
 256                 sprintf(effect_id, "eff%u", i);
 257                 phase->effect_ids.insert(make_pair(node, effect_id));
 258
 259                 if (node->incoming_links.size() == 1) {
 260                         frag_shader += string("#define INPUT ") + phase->effect_ids[node->incoming_links[0]] + "\n";
 261                 } else {
 262                         for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
 263                                 char buf[256];
 264                                 sprintf(buf, "#define INPUT%d %s\n", j + 1, phase->effect_ids[node->incoming_links[j]].c_str());
 265                                 frag_shader += buf;
 266                         }
 267                 }
 268
 269                 frag_shader += "\n";
 270                 frag_shader += string("#define FUNCNAME ") + effect_id + "\n";
 271                 frag_shader += replace_prefix(node->effect->output_convenience_uniforms(), effect_id);
 272                 frag_shader += replace_prefix(node->effect->output_fragment_shader(), effect_id);
 273                 frag_shader += "#undef PREFIX\n";
 274                 frag_shader += "#undef FUNCNAME\n";
 275                 if (node->incoming_links.size() == 1) {
 276                         frag_shader += "#undef INPUT\n";
 277                 } else {
 278                         for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
 279                                 char buf[256];
 280                                 sprintf(buf, "#undef INPUT%d\n", j + 1);
 281                                 frag_shader += buf;
 282                         }
 283                 }
 284                 frag_shader += "\n";
 285         }
 286         frag_shader += string("#define INPUT ") + phase->effect_ids[phase->effects.back()] + "\n";
 287         frag_shader.append(read_file("footer.frag"));
 288
 289         phase->glsl_program_num = resource_pool->compile_glsl_program(read_file("vs.vert"), frag_shader);
 290 }
 291
 292 // Construct GLSL programs, starting at the given effect and following
 293 // the chain from there. We end a program every time we come to an effect
 294 // marked as "needs texture bounce", one that is used by multiple other
 295 // effects, every time an effect wants to change the output size,
 296 // and of course at the end.
 297 //
 298 // We follow a quite simple depth-first search from the output, although
 299 // without recursing explicitly within each phase.
 300 Phase *EffectChain::construct_phase(Node *output, map<Node *, Phase *> *completed_effects)
 301 {
 302         if (completed_effects->count(output)) {
 303                 return (*completed_effects)[output];
 304         }
 305
 306         Phase *phase = new Phase;
 307         phase->output_node = output;
 308
 309         // Effects that we have yet to calculate, but that we know should
 310         // be in the current phase.
 311         stack<Node *> effects_todo_this_phase;
 312         effects_todo_this_phase.push(output);
 313
 314         while (!effects_todo_this_phase.empty()) {
 315                 Node *node = effects_todo_this_phase.top();
 316                 effects_todo_this_phase.pop();
 317
 318                 // This should currently only happen for effects that are inputs
 319                 // (either true inputs or phase outputs). We special-case inputs,
 320                 // and then deduplicate phase outputs below.
 321                 if (node->effect->num_inputs() == 0) {
 322                         if (find(phase->effects.begin(), phase->effects.end(), node) != phase->effects.end()) {
 323                                 continue;
 324                         }
 325                 } else {
 326                         assert(completed_effects->count(node) == 0);
 327                 }
 328
 329                 phase->effects.push_back(node);
 330
 331                 // Find all the dependencies of this effect, and add them to the stack.
 332                 vector<Node *> deps = node->incoming_links;
 333                 assert(node->effect->num_inputs() == deps.size());
 334                 for (unsigned i = 0; i < deps.size(); ++i) {
 335                         bool start_new_phase = false;
 336
 337                         if (node->effect->needs_texture_bounce() &&
 338                             !deps[i]->effect->is_single_texture()) {
 339                                 start_new_phase = true;
 340                         }
 341
 342                         if (deps[i]->outgoing_links.size() > 1) {
 343                                 if (!deps[i]->effect->is_single_texture()) {
 344                                         // More than one effect uses this as the input,
 345                                         // and it is not a texture itself.
 346                                         // The easiest thing to do (and probably also the safest
 347                                         // performance-wise in most cases) is to bounce it to a texture
 348                                         // and then let the next passes read from that.
 349                                         start_new_phase = true;
 350                                 } else {
 351                                         assert(deps[i]->effect->num_inputs() == 0);
 352
 353                                         // For textures, we try to be slightly more clever;
 354                                         // if none of our outputs need a bounce, we don't bounce
 355                                         // but instead simply use the effect many times.
 356                                         //
 357                                         // Strictly speaking, we could bounce it for some outputs
 358                                         // and use it directly for others, but the processing becomes
 359                                         // somewhat simpler if the effect is only used in one such way.
 360                                         for (unsigned j = 0; j < deps[i]->outgoing_links.size(); ++j) {
 361                                                 Node *rdep = deps[i]->outgoing_links[j];
 362                                                 start_new_phase |= rdep->effect->needs_texture_bounce();
 363                                         }
 364                                 }
 365                         }
 366
 367                         if (deps[i]->effect->changes_output_size()) {
 368                                 start_new_phase = true;
 369                         }
 370
 371                         if (start_new_phase) {
 372                                 phase->inputs.push_back(construct_phase(deps[i], completed_effects));
 373                         } else {
 374                                 effects_todo_this_phase.push(deps[i]);
 375                         }
 376                 }
 377         }
 378
 379         // No more effects to do this phase. Take all the ones we have,
 380         // and create a GLSL program for it.
 381         assert(!phase->effects.empty());
 382
 383         // Deduplicate the inputs.
 384         sort(phase->inputs.begin(), phase->inputs.end());
 385         phase->inputs.erase(unique(phase->inputs.begin(), phase->inputs.end()), phase->inputs.end());
 386
 387         // We added the effects from the output and back, but we need to output
 388         // them in topological sort order in the shader.
 389         phase->effects = topological_sort(phase->effects);
 390
 391         // Figure out if we need mipmaps or not, and if so, tell the inputs that.
 392         phase->input_needs_mipmaps = false;
 393         for (unsigned i = 0; i < phase->effects.size(); ++i) {
 394                 Node *node = phase->effects[i];
 395                 phase->input_needs_mipmaps |= node->effect->needs_mipmaps();
 396         }
 397         for (unsigned i = 0; i < phase->effects.size(); ++i) {
 398                 Node *node = phase->effects[i];
 399                 if (node->effect->num_inputs() == 0) {
 400                         CHECK(node->effect->set_int("needs_mipmaps", phase->input_needs_mipmaps));
 401                 }
 402         }
 403
 404         // Actually make the shader for this phase.
 405         compile_glsl_program(phase);
 406
 407         assert(completed_effects->count(output) == 0);
 408         completed_effects->insert(make_pair(output, phase));
 409         phases.push_back(phase);
 410         return phase;
 411 }
 412
 413 void EffectChain::output_dot(const char *filename)
 414 {
 415         if (movit_debug_level != MOVIT_DEBUG_ON) {
 416                 return;
 417         }
 418
 419         FILE *fp = fopen(filename, "w");
 420         if (fp == NULL) {
 421                 perror(filename);
 422                 exit(1);
 423         }
 424
 425         fprintf(fp, "digraph G {\n");
 426         fprintf(fp, "  output [shape=box label=\"(output)\"];\n");
 427         for (unsigned i = 0; i < nodes.size(); ++i) {
 428                 // Find out which phase this event belongs to.
