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 EffectChain::EffectChain(float aspect_nom, float aspect_denom, ResourcePool *resource_pool)
  33         : aspect_nom(aspect_nom),
  34           aspect_denom(aspect_denom),
  35           dither_effect(NULL),
  36           num_dither_bits(0),
  37           finalized(false),
  38           resource_pool(resource_pool) {
  39         if (resource_pool == NULL) {
  40                 this->resource_pool = new ResourcePool();
  41                 owns_resource_pool = true;
  42         } else {
  43                 owns_resource_pool = false;
  44         }
  45 }
  46
  47 EffectChain::~EffectChain()
  48 {
  49         for (unsigned i = 0; i < nodes.size(); ++i) {
  50                 delete nodes[i]->effect;
  51                 delete nodes[i];
  52         }
  53         for (unsigned i = 0; i < phases.size(); ++i) {
  54                 resource_pool->release_glsl_program(phases[i]->glsl_program_num);
  55                 delete phases[i];
  56         }
  57         if (owns_resource_pool) {
  58                 delete resource_pool;
  59         }
  60 }
  61
  62 Input *EffectChain::add_input(Input *input)
  63 {
  64         assert(!finalized);
  65         inputs.push_back(input);
  66         add_node(input);
  67         return input;
  68 }
  69
  70 void EffectChain::add_output(const ImageFormat &format, OutputAlphaFormat alpha_format)
  71 {
  72         assert(!finalized);
  73         output_format = format;
  74         output_alpha_format = alpha_format;
  75 }
  76
  77 Node *EffectChain::add_node(Effect *effect)
  78 {
  79         for (unsigned i = 0; i < nodes.size(); ++i) {
  80                 assert(nodes[i]->effect != effect);
  81         }
  82
  83         Node *node = new Node;
  84         node->effect = effect;
  85         node->disabled = false;
  86         node->output_color_space = COLORSPACE_INVALID;
  87         node->output_gamma_curve = GAMMA_INVALID;
  88         node->output_alpha_type = ALPHA_INVALID;
  89
  90         nodes.push_back(node);
  91         node_map[effect] = node;
  92         effect->inform_added(this);
  93         return node;
  94 }
  95
  96 void EffectChain::connect_nodes(Node *sender, Node *receiver)
  97 {
  98         sender->outgoing_links.push_back(receiver);
  99         receiver->incoming_links.push_back(sender);
 100 }
 101
 102 void EffectChain::replace_receiver(Node *old_receiver, Node *new_receiver)
 103 {
 104         new_receiver->incoming_links = old_receiver->incoming_links;
 105         old_receiver->incoming_links.clear();
 106
 107         for (unsigned i = 0; i < new_receiver->incoming_links.size(); ++i) {
 108                 Node *sender = new_receiver->incoming_links[i];
 109                 for (unsigned j = 0; j < sender->outgoing_links.size(); ++j) {
 110                         if (sender->outgoing_links[j] == old_receiver) {
 111                                 sender->outgoing_links[j] = new_receiver;
 112                         }
 113                 }
 114         }
 115 }
 116
 117 void EffectChain::replace_sender(Node *old_sender, Node *new_sender)
 118 {
 119         new_sender->outgoing_links = old_sender->outgoing_links;
 120         old_sender->outgoing_links.clear();
 121
 122         for (unsigned i = 0; i < new_sender->outgoing_links.size(); ++i) {
 123                 Node *receiver = new_sender->outgoing_links[i];
 124                 for (unsigned j = 0; j < receiver->incoming_links.size(); ++j) {
 125                         if (receiver->incoming_links[j] == old_sender) {
 126                                 receiver->incoming_links[j] = new_sender;
 127                         }
 128                 }
 129         }
 130 }
 131
 132 void EffectChain::insert_node_between(Node *sender, Node *middle, Node *receiver)
 133 {
 134         for (unsigned i = 0; i < sender->outgoing_links.size(); ++i) {
 135                 if (sender->outgoing_links[i] == receiver) {
 136                         sender->outgoing_links[i] = middle;
