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 void EffectChain::find_all_nonlinear_inputs(Node *node, vector<Node *> *nonlinear_inputs)
 153 {
 154         if (node->output_gamma_curve == GAMMA_LINEAR &&
 155             node->effect->effect_type_id() != "GammaCompressionEffect") {
 156                 return;
 157         }
 158         if (node->effect->num_inputs() == 0) {
 159                 nonlinear_inputs->push_back(node);
 160         } else {
 161                 assert(node->effect->num_inputs() == node->incoming_links.size());
 162                 for (unsigned i = 0; i < node->incoming_links.size(); ++i) {
 163                         find_all_nonlinear_inputs(node->incoming_links[i], nonlinear_inputs);
 164                 }
 165         }
 166 }
 167
 168 Effect *EffectChain::add_effect(Effect *effect, const vector<Effect *> &inputs)
 169 {
 170         assert(!finalized);
 171         assert(inputs.size() == effect->num_inputs());
 172         Node *node = add_node(effect);
 173         for (unsigned i = 0; i < inputs.size(); ++i) {
 174                 assert(node_map.count(inputs[i]) != 0);
 175                 connect_nodes(node_map[inputs[i]], node);
 176         }
 177         return effect;
 178 }
 179
 180 // GLSL pre-1.30 doesn't support token pasting. Replace PREFIX(x) with <effect_id>_x.
 181 string replace_prefix(const string &text, const string &prefix)
 182 {
 183         string output;
 184         size_t start = 0;
 185
 186         while (start < text.size()) {
 187                 size_t pos = text.find("PREFIX(", start);
 188                 if (pos == string::npos) {
 189                         output.append(text.substr(start, string::npos));
 190                         break;
 191                 }
 192
 193                 output.append(text.substr(start, pos - start));
 194                 output.append(prefix);
 195                 output.append("_");
 196
 197                 pos += strlen("PREFIX(");
 198
 199                 // Output stuff until we find the matching ), which we then eat.
 200                 int depth = 1;
 201                 size_t end_arg_pos = pos;
 202                 while (end_arg_pos < text.size()) {
 203                         if (text[end_arg_pos] == '(') {
 204                                 ++depth;
 205                         } else if (text[end_arg_pos] == ')') {
 206                                 --depth;
 207                                 if (depth == 0) {
 208                                         break;
 209                                 }
 210                         }
 211                         ++end_arg_pos;
 212                 }
 213                 output.append(text.substr(pos, end_arg_pos - pos));
 214                 ++end_arg_pos;
 215                 assert(depth == 0);
 216                 start = end_arg_pos;
 217         }
 218         return output;
 219 }
 220
 221 Phase *EffectChain::compile_glsl_program(
 222         const vector<Node *> &inputs,
 223         const vector<Node *> &effects)
 224 {
 225         Phase *phase = new Phase;
 226         assert(!effects.empty());
 227
 228         // Deduplicate the inputs.
 229         vector<Node *> true_inputs = inputs;
 230         sort(true_inputs.begin(), true_inputs.end());
 231         true_inputs.erase(unique(true_inputs.begin(), true_inputs.end()), true_inputs.end());
 232
 233         bool input_needs_mipmaps = false;
 234         string frag_shader = read_file("header.frag");
 235
 236         // Create functions for all the texture inputs that we need.
 237         for (unsigned i = 0; i < true_inputs.size(); ++i) {
 238                 Node *input = true_inputs[i];
 239                 char effect_id[256];
 240                 sprintf(effect_id, "in%u", i);
 241                 phase->effect_ids.insert(make_pair(input, effect_id));
 242
 243                 frag_shader += string("uniform sampler2D tex_") + effect_id + ";\n";
 244                 frag_shader += string("vec4 ") + effect_id + "(vec2 tc) {\n";
 245                 frag_shader += "\treturn texture2D(tex_" + string(effect_id) + ", tc);\n";
 246                 frag_shader += "}\n";
 247                 frag_shader += "\n";
 248         }
 249
 250         vector<Node *> sorted_effects = topological_sort(effects);
 251
 252         for (unsigned i = 0; i < sorted_effects.size(); ++i) {
 253                 Node *node = sorted_effects[i];
 254                 char effect_id[256];
 255                 sprintf(effect_id, "eff%u", i);
 256                 phase->effect_ids.insert(make_pair(node, effect_id));
 257
 258                 if (node->incoming_links.size() == 1) {
 259                         frag_shader += string("#define INPUT ") + phase->effect_ids[node->incoming_links[0]] + "\n";
 260                 } else {
 261                         for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
 262                                 char buf[256];
 263                                 sprintf(buf, "#define INPUT%d %s\n", j + 1, phase->effect_ids[node->incoming_links[j]].c_str());
 264                                 frag_shader += buf;
 265                         }
 266                 }
 267
 268                 frag_shader += "\n";
 269                 frag_shader += string("#define FUNCNAME ") + effect_id + "\n";
 270                 frag_shader += replace_prefix(node->effect->output_convenience_uniforms(), effect_id);
 271                 frag_shader += replace_prefix(node->effect->output_fragment_shader(), effect_id);
 272                 frag_shader += "#undef PREFIX\n";
 273                 frag_shader += "#undef FUNCNAME\n";
 274                 if (node->incoming_links.size() == 1) {
 275                         frag_shader += "#undef INPUT\n";
 276                 } else {
 277                         for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
 278                                 char buf[256];
 279                                 sprintf(buf, "#undef INPUT%d\n", j + 1);
 280                                 frag_shader += buf;
 281                         }
 282                 }
 283                 frag_shader += "\n";
 284
 285                 input_needs_mipmaps |= node->effect->needs_mipmaps();
 286         }
 287         for (unsigned i = 0; i < sorted_effects.size(); ++i) {
 288                 Node *node = sorted_effects[i];
 289                 if (node->effect->num_inputs() == 0) {
 290                         CHECK(node->effect->set_int("needs_mipmaps", input_needs_mipmaps));
 291                 }
 292         }
 293         frag_shader += string("#define INPUT ") + phase->effect_ids[sorted_effects.back()] + "\n";
 294         frag_shader.append(read_file("footer.frag"));
 295
 296         phase->glsl_program_num = resource_pool->compile_glsl_program(read_file("vs.vert"), frag_shader);
 297         phase->input_needs_mipmaps = input_needs_mipmaps;
 298         phase->inputs = true_inputs;
 299         phase->effects = sorted_effects;
 300
 301         return phase;
 302 }
 303
 304 // Construct GLSL programs, starting at the given effect and following
 305 // the chain from there. We end a program every time we come to an effect
 306 // marked as "needs texture bounce", one that is used by multiple other
 307 // effects, every time an effect wants to change the output size,
 308 // and of course at the end.
 309 //
 310 // We follow a quite simple depth-first search from the output, although
 311 // without any explicit recursion.
 312 void EffectChain::construct_glsl_programs(Node *output)
 313 {
 314         // Which effects have already been completed?
 315         // We need to keep track of it, as an effect with multiple outputs
 316         // could otherwise be calculated multiple times.
 317         set<Node *> completed_effects;
 318
 319         // Effects in the current phase, as well as inputs (outputs from other phases
 320         // that we depend on). Note that since we start iterating from the end,
 321         // the effect list will be in the reverse order.
 322         vector<Node *> this_phase_inputs;
 323         vector<Node *> this_phase_effects;
 324
 325         // Effects that we have yet to calculate, but that we know should
 326         // be in the current phase.
 327         stack<Node *> effects_todo_this_phase;
 328
 329         // Effects that we have yet to calculate, but that come from other phases.
 330         // We delay these until we have this phase done in its entirety,
 331         // at which point we pick any of them and start a new phase from that.