 429                 vector<int> in_phases;
 430                 for (unsigned j = 0; j < phases.size(); ++j) {
 431                         const Phase* p = phases[j];
 432                         if (find(p->effects.begin(), p->effects.end(), nodes[i]) != p->effects.end()) {
 433                                 in_phases.push_back(j);
 434                         }
 435                 }
 436
 437                 if (in_phases.empty()) {
 438                         fprintf(fp, "  n%ld [label=\"%s\"];\n", (long)nodes[i], nodes[i]->effect->effect_type_id().c_str());
 439                 } else if (in_phases.size() == 1) {
 440                         fprintf(fp, "  n%ld [label=\"%s\" style=\"filled\" fillcolor=\"/accent8/%d\"];\n",
 441                                 (long)nodes[i], nodes[i]->effect->effect_type_id().c_str(),
 442                                 (in_phases[0] % 8) + 1);
 443                 } else {
 444                         // If we had new enough Graphviz, style="wedged" would probably be ideal here.
 445                         // But alas.
 446                         fprintf(fp, "  n%ld [label=\"%s [in multiple phases]\" style=\"filled\" fillcolor=\"/accent8/%d\"];\n",
 447                                 (long)nodes[i], nodes[i]->effect->effect_type_id().c_str(),
 448                                 (in_phases[0] % 8) + 1);
 449                 }
 450
 451                 char from_node_id[256];
 452                 snprintf(from_node_id, 256, "n%ld", (long)nodes[i]);
 453
 454                 for (unsigned j = 0; j < nodes[i]->outgoing_links.size(); ++j) {
 455                         char to_node_id[256];
 456                         snprintf(to_node_id, 256, "n%ld", (long)nodes[i]->outgoing_links[j]);
 457
 458                         vector<string> labels = get_labels_for_edge(nodes[i], nodes[i]->outgoing_links[j]);
 459                         output_dot_edge(fp, from_node_id, to_node_id, labels);
 460                 }
 461
 462                 if (nodes[i]->outgoing_links.empty() && !nodes[i]->disabled) {
 463                         // Output node.
 464                         vector<string> labels = get_labels_for_edge(nodes[i], NULL);
 465                         output_dot_edge(fp, from_node_id, "output", labels);
 466                 }
 467         }
 468         fprintf(fp, "}\n");
 469
 470         fclose(fp);
 471 }
 472
 473 vector<string> EffectChain::get_labels_for_edge(const Node *from, const Node *to)
 474 {
 475         vector<string> labels;
 476
 477         if (to != NULL && to->effect->needs_texture_bounce()) {
 478                 labels.push_back("needs_bounce");
 479         }
 480         if (from->effect->changes_output_size()) {
 481                 labels.push_back("resize");
 482         }
 483
 484         switch (from->output_color_space) {
 485         case COLORSPACE_INVALID:
 486                 labels.push_back("spc[invalid]");
 487                 break;
 488         case COLORSPACE_REC_601_525:
 489                 labels.push_back("spc[rec601-525]");
 490                 break;
 491         case COLORSPACE_REC_601_625:
 492                 labels.push_back("spc[rec601-625]");
 493                 break;
 494         default:
 495                 break;
 496         }
 497
 498         switch (from->output_gamma_curve) {
 499         case GAMMA_INVALID:
 500                 labels.push_back("gamma[invalid]");
 501                 break;
 502         case GAMMA_sRGB:
 503                 labels.push_back("gamma[sRGB]");
 504                 break;
 505         case GAMMA_REC_601:  // and GAMMA_REC_709
 506                 labels.push_back("gamma[rec601/709]");
 507                 break;
 508         default:
 509                 break;
 510         }
 511
 512         switch (from->output_alpha_type) {
 513         case ALPHA_INVALID:
 514                 labels.push_back("alpha[invalid]");
 515                 break;
 516         case ALPHA_BLANK:
 517                 labels.push_back("alpha[blank]");
 518                 break;
 519         case ALPHA_POSTMULTIPLIED:
 520                 labels.push_back("alpha[postmult]");
 521                 break;
 522         default:
 523                 break;
 524         }
 525
 526         return labels;
 527 }
 528
 529 void EffectChain::output_dot_edge(FILE *fp,
 530                                   const string &from_node_id,
 531                                   const string &to_node_id,
 532                                   const vector<string> &labels)
 533 {
 534         if (labels.empty()) {
 535                 fprintf(fp, "  %s -> %s;\n", from_node_id.c_str(), to_node_id.c_str());
 536         } else {
 537                 string label = labels[0];
 538                 for (unsigned k = 1; k < labels.size(); ++k) {
 539                         label += ", " + labels[k];
 540                 }
 541                 fprintf(fp, "  %s -> %s [label=\"%s\"];\n", from_node_id.c_str(), to_node_id.c_str(), label.c_str());
 542         }
 543 }
 544
 545 void EffectChain::size_rectangle_to_fit(unsigned width, unsigned height, unsigned *output_width, unsigned *output_height)
 546 {
 547         unsigned scaled_width, scaled_height;
 548
 549         if (float(width) * aspect_denom >= float(height) * aspect_nom) {
 550                 // Same aspect, or W/H > aspect (image is wider than the frame).
 551                 // In either case, keep width, and adjust height.
 552                 scaled_width = width;
 553                 scaled_height = lrintf(width * aspect_denom / aspect_nom);
 554         } else {
 555                 // W/H < aspect (image is taller than the frame), so keep height,
 556                 // and adjust width.
 557                 scaled_width = lrintf(height * aspect_nom / aspect_denom);
 558                 scaled_height = height;
 559         }
 560
 561         // We should be consistently larger or smaller then the existing choice,
 562         // since we have the same aspect.
 563         assert(!(scaled_width < *output_width && scaled_height > *output_height));
 564         assert(!(scaled_height < *output_height && scaled_width > *output_width));
 565
 566         if (scaled_width >= *output_width && scaled_height >= *output_height) {
 567                 *output_width = scaled_width;
 568                 *output_height = scaled_height;
 569         }
 570 }
 571
 572 // Propagate input texture sizes throughout, and inform effects downstream.
 573 // (Like a lot of other code, we depend on effects being in topological order.)
 574 void EffectChain::inform_input_sizes(Phase *phase)
 575 {
 576         // All effects that have a defined size (inputs and RTT inputs)
 577         // get that. Reset all others.