 137                         middle->incoming_links.push_back(sender);
 138                 }
 139         }
 140         for (unsigned i = 0; i < receiver->incoming_links.size(); ++i) {
 141                 if (receiver->incoming_links[i] == sender) {
 142                         receiver->incoming_links[i] = middle;
 143                         middle->outgoing_links.push_back(receiver);
 144                 }
 145         }
 146
 147         assert(middle->incoming_links.size() == middle->effect->num_inputs());
 148 }
 149
 150 void EffectChain::find_all_nonlinear_inputs(Node *node, vector<Node *> *nonlinear_inputs)
 151 {
 152         if (node->output_gamma_curve == GAMMA_LINEAR &&
 153             node->effect->effect_type_id() != "GammaCompressionEffect") {
 154                 return;
 155         }
 156         if (node->effect->num_inputs() == 0) {
 157                 nonlinear_inputs->push_back(node);
 158         } else {
 159                 assert(node->effect->num_inputs() == node->incoming_links.size());
 160                 for (unsigned i = 0; i < node->incoming_links.size(); ++i) {
 161                         find_all_nonlinear_inputs(node->incoming_links[i], nonlinear_inputs);
 162                 }
 163         }
 164 }
 165
 166 Effect *EffectChain::add_effect(Effect *effect, const vector<Effect *> &inputs)
 167 {
 168         assert(!finalized);
 169         assert(inputs.size() == effect->num_inputs());
 170         Node *node = add_node(effect);
 171         for (unsigned i = 0; i < inputs.size(); ++i) {
 172                 assert(node_map.count(inputs[i]) != 0);
 173                 connect_nodes(node_map[inputs[i]], node);
 174         }
 175         return effect;
 176 }
 177
 178 // GLSL pre-1.30 doesn't support token pasting. Replace PREFIX(x) with <effect_id>_x.
 179 string replace_prefix(const string &text, const string &prefix)
 180 {
 181         string output;
 182         size_t start = 0;
 183
 184         while (start < text.size()) {
 185                 size_t pos = text.find("PREFIX(", start);
 186                 if (pos == string::npos) {
 187                         output.append(text.substr(start, string::npos));
 188                         break;
 189                 }
 190
 191                 output.append(text.substr(start, pos - start));
 192                 output.append(prefix);
 193                 output.append("_");
 194
 195                 pos += strlen("PREFIX(");
 196
 197                 // Output stuff until we find the matching ), which we then eat.
 198                 int depth = 1;
 199                 size_t end_arg_pos = pos;
 200                 while (end_arg_pos < text.size()) {
 201                         if (text[end_arg_pos] == '(') {
 202                                 ++depth;
 203                         } else if (text[end_arg_pos] == ')') {
 204                                 --depth;
 205                                 if (depth == 0) {
 206                                         break;
 207                                 }
 208                         }
 209                         ++end_arg_pos;
 210                 }
 211                 output.append(text.substr(pos, end_arg_pos - pos));
 212                 ++end_arg_pos;
 213                 assert(depth == 0);
 214                 start = end_arg_pos;
 215         }
 216         return output;
 217 }
 218
 219 Phase *EffectChain::compile_glsl_program(
 220         const vector<Node *> &inputs,
 221         const vector<Node *> &effects)
 222 {
 223         Phase *phase = new Phase;
 224         assert(!effects.empty());
 225
 226         // Deduplicate the inputs.
 227         vector<Node *> true_inputs = inputs;
 228         sort(true_inputs.begin(), true_inputs.end());
 229         true_inputs.erase(unique(true_inputs.begin(), true_inputs.end()), true_inputs.end());
 230
 231         bool input_needs_mipmaps = false;
 232         string frag_shader = read_file("header.frag");
 233
 234         // Create functions for all the texture inputs that we need.
