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 }
  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
  92         nodes.push_back(node);
  93         node_map[effect] = node;
  94         effect->inform_added(this);
  95         return node;
  96 }
  97
  98 void EffectChain::connect_nodes(Node *sender, Node *receiver)
  99 {
 100         sender->outgoing_links.push_back(receiver);
 101         receiver->incoming_links.push_back(sender);
 102 }
 103
 104 void EffectChain::replace_receiver(Node *old_receiver, Node *new_receiver)
 105 {
 106         new_receiver->incoming_links = old_receiver->incoming_links;
 107         old_receiver->incoming_links.clear();
 108
 109         for (unsigned i = 0; i < new_receiver->incoming_links.size(); ++i) {
 110                 Node *sender = new_receiver->incoming_links[i];
 111                 for (unsigned j = 0; j < sender->outgoing_links.size(); ++j) {
 112                         if (sender->outgoing_links[j] == old_receiver) {
 113                                 sender->outgoing_links[j] = new_receiver;
 114                         }
 115                 }
 116         }
 117 }
 118
 119 void EffectChain::replace_sender(Node *old_sender, Node *new_sender)
 120 {
 121         new_sender->outgoing_links = old_sender->outgoing_links;
 122         old_sender->outgoing_links.clear();
 123
 124         for (unsigned i = 0; i < new_sender->outgoing_links.size(); ++i) {
 125                 Node *receiver = new_sender->outgoing_links[i];
 126                 for (unsigned j = 0; j < receiver->incoming_links.size(); ++j) {
 127                         if (receiver->incoming_links[j] == old_sender) {
 128                                 receiver->incoming_links[j] = new_sender;
 129                         }
 130                 }
 131         }
 132 }
 133
 134 void EffectChain::insert_node_between(Node *sender, Node *middle, Node *receiver)
 135 {
 136         for (unsigned i = 0; i < sender->outgoing_links.size(); ++i) {
 137                 if (sender->outgoing_links[i] == receiver) {
 138                         sender->outgoing_links[i] = middle;
 139                         middle->incoming_links.push_back(sender);
 140                 }
 141         }
 142         for (unsigned i = 0; i < receiver->incoming_links.size(); ++i) {
 143                 if (receiver->incoming_links[i] == sender) {
 144                         receiver->incoming_links[i] = middle;
 145                         middle->outgoing_links.push_back(receiver);
 146                 }
 147         }
 148
 149         assert(middle->incoming_links.size() == middle->effect->num_inputs());
 150 }
 151
 152 GLenum EffectChain::get_input_sampler(Node *node, unsigned input_num) const
 153 {
 154         assert(node->effect->needs_texture_bounce());
 155         assert(input_num < node->incoming_links.size());
 156         assert(node->incoming_links[input_num]->bound_sampler_num >= 0);
 157         assert(node->incoming_links[input_num]->bound_sampler_num < 8);
 158         return GL_TEXTURE0 + node->incoming_links[input_num]->bound_sampler_num;
 159 }
 160
 161 void EffectChain::find_all_nonlinear_inputs(Node *node, vector<Node *> *nonlinear_inputs)
 162 {
 163         if (node->output_gamma_curve == GAMMA_LINEAR &&
 164             node->effect->effect_type_id() != "GammaCompressionEffect") {
 165                 return;
 166         }
 167         if (node->effect->num_inputs() == 0) {
 168                 nonlinear_inputs->push_back(node);
 169         } else {
 170                 assert(node->effect->num_inputs() == node->incoming_links.size());
 171                 for (unsigned i = 0; i < node->incoming_links.size(); ++i) {
 172                         find_all_nonlinear_inputs(node->incoming_links[i], nonlinear_inputs);
 173                 }
 174         }
 175 }
 176
 177 Effect *EffectChain::add_effect(Effect *effect, const vector<Effect *> &inputs)
 178 {
 179         assert(!finalized);
 180         assert(inputs.size() == effect->num_inputs());
 181         Node *node = add_node(effect);
 182         for (unsigned i = 0; i < inputs.size(); ++i) {
 183                 assert(node_map.count(inputs[i]) != 0);
 184                 connect_nodes(node_map[inputs[i]], node);
 185         }
 186         return effect;
 187 }
 188
 189 // GLSL pre-1.30 doesn't support token pasting. Replace PREFIX(x) with <effect_id>_x.
 190 string replace_prefix(const string &text, const string &prefix)
 191 {
 192         string output;
 193         size_t start = 0;
 194
 195         while (start < text.size()) {
 196                 size_t pos = text.find("PREFIX(", start);
 197                 if (pos == string::npos) {
 198                         output.append(text.substr(start, string::npos));
 199                         break;
 200                 }
 201
 202                 output.append(text.substr(start, pos - start));
 203                 output.append(prefix);
 204                 output.append("_");
 205
 206                 pos += strlen("PREFIX(");
 207
 208                 // Output stuff until we find the matching ), which we then eat.
 209                 int depth = 1;
 210                 size_t end_arg_pos = pos;
 211                 while (end_arg_pos < text.size()) {
 212                         if (text[end_arg_pos] == '(') {
 213                                 ++depth;
 214                         } else if (text[end_arg_pos] == ')') {
 215                                 --depth;
 216                                 if (depth == 0) {
 217                                         break;
 218                                 }
 219                         }
 220                         ++end_arg_pos;
 221                 }
 222                 output.append(text.substr(pos, end_arg_pos - pos));
 223                 ++end_arg_pos;
 224                 assert(depth == 0);
 225                 start = end_arg_pos;
 226         }
 227         return output;
 228 }
 229
 230 Phase *EffectChain::compile_glsl_program(
 231         const vector<Node *> &inputs,
 232         const vector<Node *> &effects)
 233 {
 234         Phase *phase = new Phase;
 235         assert(!effects.empty());
 236
 237         // Deduplicate the inputs.
 238         vector<Node *> true_inputs = inputs;
 239         sort(true_inputs.begin(), true_inputs.end());
 240         true_inputs.erase(unique(true_inputs.begin(), true_inputs.end()), true_inputs.end());
 241
 242         bool input_needs_mipmaps = false;
 243         string frag_shader = read_file("header.frag");
 244
 245         // Create functions for all the texture inputs that we need.
 246         for (unsigned i = 0; i < true_inputs.size(); ++i) {
 247                 Node *input = true_inputs[i];
 248                 char effect_id[256];
 249                 sprintf(effect_id, "in%u", i);
 250                 phase->effect_ids.insert(make_pair(input, effect_id));
 251
 252                 frag_shader += string("uniform sampler2D tex_") + effect_id + ";\n";
 253                 frag_shader += string("vec4 ") + effect_id + "(vec2 tc) {\n";
 254                 frag_shader += "\treturn texture2D(tex_" + string(effect_id) + ", tc);\n";
 255                 frag_shader += "}\n";
 256                 frag_shader += "\n";
 257         }
 258
 259         vector<Node *> sorted_effects = topological_sort(effects);
 260
 261         for (unsigned i = 0; i < sorted_effects.size(); ++i) {
 262                 Node *node = sorted_effects[i];
 263                 char effect_id[256];
 264                 sprintf(effect_id, "eff%u", i);
 265                 phase->effect_ids.insert(make_pair(node, effect_id));
 266
 267                 if (node->incoming_links.size() == 1) {
 268                         frag_shader += string("#define INPUT ") + phase->effect_ids[node->incoming_links[0]] + "\n";
 269                 } else {
 270                         for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
 271                                 char buf[256];
 272                                 sprintf(buf, "#define INPUT%d %s\n", j + 1, phase->effect_ids[node->incoming_links[j]].c_str());
 273                                 frag_shader += buf;
 274                         }
 275                 }
 276
 277                 frag_shader += "\n";
 278                 frag_shader += string("#define FUNCNAME ") + effect_id + "\n";
 279                 frag_shader += replace_prefix(node->effect->output_convenience_uniforms(), effect_id);
 280                 frag_shader += replace_prefix(node->effect->output_fragment_shader(), effect_id);
 281                 frag_shader += "#undef PREFIX\n";
 282                 frag_shader += "#undef FUNCNAME\n";
 283                 if (node->incoming_links.size() == 1) {
 284                         frag_shader += "#undef INPUT\n";
 285                 } else {
 286                         for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
 287                                 char buf[256];
 288                                 sprintf(buf, "#undef INPUT%d\n", j + 1);
 289                                 frag_shader += buf;
 290                         }
 291                 }
 292                 frag_shader += "\n";
 293
 294                 input_needs_mipmaps |= node->effect->needs_mipmaps();
 295         }
 296         for (unsigned i = 0; i < sorted_effects.size(); ++i) {
 297                 Node *node = sorted_effects[i];
 298                 if (node->effect->num_inputs() == 0) {
 299                         CHECK(node->effect->set_int("needs_mipmaps", input_needs_mipmaps));
 300                 }
 301         }
 302         frag_shader += string("#define INPUT ") + phase->effect_ids[sorted_effects.back()] + "\n";
 303         frag_shader.append(read_file("footer.frag"));
 304
 305         phase->glsl_program_num = resource_pool->compile_glsl_program(read_file("vs.vert"), frag_shader);
 306         phase->input_needs_mipmaps = input_needs_mipmaps;
 307         phase->inputs = true_inputs;
 308         phase->effects = sorted_effects;
 309
 310         return phase;
 311 }
 312
 313 // Construct GLSL programs, starting at the given effect and following
 314 // the chain from there. We end a program every time we come to an effect
 315 // marked as "needs texture bounce", one that is used by multiple other
 316 // effects, every time an effect wants to change the output size,
 317 // and of course at the end.