 578         for (unsigned i = 0; i < phase->effects.size(); ++i) {
 579                 Node *node = phase->effects[i];
 580                 if (node->effect->num_inputs() == 0) {
 581                         Input *input = static_cast<Input *>(node->effect);
 582                         node->output_width = input->get_width();
 583                         node->output_height = input->get_height();
 584                         assert(node->output_width != 0);
 585                         assert(node->output_height != 0);
 586                 } else {
 587                         node->output_width = node->output_height = 0;
 588                 }
 589         }
 590         for (unsigned i = 0; i < phase->inputs.size(); ++i) {
 591                 Phase *input = phase->inputs[i];
 592                 input->output_node->output_width = input->virtual_output_width;
 593                 input->output_node->output_height = input->virtual_output_height;
 594                 assert(input->output_node->output_width != 0);
 595                 assert(input->output_node->output_height != 0);
 596         }
 597
 598         // Now propagate from the inputs towards the end, and inform as we go.
 599         // The rules are simple:
 600         //
 601         //   1. Don't touch effects that already have given sizes (ie., inputs).
 602         //   2. If all of your inputs have the same size, that will be your output size.
 603         //   3. Otherwise, your output size is 0x0.
 604         for (unsigned i = 0; i < phase->effects.size(); ++i) {
 605                 Node *node = phase->effects[i];
 606                 if (node->effect->num_inputs() == 0) {
 607                         continue;
 608                 }
 609                 unsigned this_output_width = 0;
 610                 unsigned this_output_height = 0;
 611                 for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
 612                         Node *input = node->incoming_links[j];
 613                         node->effect->inform_input_size(j, input->output_width, input->output_height);
 614                         if (j == 0) {
 615                                 this_output_width = input->output_width;
 616                                 this_output_height = input->output_height;
 617                         } else if (input->output_width != this_output_width || input->output_height != this_output_height) {
 618                                 // Inputs disagree.
 619                                 this_output_width = 0;
 620                                 this_output_height = 0;
 621                         }
 622                 }
 623                 node->output_width = this_output_width;
 624                 node->output_height = this_output_height;
 625         }
 626 }
 627
 628 // Note: You should call inform_input_sizes() before this, as the last effect's
 629 // desired output size might change based on the inputs.
 630 void EffectChain::find_output_size(Phase *phase)
 631 {
 632         Node *output_node = phase->effects.back();
 633
 634         // If the last effect explicitly sets an output size, use that.
 635         if (output_node->effect->changes_output_size()) {
 636                 output_node->effect->get_output_size(&phase->output_width, &phase->output_height,
 637                                                      &phase->virtual_output_width, &phase->virtual_output_height);
 638                 return;
 639         }
 640
 641         // If all effects have the same size, use that.
 642         unsigned output_width = 0, output_height = 0;
 643         bool all_inputs_same_size = true;
 644
 645         for (unsigned i = 0; i < phase->inputs.size(); ++i) {
 646                 Phase *input = phase->inputs[i];
 647                 assert(input->output_width != 0);
 648                 assert(input->output_height != 0);
 649                 if (output_width == 0 && output_height == 0) {
 650                         output_width = input->virtual_output_width;
 651                         output_height = input->virtual_output_height;
 652                 } else if (output_width != input->virtual_output_width ||
 653                            output_height != input->virtual_output_height) {
 654                         all_inputs_same_size = false;
 655                 }
 656         }
 657         for (unsigned i = 0; i < phase->effects.size(); ++i) {
 658                 Effect *effect = phase->effects[i]->effect;
 659                 if (effect->num_inputs() != 0) {
 660                         continue;
 661                 }
 662
 663                 Input *input = static_cast<Input *>(effect);
 664                 if (output_width == 0 && output_height == 0) {
 665                         output_width = input->get_width();
 666                         output_height = input->get_height();
 667                 } else if (output_width != input->get_width() ||
 668                            output_height != input->get_height()) {
 669                         all_inputs_same_size = false;
 670                 }
 671         }
 672
 673         if (all_inputs_same_size) {
 674                 assert(output_width != 0);
 675                 assert(output_height != 0);
 676                 phase->virtual_output_width = phase->output_width = output_width;
 677                 phase->virtual_output_height = phase->output_height = output_height;
 678                 return;
 679         }
 680
 681         // If not, fit all the inputs into the current aspect, and select the largest one.
 682         output_width = 0;
 683         output_height = 0;
 684         for (unsigned i = 0; i < phase->inputs.size(); ++i) {
 685                 Phase *input = phase->inputs[i];
 686                 assert(input->output_width != 0);
 687                 assert(input->output_height != 0);
 688                 size_rectangle_to_fit(input->output_width, input->output_height, &output_width, &output_height);
 689         }
 690         for (unsigned i = 0; i < phase->effects.size(); ++i) {
 691                 Effect *effect = phase->effects[i]->effect;
 692                 if (effect->num_inputs() != 0) {
 693                         continue;
 694                 }
 695
 696                 Input *input = static_cast<Input *>(effect);
 697                 size_rectangle_to_fit(input->get_width(), input->get_height(), &output_width, &output_height);
 698         }
 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 }
 704
 705 void EffectChain::sort_all_nodes_topologically()
 706 {
 707         nodes = topological_sort(nodes);
 708 }
 709
 710 vector<Node *> EffectChain::topological_sort(const vector<Node *> &nodes)
 711 {
 712         set<Node *> nodes_left_to_visit(nodes.begin(), nodes.end());
 713         vector<Node *> sorted_list;
 714         for (unsigned i = 0; i < nodes.size(); ++i) {
 715                 topological_sort_visit_node(nodes[i], &nodes_left_to_visit, &sorted_list);
 716         }
 717         reverse(sorted_list.begin(), sorted_list.end());
 718         return sorted_list;
 719 }
 720
 721 void EffectChain::topological_sort_visit_node(Node *node, set<Node *> *nodes_left_to_visit, vector<Node *> *sorted_list)
 722 {
 723         if (nodes_left_to_visit->count(node) == 0) {
 724                 return;
 725         }
 726         nodes_left_to_visit->erase(node);
 727         for (unsigned i = 0; i < node->outgoing_links.size(); ++i) {
 728                 topological_sort_visit_node(node->outgoing_links[i], nodes_left_to_visit, sorted_list);
 729         }
 730         sorted_list->push_back(node);
 731 }
 732
 733 void EffectChain::find_color_spaces_for_inputs()
 734 {
 735         for (unsigned i = 0; i < nodes.size(); ++i) {
 736                 Node *node = nodes[i];
 737                 if (node->disabled) {
 738                         continue;
 739                 }
 740                 if (node->incoming_links.size() == 0) {
 741                         Input *input = static_cast<Input *>(node->effect);
 742                         node->output_color_space = input->get_color_space();
 743                         node->output_gamma_curve = input->get_gamma_curve();
 744
 745                         Effect::AlphaHandling alpha_handling = input->alpha_handling();
 746                         switch (alpha_handling) {
 747                         case Effect::OUTPUT_BLANK_ALPHA:
 748                                 node->output_alpha_type = ALPHA_BLANK;
 749                                 break;
 750                         case Effect::INPUT_AND_OUTPUT_PREMULTIPLIED_ALPHA:
 751                                 node->output_alpha_type = ALPHA_PREMULTIPLIED;
 752                                 break;
 753                         case Effect::OUTPUT_POSTMULTIPLIED_ALPHA:
 754                                 node->output_alpha_type = ALPHA_POSTMULTIPLIED;
 755                                 break;
 756                         case Effect::INPUT_PREMULTIPLIED_ALPHA_KEEP_BLANK:
 757                         case Effect::DONT_CARE_ALPHA_TYPE:
 758                         default:
 759                                 assert(false);
 760                         }
 761
 762                         if (node->output_alpha_type == ALPHA_PREMULTIPLIED) {
 763                                 assert(node->output_gamma_curve == GAMMA_LINEAR);
 764                         }
 765                 }
 766         }
 767 }
 768
 769 // Propagate gamma and color space information as far as we can in the graph.