 235         for (unsigned i = 0; i < true_inputs.size(); ++i) {
 236                 Node *input = true_inputs[i];
 237                 char effect_id[256];
 238                 sprintf(effect_id, "in%u", i);
 239                 phase->effect_ids.insert(make_pair(input, effect_id));
 240
 241                 frag_shader += string("uniform sampler2D tex_") + effect_id + ";\n";
 242                 frag_shader += string("vec4 ") + effect_id + "(vec2 tc) {\n";
 243                 frag_shader += "\treturn texture2D(tex_" + string(effect_id) + ", tc);\n";
 244                 frag_shader += "}\n";
 245                 frag_shader += "\n";
 246         }
 247
 248         vector<Node *> sorted_effects = topological_sort(effects);
 249
 250         for (unsigned i = 0; i < sorted_effects.size(); ++i) {
 251                 Node *node = sorted_effects[i];
 252                 char effect_id[256];
 253                 sprintf(effect_id, "eff%u", i);
 254                 phase->effect_ids.insert(make_pair(node, effect_id));
 255
 256                 if (node->incoming_links.size() == 1) {
 257                         frag_shader += string("#define INPUT ") + phase->effect_ids[node->incoming_links[0]] + "\n";
 258                 } else {
 259                         for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
 260                                 char buf[256];
 261                                 sprintf(buf, "#define INPUT%d %s\n", j + 1, phase->effect_ids[node->incoming_links[j]].c_str());
 262                                 frag_shader += buf;
 263                         }
 264                 }
 265
 266                 frag_shader += "\n";
 267                 frag_shader += string("#define FUNCNAME ") + effect_id + "\n";
 268                 frag_shader += replace_prefix(node->effect->output_convenience_uniforms(), effect_id);
 269                 frag_shader += replace_prefix(node->effect->output_fragment_shader(), effect_id);
 270                 frag_shader += "#undef PREFIX\n";
 271                 frag_shader += "#undef FUNCNAME\n";
 272                 if (node->incoming_links.size() == 1) {
 273                         frag_shader += "#undef INPUT\n";
 274                 } else {
 275                         for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
 276                                 char buf[256];
 277                                 sprintf(buf, "#undef INPUT%d\n", j + 1);
 278                                 frag_shader += buf;
 279                         }
 280                 }
 281                 frag_shader += "\n";
 282
 283                 input_needs_mipmaps |= node->effect->needs_mipmaps();
 284         }
 285         for (unsigned i = 0; i < sorted_effects.size(); ++i) {
 286                 Node *node = sorted_effects[i];
 287                 if (node->effect->num_inputs() == 0) {
 288                         CHECK(node->effect->set_int("needs_mipmaps", input_needs_mipmaps));
 289                 }
 290         }
 291         frag_shader += string("#define INPUT ") + phase->effect_ids[sorted_effects.back()] + "\n";
 292         frag_shader.append(read_file("footer.frag"));
 293
 294         phase->glsl_program_num = resource_pool->compile_glsl_program(read_file("vs.vert"), frag_shader);
 295         phase->input_needs_mipmaps = input_needs_mipmaps;
 296         phase->inputs = true_inputs;
 297         phase->effects = sorted_effects;
 298
 299         return phase;
 300 }
 301
 302 // Construct GLSL programs, starting at the given effect and following
 303 // the chain from there. We end a program every time we come to an effect
 304 // marked as "needs texture bounce", one that is used by multiple other
 305 // effects, every time an effect wants to change the output size,
 306 // and of course at the end.
 307 //
 308 // We follow a quite simple depth-first search from the output, although
 309 // without any explicit recursion.
 310 void EffectChain::construct_glsl_programs(Node *output)
 311 {
 312         // Which effects have already been completed?
 313         // We need to keep track of it, as an effect with multiple outputs
 314         // could otherwise be calculated multiple times.
 315         set<Node *> completed_effects;
 316
 317         // Effects in the current phase, as well as inputs (outputs from other phases
 318         // that we depend on). Note that since we start iterating from the end,
 319         // the effect list will be in the reverse order.
 320         vector<Node *> this_phase_inputs;
 321         vector<Node *> this_phase_effects;
 322
 323         // Effects that we have yet to calculate, but that we know should
 324         // be in the current phase.
 325         stack<Node *> effects_todo_this_phase;
 326
 327         // Effects that we have yet to calculate, but that come from other phases.
 328         // We delay these until we have this phase done in its entirety,
 329         // at which point we pick any of them and start a new phase from that.
 330         stack<Node *> effects_todo_other_phases;
 331
 332         effects_todo_this_phase.push(output);
 333
 334         for ( ;; ) {  // Termination condition within loop.
 335                 if (!effects_todo_this_phase.empty()) {
 336                         // OK, we have more to do this phase.