 332         stack<Node *> effects_todo_other_phases;
 333
 334         effects_todo_this_phase.push(output);
 335
 336         for ( ;; ) {  // Termination condition within loop.
 337                 if (!effects_todo_this_phase.empty()) {
 338                         // OK, we have more to do this phase.
 339                         Node *node = effects_todo_this_phase.top();
 340                         effects_todo_this_phase.pop();
 341
 342                         // This should currently only happen for effects that are inputs
 343                         // (either true inputs or phase outputs). We special-case inputs,
 344                         // and then deduplicate phase outputs in compile_glsl_program().
 345                         if (node->effect->num_inputs() == 0) {
 346                                 if (find(this_phase_effects.begin(), this_phase_effects.end(), node) != this_phase_effects.end()) {
 347                                         continue;
 348                                 }
 349                         } else {
 350                                 assert(completed_effects.count(node) == 0);
 351                         }
 352
 353                         this_phase_effects.push_back(node);
 354                         completed_effects.insert(node);
 355
 356                         // Find all the dependencies of this effect, and add them to the stack.
 357                         vector<Node *> deps = node->incoming_links;
 358                         assert(node->effect->num_inputs() == deps.size());
 359                         for (unsigned i = 0; i < deps.size(); ++i) {
 360                                 bool start_new_phase = false;
 361
 362                                 // FIXME: If we sample directly from a texture, we won't need this.
 363                                 if (node->effect->needs_texture_bounce()) {
 364                                         start_new_phase = true;
 365                                 }
 366
 367                                 if (deps[i]->outgoing_links.size() > 1) {
 368                                         if (deps[i]->effect->num_inputs() > 0) {
 369                                                 // More than one effect uses this as the input,
 370                                                 // and it is not a texture itself.
 371                                                 // The easiest thing to do (and probably also the safest
 372                                                 // performance-wise in most cases) is to bounce it to a texture
 373                                                 // and then let the next passes read from that.
 374                                                 start_new_phase = true;
 375                                         } else {
 376                                                 // For textures, we try to be slightly more clever;
 377                                                 // if none of our outputs need a bounce, we don't bounce
 378                                                 // but instead simply use the effect many times.
 379                                                 //
 380                                                 // Strictly speaking, we could bounce it for some outputs
 381                                                 // and use it directly for others, but the processing becomes
 382                                                 // somewhat simpler if the effect is only used in one such way.
 383                                                 for (unsigned j = 0; j < deps[i]->outgoing_links.size(); ++j) {
 384                                                         Node *rdep = deps[i]->outgoing_links[j];
 385                                                         start_new_phase |= rdep->effect->needs_texture_bounce();
 386                                                 }
 387                                         }
 388                                 }
 389
 390                                 if (deps[i]->effect->changes_output_size()) {
 391                                         start_new_phase = true;
 392                                 }
 393
 394                                 if (start_new_phase) {
 395                                         effects_todo_other_phases.push(deps[i]);
 396                                         this_phase_inputs.push_back(deps[i]);
 397                                 } else {
 398                                         effects_todo_this_phase.push(deps[i]);
 399                                 }
 400                         }
 401                         continue;
 402                 }
 403
 404                 // No more effects to do this phase. Take all the ones we have,
 405                 // and create a GLSL program for it.
 406                 if (!this_phase_effects.empty()) {
 407                         reverse(this_phase_effects.begin(), this_phase_effects.end());
 408                         phases.push_back(compile_glsl_program(this_phase_inputs, this_phase_effects));
 409                         this_phase_effects.back()->phase = phases.back();
 410                         this_phase_inputs.clear();
 411                         this_phase_effects.clear();
 412                 }
 413                 assert(this_phase_inputs.empty());
 414                 assert(this_phase_effects.empty());
 415
 416                 // If we have no effects left, exit.
 417                 if (effects_todo_other_phases.empty()) {
 418                         break;
 419                 }
 420
 421                 Node *node = effects_todo_other_phases.top();
 422                 effects_todo_other_phases.pop();
 423
 424                 if (completed_effects.count(node) == 0) {
 425                         // Start a new phase, calculating from this effect.
 426                         effects_todo_this_phase.push(node);
 427                 }
 428         }
 429
 430         // Finally, since the phases are found from the output but must be executed
 431         // from the input(s), reverse them, too.
 432         reverse(phases.begin(), phases.end());
 433 }
 434
 435 void EffectChain::output_dot(const char *filename)
 436 {
 437         if (movit_debug_level != MOVIT_DEBUG_ON) {
 438                 return;
 439         }
 440
 441         FILE *fp = fopen(filename, "w");
 442         if (fp == NULL) {
 443                 perror(filename);
 444                 exit(1);
 445         }
 446
 447         fprintf(fp, "digraph G {\n");
 448         fprintf(fp, "  output [shape=box label=\"(output)\"];\n");
 449         for (unsigned i = 0; i < nodes.size(); ++i) {
 450                 // Find out which phase this event belongs to.
 451                 vector<int> in_phases;
 452                 for (unsigned j = 0; j < phases.size(); ++j) {
 453                         const Phase* p = phases[j];
 454                         if (find(p->effects.begin(), p->effects.end(), nodes[i]) != p->effects.end()) {
 455                                 in_phases.push_back(j);
 456                         }
 457                 }
 458
 459                 if (in_phases.empty()) {
 460                         fprintf(fp, "  n%ld [label=\"%s\"];\n", (long)nodes[i], nodes[i]->effect->effect_type_id().c_str());
 461                 } else if (in_phases.size() == 1) {
 462                         fprintf(fp, "  n%ld [label=\"%s\" style=\"filled\" fillcolor=\"/accent8/%d\"];\n",
 463                                 (long)nodes[i], nodes[i]->effect->effect_type_id().c_str(),
 464                                 (in_phases[0] % 8) + 1);
 465                 } else {
 466                         // If we had new enough Graphviz, style="wedged" would probably be ideal here.
 467                         // But alas.
 468                         fprintf(fp, "  n%ld [label=\"%s [in multiple phases]\" style=\"filled\" fillcolor=\"/accent8/%d\"];\n",
 469                                 (long)nodes[i], nodes[i]->effect->effect_type_id().c_str(),
 470                                 (in_phases[0] % 8) + 1);
 471                 }
 472
 473                 char from_node_id[256];
 474                 snprintf(from_node_id, 256, "n%ld", (long)nodes[i]);
 475
 476                 for (unsigned j = 0; j < nodes[i]->outgoing_links.size(); ++j) {
 477                         char to_node_id[256];
 478                         snprintf(to_node_id, 256, "n%ld", (long)nodes[i]->outgoing_links[j]);
 479
 480                         vector<string> labels = get_labels_for_edge(nodes[i], nodes[i]->outgoing_links[j]);
 481                         output_dot_edge(fp, from_node_id, to_node_id, labels);
 482                 }
 483
 484                 if (nodes[i]->outgoing_links.empty() && !nodes[i]->disabled) {
 485                         // Output node.