 318 //
 319 // We follow a quite simple depth-first search from the output, although
 320 // without any explicit recursion.
 321 void EffectChain::construct_glsl_programs(Node *output)
 322 {
 323         // Which effects have already been completed?
 324         // We need to keep track of it, as an effect with multiple outputs
 325         // could otherwise be calculated multiple times.
 326         set<Node *> completed_effects;
 327
 328         // Effects in the current phase, as well as inputs (outputs from other phases
 329         // that we depend on). Note that since we start iterating from the end,
 330         // the effect list will be in the reverse order.
 331         vector<Node *> this_phase_inputs;
 332         vector<Node *> this_phase_effects;
 333
 334         // Effects that we have yet to calculate, but that we know should
 335         // be in the current phase.
 336         stack<Node *> effects_todo_this_phase;
 337
 338         // Effects that we have yet to calculate, but that come from other phases.
 339         // We delay these until we have this phase done in its entirety,
 340         // at which point we pick any of them and start a new phase from that.
 341         stack<Node *> effects_todo_other_phases;
 342
 343         effects_todo_this_phase.push(output);
 344
 345         for ( ;; ) {  // Termination condition within loop.
 346                 if (!effects_todo_this_phase.empty()) {
 347                         // OK, we have more to do this phase.
 348                         Node *node = effects_todo_this_phase.top();
 349                         effects_todo_this_phase.pop();
 350
 351                         // This should currently only happen for effects that are inputs
 352                         // (either true inputs or phase outputs). We special-case inputs,
 353                         // and then deduplicate phase outputs in compile_glsl_program().
 354                         if (node->effect->num_inputs() == 0) {
 355                                 if (find(this_phase_effects.begin(), this_phase_effects.end(), node) != this_phase_effects.end()) {
 356                                         continue;
 357                                 }
 358                         } else {
 359                                 assert(completed_effects.count(node) == 0);
 360                         }
 361
 362                         this_phase_effects.push_back(node);
 363                         completed_effects.insert(node);
 364
 365                         // Find all the dependencies of this effect, and add them to the stack.
 366                         vector<Node *> deps = node->incoming_links;
 367                         assert(node->effect->num_inputs() == deps.size());
 368                         for (unsigned i = 0; i < deps.size(); ++i) {
 369                                 bool start_new_phase = false;
 370
 371                                 if (node->effect->needs_texture_bounce() &&
 372                                     !deps[i]->effect->is_single_texture()) {
 373                                         start_new_phase = true;
 374                                 }
 375
 376                                 if (deps[i]->outgoing_links.size() > 1) {
 377                                         if (!deps[i]->effect->is_single_texture()) {
 378                                                 // More than one effect uses this as the input,
 379                                                 // and it is not a texture itself.
 380                                                 // The easiest thing to do (and probably also the safest
 381                                                 // performance-wise in most cases) is to bounce it to a texture
 382                                                 // and then let the next passes read from that.
 383                                                 start_new_phase = true;
 384                                         } else {
 385                                                 assert(deps[i]->effect->num_inputs() == 0);
 386
 387                                                 // For textures, we try to be slightly more clever;
 388                                                 // if none of our outputs need a bounce, we don't bounce
 389                                                 // but instead simply use the effect many times.
 390                                                 //
 391                                                 // Strictly speaking, we could bounce it for some outputs
 392                                                 // and use it directly for others, but the processing becomes
 393                                                 // somewhat simpler if the effect is only used in one such way.
 394                                                 for (unsigned j = 0; j < deps[i]->outgoing_links.size(); ++j) {
 395                                                         Node *rdep = deps[i]->outgoing_links[j];
 396                                                         start_new_phase |= rdep->effect->needs_texture_bounce();
 397                                                 }
 398                                         }
 399                                 }
 400
 401                                 if (deps[i]->effect->changes_output_size()) {
 402                                         start_new_phase = true;
 403                                 }
 404
 405                                 if (start_new_phase) {
 406                                         effects_todo_other_phases.push(deps[i]);
 407                                         this_phase_inputs.push_back(deps[i]);
 408                                 } else {
 409                                         effects_todo_this_phase.push(deps[i]);
 410                                 }
 411                         }
 412                         continue;
 413                 }
 414
 415                 // No more effects to do this phase. Take all the ones we have,
 416                 // and create a GLSL program for it.
 417                 if (!this_phase_effects.empty()) {
 418                         reverse(this_phase_effects.begin(), this_phase_effects.end());
 419                         phases.push_back(compile_glsl_program(this_phase_inputs, this_phase_effects));
 420                         this_phase_effects.back()->phase = phases.back();
 421                         this_phase_inputs.clear();
 422                         this_phase_effects.clear();
 423                 }
 424                 assert(this_phase_inputs.empty());
 425                 assert(this_phase_effects.empty());
 426
 427                 // If we have no effects left, exit.
 428                 if (effects_todo_other_phases.empty()) {
 429                         break;
 430                 }
 431
 432                 Node *node = effects_todo_other_phases.top();
 433                 effects_todo_other_phases.pop();
 434
 435                 if (completed_effects.count(node) == 0) {
 436                         // Start a new phase, calculating from this effect.
 437                         effects_todo_this_phase.push(node);
 438                 }
 439         }
 440
 441         // Finally, since the phases are found from the output but must be executed
 442         // from the input(s), reverse them, too.
 443         reverse(phases.begin(), phases.end());
 444 }
 445
 446 void EffectChain::output_dot(const char *filename)
 447 {
 448         if (movit_debug_level != MOVIT_DEBUG_ON) {
 449                 return;
 450         }
 451
 452         FILE *fp = fopen(filename, "w");
 453         if (fp == NULL) {
 454                 perror(filename);
 455                 exit(1);
 456         }
 457
 458         fprintf(fp, "digraph G {\n");
 459         fprintf(fp, "  output [shape=box label=\"(output)\"];\n");
 460         for (unsigned i = 0; i < nodes.size(); ++i) {
 461                 // Find out which phase this event belongs to.