 770 // The rules are simple: Anything where all the inputs agree, get that as
 771 // output as well. Anything else keeps having *_INVALID.
 772 void EffectChain::propagate_gamma_and_color_space()
 773 {
 774         // We depend on going through the nodes in order.
 775         sort_all_nodes_topologically();
 776
 777         for (unsigned i = 0; i < nodes.size(); ++i) {
 778                 Node *node = nodes[i];
 779                 if (node->disabled) {
 780                         continue;
 781                 }
 782                 assert(node->incoming_links.size() == node->effect->num_inputs());
 783                 if (node->incoming_links.size() == 0) {
 784                         assert(node->output_color_space != COLORSPACE_INVALID);
 785                         assert(node->output_gamma_curve != GAMMA_INVALID);
 786                         continue;
 787                 }
 788
 789                 Colorspace color_space = node->incoming_links[0]->output_color_space;
 790                 GammaCurve gamma_curve = node->incoming_links[0]->output_gamma_curve;
 791                 for (unsigned j = 1; j < node->incoming_links.size(); ++j) {
 792                         if (node->incoming_links[j]->output_color_space != color_space) {
 793                                 color_space = COLORSPACE_INVALID;
 794                         }
 795                         if (node->incoming_links[j]->output_gamma_curve != gamma_curve) {
 796                                 gamma_curve = GAMMA_INVALID;
 797                         }
 798                 }
 799
 800                 // The conversion effects already have their outputs set correctly,
 801                 // so leave them alone.
 802                 if (node->effect->effect_type_id() != "ColorspaceConversionEffect") {
 803                         node->output_color_space = color_space;
 804                 }
 805                 if (node->effect->effect_type_id() != "GammaCompressionEffect" &&
 806                     node->effect->effect_type_id() != "GammaExpansionEffect") {
 807                         node->output_gamma_curve = gamma_curve;
 808                 }
 809         }
 810 }
 811
 812 // Propagate alpha information as far as we can in the graph.
 813 // Similar to propagate_gamma_and_color_space().
 814 void EffectChain::propagate_alpha()
 815 {
 816         // We depend on going through the nodes in order.
 817         sort_all_nodes_topologically();
 818
 819         for (unsigned i = 0; i < nodes.size(); ++i) {
 820                 Node *node = nodes[i];
 821                 if (node->disabled) {
 822                         continue;
 823                 }
 824                 assert(node->incoming_links.size() == node->effect->num_inputs());
 825                 if (node->incoming_links.size() == 0) {
 826                         assert(node->output_alpha_type != ALPHA_INVALID);
 827                         continue;
 828                 }
 829
 830                 // The alpha multiplication/division effects are special cases.
 831                 if (node->effect->effect_type_id() == "AlphaMultiplicationEffect") {
 832                         assert(node->incoming_links.size() == 1);
 833                         assert(node->incoming_links[0]->output_alpha_type == ALPHA_POSTMULTIPLIED);
 834                         node->output_alpha_type = ALPHA_PREMULTIPLIED;
 835                         continue;
 836                 }
 837                 if (node->effect->effect_type_id() == "AlphaDivisionEffect") {
 838                         assert(node->incoming_links.size() == 1);
 839                         assert(node->incoming_links[0]->output_alpha_type == ALPHA_PREMULTIPLIED);
 840                         node->output_alpha_type = ALPHA_POSTMULTIPLIED;
 841                         continue;
 842                 }
 843
 844                 // GammaCompressionEffect and GammaExpansionEffect are also a special case,
 845                 // because they are the only one that _need_ postmultiplied alpha.
 846                 if (node->effect->effect_type_id() == "GammaCompressionEffect" ||
 847                     node->effect->effect_type_id() == "GammaExpansionEffect") {
 848                         assert(node->incoming_links.size() == 1);
 849                         if (node->incoming_links[0]->output_alpha_type == ALPHA_BLANK) {
 850                                 node->output_alpha_type = ALPHA_BLANK;
 851                         } else if (node->incoming_links[0]->output_alpha_type == ALPHA_POSTMULTIPLIED) {
 852                                 node->output_alpha_type = ALPHA_POSTMULTIPLIED;
 853                         } else {
 854                                 node->output_alpha_type = ALPHA_INVALID;
 855                         }
 856                         continue;
 857                 }
 858
 859                 // Only inputs can have unconditional alpha output (OUTPUT_BLANK_ALPHA
 860                 // or OUTPUT_POSTMULTIPLIED_ALPHA), and they have already been
 861                 // taken care of above. Rationale: Even if you could imagine
 862                 // e.g. an effect that took in an image and set alpha=1.0
 863                 // unconditionally, it wouldn't make any sense to have it as
 864                 // e.g. OUTPUT_BLANK_ALPHA, since it wouldn't know whether it
 865                 // got its input pre- or postmultiplied, so it wouldn't know
 866                 // whether to divide away the old alpha or not.
 867                 Effect::AlphaHandling alpha_handling = node->effect->alpha_handling();
 868                 assert(alpha_handling == Effect::INPUT_AND_OUTPUT_PREMULTIPLIED_ALPHA ||
 869                        alpha_handling == Effect::INPUT_PREMULTIPLIED_ALPHA_KEEP_BLANK ||
 870                        alpha_handling == Effect::DONT_CARE_ALPHA_TYPE);
 871
 872                 // If the node has multiple inputs, check that they are all valid and
 873                 // the same.
 874                 bool any_invalid = false;
 875                 bool any_premultiplied = false;
 876                 bool any_postmultiplied = false;
 877
 878                 for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
 879                         switch (node->incoming_links[j]->output_alpha_type) {
 880                         case ALPHA_INVALID:
 881                                 any_invalid = true;
 882                                 break;
 883                         case ALPHA_BLANK:
 884                                 // Blank is good as both pre- and postmultiplied alpha,
 885                                 // so just ignore it.
 886                                 break;
 887                         case ALPHA_PREMULTIPLIED:
 888                                 any_premultiplied = true;
 889                                 break;
 890                         case ALPHA_POSTMULTIPLIED:
 891                                 any_postmultiplied = true;
 892                                 break;
 893                         default:
 894                                 assert(false);
 895                         }
 896                 }
 897
 898                 if (any_invalid) {
 899                         node->output_alpha_type = ALPHA_INVALID;
 900                         continue;
 901                 }
 902
 903                 // Inputs must be of the same type.