 337                         Node *node = effects_todo_this_phase.top();
 338                         effects_todo_this_phase.pop();
 339
 340                         // This should currently only happen for effects that are inputs
 341                         // (either true inputs or phase outputs). We special-case inputs,
 342                         // and then deduplicate phase outputs in compile_glsl_program().
 343                         if (node->effect->num_inputs() == 0) {
 344                                 if (find(this_phase_effects.begin(), this_phase_effects.end(), node) != this_phase_effects.end()) {
 345                                         continue;
 346                                 }
 347                         } else {
 348                                 assert(completed_effects.count(node) == 0);
 349                         }
 350
 351                         this_phase_effects.push_back(node);
 352                         completed_effects.insert(node);
 353
 354                         // Find all the dependencies of this effect, and add them to the stack.
 355                         vector<Node *> deps = node->incoming_links;
 356                         assert(node->effect->num_inputs() == deps.size());
 357                         for (unsigned i = 0; i < deps.size(); ++i) {
 358                                 bool start_new_phase = false;
 359
 360                                 // FIXME: If we sample directly from a texture, we won't need this.
 361                                 if (node->effect->needs_texture_bounce()) {
 362                                         start_new_phase = true;
 363                                 }
 364
 365                                 if (deps[i]->outgoing_links.size() > 1) {
 366                                         if (deps[i]->effect->num_inputs() > 0) {
 367                                                 // More than one effect uses this as the input,
 368                                                 // and it is not a texture itself.
 369                                                 // The easiest thing to do (and probably also the safest
 370                                                 // performance-wise in most cases) is to bounce it to a texture
 371                                                 // and then let the next passes read from that.
 372                                                 start_new_phase = true;
 373                                         } else {
 374                                                 // For textures, we try to be slightly more clever;
 375                                                 // if none of our outputs need a bounce, we don't bounce
 376                                                 // but instead simply use the effect many times.
 377                                                 //
 378                                                 // Strictly speaking, we could bounce it for some outputs
 379                                                 // and use it directly for others, but the processing becomes
 380                                                 // somewhat simpler if the effect is only used in one such way.
 381                                                 for (unsigned j = 0; j < deps[i]->outgoing_links.size(); ++j) {
 382                                                         Node *rdep = deps[i]->outgoing_links[j];
 383                                                         start_new_phase |= rdep->effect->needs_texture_bounce();
 384                                                 }
 385                                         }
 386                                 }
 387
 388                                 if (deps[i]->effect->changes_output_size()) {
 389                                         start_new_phase = true;
 390                                 }
 391
 392                                 if (start_new_phase) {
 393                                         effects_todo_other_phases.push(deps[i]);
 394                                         this_phase_inputs.push_back(deps[i]);
 395                                 } else {
 396                                         effects_todo_this_phase.push(deps[i]);
 397                                 }
 398                         }
 399                         continue;
 400                 }
 401
 402                 // No more effects to do this phase. Take all the ones we have,
 403                 // and create a GLSL program for it.
 404                 if (!this_phase_effects.empty()) {
 405                         reverse(this_phase_effects.begin(), this_phase_effects.end());
 406                         phases.push_back(compile_glsl_program(this_phase_inputs, this_phase_effects));
 407                         this_phase_effects.back()->phase = phases.back();
 408                         this_phase_inputs.clear();
 409                         this_phase_effects.clear();
 410                 }
 411                 assert(this_phase_inputs.empty());
 412                 assert(this_phase_effects.empty());
 413
 414                 // If we have no effects left, exit.
 415                 if (effects_todo_other_phases.empty()) {
 416                         break;
 417                 }
 418
 419                 Node *node = effects_todo_other_phases.top();
 420                 effects_todo_other_phases.pop();
 421
 422                 if (completed_effects.count(node) == 0) {
 423                         // Start a new phase, calculating from this effect.
 424                         effects_todo_this_phase.push(node);
 425                 }
 426         }
 427
 428         // Finally, since the phases are found from the output but must be executed
 429         // from the input(s), reverse them, too.
