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

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