 904                 if (any_premultiplied && any_postmultiplied) {
 905                         node->output_alpha_type = ALPHA_INVALID;
 906                         continue;
 907                 }
 908
 909                 if (alpha_handling == Effect::INPUT_AND_OUTPUT_PREMULTIPLIED_ALPHA ||
 910                     alpha_handling == Effect::INPUT_PREMULTIPLIED_ALPHA_KEEP_BLANK) {
 911                         // If the effect has asked for premultiplied alpha, check that it has got it.
 912                         if (any_postmultiplied) {
 913                                 node->output_alpha_type = ALPHA_INVALID;
 914                         } else if (!any_premultiplied &&
 915                                    alpha_handling == Effect::INPUT_PREMULTIPLIED_ALPHA_KEEP_BLANK) {
 916                                 // Blank input alpha, and the effect preserves blank alpha.
 917                                 node->output_alpha_type = ALPHA_BLANK;
 918                         } else {
 919                                 node->output_alpha_type = ALPHA_PREMULTIPLIED;
 920                         }
 921                 } else {
 922                         // OK, all inputs are the same, and this effect is not going
 923                         // to change it.
 924                         assert(alpha_handling == Effect::DONT_CARE_ALPHA_TYPE);
 925                         if (any_premultiplied) {
 926                                 node->output_alpha_type = ALPHA_PREMULTIPLIED;
 927                         } else if (any_postmultiplied) {
 928                                 node->output_alpha_type = ALPHA_POSTMULTIPLIED;
 929                         } else {
 930                                 node->output_alpha_type = ALPHA_BLANK;
 931                         }
 932                 }
 933         }
 934 }
 935
 936 bool EffectChain::node_needs_colorspace_fix(Node *node)
 937 {
 938         if (node->disabled) {
 939                 return false;
 940         }
 941         if (node->effect->num_inputs() == 0) {
 942                 return false;
 943         }
 944
 945         // propagate_gamma_and_color_space() has already set our output
 946         // to COLORSPACE_INVALID if the inputs differ, so we can rely on that.
 947         if (node->output_color_space == COLORSPACE_INVALID) {
 948                 return true;
 949         }
 950         return (node->effect->needs_srgb_primaries() && node->output_color_space != COLORSPACE_sRGB);
 951 }
 952
 953 // Fix up color spaces so that there are no COLORSPACE_INVALID nodes left in
 954 // the graph. Our strategy is not always optimal, but quite simple:
 955 // Find an effect that's as early as possible where the inputs are of
 956 // unacceptable colorspaces (that is, either different, or, if the effect only
 957 // wants sRGB, not sRGB.) Add appropriate conversions on all its inputs,
 958 // propagate the information anew, and repeat until there are no more such
 959 // effects.
 960 void EffectChain::fix_internal_color_spaces()
 961 {
 962         unsigned colorspace_propagation_pass = 0;
 963         bool found_any;
 964         do {
 965                 found_any = false;
 966                 for (unsigned i = 0; i < nodes.size(); ++i) {
 967                         Node *node = nodes[i];
 968                         if (!node_needs_colorspace_fix(node)) {
 969                                 continue;
 970                         }
 971
 972                         // Go through each input that is not sRGB, and insert
 973                         // a colorspace conversion after it.
 974                         for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
 975                                 Node *input = node->incoming_links[j];
 976                                 assert(input->output_color_space != COLORSPACE_INVALID);
 977                                 if (input->output_color_space == COLORSPACE_sRGB) {
 978                                         continue;
 979                                 }
 980                                 Node *conversion = add_node(new ColorspaceConversionEffect());
 981                                 CHECK(conversion->effect->set_int("source_space", input->output_color_space));
 982                                 CHECK(conversion->effect->set_int("destination_space", COLORSPACE_sRGB));
 983                                 conversion->output_color_space = COLORSPACE_sRGB;
 984                                 replace_sender(input, conversion);
 985                                 connect_nodes(input, conversion);
 986                         }
 987
 988                         // Re-sort topologically, and propagate the new information.
 989                         propagate_gamma_and_color_space();
 990
 991                         found_any = true;
 992                         break;
 993                 }
 994
 995                 char filename[256];
 996                 sprintf(filename, "step5-colorspacefix-iter%u.dot", ++colorspace_propagation_pass);
 997                 output_dot(filename);
 998                 assert(colorspace_propagation_pass < 100);
 999         } while (found_any);
1000
1001         for (unsigned i = 0; i < nodes.size(); ++i) {
1002                 Node *node = nodes[i];
1003                 if (node->disabled) {
1004                         continue;
1005                 }
1006                 assert(node->output_color_space != COLORSPACE_INVALID);
1007         }
1008 }
1009
1010 bool EffectChain::node_needs_alpha_fix(Node *node)
1011 {
1012         if (node->disabled) {
1013                 return false;
1014         }
1015
1016         // propagate_alpha() has already set our output to ALPHA_INVALID if the
1017         // inputs differ or we are otherwise in mismatch, so we can rely on that.
1018         return (node->output_alpha_type == ALPHA_INVALID);
1019 }
1020
1021 // Fix up alpha so that there are no ALPHA_INVALID nodes left in
1022 // the graph. Similar to fix_internal_color_spaces().
1023 void EffectChain::fix_internal_alpha(unsigned step)
1024 {
1025         unsigned alpha_propagation_pass = 0;
1026         bool found_any;
1027         do {
1028                 found_any = false;
1029                 for (unsigned i = 0; i < nodes.size(); ++i) {
1030                         Node *node = nodes[i];
1031                         if (!node_needs_alpha_fix(node)) {
1032                                 continue;
1033                         }
1034
1035                         // If we need to fix up GammaExpansionEffect, then clearly something
1036                         // is wrong, since the combination of premultiplied alpha and nonlinear inputs
1037                         // is meaningless.
1038                         assert(node->effect->effect_type_id() != "GammaExpansionEffect");
1039
1040                         AlphaType desired_type = ALPHA_PREMULTIPLIED;
1041
1042                         // GammaCompressionEffect is special; it needs postmultiplied alpha.
1043                         if (node->effect->effect_type_id() == "GammaCompressionEffect") {
1044                                 assert(node->incoming_links.size() == 1);
1045                                 assert(node->incoming_links[0]->output_alpha_type == ALPHA_PREMULTIPLIED);
1046                                 desired_type = ALPHA_POSTMULTIPLIED;
1047                         }
1048
1049                         // Go through each input that is not premultiplied alpha, and insert
1050                         // a conversion before it.
1051                         for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
1052                                 Node *input = node->incoming_links[j];
1053                                 assert(input->output_alpha_type != ALPHA_INVALID);
1054                                 if (input->output_alpha_type == desired_type ||
1055                                     input->output_alpha_type == ALPHA_BLANK) {
1056                                         continue;
1057                                 }
1058                                 Node *conversion;
1059                                 if (desired_type == ALPHA_PREMULTIPLIED) {
1060                                         conversion = add_node(new AlphaMultiplicationEffect());
1061                                 } else {
1062                                         conversion = add_node(new AlphaDivisionEffect());
1063                                 }
1064                                 conversion->output_alpha_type = desired_type;
1065                                 replace_sender(input, conversion);
1066                                 connect_nodes(input, conversion);
1067                         }
1068
1069                         // Re-sort topologically, and propagate the new information.