 430         reverse(phases.begin(), phases.end());
 431 }
 432
 433 void EffectChain::output_dot(const char *filename)
 434 {
 435         if (movit_debug_level != MOVIT_DEBUG_ON) {
 436                 return;
 437         }
 438
 439         FILE *fp = fopen(filename, "w");
 440         if (fp == NULL) {
 441                 perror(filename);
 442                 exit(1);
 443         }
 444
 445         fprintf(fp, "digraph G {\n");
 446         fprintf(fp, "  output [shape=box label=\"(output)\"];\n");
 447         for (unsigned i = 0; i < nodes.size(); ++i) {
 448                 // Find out which phase this event belongs to.
 449                 vector<int> in_phases;
 450                 for (unsigned j = 0; j < phases.size(); ++j) {
 451                         const Phase* p = phases[j];
 452                         if (find(p->effects.begin(), p->effects.end(), nodes[i]) != p->effects.end()) {
 453                                 in_phases.push_back(j);
 454                         }
 455                 }
 456
 457                 if (in_phases.empty()) {
 458                         fprintf(fp, "  n%ld [label=\"%s\"];\n", (long)nodes[i], nodes[i]->effect->effect_type_id().c_str());
 459                 } else if (in_phases.size() == 1) {
 460                         fprintf(fp, "  n%ld [label=\"%s\" style=\"filled\" fillcolor=\"/accent8/%d\"];\n",
 461                                 (long)nodes[i], nodes[i]->effect->effect_type_id().c_str(),
 462                                 (in_phases[0] % 8) + 1);
 463                 } else {
 464                         // If we had new enough Graphviz, style="wedged" would probably be ideal here.
 465                         // But alas.
 466                         fprintf(fp, "  n%ld [label=\"%s [in multiple phases]\" 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                 }
 470
 471                 char from_node_id[256];
 472                 snprintf(from_node_id, 256, "n%ld", (long)nodes[i]);
 473
 474                 for (unsigned j = 0; j < nodes[i]->outgoing_links.size(); ++j) {
 475                         char to_node_id[256];
 476                         snprintf(to_node_id, 256, "n%ld", (long)nodes[i]->outgoing_links[j]);
 477
 478                         vector<string> labels = get_labels_for_edge(nodes[i], nodes[i]->outgoing_links[j]);
 479                         output_dot_edge(fp, from_node_id, to_node_id, labels);
 480                 }
 481
 482                 if (nodes[i]->outgoing_links.empty() && !nodes[i]->disabled) {
 483                         // Output node.
 484                         vector<string> labels = get_labels_for_edge(nodes[i], NULL);
 485                         output_dot_edge(fp, from_node_id, "output", labels);
 486                 }
 487         }
 488         fprintf(fp, "}\n");
 489
 490         fclose(fp);
 491 }
 492
 493 vector<string> EffectChain::get_labels_for_edge(const Node *from, const Node *to)
 494 {
 495         vector<string> labels;
 496
 497         if (to != NULL && to->effect->needs_texture_bounce()) {
 498                 labels.push_back("needs_bounce");
 499         }
 500         if (from->effect->changes_output_size()) {
 501                 labels.push_back("resize");
 502         }
 503
 504         switch (from->output_color_space) {
 505         case COLORSPACE_INVALID:
 506                 labels.push_back("spc[invalid]");
 507                 break;
 508         case COLORSPACE_REC_601_525:
 509                 labels.push_back("spc[rec601-525]");
 510                 break;
 511         case COLORSPACE_REC_601_625:
 512                 labels.push_back("spc[rec601-625]");
 513                 break;
 514         default:
 515                 break;
 516         }
 517
 518         switch (from->output_gamma_curve) {
 519         case GAMMA_INVALID:
 520                 labels.push_back("gamma[invalid]");
 521                 break;
 522         case GAMMA_sRGB:
 523                 labels.push_back("gamma[sRGB]");
 524                 break;
 525         case GAMMA_REC_601:  // and GAMMA_REC_709
 526                 labels.push_back("gamma[rec601/709]");
 527                 break;
 528         default:
 529                 break;
 530         }
 531
 532         switch (from->output_alpha_type) {
 533         case ALPHA_INVALID:
 534                 labels.push_back("alpha[invalid]");
 535                 break;
 536         case ALPHA_BLANK:
 537                 labels.push_back("alpha[blank]");
 538                 break;
 539         case ALPHA_POSTMULTIPLIED:
 540                 labels.push_back("alpha[postmult]");
 541                 break;
 542         default:
 543                 break;
 544         }
 545
 546         return labels;
 547 }
 548
 549 void EffectChain::output_dot_edge(FILE *fp,