 462                 vector<int> in_phases;
 463                 for (unsigned j = 0; j < phases.size(); ++j) {
 464                         const Phase* p = phases[j];
 465                         if (find(p->effects.begin(), p->effects.end(), nodes[i]) != p->effects.end()) {
 466                                 in_phases.push_back(j);
 467                         }
 468                 }
 469
 470                 if (in_phases.empty()) {
 471                         fprintf(fp, "  n%ld [label=\"%s\"];\n", (long)nodes[i], nodes[i]->effect->effect_type_id().c_str());
 472                 } else if (in_phases.size() == 1) {
 473                         fprintf(fp, "  n%ld [label=\"%s\" style=\"filled\" fillcolor=\"/accent8/%d\"];\n",
 474                                 (long)nodes[i], nodes[i]->effect->effect_type_id().c_str(),
 475                                 (in_phases[0] % 8) + 1);
 476                 } else {
 477                         // If we had new enough Graphviz, style="wedged" would probably be ideal here.
 478                         // But alas.
 479                         fprintf(fp, "  n%ld [label=\"%s [in multiple phases]\" style=\"filled\" fillcolor=\"/accent8/%d\"];\n",
 480                                 (long)nodes[i], nodes[i]->effect->effect_type_id().c_str(),
 481                                 (in_phases[0] % 8) + 1);
 482                 }
 483
 484                 char from_node_id[256];
 485                 snprintf(from_node_id, 256, "n%ld", (long)nodes[i]);
 486
 487                 for (unsigned j = 0; j < nodes[i]->outgoing_links.size(); ++j) {
 488                         char to_node_id[256];
 489                         snprintf(to_node_id, 256, "n%ld", (long)nodes[i]->outgoing_links[j]);
 490
 491                         vector<string> labels = get_labels_for_edge(nodes[i], nodes[i]->outgoing_links[j]);
 492                         output_dot_edge(fp, from_node_id, to_node_id, labels);
 493                 }
 494
 495                 if (nodes[i]->outgoing_links.empty() && !nodes[i]->disabled) {
 496                         // Output node.
 497                         vector<string> labels = get_labels_for_edge(nodes[i], NULL);
 498                         output_dot_edge(fp, from_node_id, "output", labels);
 499                 }
 500         }
 501         fprintf(fp, "}\n");
 502
 503         fclose(fp);
 504 }
 505
 506 vector<string> EffectChain::get_labels_for_edge(const Node *from, const Node *to)
 507 {
 508         vector<string> labels;
 509
 510         if (to != NULL && to->effect->needs_texture_bounce()) {
 511                 labels.push_back("needs_bounce");
 512         }
 513         if (from->effect->changes_output_size()) {
 514                 labels.push_back("resize");
 515         }
 516
 517         switch (from->output_color_space) {
 518         case COLORSPACE_INVALID:
 519                 labels.push_back("spc[invalid]");
 520                 break;
 521         case COLORSPACE_REC_601_525:
 522                 labels.push_back("spc[rec601-525]");
 523                 break;
 524         case COLORSPACE_REC_601_625:
 525                 labels.push_back("spc[rec601-625]");
 526                 break;
 527         default:
 528                 break;
 529         }
 530
 531         switch (from->output_gamma_curve) {
 532         case GAMMA_INVALID:
 533                 labels.push_back("gamma[invalid]");
 534                 break;
 535         case GAMMA_sRGB:
 536                 labels.push_back("gamma[sRGB]");
 537                 break;
 538         case GAMMA_REC_601:  // and GAMMA_REC_709
 539                 labels.push_back("gamma[rec601/709]");
 540                 break;
 541         default:
 542                 break;
 543         }
 544
 545         switch (from->output_alpha_type) {
 546         case ALPHA_INVALID:
 547                 labels.push_back("alpha[invalid]");
 548                 break;
 549         case ALPHA_BLANK:
 550                 labels.push_back("alpha[blank]");
 551                 break;
 552         case ALPHA_POSTMULTIPLIED:
 553                 labels.push_back("alpha[postmult]");
 554                 break;
 555         default:
 556                 break;
 557         }
 558
 559         return labels;
 560 }
 561
 562 void EffectChain::output_dot_edge(FILE *fp,
 563                                   const string &from_node_id,
 564                                   const string &to_node_id,
 565                                   const vector<string> &labels)
 566 {
 567         if (labels.empty()) {
 568                 fprintf(fp, "  %s -> %s;\n", from_node_id.c_str(), to_node_id.c_str());
 569         } else {
 570                 string label = labels[0];
 571                 for (unsigned k = 1; k < labels.size(); ++k) {
 572                         label += ", " + labels[k];
 573                 }
 574                 fprintf(fp, "  %s -> %s [label=\"%s\"];\n", from_node_id.c_str(), to_node_id.c_str(), label.c_str());
 575         }
 576 }
 577
 578 void EffectChain::size_rectangle_to_fit(unsigned width, unsigned height, unsigned *output_width, unsigned *output_height)
 579 {
 580         unsigned scaled_width, scaled_height;
 581
 582         if (float(width) * aspect_denom >= float(height) * aspect_nom) {
 583                 // Same aspect, or W/H > aspect (image is wider than the frame).
 584                 // In either case, keep width, and adjust height.
 585                 scaled_width = width;
 586                 scaled_height = lrintf(width * aspect_denom / aspect_nom);
 587         } else {
 588                 // W/H < aspect (image is taller than the frame), so keep height,
 589                 // and adjust width.
 590                 scaled_width = lrintf(height * aspect_nom / aspect_denom);
 591                 scaled_height = height;
 592         }
 593
 594         // We should be consistently larger or smaller then the existing choice,
 595         // since we have the same aspect.
 596         assert(!(scaled_width < *output_width && scaled_height > *output_height));
 597         assert(!(scaled_height < *output_height && scaled_width > *output_width));
 598
 599         if (scaled_width >= *output_width && scaled_height >= *output_height) {
 600                 *output_width = scaled_width;
 601                 *output_height = scaled_height;
 602         }
 603 }
 604
 605 // Propagate input texture sizes throughout, and inform effects downstream.
 606 // (Like a lot of other code, we depend on effects being in topological order.)
 607 void EffectChain::inform_input_sizes(Phase *phase)
 608 {
 609         // All effects that have a defined size (inputs and RTT inputs)
 610         // get that. Reset all others.
 611         for (unsigned i = 0; i < phase->effects.size(); ++i) {
 612                 Node *node = phase->effects[i];
 613                 if (node->effect->num_inputs() == 0) {
 614                         Input *input = static_cast<Input *>(node->effect);
 615                         node->output_width = input->get_width();
 616                         node->output_height = input->get_height();
 617                         assert(node->output_width != 0);
 618                         assert(node->output_height != 0);
 619                 } else {
 620                         node->output_width = node->output_height = 0;
 621                 }
 622         }
 623         for (unsigned i = 0; i < phase->inputs.size(); ++i) {
 624                 Node *input = phase->inputs[i];
 625                 input->output_width = input->phase->virtual_output_width;
 626                 input->output_height = input->phase->virtual_output_height;
 627                 assert(input->output_width != 0);
 628                 assert(input->output_height != 0);
 629         }
 630
 631         // Now propagate from the inputs towards the end, and inform as we go.
 632         // The rules are simple:
 633         //
 634         //   1. Don't touch effects that already have given sizes (ie., inputs).
 635         //   2. If all of your inputs have the same size, that will be your output size.
 636         //   3. Otherwise, your output size is 0x0.
 637         for (unsigned i = 0; i < phase->effects.size(); ++i) {
 638                 Node *node = phase->effects[i];
 639                 if (node->effect->num_inputs() == 0) {
 640                         continue;
 641                 }
 642                 unsigned this_output_width = 0;
 643                 unsigned this_output_height = 0;
 644                 for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
 645                         Node *input = node->incoming_links[j];
 646                         node->effect->inform_input_size(j, input->output_width, input->output_height);
 647                         if (j == 0) {
 648                                 this_output_width = input->output_width;
 649                                 this_output_height = input->output_height;
 650                         } else if (input->output_width != this_output_width || input->output_height != this_output_height) {
 651                                 // Inputs disagree.
 652                                 this_output_width = 0;
 653                                 this_output_height = 0;
 654                         }
 655                 }
 656                 node->output_width = this_output_width;
 657                 node->output_height = this_output_height;
 658         }
 659 }
 660
 661 // Note: You should call inform_input_sizes() before this, as the last effect's
 662 // desired output size might change based on the inputs.