1070                         propagate_gamma_and_color_space();
1071                         propagate_alpha();
1072
1073                         found_any = true;
1074                         break;
1075                 }
1076
1077                 char filename[256];
1078                 sprintf(filename, "step%u-alphafix-iter%u.dot", step, ++alpha_propagation_pass);
1079                 output_dot(filename);
1080                 assert(alpha_propagation_pass < 100);
1081         } while (found_any);
1082
1083         for (unsigned i = 0; i < nodes.size(); ++i) {
1084                 Node *node = nodes[i];
1085                 if (node->disabled) {
1086                         continue;
1087                 }
1088                 assert(node->output_alpha_type != ALPHA_INVALID);
1089         }
1090 }
1091
1092 // Make so that the output is in the desired color space.
1093 void EffectChain::fix_output_color_space()
1094 {
1095         Node *output = find_output_node();
1096         if (output->output_color_space != output_format.color_space) {
1097                 Node *conversion = add_node(new ColorspaceConversionEffect());
1098                 CHECK(conversion->effect->set_int("source_space", output->output_color_space));
1099                 CHECK(conversion->effect->set_int("destination_space", output_format.color_space));
1100                 conversion->output_color_space = output_format.color_space;
1101                 connect_nodes(output, conversion);
1102                 propagate_alpha();
1103                 propagate_gamma_and_color_space();
1104         }
1105 }
1106
1107 // Make so that the output is in the desired pre-/postmultiplication alpha state.
1108 void EffectChain::fix_output_alpha()
1109 {
1110         Node *output = find_output_node();
1111         assert(output->output_alpha_type != ALPHA_INVALID);
1112         if (output->output_alpha_type == ALPHA_BLANK) {
1113                 // No alpha output, so we don't care.
1114                 return;
1115         }
1116         if (output->output_alpha_type == ALPHA_PREMULTIPLIED &&
1117             output_alpha_format == OUTPUT_ALPHA_FORMAT_POSTMULTIPLIED) {
1118                 Node *conversion = add_node(new AlphaDivisionEffect());
1119                 connect_nodes(output, conversion);
1120                 propagate_alpha();
1121                 propagate_gamma_and_color_space();
1122         }
1123         if (output->output_alpha_type == ALPHA_POSTMULTIPLIED &&
1124             output_alpha_format == OUTPUT_ALPHA_FORMAT_PREMULTIPLIED) {
1125                 Node *conversion = add_node(new AlphaMultiplicationEffect());
1126                 connect_nodes(output, conversion);
1127                 propagate_alpha();
1128                 propagate_gamma_and_color_space();
1129         }
1130 }
1131
1132 bool EffectChain::node_needs_gamma_fix(Node *node)
1133 {
1134         if (node->disabled) {
1135                 return false;
1136         }
1137
1138         // Small hack since the output is not an explicit node:
1139         // If we are the last node and our output is in the wrong
1140         // space compared to EffectChain's output, we need to fix it.
1141         // This will only take us to linear, but fix_output_gamma()
1142         // will come and take us to the desired output gamma
1143         // if it is needed.
1144         //
1145         // This needs to be before everything else, since it could
1146         // even apply to inputs (if they are the only effect).
1147         if (node->outgoing_links.empty() &&
1148             node->output_gamma_curve != output_format.gamma_curve &&
1149             node->output_gamma_curve != GAMMA_LINEAR) {
1150                 return true;
1151         }
1152
1153         if (node->effect->num_inputs() == 0) {
1154                 return false;
1155         }
1156
1157         // propagate_gamma_and_color_space() has already set our output
1158         // to GAMMA_INVALID if the inputs differ, so we can rely on that,
1159         // except for GammaCompressionEffect.
1160         if (node->output_gamma_curve == GAMMA_INVALID) {
1161                 return true;
1162         }
1163         if (node->effect->effect_type_id() == "GammaCompressionEffect") {
1164                 assert(node->incoming_links.size() == 1);
1165                 return node->incoming_links[0]->output_gamma_curve != GAMMA_LINEAR;
1166         }
1167
1168         return (node->effect->needs_linear_light() && node->output_gamma_curve != GAMMA_LINEAR);
1169 }
1170
1171 // Very similar to fix_internal_color_spaces(), but for gamma.
1172 // There is one difference, though; before we start adding conversion nodes,
1173 // we see if we can get anything out of asking the sources to deliver
1174 // linear gamma directly. fix_internal_gamma_by_asking_inputs()
1175 // does that part, while fix_internal_gamma_by_inserting_nodes()
1176 // inserts nodes as needed afterwards.
1177 void EffectChain::fix_internal_gamma_by_asking_inputs(unsigned step)
1178 {
1179         unsigned gamma_propagation_pass = 0;
1180         bool found_any;
1181         do {
1182                 found_any = false;
1183                 for (unsigned i = 0; i < nodes.size(); ++i) {
1184                         Node *node = nodes[i];
1185                         if (!node_needs_gamma_fix(node)) {
1186                                 continue;
1187                         }
1188
1189                         // See if all inputs can give us linear gamma. If not, leave it.
1190                         vector<Node *> nonlinear_inputs;
1191                         find_all_nonlinear_inputs(node, &nonlinear_inputs);
1192                         assert(!nonlinear_inputs.empty());
1193
1194                         bool all_ok = true;
1195                         for (unsigned i = 0; i < nonlinear_inputs.size(); ++i) {
1196                                 Input *input = static_cast<Input *>(nonlinear_inputs[i]->effect);
1197                                 all_ok &= input->can_output_linear_gamma();
1198                         }
1199
1200                         if (!all_ok) {
1201                                 continue;
1202                         }
1203
1204                         for (unsigned i = 0; i < nonlinear_inputs.size(); ++i) {
1205                                 CHECK(nonlinear_inputs[i]->effect->set_int("output_linear_gamma", 1));
1206                                 nonlinear_inputs[i]->output_gamma_curve = GAMMA_LINEAR;
1207                         }
1208
1209                         // Re-sort topologically, and propagate the new information.
1210                         propagate_gamma_and_color_space();
1211
1212                         found_any = true;
1213                         break;
1214                 }
1215
1216                 char filename[256];
1217                 sprintf(filename, "step%u-gammafix-iter%u.dot", step, ++gamma_propagation_pass);
1218                 output_dot(filename);
1219                 assert(gamma_propagation_pass < 100);
1220         } while (found_any);
1221 }
1222
1223 void EffectChain::fix_internal_gamma_by_inserting_nodes(unsigned step)
1224 {
1225         unsigned gamma_propagation_pass = 0;
1226         bool found_any;
1227         do {
1228                 found_any = false;
1229                 for (unsigned i = 0; i < nodes.size(); ++i) {
1230                         Node *node = nodes[i];
1231                         if (!node_needs_gamma_fix(node)) {
1232                                 continue;
1233                         }
1234
1235                         // Special case: We could be an input and still be asked to
1236                         // fix our gamma; if so, we should be the only node
1237                         // (as node_needs_gamma_fix() would only return true in
1238                         // for an input in that case). That means we should insert
1239                         // a conversion node _after_ ourselves.