 550                                   const string &from_node_id,
 551                                   const string &to_node_id,
 552                                   const vector<string> &labels)
 553 {
 554         if (labels.empty()) {
 555                 fprintf(fp, "  %s -> %s;\n", from_node_id.c_str(), to_node_id.c_str());
 556         } else {
 557                 string label = labels[0];
 558                 for (unsigned k = 1; k < labels.size(); ++k) {
 559                         label += ", " + labels[k];
 560                 }
 561                 fprintf(fp, "  %s -> %s [label=\"%s\"];\n", from_node_id.c_str(), to_node_id.c_str(), label.c_str());
 562         }
 563 }
 564
 565 void EffectChain::size_rectangle_to_fit(unsigned width, unsigned height, unsigned *output_width, unsigned *output_height)
 566 {
 567         unsigned scaled_width, scaled_height;
 568
 569         if (float(width) * aspect_denom >= float(height) * aspect_nom) {
 570                 // Same aspect, or W/H > aspect (image is wider than the frame).
 571                 // In either case, keep width, and adjust height.
 572                 scaled_width = width;
 573                 scaled_height = lrintf(width * aspect_denom / aspect_nom);
 574         } else {
 575                 // W/H < aspect (image is taller than the frame), so keep height,
 576                 // and adjust width.
 577                 scaled_width = lrintf(height * aspect_nom / aspect_denom);
 578                 scaled_height = height;
 579         }
 580
 581         // We should be consistently larger or smaller then the existing choice,
 582         // since we have the same aspect.
 583         assert(!(scaled_width < *output_width && scaled_height > *output_height));
 584         assert(!(scaled_height < *output_height && scaled_width > *output_width));
 585
 586         if (scaled_width >= *output_width && scaled_height >= *output_height) {
 587                 *output_width = scaled_width;
 588                 *output_height = scaled_height;
 589         }
 590 }
 591
 592 // Propagate input texture sizes throughout, and inform effects downstream.
 593 // (Like a lot of other code, we depend on effects being in topological order.)
 594 void EffectChain::inform_input_sizes(Phase *phase)
 595 {
 596         // All effects that have a defined size (inputs and RTT inputs)
 597         // get that. Reset all others.
 598         for (unsigned i = 0; i < phase->effects.size(); ++i) {
 599                 Node *node = phase->effects[i];
 600                 if (node->effect->num_inputs() == 0) {
 601                         Input *input = static_cast<Input *>(node->effect);
 602                         node->output_width = input->get_width();
 603                         node->output_height = input->get_height();
 604                         assert(node->output_width != 0);
 605                         assert(node->output_height != 0);
 606                 } else {
 607                         node->output_width = node->output_height = 0;
 608                 }
 609         }
 610         for (unsigned i = 0; i < phase->inputs.size(); ++i) {
 611                 Node *input = phase->inputs[i];
 612                 input->output_width = input->phase->virtual_output_width;
 613                 input->output_height = input->phase->virtual_output_height;
 614                 assert(input->output_width != 0);
 615                 assert(input->output_height != 0);
 616         }
 617
 618         // Now propagate from the inputs towards the end, and inform as we go.
 619         // The rules are simple:
 620         //
 621         //   1. Don't touch effects that already have given sizes (ie., inputs).
 622         //   2. If all of your inputs have the same size, that will be your output size.
 623         //   3. Otherwise, your output size is 0x0.
 624         for (unsigned i = 0; i < phase->effects.size(); ++i) {
 625                 Node *node = phase->effects[i];
 626                 if (node->effect->num_inputs() == 0) {
 627                         continue;
 628                 }
 629                 unsigned this_output_width = 0;
 630                 unsigned this_output_height = 0;
 631                 for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
 632                         Node *input = node->incoming_links[j];
 633                         node->effect->inform_input_size(j, input->output_width, input->output_height);
 634                         if (j == 0) {
 635                                 this_output_width = input->output_width;
 636                                 this_output_height = input->output_height;
 637                         } else if (input->output_width != this_output_width || input->output_height != this_output_height) {
 638                                 // Inputs disagree.