 663 void EffectChain::find_output_size(Phase *phase)
 664 {
 665         Node *output_node = phase->effects.back();
 666
 667         // If the last effect explicitly sets an output size, use that.
 668         if (output_node->effect->changes_output_size()) {
 669                 output_node->effect->get_output_size(&phase->output_width, &phase->output_height,
 670                                                      &phase->virtual_output_width, &phase->virtual_output_height);
 671                 return;
 672         }
 673
 674         // If all effects have the same size, use that.
 675         unsigned output_width = 0, output_height = 0;
 676         bool all_inputs_same_size = true;
 677
 678         for (unsigned i = 0; i < phase->inputs.size(); ++i) {
 679                 Node *input = phase->inputs[i];
 680                 assert(input->phase->output_width != 0);
 681                 assert(input->phase->output_height != 0);
 682                 if (output_width == 0 && output_height == 0) {
 683                         output_width = input->phase->virtual_output_width;
 684                         output_height = input->phase->virtual_output_height;
 685                 } else if (output_width != input->phase->virtual_output_width ||
 686                            output_height != input->phase->virtual_output_height) {
 687                         all_inputs_same_size = false;
 688                 }
 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                 if (output_width == 0 && output_height == 0) {
 698                         output_width = input->get_width();
 699                         output_height = input->get_height();
 700                 } else if (output_width != input->get_width() ||
 701                            output_height != input->get_height()) {
 702                         all_inputs_same_size = false;
 703                 }
 704         }
 705
 706         if (all_inputs_same_size) {
 707                 assert(output_width != 0);
 708                 assert(output_height != 0);
 709                 phase->virtual_output_width = phase->output_width = output_width;
 710                 phase->virtual_output_height = phase->output_height = output_height;
 711                 return;
 712         }
 713
 714         // If not, fit all the inputs into the current aspect, and select the largest one.
 715         output_width = 0;
 716         output_height = 0;
 717         for (unsigned i = 0; i < phase->inputs.size(); ++i) {
 718                 Node *input = phase->inputs[i];
 719                 assert(input->phase->output_width != 0);
 720                 assert(input->phase->output_height != 0);
 721                 size_rectangle_to_fit(input->phase->output_width, input->phase->output_height, &output_width, &output_height);
 722         }
 723         for (unsigned i = 0; i < phase->effects.size(); ++i) {
 724                 Effect *effect = phase->effects[i]->effect;
 725                 if (effect->num_inputs() != 0) {
 726                         continue;
 727                 }
 728
 729                 Input *input = static_cast<Input *>(effect);
 730                 size_rectangle_to_fit(input->get_width(), input->get_height(), &output_width, &output_height);
 731         }
 732         assert(output_width != 0);
 733         assert(output_height != 0);
 734         phase->virtual_output_width = phase->output_width = output_width;
 735         phase->virtual_output_height = phase->output_height = output_height;
 736 }
 737
 738 void EffectChain::sort_all_nodes_topologically()
 739 {
 740         nodes = topological_sort(nodes);
 741 }
 742
 743 vector<Node *> EffectChain::topological_sort(const vector<Node *> &nodes)
 744 {
 745         set<Node *> nodes_left_to_visit(nodes.begin(), nodes.end());
 746         vector<Node *> sorted_list;
 747         for (unsigned i = 0; i < nodes.size(); ++i) {
 748                 topological_sort_visit_node(nodes[i], &nodes_left_to_visit, &sorted_list);
 749         }
 750         reverse(sorted_list.begin(), sorted_list.end());
 751         return sorted_list;
 752 }
 753
 754 void EffectChain::topological_sort_visit_node(Node *node, set<Node *> *nodes_left_to_visit, vector<Node *> *sorted_list)
 755 {
 756         if (nodes_left_to_visit->count(node) == 0) {
 757                 return;
 758         }
 759         nodes_left_to_visit->erase(node);
 760         for (unsigned i = 0; i < node->outgoing_links.size(); ++i) {
 761                 topological_sort_visit_node(node->outgoing_links[i], nodes_left_to_visit, sorted_list);
 762         }
 763         sorted_list->push_back(node);
 764 }
 765
 766 void EffectChain::find_color_spaces_for_inputs()
 767 {
 768         for (unsigned i = 0; i < nodes.size(); ++i) {
 769                 Node *node = nodes[i];
 770                 if (node->disabled) {
 771                         continue;
 772                 }
 773                 if (node->incoming_links.size() == 0) {
 774                         Input *input = static_cast<Input *>(node->effect);
 775                         node->output_color_space = input->get_color_space();
 776                         node->output_gamma_curve = input->get_gamma_curve();
 777
 778                         Effect::AlphaHandling alpha_handling = input->alpha_handling();
 779                         switch (alpha_handling) {
 780                         case Effect::OUTPUT_BLANK_ALPHA:
 781                                 node->output_alpha_type = ALPHA_BLANK;
 782                                 break;
 783                         case Effect::INPUT_AND_OUTPUT_PREMULTIPLIED_ALPHA:
 784                                 node->output_alpha_type = ALPHA_PREMULTIPLIED;
 785                                 break;
 786                         case Effect::OUTPUT_POSTMULTIPLIED_ALPHA:
 787                                 node->output_alpha_type = ALPHA_POSTMULTIPLIED;
 788                                 break;
 789                         case Effect::INPUT_PREMULTIPLIED_ALPHA_KEEP_BLANK:
 790                         case Effect::DONT_CARE_ALPHA_TYPE:
 791                         default:
 792                                 assert(false);
 793                         }
 794
 795                         if (node->output_alpha_type == ALPHA_PREMULTIPLIED) {
 796                                 assert(node->output_gamma_curve == GAMMA_LINEAR);
 797                         }
 798                 }
 799         }
 800 }
 801
 802 // Propagate gamma and color space information as far as we can in the graph.
 803 // The rules are simple: Anything where all the inputs agree, get that as
 804 // output as well. Anything else keeps having *_INVALID.
 805 void EffectChain::propagate_gamma_and_color_space()
 806 {
 807         // We depend on going through the nodes in order.
 808         sort_all_nodes_topologically();
 809
 810         for (unsigned i = 0; i < nodes.size(); ++i) {
 811                 Node *node = nodes[i];
 812                 if (node->disabled) {
 813                         continue;
 814                 }
 815                 assert(node->incoming_links.size() == node->effect->num_inputs());
 816                 if (node->incoming_links.size() == 0) {
 817                         assert(node->output_color_space != COLORSPACE_INVALID);
 818                         assert(node->output_gamma_curve != GAMMA_INVALID);
 819                         continue;
 820                 }
 821
 822                 Colorspace color_space = node->incoming_links[0]->output_color_space;
 823                 GammaCurve gamma_curve = node->incoming_links[0]->output_gamma_curve;
 824                 for (unsigned j = 1; j < node->incoming_links.size(); ++j) {
 825                         if (node->incoming_links[j]->output_color_space != color_space) {
 826                                 color_space = COLORSPACE_INVALID;
 827                         }
 828                         if (node->incoming_links[j]->output_gamma_curve != gamma_curve) {
 829                                 gamma_curve = GAMMA_INVALID;
 830                         }
 831                 }
 832
 833                 // The conversion effects already have their outputs set correctly,
 834                 // so leave them alone.
 835                 if (node->effect->effect_type_id() != "ColorspaceConversionEffect") {
 836                         node->output_color_space = color_space;
 837                 }
 838                 if (node->effect->effect_type_id() != "GammaCompressionEffect" &&
 839                     node->effect->effect_type_id() != "GammaExpansionEffect") {
 840                         node->output_gamma_curve = gamma_curve;
 841                 }
 842         }
 843 }
 844
 845 // Propagate alpha information as far as we can in the graph.
 846 // Similar to propagate_gamma_and_color_space().
 847 void EffectChain::propagate_alpha()
 848 {
 849         // We depend on going through the nodes in order.