1240                         if (node->incoming_links.empty()) {
1241                                 assert(node->outgoing_links.empty());
1242                                 Node *conversion = add_node(new GammaExpansionEffect());
1243                                 CHECK(conversion->effect->set_int("source_curve", node->output_gamma_curve));
1244                                 conversion->output_gamma_curve = GAMMA_LINEAR;
1245                                 connect_nodes(node, conversion);
1246                         }
1247
1248                         // If not, go through each input that is not linear gamma,
1249                         // and insert a gamma conversion after it.
1250                         for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
1251                                 Node *input = node->incoming_links[j];
1252                                 assert(input->output_gamma_curve != GAMMA_INVALID);
1253                                 if (input->output_gamma_curve == GAMMA_LINEAR) {
1254                                         continue;
1255                                 }
1256                                 Node *conversion = add_node(new GammaExpansionEffect());
1257                                 CHECK(conversion->effect->set_int("source_curve", input->output_gamma_curve));
1258                                 conversion->output_gamma_curve = GAMMA_LINEAR;
1259                                 replace_sender(input, conversion);
1260                                 connect_nodes(input, conversion);
1261                         }
1262
1263                         // Re-sort topologically, and propagate the new information.
1264                         propagate_alpha();
1265                         propagate_gamma_and_color_space();
1266
1267                         found_any = true;
1268                         break;
1269                 }
1270
1271                 char filename[256];
1272                 sprintf(filename, "step%u-gammafix-iter%u.dot", step, ++gamma_propagation_pass);
1273                 output_dot(filename);
1274                 assert(gamma_propagation_pass < 100);
1275         } while (found_any);
1276
1277         for (unsigned i = 0; i < nodes.size(); ++i) {
1278                 Node *node = nodes[i];
1279                 if (node->disabled) {
1280                         continue;
1281                 }
1282                 assert(node->output_gamma_curve != GAMMA_INVALID);
1283         }
1284 }
1285
1286 // Make so that the output is in the desired gamma.
1287 // Note that this assumes linear input gamma, so it might create the need
1288 // for another pass of fix_internal_gamma().
1289 void EffectChain::fix_output_gamma()
1290 {
1291         Node *output = find_output_node();
1292         if (output->output_gamma_curve != output_format.gamma_curve) {
1293                 Node *conversion = add_node(new GammaCompressionEffect());
1294                 CHECK(conversion->effect->set_int("destination_curve", output_format.gamma_curve));
1295                 conversion->output_gamma_curve = output_format.gamma_curve;
1296                 connect_nodes(output, conversion);
1297         }
1298 }
1299
1300 // If the user has requested dither, add a DitherEffect right at the end
1301 // (after GammaCompressionEffect etc.). This needs to be done after everything else,
1302 // since dither is about the only effect that can _not_ be done in linear space.
1303 void EffectChain::add_dither_if_needed()
1304 {
1305         if (num_dither_bits == 0) {
1306                 return;
1307         }
1308         Node *output = find_output_node();
1309         Node *dither = add_node(new DitherEffect());
1310         CHECK(dither->effect->set_int("num_bits", num_dither_bits));
1311         connect_nodes(output, dither);
1312
1313         dither_effect = dither->effect;
1314 }
1315
1316 // Find the output node. This is, simply, one that has no outgoing links.
1317 // If there are multiple ones, the graph is malformed (we do not support
1318 // multiple outputs right now).
1319 Node *EffectChain::find_output_node()
1320 {
1321         vector<Node *> output_nodes;
1322         for (unsigned i = 0; i < nodes.size(); ++i) {
1323                 Node *node = nodes[i];
1324                 if (node->disabled) {
1325                         continue;
1326                 }
1327                 if (node->outgoing_links.empty()) {
1328                         output_nodes.push_back(node);
1329                 }
1330         }
1331         assert(output_nodes.size() == 1);
1332         return output_nodes[0];
1333 }
1334
1335 void EffectChain::finalize()
1336 {
1337         // Save the current locale, and set it to C, so that we can output decimal
1338         // numbers with printf and be sure to get them in the format mandated by GLSL.
1339         char *saved_locale = setlocale(LC_NUMERIC, "C");
1340
1341         // Output the graph as it is before we do any conversions on it.
1342         output_dot("step0-start.dot");
1343
1344         // Give each effect in turn a chance to rewrite its own part of the graph.
1345         // Note that if more effects are added as part of this, they will be
1346         // picked up as part of the same for loop, since they are added at the end.
1347         for (unsigned i = 0; i < nodes.size(); ++i) {
1348                 nodes[i]->effect->rewrite_graph(this, nodes[i]);
1349         }
1350         output_dot("step1-rewritten.dot");
1351
1352         find_color_spaces_for_inputs();
1353         output_dot("step2-input-colorspace.dot");
1354
1355         propagate_alpha();
1356         output_dot("step3-propagated-alpha.dot");
1357
1358         propagate_gamma_and_color_space();
1359         output_dot("step4-propagated-all.dot");
1360
1361         fix_internal_color_spaces();
1362         fix_internal_alpha(6);
1363         fix_output_color_space();
1364         output_dot("step7-output-colorspacefix.dot");
1365         fix_output_alpha();
1366         output_dot("step8-output-alphafix.dot");
1367
1368         // Note that we need to fix gamma after colorspace conversion,
1369         // because colorspace conversions might create needs for gamma conversions.
1370         // Also, we need to run an extra pass of fix_internal_gamma() after
1371         // fixing the output gamma, as we only have conversions to/from linear,
1372         // and fix_internal_alpha() since GammaCompressionEffect needs
1373         // postmultiplied input.
1374         fix_internal_gamma_by_asking_inputs(9);
1375         fix_internal_gamma_by_inserting_nodes(10);
1376         fix_output_gamma();
1377         output_dot("step11-output-gammafix.dot");
1378         propagate_alpha();
1379         output_dot("step12-output-alpha-propagated.dot");
1380         fix_internal_alpha(13);
1381         output_dot("step14-output-alpha-fixed.dot");
1382         fix_internal_gamma_by_asking_inputs(15);
1383         fix_internal_gamma_by_inserting_nodes(16);
1384
1385         output_dot("step17-before-dither.dot");
1386
1387         add_dither_if_needed();
1388
1389         output_dot("step18-final.dot");
1390
1391         // Construct all needed GLSL programs, starting at the output.
1392         // We need to keep track of which effects have already been computed,
1393         // as an effect with multiple users could otherwise be calculated
1394         // multiple times.
1395         map<Node *, Phase *> completed_effects;
1396         construct_phase(find_output_node(), &completed_effects);
1397
1398         output_dot("step19-split-to-phases.dot");
1399
1400         assert(phases[0]->inputs.empty());
1401
1402         finalized = true;
1403         setlocale(LC_NUMERIC, saved_locale);
1404 }
1405
1406 void EffectChain::render_to_fbo(GLuint dest_fbo, unsigned width, unsigned height)
1407 {
1408         assert(finalized);
1409
1410         // Save original viewport.