 486                         vector<string> labels = get_labels_for_edge(nodes[i], NULL);
 487                         output_dot_edge(fp, from_node_id, "output", labels);
 488                 }
 489         }
 490         fprintf(fp, "}\n");
 491
 492         fclose(fp);
 493 }
 494
 495 vector<string> EffectChain::get_labels_for_edge(const Node *from, const Node *to)
 496 {
 497         vector<string> labels;
 498
 499         if (to != NULL && to->effect->needs_texture_bounce()) {
 500                 labels.push_back("needs_bounce");
 501         }
 502         if (from->effect->changes_output_size()) {
 503                 labels.push_back("resize");
 504         }
 505
 506         switch (from->output_color_space) {
 507         case COLORSPACE_INVALID:
 508                 labels.push_back("spc[invalid]");
 509                 break;
 510         case COLORSPACE_REC_601_525:
 511                 labels.push_back("spc[rec601-525]");
 512                 break;
 513         case COLORSPACE_REC_601_625:
 514                 labels.push_back("spc[rec601-625]");
 515                 break;
 516         default:
 517                 break;
 518         }
 519
 520         switch (from->output_gamma_curve) {
 521         case GAMMA_INVALID:
 522                 labels.push_back("gamma[invalid]");
 523                 break;
 524         case GAMMA_sRGB:
 525                 labels.push_back("gamma[sRGB]");
 526                 break;
 527         case GAMMA_REC_601:  // and GAMMA_REC_709
 528                 labels.push_back("gamma[rec601/709]");
 529                 break;
 530         default:
 531                 break;
 532         }
 533
 534         switch (from->output_alpha_type) {
 535         case ALPHA_INVALID:
 536                 labels.push_back("alpha[invalid]");
 537                 break;
 538         case ALPHA_BLANK:
 539                 labels.push_back("alpha[blank]");
 540                 break;
 541         case ALPHA_POSTMULTIPLIED:
 542                 labels.push_back("alpha[postmult]");
 543                 break;
 544         default:
 545                 break;
 546         }
 547
 548         return labels;
 549 }
 550
 551 void EffectChain::output_dot_edge(FILE *fp,
 552                                   const string &from_node_id,
 553                                   const string &to_node_id,
 554                                   const vector<string> &labels)
 555 {
 556         if (labels.empty()) {
 557                 fprintf(fp, "  %s -> %s;\n", from_node_id.c_str(), to_node_id.c_str());
 558         } else {
 559                 string label = labels[0];
 560                 for (unsigned k = 1; k < labels.size(); ++k) {
 561                         label += ", " + labels[k];
 562                 }
 563                 fprintf(fp, "  %s -> %s [label=\"%s\"];\n", from_node_id.c_str(), to_node_id.c_str(), label.c_str());
 564         }
 565 }
 566
 567 void EffectChain::size_rectangle_to_fit(unsigned width, unsigned height, unsigned *output_width, unsigned *output_height)
 568 {
 569         unsigned scaled_width, scaled_height;
 570
 571         if (float(width) * aspect_denom >= float(height) * aspect_nom) {
 572                 // Same aspect, or W/H > aspect (image is wider than the frame).
 573                 // In either case, keep width, and adjust height.
 574                 scaled_width = width;
 575                 scaled_height = lrintf(width * aspect_denom / aspect_nom);
 576         } else {
 577                 // W/H < aspect (image is taller than the frame), so keep height,
 578                 // and adjust width.
 579                 scaled_width = lrintf(height * aspect_nom / aspect_denom);
 580                 scaled_height = height;
 581         }
 582
 583         // We should be consistently larger or smaller then the existing choice,
 584         // since we have the same aspect.
 585         assert(!(scaled_width < *output_width && scaled_height > *output_height));
 586         assert(!(scaled_height < *output_height && scaled_width > *output_width));
 587
 588         if (scaled_width >= *output_width && scaled_height >= *output_height) {
 589                 *output_width = scaled_width;
 590                 *output_height = scaled_height;
 591         }
 592 }
 593
 594 // Propagate input texture sizes throughout, and inform effects downstream.
 595 // (Like a lot of other code, we depend on effects being in topological order.)
 596 void EffectChain::inform_input_sizes(Phase *phase)
 597 {
 598         // All effects that have a defined size (inputs and RTT inputs)
 599         // get that. Reset all others.
 600         for (unsigned i = 0; i < phase->effects.size(); ++i) {
 601                 Node *node = phase->effects[i];
 602                 if (node->effect->num_inputs() == 0) {
 603                         Input *input = static_cast<Input *>(node->effect);
 604                         node->output_width = input->get_width();
 605                         node->output_height = input->get_height();
 606                         assert(node->output_width != 0);
 607                         assert(node->output_height != 0);
 608                 } else {
 609                         node->output_width = node->output_height = 0;
 610                 }
 611         }
 612         for (unsigned i = 0; i < phase->inputs.size(); ++i) {
 613                 Node *input = phase->inputs[i];
 614                 input->output_width = input->phase->virtual_output_width;
 615                 input->output_height = input->phase->virtual_output_height;
 616                 assert(input->output_width != 0);
 617                 assert(input->output_height != 0);
 618         }
 619
 620         // Now propagate from the inputs towards the end, and inform as we go.
 621         // The rules are simple:
 622         //
 623         //   1. Don't touch effects that already have given sizes (ie., inputs).
 624         //   2. If all of your inputs have the same size, that will be your output size.
 625         //   3. Otherwise, your output size is 0x0.
 626         for (unsigned i = 0; i < phase->effects.size(); ++i) {
 627                 Node *node = phase->effects[i];
 628                 if (node->effect->num_inputs() == 0) {
 629                         continue;
 630                 }
 631                 unsigned this_output_width = 0;
 632                 unsigned this_output_height = 0;
 633                 for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
 634                         Node *input = node->incoming_links[j];
 635                         node->effect->inform_input_size(j, input->output_width, input->output_height);
 636                         if (j == 0) {
 637                                 this_output_width = input->output_width;
 638                                 this_output_height = input->output_height;
 639                         } else if (input->output_width != this_output_width || input->output_height != this_output_height) {
 640                                 // Inputs disagree.
 641                                 this_output_width = 0;
 642                                 this_output_height = 0;
 643                         }
 644                 }
 645                 node->output_width = this_output_width;
 646                 node->output_height = this_output_height;
 647         }
 648 }
 649
 650 // Note: You should call inform_input_sizes() before this, as the last effect's
 651 // desired output size might change based on the inputs.
 652 void EffectChain::find_output_size(Phase *phase)
 653 {
 654         Node *output_node = phase->effects.back();
 655
 656         // If the last effect explicitly sets an output size, use that.
 657         if (output_node->effect->changes_output_size()) {
 658                 output_node->effect->get_output_size(&phase->output_width, &phase->output_height,
 659                                                      &phase->virtual_output_width, &phase->virtual_output_height);
 660                 return;
 661         }
 662
 663         // If all effects have the same size, use that.
 664         unsigned output_width = 0, output_height = 0;
 665         bool all_inputs_same_size = true;
 666
 667         for (unsigned i = 0; i < phase->inputs.size(); ++i) {
 668                 Node *input = phase->inputs[i];
 669                 assert(input->phase->output_width != 0);
 670                 assert(input->phase->output_height != 0);
 671                 if (output_width == 0 && output_height == 0) {
 672                         output_width = input->phase->virtual_output_width;
 673                         output_height = input->phase->virtual_output_height;
 674                 } else if (output_width != input->phase->virtual_output_width ||
 675                            output_height != input->phase->virtual_output_height) {
 676                         all_inputs_same_size = false;
 677                 }
 678         }
 679         for (unsigned i = 0; i < phase->effects.size(); ++i) {
 680                 Effect *effect = phase->effects[i]->effect;
 681                 if (effect->num_inputs() != 0) {
 682                         continue;
 683                 }
 684
 685                 Input *input = static_cast<Input *>(effect);
 686                 if (output_width == 0 && output_height == 0) {
 687                         output_width = input->get_width();
 688                         output_height = input->get_height();
 689                 } else if (output_width != input->get_width() ||
 690                            output_height != input->get_height()) {
 691                         all_inputs_same_size = false;
 692                 }
 693         }
 694
 695         if (all_inputs_same_size) {
 696                 assert(output_width != 0);
 697                 assert(output_height != 0);
 698                 phase->virtual_output_width = phase->output_width = output_width;
 699                 phase->virtual_output_height = phase->output_height = output_height;
 700                 return;
 701         }
 702
 703         // If not, fit all the inputs into the current aspect, and select the largest one.