 850         sort_all_nodes_topologically();
 851
 852         for (unsigned i = 0; i < nodes.size(); ++i) {
 853                 Node *node = nodes[i];
 854                 if (node->disabled) {
 855                         continue;
 856                 }
 857                 assert(node->incoming_links.size() == node->effect->num_inputs());
 858                 if (node->incoming_links.size() == 0) {
 859                         assert(node->output_alpha_type != ALPHA_INVALID);
 860                         continue;
 861                 }
 862
 863                 // The alpha multiplication/division effects are special cases.
 864                 if (node->effect->effect_type_id() == "AlphaMultiplicationEffect") {
 865                         assert(node->incoming_links.size() == 1);
 866                         assert(node->incoming_links[0]->output_alpha_type == ALPHA_POSTMULTIPLIED);
 867                         node->output_alpha_type = ALPHA_PREMULTIPLIED;
 868                         continue;
 869                 }
 870                 if (node->effect->effect_type_id() == "AlphaDivisionEffect") {
 871                         assert(node->incoming_links.size() == 1);
 872                         assert(node->incoming_links[0]->output_alpha_type == ALPHA_PREMULTIPLIED);
 873                         node->output_alpha_type = ALPHA_POSTMULTIPLIED;
 874                         continue;
 875                 }
 876
 877                 // GammaCompressionEffect and GammaExpansionEffect are also a special case,
 878                 // because they are the only one that _need_ postmultiplied alpha.
 879                 if (node->effect->effect_type_id() == "GammaCompressionEffect" ||
 880                     node->effect->effect_type_id() == "GammaExpansionEffect") {
 881                         assert(node->incoming_links.size() == 1);
 882                         if (node->incoming_links[0]->output_alpha_type == ALPHA_BLANK) {
 883                                 node->output_alpha_type = ALPHA_BLANK;
 884                         } else if (node->incoming_links[0]->output_alpha_type == ALPHA_POSTMULTIPLIED) {
 885                                 node->output_alpha_type = ALPHA_POSTMULTIPLIED;
 886                         } else {
 887                                 node->output_alpha_type = ALPHA_INVALID;
 888                         }
 889                         continue;
 890                 }
 891
 892                 // Only inputs can have unconditional alpha output (OUTPUT_BLANK_ALPHA
 893                 // or OUTPUT_POSTMULTIPLIED_ALPHA), and they have already been
 894                 // taken care of above. Rationale: Even if you could imagine
 895                 // e.g. an effect that took in an image and set alpha=1.0
 896                 // unconditionally, it wouldn't make any sense to have it as
 897                 // e.g. OUTPUT_BLANK_ALPHA, since it wouldn't know whether it
 898                 // got its input pre- or postmultiplied, so it wouldn't know
 899                 // whether to divide away the old alpha or not.
 900                 Effect::AlphaHandling alpha_handling = node->effect->alpha_handling();
 901                 assert(alpha_handling == Effect::INPUT_AND_OUTPUT_PREMULTIPLIED_ALPHA ||
 902                        alpha_handling == Effect::INPUT_PREMULTIPLIED_ALPHA_KEEP_BLANK ||
 903                        alpha_handling == Effect::DONT_CARE_ALPHA_TYPE);
 904
 905                 // If the node has multiple inputs, check that they are all valid and
 906                 // the same.
 907                 bool any_invalid = false;
 908                 bool any_premultiplied = false;
 909                 bool any_postmultiplied = false;
 910
 911                 for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
 912                         switch (node->incoming_links[j]->output_alpha_type) {
 913                         case ALPHA_INVALID:
 914                                 any_invalid = true;
 915                                 break;
 916                         case ALPHA_BLANK:
 917                                 // Blank is good as both pre- and postmultiplied alpha,
 918                                 // so just ignore it.
 919                                 break;
 920                         case ALPHA_PREMULTIPLIED:
 921                                 any_premultiplied = true;
 922                                 break;
 923                         case ALPHA_POSTMULTIPLIED:
 924                                 any_postmultiplied = true;
 925                                 break;
 926                         default:
 927                                 assert(false);
 928                         }
 929                 }
 930
 931                 if (any_invalid) {
 932                         node->output_alpha_type = ALPHA_INVALID;
 933                         continue;
 934                 }
 935
 936                 // Inputs must be of the same type.
 937                 if (any_premultiplied && any_postmultiplied) {
 938                         node->output_alpha_type = ALPHA_INVALID;
 939                         continue;
 940                 }
 941
 942                 if (alpha_handling == Effect::INPUT_AND_OUTPUT_PREMULTIPLIED_ALPHA ||
 943                     alpha_handling == Effect::INPUT_PREMULTIPLIED_ALPHA_KEEP_BLANK) {
 944                         // If the effect has asked for premultiplied alpha, check that it has got it.
 945                         if (any_postmultiplied) {
 946                                 node->output_alpha_type = ALPHA_INVALID;
 947                         } else if (!any_premultiplied &&
 948                                    alpha_handling == Effect::INPUT_PREMULTIPLIED_ALPHA_KEEP_BLANK) {
 949                                 // Blank input alpha, and the effect preserves blank alpha.
 950                                 node->output_alpha_type = ALPHA_BLANK;
 951                         } else {
 952                                 node->output_alpha_type = ALPHA_PREMULTIPLIED;
 953                         }
 954                 } else {
 955                         // OK, all inputs are the same, and this effect is not going
 956                         // to change it.
 957                         assert(alpha_handling == Effect::DONT_CARE_ALPHA_TYPE);
 958                         if (any_premultiplied) {
 959                                 node->output_alpha_type = ALPHA_PREMULTIPLIED;
 960                         } else if (any_postmultiplied) {
 961                                 node->output_alpha_type = ALPHA_POSTMULTIPLIED;
 962                         } else {
 963                                 node->output_alpha_type = ALPHA_BLANK;
 964                         }
 965                 }
 966         }
 967 }
 968
 969 bool EffectChain::node_needs_colorspace_fix(Node *node)
 970 {
 971         if (node->disabled) {
 972                 return false;
 973         }
 974         if (node->effect->num_inputs() == 0) {
 975                 return false;
 976         }
 977
 978         // propagate_gamma_and_color_space() has already set our output
 979         // to COLORSPACE_INVALID if the inputs differ, so we can rely on that.
 980         if (node->output_color_space == COLORSPACE_INVALID) {
 981                 return true;
 982         }
 983         return (node->effect->needs_srgb_primaries() && node->output_color_space != COLORSPACE_sRGB);
 984 }
 985
 986 // Fix up color spaces so that there are no COLORSPACE_INVALID nodes left in
 987 // the graph. Our strategy is not always optimal, but quite simple:
 988 // Find an effect that's as early as possible where the inputs are of
 989 // unacceptable colorspaces (that is, either different, or, if the effect only
 990 // wants sRGB, not sRGB.) Add appropriate conversions on all its inputs,
 991 // propagate the information anew, and repeat until there are no more such
 992 // effects.
 993 void EffectChain::fix_internal_color_spaces()
 994 {
 995         unsigned colorspace_propagation_pass = 0;
 996         bool found_any;
 997         do {
 998                 found_any = false;
 999                 for (unsigned i = 0; i < nodes.size(); ++i) {
1000                         Node *node = nodes[i];
1001                         if (!node_needs_colorspace_fix(node)) {
1002                                 continue;
1003                         }
1004
1005                         // Go through each input that is not sRGB, and insert
1006                         // a colorspace conversion after it.
1007                         for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
1008                                 Node *input = node->incoming_links[j];
1009                                 assert(input->output_color_space != COLORSPACE_INVALID);
1010                                 if (input->output_color_space == COLORSPACE_sRGB) {
1011                                         continue;
1012                                 }
1013                                 Node *conversion = add_node(new ColorspaceConversionEffect());
1014                                 CHECK(conversion->effect->set_int("source_space", input->output_color_space));
1015                                 CHECK(conversion->effect->set_int("destination_space", COLORSPACE_sRGB));
1016                                 conversion->output_color_space = COLORSPACE_sRGB;
1017                                 replace_sender(input, conversion);
1018                                 connect_nodes(input, conversion);
1019                         }
1020
1021                         // Re-sort topologically, and propagate the new information.