 639                                 this_output_width = 0;
 640                                 this_output_height = 0;
 641                         }
 642                 }
 643                 node->output_width = this_output_width;
 644                 node->output_height = this_output_height;
 645         }
 646 }
 647
 648 // Note: You should call inform_input_sizes() before this, as the last effect's
 649 // desired output size might change based on the inputs.
 650 void EffectChain::find_output_size(Phase *phase)
 651 {
 652         Node *output_node = phase->effects.back();
 653
 654         // If the last effect explicitly sets an output size, use that.
 655         if (output_node->effect->changes_output_size()) {
 656                 output_node->effect->get_output_size(&phase->output_width, &phase->output_height,
 657                                                      &phase->virtual_output_width, &phase->virtual_output_height);
 658                 return;
 659         }
 660
 661         // If all effects have the same size, use that.
 662         unsigned output_width = 0, output_height = 0;
 663         bool all_inputs_same_size = true;
 664
 665         for (unsigned i = 0; i < phase->inputs.size(); ++i) {
 666                 Node *input = phase->inputs[i];
 667                 assert(input->phase->output_width != 0);
 668                 assert(input->phase->output_height != 0);
 669                 if (output_width == 0 && output_height == 0) {
 670                         output_width = input->phase->virtual_output_width;
 671                         output_height = input->phase->virtual_output_height;
 672                 } else if (output_width != input->phase->virtual_output_width ||
 673                            output_height != input->phase->virtual_output_height) {
 674                         all_inputs_same_size = false;
 675                 }
 676         }
 677         for (unsigned i = 0; i < phase->effects.size(); ++i) {
 678                 Effect *effect = phase->effects[i]->effect;
 679                 if (effect->num_inputs() != 0) {
 680                         continue;
 681                 }
 682
 683                 Input *input = static_cast<Input *>(effect);
 684                 if (output_width == 0 && output_height == 0) {
 685                         output_width = input->get_width();
 686                         output_height = input->get_height();
 687                 } else if (output_width != input->get_width() ||
 688                            output_height != input->get_height()) {
 689                         all_inputs_same_size = false;
 690                 }
 691         }
 692
 693         if (all_inputs_same_size) {
 694                 assert(output_width != 0);
 695                 assert(output_height != 0);
 696                 phase->virtual_output_width = phase->output_width = output_width;
 697                 phase->virtual_output_height = phase->output_height = output_height;
 698                 return;
 699         }
 700
 701         // If not, fit all the inputs into the current aspect, and select the largest one.
 702         output_width = 0;
 703         output_height = 0;
 704         for (unsigned i = 0; i < phase->inputs.size(); ++i) {
 705                 Node *input = phase->inputs[i];
 706                 assert(input->phase->output_width != 0);
 707                 assert(input->phase->output_height != 0);
 708                 size_rectangle_to_fit(input->phase->output_width, input->phase->output_height, &output_width, &output_height);
 709         }
 710         for (unsigned i = 0; i < phase->effects.size(); ++i) {
 711                 Effect *effect = phase->effects[i]->effect;
 712                 if (effect->num_inputs() != 0) {
 713                         continue;
 714                 }
 715
 716                 Input *input = static_cast<Input *>(effect);
 717                 size_rectangle_to_fit(input->get_width(), input->get_height(), &output_width, &output_height);
 718         }
 719         assert(output_width != 0);
 720         assert(output_height != 0);
 721         phase->virtual_output_width = phase->output_width = output_width;
 722         phase->virtual_output_height = phase->output_height = output_height;
 723 }
 724
 725 void EffectChain::sort_all_nodes_topologically()
 726 {
 727         nodes = topological_sort(nodes);
 728 }
 729
 730 vector<Node *> EffectChain::topological_sort(const vector<Node *> &nodes)
 731 {
 732         set<Node *> nodes_left_to_visit(nodes.begin(), nodes.end());
 733         vector<Node *> sorted_list;