 704         output_width = 0;
 705         output_height = 0;
 706         for (unsigned i = 0; i < phase->inputs.size(); ++i) {
 707                 Node *input = phase->inputs[i];
 708                 assert(input->phase->output_width != 0);
 709                 assert(input->phase->output_height != 0);
 710                 size_rectangle_to_fit(input->phase->output_width, input->phase->output_height, &output_width, &output_height);
 711         }
 712         for (unsigned i = 0; i < phase->effects.size(); ++i) {
 713                 Effect *effect = phase->effects[i]->effect;
 714                 if (effect->num_inputs() != 0) {
 715                         continue;
 716                 }
 717
 718                 Input *input = static_cast<Input *>(effect);
 719                 size_rectangle_to_fit(input->get_width(), input->get_height(), &output_width, &output_height);
 720         }
 721         assert(output_width != 0);
 722         assert(output_height != 0);
 723         phase->virtual_output_width = phase->output_width = output_width;
 724         phase->virtual_output_height = phase->output_height = output_height;
 725 }
 726
 727 void EffectChain::sort_all_nodes_topologically()
 728 {
 729         nodes = topological_sort(nodes);
 730 }
 731
 732 vector<Node *> EffectChain::topological_sort(const vector<Node *> &nodes)
 733 {
 734         set<Node *> nodes_left_to_visit(nodes.begin(), nodes.end());
 735         vector<Node *> sorted_list;
 736         for (unsigned i = 0; i < nodes.size(); ++i) {
 737                 topological_sort_visit_node(nodes[i], &nodes_left_to_visit, &sorted_list);
 738         }
 739         reverse(sorted_list.begin(), sorted_list.end());
 740         return sorted_list;
 741 }
 742
 743 void EffectChain::topological_sort_visit_node(Node *node, set<Node *> *nodes_left_to_visit, vector<Node *> *sorted_list)
 744 {
 745         if (nodes_left_to_visit->count(node) == 0) {
 746                 return;
 747         }
 748         nodes_left_to_visit->erase(node);
 749         for (unsigned i = 0; i < node->outgoing_links.size(); ++i) {
 750                 topological_sort_visit_node(node->outgoing_links[i], nodes_left_to_visit, sorted_list);
 751         }
 752         sorted_list->push_back(node);
 753 }
 754
 755 void EffectChain::find_color_spaces_for_inputs()
 756 {
 757         for (unsigned i = 0; i < nodes.size(); ++i) {
 758                 Node *node = nodes[i];
 759                 if (node->disabled) {
 760                         continue;
 761                 }
 762                 if (node->incoming_links.size() == 0) {
 763                         Input *input = static_cast<Input *>(node->effect);
 764                         node->output_color_space = input->get_color_space();
 765                         node->output_gamma_curve = input->get_gamma_curve();
 766
 767                         Effect::AlphaHandling alpha_handling = input->alpha_handling();
 768                         switch (alpha_handling) {
 769                         case Effect::OUTPUT_BLANK_ALPHA:
 770                                 node->output_alpha_type = ALPHA_BLANK;
 771                                 break;
 772                         case Effect::INPUT_AND_OUTPUT_PREMULTIPLIED_ALPHA:
 773                                 node->output_alpha_type = ALPHA_PREMULTIPLIED;
 774                                 break;
 775                         case Effect::OUTPUT_POSTMULTIPLIED_ALPHA:
 776                                 node->output_alpha_type = ALPHA_POSTMULTIPLIED;
 777                                 break;
 778                         case Effect::INPUT_PREMULTIPLIED_ALPHA_KEEP_BLANK:
 779                         case Effect::DONT_CARE_ALPHA_TYPE:
 780                         default:
 781                                 assert(false);
 782                         }
 783
 784                         if (node->output_alpha_type == ALPHA_PREMULTIPLIED) {
 785                                 assert(node->output_gamma_curve == GAMMA_LINEAR);
 786                         }
 787                 }
 788         }
 789 }
 790
 791 // Propagate gamma and color space information as far as we can in the graph.
 792 // The rules are simple: Anything where all the inputs agree, get that as
 793 // output as well. Anything else keeps having *_INVALID.
 794 void EffectChain::propagate_gamma_and_color_space()
 795 {
 796         // We depend on going through the nodes in order.
 797         sort_all_nodes_topologically();
 798
 799         for (unsigned i = 0; i < nodes.size(); ++i) {
 800                 Node *node = nodes[i];
 801                 if (node->disabled) {
 802                         continue;
 803                 }
 804                 assert(node->incoming_links.size() == node->effect->num_inputs());
 805                 if (node->incoming_links.size() == 0) {
 806                         assert(node->output_color_space != COLORSPACE_INVALID);
 807                         assert(node->output_gamma_curve != GAMMA_INVALID);
 808                         continue;
 809                 }
 810
 811                 Colorspace color_space = node->incoming_links[0]->output_color_space;
 812                 GammaCurve gamma_curve = node->incoming_links[0]->output_gamma_curve;
 813                 for (unsigned j = 1; j < node->incoming_links.size(); ++j) {
 814                         if (node->incoming_links[j]->output_color_space != color_space) {
 815                                 color_space = COLORSPACE_INVALID;
 816                         }
 817                         if (node->incoming_links[j]->output_gamma_curve != gamma_curve) {
 818                                 gamma_curve = GAMMA_INVALID;
 819                         }
 820                 }
 821
 822                 // The conversion effects already have their outputs set correctly,
 823                 // so leave them alone.
 824                 if (node->effect->effect_type_id() != "ColorspaceConversionEffect") {
 825                         node->output_color_space = color_space;
 826                 }
 827                 if (node->effect->effect_type_id() != "GammaCompressionEffect" &&
 828                     node->effect->effect_type_id() != "GammaExpansionEffect") {
 829                         node->output_gamma_curve = gamma_curve;
 830                 }
 831         }
 832 }
 833
 834 // Propagate alpha information as far as we can in the graph.
 835 // Similar to propagate_gamma_and_color_space().
 836 void EffectChain::propagate_alpha()
 837 {
 838         // We depend on going through the nodes in order.
 839         sort_all_nodes_topologically();
 840
 841         for (unsigned i = 0; i < nodes.size(); ++i) {
 842                 Node *node = nodes[i];
 843                 if (node->disabled) {
 844                         continue;
 845                 }
 846                 assert(node->incoming_links.size() == node->effect->num_inputs());
 847                 if (node->incoming_links.size() == 0) {
 848                         assert(node->output_alpha_type != ALPHA_INVALID);
 849                         continue;
 850                 }
 851
 852                 // The alpha multiplication/division effects are special cases.
 853                 if (node->effect->effect_type_id() == "AlphaMultiplicationEffect") {
 854                         assert(node->incoming_links.size() == 1);
 855                         assert(node->incoming_links[0]->output_alpha_type == ALPHA_POSTMULTIPLIED);
 856                         node->output_alpha_type = ALPHA_PREMULTIPLIED;
 857                         continue;
 858                 }
 859                 if (node->effect->effect_type_id() == "AlphaDivisionEffect") {
 860                         assert(node->incoming_links.size() == 1);
 861                         assert(node->incoming_links[0]->output_alpha_type == ALPHA_PREMULTIPLIED);
 862                         node->output_alpha_type = ALPHA_POSTMULTIPLIED;
 863                         continue;
 864                 }
 865
 866                 // GammaCompressionEffect and GammaExpansionEffect are also a special case,
 867                 // because they are the only one that _need_ postmultiplied alpha.