1022                         propagate_gamma_and_color_space();
1023
1024                         found_any = true;
1025                         break;
1026                 }
1027
1028                 char filename[256];
1029                 sprintf(filename, "step5-colorspacefix-iter%u.dot", ++colorspace_propagation_pass);
1030                 output_dot(filename);
1031                 assert(colorspace_propagation_pass < 100);
1032         } while (found_any);
1033
1034         for (unsigned i = 0; i < nodes.size(); ++i) {
1035                 Node *node = nodes[i];
1036                 if (node->disabled) {
1037                         continue;
1038                 }
1039                 assert(node->output_color_space != COLORSPACE_INVALID);
1040         }
1041 }
1042
1043 bool EffectChain::node_needs_alpha_fix(Node *node)
1044 {
1045         if (node->disabled) {
1046                 return false;
1047         }
1048
1049         // propagate_alpha() has already set our output to ALPHA_INVALID if the
1050         // inputs differ or we are otherwise in mismatch, so we can rely on that.
1051         return (node->output_alpha_type == ALPHA_INVALID);
1052 }
1053
1054 // Fix up alpha so that there are no ALPHA_INVALID nodes left in
1055 // the graph. Similar to fix_internal_color_spaces().
1056 void EffectChain::fix_internal_alpha(unsigned step)
1057 {
1058         unsigned alpha_propagation_pass = 0;
1059         bool found_any;
1060         do {
1061                 found_any = false;
1062                 for (unsigned i = 0; i < nodes.size(); ++i) {
1063                         Node *node = nodes[i];
1064                         if (!node_needs_alpha_fix(node)) {
1065                                 continue;
1066                         }
1067
1068                         // If we need to fix up GammaExpansionEffect, then clearly something
1069                         // is wrong, since the combination of premultiplied alpha and nonlinear inputs
1070                         // is meaningless.
1071                         assert(node->effect->effect_type_id() != "GammaExpansionEffect");
1072
1073                         AlphaType desired_type = ALPHA_PREMULTIPLIED;
1074
1075                         // GammaCompressionEffect is special; it needs postmultiplied alpha.
1076                         if (node->effect->effect_type_id() == "GammaCompressionEffect") {
1077                                 assert(node->incoming_links.size() == 1);
1078                                 assert(node->incoming_links[0]->output_alpha_type == ALPHA_PREMULTIPLIED);
1079                                 desired_type = ALPHA_POSTMULTIPLIED;
1080                         }
1081
1082                         // Go through each input that is not premultiplied alpha, and insert
1083                         // a conversion before it.
1084                         for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
1085                                 Node *input = node->incoming_links[j];
1086                                 assert(input->output_alpha_type != ALPHA_INVALID);
1087                                 if (input->output_alpha_type == desired_type ||
1088                                     input->output_alpha_type == ALPHA_BLANK) {
1089                                         continue;
1090                                 }
1091                                 Node *conversion;
1092                                 if (desired_type == ALPHA_PREMULTIPLIED) {
1093                                         conversion = add_node(new AlphaMultiplicationEffect());
1094                                 } else {
1095                                         conversion = add_node(new AlphaDivisionEffect());
1096                                 }
1097                                 conversion->output_alpha_type = desired_type;
1098                                 replace_sender(input, conversion);
1099                                 connect_nodes(input, conversion);
1100                         }
1101
1102                         // Re-sort topologically, and propagate the new information.
1103                         propagate_gamma_and_color_space();
1104                         propagate_alpha();
1105
1106                         found_any = true;
1107                         break;
1108                 }
1109
1110                 char filename[256];
1111                 sprintf(filename, "step%u-alphafix-iter%u.dot", step, ++alpha_propagation_pass);
1112                 output_dot(filename);
1113                 assert(alpha_propagation_pass < 100);
1114         } while (found_any);
1115
1116         for (unsigned i = 0; i < nodes.size(); ++i) {
1117                 Node *node = nodes[i];
1118                 if (node->disabled) {
1119                         continue;
1120                 }
1121                 assert(node->output_alpha_type != ALPHA_INVALID);
1122         }
1123 }
1124
1125 // Make so that the output is in the desired color space.
1126 void EffectChain::fix_output_color_space()
1127 {
1128         Node *output = find_output_node();
1129         if (output->output_color_space != output_format.color_space) {
1130                 Node *conversion = add_node(new ColorspaceConversionEffect());
1131                 CHECK(conversion->effect->set_int("source_space", output->output_color_space));
1132                 CHECK(conversion->effect->set_int("destination_space", output_format.color_space));
1133                 conversion->output_color_space = output_format.color_space;
1134                 connect_nodes(output, conversion);
1135                 propagate_alpha();
1136                 propagate_gamma_and_color_space();
1137         }
1138 }
1139
1140 // Make so that the output is in the desired pre-/postmultiplication alpha state.
1141 void EffectChain::fix_output_alpha()
1142 {
1143         Node *output = find_output_node();
1144         assert(output->output_alpha_type != ALPHA_INVALID);
1145         if (output->output_alpha_type == ALPHA_BLANK) {
1146                 // No alpha output, so we don't care.
1147                 return;
1148         }
1149         if (output->output_alpha_type == ALPHA_PREMULTIPLIED &&
1150             output_alpha_format == OUTPUT_ALPHA_FORMAT_POSTMULTIPLIED) {
1151                 Node *conversion = add_node(new AlphaDivisionEffect());
1152                 connect_nodes(output, conversion);
1153                 propagate_alpha();
1154                 propagate_gamma_and_color_space();
1155         }
1156         if (output->output_alpha_type == ALPHA_POSTMULTIPLIED &&
1157             output_alpha_format == OUTPUT_ALPHA_FORMAT_PREMULTIPLIED) {
1158                 Node *conversion = add_node(new AlphaMultiplicationEffect());
1159                 connect_nodes(output, conversion);
1160                 propagate_alpha();
1161                 propagate_gamma_and_color_space();
1162         }
1163 }
1164
1165 bool EffectChain::node_needs_gamma_fix(Node *node)
1166 {
1167         if (node->disabled) {
1168                 return false;
1169         }
1170
1171         // Small hack since the output is not an explicit node:
1172         // If we are the last node and our output is in the wrong
1173         // space compared to EffectChain's output, we need to fix it.
1174         // This will only take us to linear, but fix_output_gamma()
1175         // will come and take us to the desired output gamma
1176         // if it is needed.
1177         //
1178         // This needs to be before everything else, since it could
1179         // even apply to inputs (if they are the only effect).
1180         if (node->outgoing_links.empty() &&
1181             node->output_gamma_curve != output_format.gamma_curve &&
1182             node->output_gamma_curve != GAMMA_LINEAR) {
1183                 return true;
1184         }
1185
1186         if (node->effect->num_inputs() == 0) {
1187                 return false;
1188         }
1189
1190         // propagate_gamma_and_color_space() has already set our output
1191         // to GAMMA_INVALID if the inputs differ, so we can rely on that,
1192         // except for GammaCompressionEffect.
1193         if (node->output_gamma_curve == GAMMA_INVALID) {
1194                 return true;
1195         }
1196         if (node->effect->effect_type_id() == "GammaCompressionEffect") {
1197                 assert(node->incoming_links.size() == 1);
1198                 return node->incoming_links[0]->output_gamma_curve != GAMMA_LINEAR;
1199         }
1200
1201         return (node->effect->needs_linear_light() && node->output_gamma_curve != GAMMA_LINEAR);
1202 }
1203
1204 // Very similar to fix_internal_color_spaces(), but for gamma.
1205 // There is one difference, though; before we start adding conversion nodes,
1206 // we see if we can get anything out of asking the sources to deliver
1207 // linear gamma directly. fix_internal_gamma_by_asking_inputs()
1208 // does that part, while fix_internal_gamma_by_inserting_nodes()
1209 // inserts nodes as needed afterwards.