1411         GLuint x = 0, y = 0;
1412         GLuint fbo = 0;
1413         void *context = get_gl_context_identifier();
1414
1415         if (width == 0 && height == 0) {
1416                 GLint viewport[4];
1417                 glGetIntegerv(GL_VIEWPORT, viewport);
1418                 x = viewport[0];
1419                 y = viewport[1];
1420                 width = viewport[2];
1421                 height = viewport[3];
1422         }
1423
1424         // Basic state.
1425         glDisable(GL_BLEND);
1426         check_error();
1427         glDisable(GL_DEPTH_TEST);
1428         check_error();
1429         glDepthMask(GL_FALSE);
1430         check_error();
1431
1432         if (phases.size() > 1) {
1433                 if (fbos.count(context) == 0) {
1434                         glGenFramebuffers(1, &fbo);
1435                         check_error();
1436                         fbos.insert(make_pair(context, fbo));
1437                 } else {
1438                         fbo = fbos[context];
1439                 }
1440                 glBindFramebuffer(GL_FRAMEBUFFER, fbo);
1441                 check_error();
1442         }
1443
1444         set<Phase *> generated_mipmaps;
1445
1446         // We choose the simplest option of having one texture per output,
1447         // since otherwise this turns into an (albeit simple) register allocation problem.
1448         map<Phase *, GLuint> output_textures;
1449
1450         for (unsigned phase = 0; phase < phases.size(); ++phase) {
1451                 // Find a texture for this phase.
1452                 inform_input_sizes(phases[phase]);
1453                 if (phase != phases.size() - 1) {
1454                         find_output_size(phases[phase]);
1455
1456                         GLuint tex_num = resource_pool->create_2d_texture(GL_RGBA16F_ARB, phases[phase]->output_width, phases[phase]->output_height);
1457                         output_textures.insert(make_pair(phases[phase], tex_num));
1458                 }
1459
1460                 const GLuint glsl_program_num = phases[phase]->glsl_program_num;
1461                 check_error();
1462                 glUseProgram(glsl_program_num);
1463                 check_error();
1464
1465                 // Set up RTT inputs for this phase.
1466                 for (unsigned sampler = 0; sampler < phases[phase]->inputs.size(); ++sampler) {
1467                         glActiveTexture(GL_TEXTURE0 + sampler);
1468                         Phase *input = phases[phase]->inputs[sampler];
1469                         input->output_node->bound_sampler_num = sampler;
1470                         glBindTexture(GL_TEXTURE_2D, output_textures[input]);
1471                         check_error();
1472                         if (phases[phase]->input_needs_mipmaps) {
1473                                 if (generated_mipmaps.count(input) == 0) {
1474                                         glGenerateMipmap(GL_TEXTURE_2D);
1475                                         check_error();
1476                                         generated_mipmaps.insert(input);
1477                                 }
1478                                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_NEAREST);
1479                                 check_error();
1480                         } else {
1481                                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
1482                                 check_error();
1483                         }
1484                         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
1485                         check_error();
1486                         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
1487                         check_error();
1488
1489                         string texture_name = string("tex_") + phases[phase]->effect_ids[input->output_node];
1490                         glUniform1i(glGetUniformLocation(glsl_program_num, texture_name.c_str()), sampler);
1491                         check_error();
1492                 }
1493
1494                 // And now the output.
1495                 if (phase == phases.size() - 1) {
1496                         // Last phase goes to the output the user specified.
1497                         glBindFramebuffer(GL_FRAMEBUFFER, dest_fbo);
1498                         check_error();
1499                         GLenum status = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);
1500                         assert(status == GL_FRAMEBUFFER_COMPLETE);
1501                         glViewport(x, y, width, height);
1502                         if (dither_effect != NULL) {
1503                                 CHECK(dither_effect->set_int("output_width", width));
1504                                 CHECK(dither_effect->set_int("output_height", height));
1505                         }
1506                 } else {
1507                         glFramebufferTexture2D(
1508                                 GL_FRAMEBUFFER,
1509                                 GL_COLOR_ATTACHMENT0,
1510                                 GL_TEXTURE_2D,
1511                                 output_textures[phases[phase]],
1512                                 0);
1513                         check_error();
1514                         GLenum status = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);
1515                         assert(status == GL_FRAMEBUFFER_COMPLETE);
1516                         glViewport(0, 0, phases[phase]->output_width, phases[phase]->output_height);
1517                 }
1518
1519                 // Give the required parameters to all the effects.
1520                 unsigned sampler_num = phases[phase]->inputs.size();
1521                 for (unsigned i = 0; i < phases[phase]->effects.size(); ++i) {
1522                         Node *node = phases[phase]->effects[i];
1523                         unsigned old_sampler_num = sampler_num;
1524                         node->effect->set_gl_state(glsl_program_num, phases[phase]->effect_ids[node], &sampler_num);
1525                         check_error();
1526
1527                         if (node->effect->is_single_texture()) {
1528                                 assert(sampler_num - old_sampler_num == 1);
1529                                 node->bound_sampler_num = old_sampler_num;
1530                         } else {
1531                                 node->bound_sampler_num = -1;
1532                         }
1533                 }
1534
1535                 // Now draw!
1536                 float vertices[] = {
1537                         0.0f, 1.0f,
1538                         0.0f, 0.0f,
1539                         1.0f, 1.0f,
1540                         1.0f, 0.0f
1541                 };
1542
1543                 GLuint vao;
1544                 glGenVertexArrays(1, &vao);
1545                 check_error();
1546                 glBindVertexArray(vao);
1547                 check_error();
1548
1549                 GLuint position_vbo = fill_vertex_attribute(glsl_program_num, "position", 2, GL_FLOAT, sizeof(vertices), vertices);
1550                 GLuint texcoord_vbo = fill_vertex_attribute(glsl_program_num, "texcoord", 2, GL_FLOAT, sizeof(vertices), vertices);  // Same as vertices.
1551
1552                 glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
1553                 check_error();
1554
1555                 cleanup_vertex_attribute(glsl_program_num, "position", position_vbo);
1556                 cleanup_vertex_attribute(glsl_program_num, "texcoord", texcoord_vbo);
1557
1558                 glUseProgram(0);
1559                 check_error();
1560
1561                 for (unsigned i = 0; i < phases[phase]->effects.size(); ++i) {
1562                         Node *node = phases[phase]->effects[i];
1563                         node->effect->clear_gl_state();
1564                 }
1565
1566                 glDeleteVertexArrays(1, &vao);
1567                 check_error();
1568         }
1569
1570         for (map<Phase *, GLuint>::const_iterator texture_it = output_textures.begin();
1571              texture_it != output_textures.end();
1572              ++texture_it) {
1573                 resource_pool->release_2d_texture(texture_it->second);
1574         }
1575
1576         glBindFramebuffer(GL_FRAMEBUFFER, 0);
1577         check_error();
1578 }
1579
1580 }  // namespace movit