 868                 if (node->effect->effect_type_id() == "GammaCompressionEffect" ||
 869                     node->effect->effect_type_id() == "GammaExpansionEffect") {
 870                         assert(node->incoming_links.size() == 1);
 871                         if (node->incoming_links[0]->output_alpha_type == ALPHA_BLANK) {
 872                                 node->output_alpha_type = ALPHA_BLANK;
 873                         } else if (node->incoming_links[0]->output_alpha_type == ALPHA_POSTMULTIPLIED) {
 874                                 node->output_alpha_type = ALPHA_POSTMULTIPLIED;
 875                         } else {
 876                                 node->output_alpha_type = ALPHA_INVALID;
 877                         }
 878                         continue;
 879                 }
 880
 881                 // Only inputs can have unconditional alpha output (OUTPUT_BLANK_ALPHA
 882                 // or OUTPUT_POSTMULTIPLIED_ALPHA), and they have already been
 883                 // taken care of above. Rationale: Even if you could imagine
 884                 // e.g. an effect that took in an image and set alpha=1.0
 885                 // unconditionally, it wouldn't make any sense to have it as
 886                 // e.g. OUTPUT_BLANK_ALPHA, since it wouldn't know whether it
 887                 // got its input pre- or postmultiplied, so it wouldn't know
 888                 // whether to divide away the old alpha or not.
 889                 Effect::AlphaHandling alpha_handling = node->effect->alpha_handling();
 890                 assert(alpha_handling == Effect::INPUT_AND_OUTPUT_PREMULTIPLIED_ALPHA ||
 891                        alpha_handling == Effect::INPUT_PREMULTIPLIED_ALPHA_KEEP_BLANK ||
 892                        alpha_handling == Effect::DONT_CARE_ALPHA_TYPE);
 893
 894                 // If the node has multiple inputs, check that they are all valid and
 895                 // the same.
 896                 bool any_invalid = false;
 897                 bool any_premultiplied = false;
 898                 bool any_postmultiplied = false;
 899
 900                 for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
 901                         switch (node->incoming_links[j]->output_alpha_type) {
 902                         case ALPHA_INVALID:
 903                                 any_invalid = true;
 904                                 break;
 905                         case ALPHA_BLANK:
 906                                 // Blank is good as both pre- and postmultiplied alpha,
 907                                 // so just ignore it.
 908                                 break;
 909                         case ALPHA_PREMULTIPLIED:
 910                                 any_premultiplied = true;
 911                                 break;
 912                         case ALPHA_POSTMULTIPLIED:
 913                                 any_postmultiplied = true;
 914                                 break;
 915                         default:
 916                                 assert(false);
 917                         }
 918                 }
 919
 920                 if (any_invalid) {
 921                         node->output_alpha_type = ALPHA_INVALID;
 922                         continue;
 923                 }
 924
 925                 // Inputs must be of the same type.
 926                 if (any_premultiplied && any_postmultiplied) {
 927                         node->output_alpha_type = ALPHA_INVALID;
 928                         continue;
 929                 }
 930
 931                 if (alpha_handling == Effect::INPUT_AND_OUTPUT_PREMULTIPLIED_ALPHA ||
 932                     alpha_handling == Effect::INPUT_PREMULTIPLIED_ALPHA_KEEP_BLANK) {
 933                         // If the effect has asked for premultiplied alpha, check that it has got it.
 934                         if (any_postmultiplied) {
 935                                 node->output_alpha_type = ALPHA_INVALID;
 936                         } else if (!any_premultiplied &&
 937                                    alpha_handling == Effect::INPUT_PREMULTIPLIED_ALPHA_KEEP_BLANK) {
 938                                 // Blank input alpha, and the effect preserves blank alpha.
 939                                 node->output_alpha_type = ALPHA_BLANK;
 940                         } else {
 941                                 node->output_alpha_type = ALPHA_PREMULTIPLIED;
 942                         }
 943                 } else {
 944                         // OK, all inputs are the same, and this effect is not going
 945                         // to change it.
 946                         assert(alpha_handling == Effect::DONT_CARE_ALPHA_TYPE);
 947                         if (any_premultiplied) {
 948                                 node->output_alpha_type = ALPHA_PREMULTIPLIED;
 949                         } else if (any_postmultiplied) {
 950                                 node->output_alpha_type = ALPHA_POSTMULTIPLIED;
 951                         } else {
 952                                 node->output_alpha_type = ALPHA_BLANK;
 953                         }
 954                 }
 955         }
 956 }
 957
 958 bool EffectChain::node_needs_colorspace_fix(Node *node)
 959 {
 960         if (node->disabled) {
 961                 return false;
 962         }
 963         if (node->effect->num_inputs() == 0) {
 964                 return false;
 965         }
 966
 967         // propagate_gamma_and_color_space() has already set our output
 968         // to COLORSPACE_INVALID if the inputs differ, so we can rely on that.
 969         if (node->output_color_space == COLORSPACE_INVALID) {
 970                 return true;
 971         }
 972         return (node->effect->needs_srgb_primaries() && node->output_color_space != COLORSPACE_sRGB);
 973 }
 974
 975 // Fix up color spaces so that there are no COLORSPACE_INVALID nodes left in
 976 // the graph. Our strategy is not always optimal, but quite simple:
 977 // Find an effect that's as early as possible where the inputs are of
 978 // unacceptable colorspaces (that is, either different, or, if the effect only
 979 // wants sRGB, not sRGB.) Add appropriate conversions on all its inputs,
 980 // propagate the information anew, and repeat until there are no more such
 981 // effects.
 982 void EffectChain::fix_internal_color_spaces()
 983 {
 984         unsigned colorspace_propagation_pass = 0;
 985         bool found_any;
 986         do {
 987                 found_any = false;
 988                 for (unsigned i = 0; i < nodes.size(); ++i) {
 989                         Node *node = nodes[i];
 990                         if (!node_needs_colorspace_fix(node)) {
 991                                 continue;
 992                         }
 993
 994                         // Go through each input that is not sRGB, and insert
 995                         // a colorspace conversion after it.
 996                         for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
 997                                 Node *input = node->incoming_links[j];
 998                                 assert(input->output_color_space != COLORSPACE_INVALID);
 999                                 if (input->output_color_space == COLORSPACE_sRGB) {
1000                                         continue;
1001                                 }
1002                                 Node *conversion = add_node(new ColorspaceConversionEffect());
1003                                 CHECK(conversion->effect->set_int("source_space", input->output_color_space));
1004                                 CHECK(conversion->effect->set_int("destination_space", COLORSPACE_sRGB));
1005                                 conversion->output_color_space = COLORSPACE_sRGB;
1006                                 replace_sender(input, conversion);
1007                                 connect_nodes(input, conversion);
1008                         }
1009
1010                         // Re-sort topologically, and propagate the new information.
1011                         propagate_gamma_and_color_space();
1012
1013                         found_any = true;
1014                         break;
1015                 }
1016
1017                 char filename[256];
1018                 sprintf(filename, "step5-colorspacefix-iter%u.dot", ++colorspace_propagation_pass);
1019                 output_dot(filename);
1020                 assert(colorspace_propagation_pass < 100);
1021         } while (found_any);
1022
1023         for (unsigned i = 0; i < nodes.size(); ++i) {
1024                 Node *node = nodes[i];
1025                 if (node->disabled) {
1026                         continue;
1027                 }
1028                 assert(node->output_color_space != COLORSPACE_INVALID);
1029         }
1030 }
1031
1032 bool EffectChain::node_needs_alpha_fix(Node *node)
1033 {
1034         if (node->disabled) {
1035                 return false;
1036         }
1037
1038         // propagate_alpha() has already set our output to ALPHA_INVALID if the
1039         // inputs differ or we are otherwise in mismatch, so we can rely on that.