1210 void EffectChain::fix_internal_gamma_by_asking_inputs(unsigned step)
1211 {
1212         unsigned gamma_propagation_pass = 0;
1213         bool found_any;
1214         do {
1215                 found_any = false;
1216                 for (unsigned i = 0; i < nodes.size(); ++i) {
1217                         Node *node = nodes[i];
1218                         if (!node_needs_gamma_fix(node)) {
1219                                 continue;
1220                         }
1221
1222                         // See if all inputs can give us linear gamma. If not, leave it.
1223                         vector<Node *> nonlinear_inputs;
1224                         find_all_nonlinear_inputs(node, &nonlinear_inputs);
1225                         assert(!nonlinear_inputs.empty());
1226
1227                         bool all_ok = true;
1228                         for (unsigned i = 0; i < nonlinear_inputs.size(); ++i) {
1229                                 Input *input = static_cast<Input *>(nonlinear_inputs[i]->effect);
1230                                 all_ok &= input->can_output_linear_gamma();
1231                         }
1232
1233                         if (!all_ok) {
1234                                 continue;
1235                         }
1236
1237                         for (unsigned i = 0; i < nonlinear_inputs.size(); ++i) {
1238                                 CHECK(nonlinear_inputs[i]->effect->set_int("output_linear_gamma", 1));
1239                                 nonlinear_inputs[i]->output_gamma_curve = GAMMA_LINEAR;
1240                         }
1241
1242                         // Re-sort topologically, and propagate the new information.
1243                         propagate_gamma_and_color_space();
1244
1245                         found_any = true;
1246                         break;
1247                 }
1248
1249                 char filename[256];
1250                 sprintf(filename, "step%u-gammafix-iter%u.dot", step, ++gamma_propagation_pass);
1251                 output_dot(filename);
1252                 assert(gamma_propagation_pass < 100);
1253         } while (found_any);
1254 }
1255
1256 void EffectChain::fix_internal_gamma_by_inserting_nodes(unsigned step)
1257 {
1258         unsigned gamma_propagation_pass = 0;
1259         bool found_any;
1260         do {
1261                 found_any = false;
1262                 for (unsigned i = 0; i < nodes.size(); ++i) {
1263                         Node *node = nodes[i];
1264                         if (!node_needs_gamma_fix(node)) {
1265                                 continue;
1266                         }
1267
1268                         // Special case: We could be an input and still be asked to
1269                         // fix our gamma; if so, we should be the only node
1270                         // (as node_needs_gamma_fix() would only return true in
1271                         // for an input in that case). That means we should insert
1272                         // a conversion node _after_ ourselves.
1273                         if (node->incoming_links.empty()) {
1274                                 assert(node->outgoing_links.empty());
1275                                 Node *conversion = add_node(new GammaExpansionEffect());
1276                                 CHECK(conversion->effect->set_int("source_curve", node->output_gamma_curve));
1277                                 conversion->output_gamma_curve = GAMMA_LINEAR;
1278                                 connect_nodes(node, conversion);
1279                         }
1280
1281                         // If not, go through each input that is not linear gamma,
1282                         // and insert a gamma conversion after it.
1283                         for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
1284                                 Node *input = node->incoming_links[j];
1285                                 assert(input->output_gamma_curve != GAMMA_INVALID);
1286                                 if (input->output_gamma_curve == GAMMA_LINEAR) {
1287                                         continue;
1288                                 }
1289                                 Node *conversion = add_node(new GammaExpansionEffect());
1290                                 CHECK(conversion->effect->set_int("source_curve", input->output_gamma_curve));
1291                                 conversion->output_gamma_curve = GAMMA_LINEAR;
1292                                 replace_sender(input, conversion);
1293                                 connect_nodes(input, conversion);
1294                         }
1295
1296                         // Re-sort topologically, and propagate the new information.
1297                         propagate_alpha();
1298                         propagate_gamma_and_color_space();
1299
1300                         found_any = true;
1301                         break;
1302                 }
1303
1304                 char filename[256];
1305                 sprintf(filename, "step%u-gammafix-iter%u.dot", step, ++gamma_propagation_pass);
1306                 output_dot(filename);
1307                 assert(gamma_propagation_pass < 100);
1308         } while (found_any);
1309
1310         for (unsigned i = 0; i < nodes.size(); ++i) {
1311                 Node *node = nodes[i];
1312                 if (node->disabled) {
1313                         continue;
1314                 }
1315                 assert(node->output_gamma_curve != GAMMA_INVALID);
1316         }
1317 }
1318
1319 // Make so that the output is in the desired gamma.
1320 // Note that this assumes linear input gamma, so it might create the need
1321 // for another pass of fix_internal_gamma().
1322 void EffectChain::fix_output_gamma()
1323 {
1324         Node *output = find_output_node();
1325         if (output->output_gamma_curve != output_format.gamma_curve) {
1326                 Node *conversion = add_node(new GammaCompressionEffect());
1327                 CHECK(conversion->effect->set_int("destination_curve", output_format.gamma_curve));
1328                 conversion->output_gamma_curve = output_format.gamma_curve;
1329                 connect_nodes(output, conversion);
1330         }
1331 }
1332
1333 // If the user has requested dither, add a DitherEffect right at the end
1334 // (after GammaCompressionEffect etc.). This needs to be done after everything else,
1335 // since dither is about the only effect that can _not_ be done in linear space.
1336 void EffectChain::add_dither_if_needed()
1337 {
1338         if (num_dither_bits == 0) {
1339                 return;
1340         }
1341         Node *output = find_output_node();
1342         Node *dither = add_node(new DitherEffect());
1343         CHECK(dither->effect->set_int("num_bits", num_dither_bits));
1344         connect_nodes(output, dither);
1345
1346         dither_effect = dither->effect;
1347 }
1348
1349 // Find the output node. This is, simply, one that has no outgoing links.
1350 // If there are multiple ones, the graph is malformed (we do not support
1351 // multiple outputs right now).
1352 Node *EffectChain::find_output_node()
1353 {
1354         vector<Node *> output_nodes;
1355         for (unsigned i = 0; i < nodes.size(); ++i) {
1356                 Node *node = nodes[i];
1357                 if (node->disabled) {
1358                         continue;
1359                 }
1360                 if (node->outgoing_links.empty()) {
1361                         output_nodes.push_back(node);
1362                 }
1363         }
1364         assert(output_nodes.size() == 1);
1365         return output_nodes[0];
1366 }
1367
1368 void EffectChain::finalize()
1369 {
1370         // Save the current locale, and set it to C, so that we can output decimal
1371         // numbers with printf and be sure to get them in the format mandated by GLSL.
1372         char *saved_locale = setlocale(LC_NUMERIC, "C");
1373
1374         // Output the graph as it is before we do any conversions on it.
1375         output_dot("step0-start.dot");
1376
1377         // Give each effect in turn a chance to rewrite its own part of the graph.
1378         // Note that if more effects are added as part of this, they will be
1379         // picked up as part of the same for loop, since they are added at the end.
1380         for (unsigned i = 0; i < nodes.size(); ++i) {
1381                 nodes[i]->effect->rewrite_graph(this, nodes[i]);
1382         }
1383         output_dot("step1-rewritten.dot");
1384
1385         find_color_spaces_for_inputs();
1386         output_dot("step2-input-colorspace.dot");
1387
1388         propagate_alpha();
1389         output_dot("step3-propagated-alpha.dot");
1390
1391         propagate_gamma_and_color_space();
1392         output_dot("step4-propagated-all.dot");
1393
1394         fix_internal_color_spaces();
1395         fix_internal_alpha(6);
1396         fix_output_color_space();
1397         output_dot("step7-output-colorspacefix.dot");
1398         fix_output_alpha();
1399         output_dot("step8-output-alphafix.dot");
1400
1401         // Note that we need to fix gamma after colorspace conversion,
1402         // because colorspace conversions might create needs for gamma conversions.