1040         return (node->output_alpha_type == ALPHA_INVALID);
1041 }
1042
1043 // Fix up alpha so that there are no ALPHA_INVALID nodes left in
1044 // the graph. Similar to fix_internal_color_spaces().
1045 void EffectChain::fix_internal_alpha(unsigned step)
1046 {
1047         unsigned alpha_propagation_pass = 0;
1048         bool found_any;
1049         do {
1050                 found_any = false;
1051                 for (unsigned i = 0; i < nodes.size(); ++i) {
1052                         Node *node = nodes[i];
1053                         if (!node_needs_alpha_fix(node)) {
1054                                 continue;
1055                         }
1056
1057                         // If we need to fix up GammaExpansionEffect, then clearly something
1058                         // is wrong, since the combination of premultiplied alpha and nonlinear inputs
1059                         // is meaningless.
1060                         assert(node->effect->effect_type_id() != "GammaExpansionEffect");
1061
1062                         AlphaType desired_type = ALPHA_PREMULTIPLIED;
1063
1064                         // GammaCompressionEffect is special; it needs postmultiplied alpha.
1065                         if (node->effect->effect_type_id() == "GammaCompressionEffect") {
1066                                 assert(node->incoming_links.size() == 1);
1067                                 assert(node->incoming_links[0]->output_alpha_type == ALPHA_PREMULTIPLIED);
1068                                 desired_type = ALPHA_POSTMULTIPLIED;
1069                         }
1070
1071                         // Go through each input that is not premultiplied alpha, and insert
1072                         // a conversion before it.
1073                         for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
1074                                 Node *input = node->incoming_links[j];
1075                                 assert(input->output_alpha_type != ALPHA_INVALID);
1076                                 if (input->output_alpha_type == desired_type ||
1077                                     input->output_alpha_type == ALPHA_BLANK) {
1078                                         continue;
1079                                 }
1080                                 Node *conversion;
1081                                 if (desired_type == ALPHA_PREMULTIPLIED) {
1082                                         conversion = add_node(new AlphaMultiplicationEffect());
1083                                 } else {
1084                                         conversion = add_node(new AlphaDivisionEffect());
1085                                 }
1086                                 conversion->output_alpha_type = desired_type;
1087                                 replace_sender(input, conversion);
1088                                 connect_nodes(input, conversion);
1089                         }
1090
1091                         // Re-sort topologically, and propagate the new information.
1092                         propagate_gamma_and_color_space();
1093                         propagate_alpha();
1094
1095                         found_any = true;
1096                         break;
1097                 }
1098
1099                 char filename[256];
1100                 sprintf(filename, "step%u-alphafix-iter%u.dot", step, ++alpha_propagation_pass);
1101                 output_dot(filename);
1102                 assert(alpha_propagation_pass < 100);
1103         } while (found_any);
1104
1105         for (unsigned i = 0; i < nodes.size(); ++i) {
1106                 Node *node = nodes[i];
1107                 if (node->disabled) {
1108                         continue;
1109                 }
1110                 assert(node->output_alpha_type != ALPHA_INVALID);
1111         }
1112 }
1113
1114 // Make so that the output is in the desired color space.
1115 void EffectChain::fix_output_color_space()
1116 {
1117         Node *output = find_output_node();
1118         if (output->output_color_space != output_format.color_space) {
1119                 Node *conversion = add_node(new ColorspaceConversionEffect());
1120                 CHECK(conversion->effect->set_int("source_space", output->output_color_space));
1121                 CHECK(conversion->effect->set_int("destination_space", output_format.color_space));
1122                 conversion->output_color_space = output_format.color_space;
1123                 connect_nodes(output, conversion);
1124                 propagate_alpha();
1125                 propagate_gamma_and_color_space();
1126         }
1127 }
1128
1129 // Make so that the output is in the desired pre-/postmultiplication alpha state.
1130 void EffectChain::fix_output_alpha()
1131 {
1132         Node *output = find_output_node();
1133         assert(output->output_alpha_type != ALPHA_INVALID);
1134         if (output->output_alpha_type == ALPHA_BLANK) {
1135                 // No alpha output, so we don't care.
1136                 return;
1137         }
1138         if (output->output_alpha_type == ALPHA_PREMULTIPLIED &&
1139             output_alpha_format == OUTPUT_ALPHA_FORMAT_POSTMULTIPLIED) {
1140                 Node *conversion = add_node(new AlphaDivisionEffect());
1141                 connect_nodes(output, conversion);
1142                 propagate_alpha();
1143                 propagate_gamma_and_color_space();
1144         }
1145         if (output->output_alpha_type == ALPHA_POSTMULTIPLIED &&
1146             output_alpha_format == OUTPUT_ALPHA_FORMAT_PREMULTIPLIED) {
1147                 Node *conversion = add_node(new AlphaMultiplicationEffect());
1148                 connect_nodes(output, conversion);
1149                 propagate_alpha();
1150                 propagate_gamma_and_color_space();
1151         }
1152 }
1153
1154 bool EffectChain::node_needs_gamma_fix(Node *node)
1155 {
1156         if (node->disabled) {
1157                 return false;
1158         }
1159
1160         // Small hack since the output is not an explicit node:
1161         // If we are the last node and our output is in the wrong
1162         // space compared to EffectChain's output, we need to fix it.
1163         // This will only take us to linear, but fix_output_gamma()
1164         // will come and take us to the desired output gamma
1165         // if it is needed.
1166         //
1167         // This needs to be before everything else, since it could
1168         // even apply to inputs (if they are the only effect).
1169         if (node->outgoing_links.empty() &&
1170             node->output_gamma_curve != output_format.gamma_curve &&
1171             node->output_gamma_curve != GAMMA_LINEAR) {
1172                 return true;
1173         }
1174
1175         if (node->effect->num_inputs() == 0) {
1176                 return false;
1177         }
1178
1179         // propagate_gamma_and_color_space() has already set our output
1180         // to GAMMA_INVALID if the inputs differ, so we can rely on that,
1181         // except for GammaCompressionEffect.
1182         if (node->output_gamma_curve == GAMMA_INVALID) {
1183                 return true;
1184         }
1185         if (node->effect->effect_type_id() == "GammaCompressionEffect") {
1186                 assert(node->incoming_links.size() == 1);
1187                 return node->incoming_links[0]->output_gamma_curve != GAMMA_LINEAR;
1188         }
1189
1190         return (node->effect->needs_linear_light() && node->output_gamma_curve != GAMMA_LINEAR);
1191 }
1192
1193 // Very similar to fix_internal_color_spaces(), but for gamma.
1194 // There is one difference, though; before we start adding conversion nodes,
1195 // we see if we can get anything out of asking the sources to deliver
1196 // linear gamma directly. fix_internal_gamma_by_asking_inputs()
1197 // does that part, while fix_internal_gamma_by_inserting_nodes()
1198 // inserts nodes as needed afterwards.
1199 void EffectChain::fix_internal_gamma_by_asking_inputs(unsigned step)
1200 {
1201         unsigned gamma_propagation_pass = 0;
1202         bool found_any;
1203         do {
1204                 found_any = false;
1205                 for (unsigned i = 0; i < nodes.size(); ++i) {
1206                         Node *node = nodes[i];
1207                         if (!node_needs_gamma_fix(node)) {
1208                                 continue;
1209                         }
1210
1211                         // See if all inputs can give us linear gamma. If not, leave it.
1212                         vector<Node *> nonlinear_inputs;
1213                         find_all_nonlinear_inputs(node, &nonlinear_inputs);
1214                         assert(!nonlinear_inputs.empty());
1215
1216                         bool all_ok = true;
1217                         for (unsigned i = 0; i < nonlinear_inputs.size(); ++i) {
1218                                 Input *input = static_cast<Input *>(nonlinear_inputs[i]->effect);
1219                                 all_ok &= input->can_output_linear_gamma();
1220                         }
1221
1222                         if (!all_ok) {
1223                                 continue;
1224                         }
1225
1226                         for (unsigned i = 0; i < nonlinear_inputs.size(); ++i) {
1227                                 CHECK(nonlinear_inputs[i]->effect->set_int("output_linear_gamma", 1));
1228                                 nonlinear_inputs[i]->output_gamma_curve = GAMMA_LINEAR;
1229                         }
1230
1231                         // Re-sort topologically, and propagate the new information.
1232                         propagate_gamma_and_color_space();
1233
1234                         found_any = true;
1235                         break;
1236                 }
1237
1238                 char filename[256];
1239                 sprintf(filename, "step%u-gammafix-iter%u.dot", step, ++gamma_propagation_pass);
1240                 output_dot(filename);
1241                 assert(gamma_propagation_pass < 100);
1242         } while (found_any);
1243 }
1244
1245 void EffectChain::fix_internal_gamma_by_inserting_nodes(unsigned step)
1246 {
1247         unsigned gamma_propagation_pass = 0;
1248         bool found_any;
1249         do {
1250                 found_any = false;
1251                 for (unsigned i = 0; i < nodes.size(); ++i) {
1252                         Node *node = nodes[i];
1253                         if (!node_needs_gamma_fix(node)) {
1254                                 continue;
1255                         }
1256
1257                         // Special case: We could be an input and still be asked to
1258                         // fix our gamma; if so, we should be the only node
1259                         // (as node_needs_gamma_fix() would only return true in
1260                         // for an input in that case). That means we should insert
1261                         // a conversion node _after_ ourselves.
1262                         if (node->incoming_links.empty()) {
1263                                 assert(node->outgoing_links.empty());
1264                                 Node *conversion = add_node(new GammaExpansionEffect());
1265                                 CHECK(conversion->effect->set_int("source_curve", node->output_gamma_curve));
1266                                 conversion->output_gamma_curve = GAMMA_LINEAR;
1267                                 connect_nodes(node, conversion);
1268                         }
1269
1270                         // If not, go through each input that is not linear gamma,
1271                         // and insert a gamma conversion after it.
1272                         for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
1273                                 Node *input = node->incoming_links[j];
1274                                 assert(input->output_gamma_curve != GAMMA_INVALID);
1275                                 if (input->output_gamma_curve == GAMMA_LINEAR) {
1276                                         continue;
1277                                 }
1278                                 Node *conversion = add_node(new GammaExpansionEffect());
1279                                 CHECK(conversion->effect->set_int("source_curve", input->output_gamma_curve));
1280                                 conversion->output_gamma_curve = GAMMA_LINEAR;
1281                                 replace_sender(input, conversion);
1282                                 connect_nodes(input, conversion);
1283                         }
1284
1285                         // Re-sort topologically, and propagate the new information.
1286                         propagate_alpha();
1287                         propagate_gamma_and_color_space();
1288
1289                         found_any = true;
1290                         break;
1291                 }
1292
1293                 char filename[256];
1294                 sprintf(filename, "step%u-gammafix-iter%u.dot", step, ++gamma_propagation_pass);
1295                 output_dot(filename);
1296                 assert(gamma_propagation_pass < 100);
1297         } while (found_any);
1298
1299         for (unsigned i = 0; i < nodes.size(); ++i) {
1300                 Node *node = nodes[i];
1301                 if (node->disabled) {
1302                         continue;
1303                 }
1304                 assert(node->output_gamma_curve != GAMMA_INVALID);
1305         }
1306 }
1307
1308 // Make so that the output is in the desired gamma.
1309 // Note that this assumes linear input gamma, so it might create the need
1310 // for another pass of fix_internal_gamma().
1311 void EffectChain::fix_output_gamma()
1312 {
1313         Node *output = find_output_node();
1314         if (output->output_gamma_curve != output_format.gamma_curve) {
1315                 Node *conversion = add_node(new GammaCompressionEffect());
1316                 CHECK(conversion->effect->set_int("destination_curve", output_format.gamma_curve));
1317                 conversion->output_gamma_curve = output_format.gamma_curve;
1318                 connect_nodes(output, conversion);
1319         }
1320 }
1321
1322 // If the user has requested dither, add a DitherEffect right at the end
1323 // (after GammaCompressionEffect etc.). This needs to be done after everything else,
1324 // since dither is about the only effect that can _not_ be done in linear space.
1325 void EffectChain::add_dither_if_needed()
1326 {
1327         if (num_dither_bits == 0) {
1328                 return;
1329         }
1330         Node *output = find_output_node();
1331         Node *dither = add_node(new DitherEffect());
1332         CHECK(dither->effect->set_int("num_bits", num_dither_bits));
1333         connect_nodes(output, dither);
1334
1335         dither_effect = dither->effect;
1336 }
1337
1338 // Find the output node. This is, simply, one that has no outgoing links.
1339 // If there are multiple ones, the graph is malformed (we do not support
1340 // multiple outputs right now).
1341 Node *EffectChain::find_output_node()
1342 {
1343         vector<Node *> output_nodes;
1344         for (unsigned i = 0; i < nodes.size(); ++i) {
1345                 Node *node = nodes[i];
1346                 if (node->disabled) {
1347                         continue;
1348                 }
1349                 if (node->outgoing_links.empty()) {
1350                         output_nodes.push_back(node);
1351                 }
1352         }
1353         assert(output_nodes.size() == 1);
1354         return output_nodes[0];
1355 }
1356
1357 void EffectChain::finalize()
1358 {
1359         // Save the current locale, and set it to C, so that we can output decimal
1360         // numbers with printf and be sure to get them in the format mandated by GLSL.
1361         char *saved_locale = setlocale(LC_NUMERIC, "C");
1362
1363         // Output the graph as it is before we do any conversions on it.
1364         output_dot("step0-start.dot");
1365
1366         // Give each effect in turn a chance to rewrite its own part of the graph.
1367         // Note that if more effects are added as part of this, they will be
1368         // picked up as part of the same for loop, since they are added at the end.
1369         for (unsigned i = 0; i < nodes.size(); ++i) {
1370                 nodes[i]->effect->rewrite_graph(this, nodes[i]);
1371         }
1372         output_dot("step1-rewritten.dot");
1373
1374         find_color_spaces_for_inputs();
1375         output_dot("step2-input-colorspace.dot");
1376
1377         propagate_alpha();
1378         output_dot("step3-propagated-alpha.dot");
1379
1380         propagate_gamma_and_color_space();
1381         output_dot("step4-propagated-all.dot");
1382
1383         fix_internal_color_spaces();
1384         fix_internal_alpha(6);
1385         fix_output_color_space();
1386         output_dot("step7-output-colorspacefix.dot");
1387         fix_output_alpha();
1388         output_dot("step8-output-alphafix.dot");
1389
1390         // Note that we need to fix gamma after colorspace conversion,
1391         // because colorspace conversions might create needs for gamma conversions.
1392         // Also, we need to run an extra pass of fix_internal_gamma() after
1393         // fixing the output gamma, as we only have conversions to/from linear,
1394         // and fix_internal_alpha() since GammaCompressionEffect needs
1395         // postmultiplied input.