1403         // Also, we need to run an extra pass of fix_internal_gamma() after
1404         // fixing the output gamma, as we only have conversions to/from linear,
1405         // and fix_internal_alpha() since GammaCompressionEffect needs
1406         // postmultiplied input.
1407         fix_internal_gamma_by_asking_inputs(9);
1408         fix_internal_gamma_by_inserting_nodes(10);
1409         fix_output_gamma();
1410         output_dot("step11-output-gammafix.dot");
1411         propagate_alpha();
1412         output_dot("step12-output-alpha-propagated.dot");
1413         fix_internal_alpha(13);
1414         output_dot("step14-output-alpha-fixed.dot");
1415         fix_internal_gamma_by_asking_inputs(15);
1416         fix_internal_gamma_by_inserting_nodes(16);
1417
1418         output_dot("step17-before-dither.dot");
1419
1420         add_dither_if_needed();
1421
1422         output_dot("step18-final.dot");
1423
1424         // Construct all needed GLSL programs, starting at the output.
1425         construct_glsl_programs(find_output_node());
1426
1427         output_dot("step19-split-to-phases.dot");
1428
1429         assert(phases[0]->inputs.empty());
1430
1431         finalized = true;
1432         setlocale(LC_NUMERIC, saved_locale);
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         GLuint fbo = 0;
1442
1443         if (width == 0 && height == 0) {
1444                 GLint viewport[4];
1445                 glGetIntegerv(GL_VIEWPORT, viewport);
1446                 x = viewport[0];
1447                 y = viewport[1];
1448                 width = viewport[2];
1449                 height = viewport[3];
1450         }
1451
1452         // Basic state.
1453         glDisable(GL_BLEND);
1454         check_error();
1455         glDisable(GL_DEPTH_TEST);
1456         check_error();
1457         glDepthMask(GL_FALSE);
1458         check_error();
1459
1460         if (phases.size() > 1) {
1461                 glGenFramebuffers(1, &fbo);
1462                 check_error();
1463                 glBindFramebuffer(GL_FRAMEBUFFER, fbo);
1464                 check_error();
1465         }
1466
1467         set<Node *> generated_mipmaps;
1468
1469         // We choose the simplest option of having one texture per output,
1470         // since otherwise this turns into an (albeit simple) register allocation problem.
1471         map<Phase *, GLuint> output_textures;
1472
1473         for (unsigned phase = 0; phase < phases.size(); ++phase) {
1474                 // Find a texture for this phase.
1475                 inform_input_sizes(phases[phase]);
1476                 if (phase != phases.size() - 1) {
1477                         find_output_size(phases[phase]);
1478
1479                         GLuint tex_num = resource_pool->create_2d_texture(GL_RGBA16F_ARB, phases[phase]->output_width, phases[phase]->output_height);
1480                         output_textures.insert(make_pair(phases[phase], tex_num));
1481                 }
1482
1483                 const GLuint glsl_program_num = phases[phase]->glsl_program_num;
1484                 check_error();
1485                 glUseProgram(glsl_program_num);
1486                 check_error();
1487
1488                 // Set up RTT inputs for this phase.
1489                 for (unsigned sampler = 0; sampler < phases[phase]->inputs.size(); ++sampler) {
1490                         glActiveTexture(GL_TEXTURE0 + sampler);
1491                         Node *input = phases[phase]->inputs[sampler];
1492                         input->bound_sampler_num = sampler;
1493                         glBindTexture(GL_TEXTURE_2D, output_textures[input->phase]);
1494                         check_error();
1495                         if (phases[phase]->input_needs_mipmaps) {
1496                                 if (generated_mipmaps.count(input) == 0) {
1497                                         glGenerateMipmap(GL_TEXTURE_2D);
1498                                         check_error();
1499                                         generated_mipmaps.insert(input);
1500                                 }
1501                                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_NEAREST);
1502                                 check_error();
1503                         } else {
1504                                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
1505                                 check_error();
1506                         }
1507                         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
1508                         check_error();
1509                         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
1510                         check_error();
1511
1512                         string texture_name = string("tex_") + phases[phase]->effect_ids[input];
1513                         glUniform1i(glGetUniformLocation(glsl_program_num, texture_name.c_str()), sampler);
1514                         check_error();
1515                 }
1516
1517                 // And now the output.
1518                 if (phase == phases.size() - 1) {
1519                         // Last phase goes to the output the user specified.
1520                         glBindFramebuffer(GL_FRAMEBUFFER, dest_fbo);
1521                         check_error();
1522                         GLenum status = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);
1523                         assert(status == GL_FRAMEBUFFER_COMPLETE);
1524                         glViewport(x, y, width, height);
1525                         if (dither_effect != NULL) {
1526                                 CHECK(dither_effect->set_int("output_width", width));
1527                                 CHECK(dither_effect->set_int("output_height", height));
1528                         }
1529                 } else {
1530                         glFramebufferTexture2D(
1531                                 GL_FRAMEBUFFER,
1532                                 GL_COLOR_ATTACHMENT0,
1533                                 GL_TEXTURE_2D,
1534                                 output_textures[phases[phase]],
1535                                 0);
1536                         check_error();
1537                         GLenum status = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);
1538                         assert(status == GL_FRAMEBUFFER_COMPLETE);
1539                         glViewport(0, 0, phases[phase]->output_width, phases[phase]->output_height);
1540                 }
1541
1542                 // Give the required parameters to all the effects.
1543                 unsigned sampler_num = phases[phase]->inputs.size();
1544                 for (unsigned i = 0; i < phases[phase]->effects.size(); ++i) {
1545                         Node *node = phases[phase]->effects[i];
1546                         unsigned old_sampler_num = sampler_num;
1547                         node->effect->set_gl_state(glsl_program_num, phases[phase]->effect_ids[node], &sampler_num);
1548                         check_error();
1549
1550                         if (node->effect->is_single_texture()) {
1551                                 assert(sampler_num - old_sampler_num == 1);
1552                                 node->bound_sampler_num = old_sampler_num;
1553                         } else {
1554                                 node->bound_sampler_num = -1;
1555                         }
1556                 }
1557
1558                 // Now draw!
1559                 float vertices[] = {
1560                         0.0f, 1.0f,
1561                         0.0f, 0.0f,
1562                         1.0f, 1.0f,
1563                         1.0f, 0.0f
1564                 };
1565
1566                 GLuint vao;
1567                 glGenVertexArrays(1, &vao);
1568                 check_error();
1569                 glBindVertexArray(vao);
1570                 check_error();
1571
1572                 GLuint position_vbo = fill_vertex_attribute(glsl_program_num, "position", 2, GL_FLOAT, sizeof(vertices), vertices);
1573                 GLuint texcoord_vbo = fill_vertex_attribute(glsl_program_num, "texcoord", 2, GL_FLOAT, sizeof(vertices), vertices);  // Same as vertices.
1574
1575                 glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
1576                 check_error();
1577
1578                 cleanup_vertex_attribute(glsl_program_num, "position", position_vbo);
1579                 cleanup_vertex_attribute(glsl_program_num, "texcoord", texcoord_vbo);
1580
1581                 glUseProgram(0);
1582                 check_error();
1583
1584                 for (unsigned i = 0; i < phases[phase]->effects.size(); ++i) {
1585                         Node *node = phases[phase]->effects[i];
1586                         node->effect->clear_gl_state();
1587                 }
1588
1589                 glDeleteVertexArrays(1, &vao);
1590                 check_error();
1591         }
1592
1593         for (map<Phase *, GLuint>::const_iterator texture_it = output_textures.begin();
1594              texture_it != output_textures.end();
1595              ++texture_it) {
1596                 resource_pool->release_2d_texture(texture_it->second);
1597         }
1598
1599         glBindFramebuffer(GL_FRAMEBUFFER, 0);
1600         check_error();
1601
1602         if (fbo != 0) {
1603                 glDeleteFramebuffers(1, &fbo);
1604                 check_error();
1605         }
1606 }
1607
1608 }  // namespace movit