1396         fix_internal_gamma_by_asking_inputs(9);
1397         fix_internal_gamma_by_inserting_nodes(10);
1398         fix_output_gamma();
1399         output_dot("step11-output-gammafix.dot");
1400         propagate_alpha();
1401         output_dot("step12-output-alpha-propagated.dot");
1402         fix_internal_alpha(13);
1403         output_dot("step14-output-alpha-fixed.dot");
1404         fix_internal_gamma_by_asking_inputs(15);
1405         fix_internal_gamma_by_inserting_nodes(16);
1406
1407         output_dot("step17-before-dither.dot");
1408
1409         add_dither_if_needed();
1410
1411         output_dot("step18-final.dot");
1412
1413         // Construct all needed GLSL programs, starting at the output.
1414         construct_glsl_programs(find_output_node());
1415
1416         output_dot("step19-split-to-phases.dot");
1417
1418         assert(phases[0]->inputs.empty());
1419
1420         finalized = true;
1421         setlocale(LC_NUMERIC, saved_locale);
1422 }
1423
1424 void EffectChain::render_to_fbo(GLuint dest_fbo, unsigned width, unsigned height)
1425 {
1426         assert(finalized);
1427
1428         // Save original viewport.
1429         GLuint x = 0, y = 0;
1430         GLuint fbo = 0;
1431
1432         if (width == 0 && height == 0) {
1433                 GLint viewport[4];
1434                 glGetIntegerv(GL_VIEWPORT, viewport);
1435                 x = viewport[0];
1436                 y = viewport[1];
1437                 width = viewport[2];
1438                 height = viewport[3];
1439         }
1440
1441         // Basic state.
1442         glDisable(GL_BLEND);
1443         check_error();
1444         glDisable(GL_DEPTH_TEST);
1445         check_error();
1446         glDepthMask(GL_FALSE);
1447         check_error();
1448
1449         if (phases.size() > 1) {
1450                 glGenFramebuffers(1, &fbo);
1451                 check_error();
1452                 glBindFramebuffer(GL_FRAMEBUFFER, fbo);
1453                 check_error();
1454         }
1455
1456         set<Node *> generated_mipmaps;
1457
1458         // We choose the simplest option of having one texture per output,
1459         // since otherwise this turns into an (albeit simple) register allocation problem.
1460         map<Phase *, GLuint> output_textures;
1461
1462         for (unsigned phase = 0; phase < phases.size(); ++phase) {
1463                 // Find a texture for this phase.
1464                 inform_input_sizes(phases[phase]);
1465                 if (phase != phases.size() - 1) {
1466                         find_output_size(phases[phase]);
1467
1468                         GLuint tex_num = resource_pool->create_2d_texture(GL_RGBA16F_ARB, phases[phase]->output_width, phases[phase]->output_height);
1469                         output_textures.insert(make_pair(phases[phase], tex_num));
1470                 }
1471
1472                 const GLuint glsl_program_num = phases[phase]->glsl_program_num;
1473                 glUseProgram(glsl_program_num);
1474                 check_error();
1475
1476                 // Set up RTT inputs for this phase.
1477                 for (unsigned sampler = 0; sampler < phases[phase]->inputs.size(); ++sampler) {
1478                         glActiveTexture(GL_TEXTURE0 + sampler);
1479                         Node *input = phases[phase]->inputs[sampler];
1480                         glBindTexture(GL_TEXTURE_2D, output_textures[input->phase]);
1481                         check_error();
1482                         if (phases[phase]->input_needs_mipmaps) {
1483                                 if (generated_mipmaps.count(input) == 0) {
1484                                         glGenerateMipmap(GL_TEXTURE_2D);
1485                                         check_error();
1486                                         generated_mipmaps.insert(input);
1487                                 }
1488                                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_NEAREST);
1489                                 check_error();
1490                         } else {
1491                                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
1492                                 check_error();
1493                         }
1494                         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
1495                         check_error();
1496                         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
1497                         check_error();
1498
1499                         string texture_name = string("tex_") + phases[phase]->effect_ids[input];
1500                         glUniform1i(glGetUniformLocation(glsl_program_num, texture_name.c_str()), sampler);
1501                         check_error();
1502                 }
1503
1504                 // And now the output.
1505                 if (phase == phases.size() - 1) {
1506                         // Last phase goes to the output the user specified.
1507                         glBindFramebuffer(GL_FRAMEBUFFER, dest_fbo);
1508                         check_error();
1509                         GLenum status = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);
1510                         assert(status == GL_FRAMEBUFFER_COMPLETE);
1511                         glViewport(x, y, width, height);
1512                         if (dither_effect != NULL) {
1513                                 CHECK(dither_effect->set_int("output_width", width));
1514                                 CHECK(dither_effect->set_int("output_height", height));
1515                         }
1516                 } else {
1517                         glFramebufferTexture2D(
1518                                 GL_FRAMEBUFFER,
1519                                 GL_COLOR_ATTACHMENT0,
1520                                 GL_TEXTURE_2D,
1521                                 output_textures[phases[phase]],
1522                                 0);
1523                         check_error();
1524                         GLenum status = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);
1525                         assert(status == GL_FRAMEBUFFER_COMPLETE);
1526                         glViewport(0, 0, phases[phase]->output_width, phases[phase]->output_height);
1527                 }
1528
1529                 // Give the required parameters to all the effects.
1530                 unsigned sampler_num = phases[phase]->inputs.size();
1531                 for (unsigned i = 0; i < phases[phase]->effects.size(); ++i) {
1532                         Node *node = phases[phase]->effects[i];
1533                         node->effect->set_gl_state(glsl_program_num, phases[phase]->effect_ids[node], &sampler_num);
1534                         check_error();
1535                 }
1536
1537                 // Now draw!
1538                 float vertices[] = {
1539                         0.0f, 0.0f,
1540                         1.0f, 0.0f,
1541                         1.0f, 1.0f,
1542                         0.0f, 1.0f
1543                 };
1544
1545                 int position_attrib = glGetAttribLocation(glsl_program_num, "position");
1546                 assert(position_attrib != -1);
1547                 glEnableVertexAttribArray(position_attrib);
1548                 check_error();
1549                 glVertexAttribPointer(position_attrib, 2, GL_FLOAT, GL_FALSE, 0, vertices);
1550                 check_error();
1551
1552                 int texcoord_attrib = glGetAttribLocation(glsl_program_num, "texcoord");
1553                 if (texcoord_attrib != -1) {
1554                         glEnableVertexAttribArray(texcoord_attrib);
1555                         check_error();
1556                         glVertexAttribPointer(texcoord_attrib, 2, GL_FLOAT, GL_FALSE, 0, vertices);  // Same as texcoords.
1557                         check_error();
1558                 }
1559
1560                 glDrawArrays(GL_QUADS, 0, 4);
1561                 check_error();
1562
1563                 glUseProgram(0);
1564                 check_error();
1565                 glDisableVertexAttribArray(position_attrib);
1566                 check_error();
1567                 if (texcoord_attrib != -1) {
1568                         glDisableVertexAttribArray(texcoord_attrib);
1569                         check_error();
1570                 }
1571
1572                 for (unsigned i = 0; i < phases[phase]->effects.size(); ++i) {
1573                         Node *node = phases[phase]->effects[i];
1574                         node->effect->clear_gl_state();
1575                 }
1576         }
1577
1578         for (map<Phase *, GLuint>::const_iterator texture_it = output_textures.begin();
1579              texture_it != output_textures.end();
1580              ++texture_it) {
1581                 resource_pool->release_2d_texture(texture_it->second);
1582         }
1583
1584         glBindFramebuffer(GL_FRAMEBUFFER, 0);
1585         check_error();
1586
1587         if (fbo != 0) {
1588                 glDeleteFramebuffers(1, &fbo);
1589                 check_error();
1590         }
1591 }
1592
1593 }  // namespace movit