 734         for (unsigned i = 0; i < nodes.size(); ++i) {
 735                 topological_sort_visit_node(nodes[i], &nodes_left_to_visit, &sorted_list);
 736         }
 737         reverse(sorted_list.begin(), sorted_list.end());
 738         return sorted_list;
 739 }
 740
 741 void EffectChain::topological_sort_visit_node(Node *node, set<Node *> *nodes_left_to_visit, vector<Node *> *sorted_list)
 742 {
 743         if (nodes_left_to_visit->count(node) == 0) {
 744                 return;
 745         }
 746         nodes_left_to_visit->erase(node);
 747         for (unsigned i = 0; i < node->outgoing_links.size(); ++i) {
 748                 topological_sort_visit_node(node->outgoing_links[i], nodes_left_to_visit, sorted_list);
 749         }
 750         sorted_list->push_back(node);
 751 }
 752
 753 void EffectChain::find_color_spaces_for_inputs()
 754 {
 755         for (unsigned i = 0; i < nodes.size(); ++i) {
 756                 Node *node = nodes[i];
 757                 if (node->disabled) {
 758                         continue;
 759                 }
 760                 if (node->incoming_links.size() == 0) {
 761                         Input *input = static_cast<Input *>(node->effect);
 762                         node->output_color_space = input->get_color_space();
 763                         node->output_gamma_curve = input->get_gamma_curve();
 764
 765                         Effect::AlphaHandling alpha_handling = input->alpha_handling();
 766                         switch (alpha_handling) {
 767                         case Effect::OUTPUT_BLANK_ALPHA:
 768                                 node->output_alpha_type = ALPHA_BLANK;
 769                                 break;
 770                         case Effect::INPUT_AND_OUTPUT_PREMULTIPLIED_ALPHA:
 771                                 node->output_alpha_type = ALPHA_PREMULTIPLIED;
 772                                 break;
 773                         case Effect::OUTPUT_POSTMULTIPLIED_ALPHA:
 774                                 node->output_alpha_type = ALPHA_POSTMULTIPLIED;
 775                                 break;
 776                         case Effect::INPUT_PREMULTIPLIED_ALPHA_KEEP_BLANK:
 777                         case Effect::DONT_CARE_ALPHA_TYPE:
 778                         default:
 779                                 assert(false);
 780                         }
 781
 782                         if (node->output_alpha_type == ALPHA_PREMULTIPLIED) {
 783                                 assert(node->output_gamma_curve == GAMMA_LINEAR);
 784                         }
 785                 }
 786         }
 787 }
 788
 789 // Propagate gamma and color space information as far as we can in the graph.
 790 // The rules are simple: Anything where all the inputs agree, get that as
 791 // output as well. Anything else keeps having *_INVALID.
 792 void EffectChain::propagate_gamma_and_color_space()
 793 {
 794         // We depend on going through the nodes in order.
 795         sort_all_nodes_topologically();
 796
 797         for (unsigned i = 0; i < nodes.size(); ++i) {
 798                 Node *node = nodes[i];
 799                 if (node->disabled) {
 800                         continue;
 801                 }
 802                 assert(node->incoming_links.size() == node->effect->num_inputs());
 803                 if (node->incoming_links.size() == 0) {
 804                         assert(node->output_color_space != COLORSPACE_INVALID);
 805                         assert(node->output_gamma_curve != GAMMA_INVALID);
 806                         continue;
 807                 }
 808
 809                 Colorspace color_space = node->incoming_links[0]->output_color_space;
 810                 GammaCurve gamma_curve = node->incoming_links[0]->output_gamma_curve;
 811                 for (unsigned j = 1; j < node->incoming_links.size(); ++j) {
 812                         if (node->incoming_links[j]->output_color_space != color_space) {
 813                                 color_space = COLORSPACE_INVALID;
 814                         }
 815                         if (node->incoming_links[j]->output_gamma_curve != gamma_curve) {
 816                                 gamma_curve = GAMMA_INVALID;
 817                         }
 818                 }
 819
 820                 // The conversion effects already have their outputs set correctly,
 821                 // so leave them alone.
 822                 if (node->effect->effect_type_id() != "ColorspaceConversionEffect") {
 823                         node->output_color_space = color_space;
 824                 }
 825                 if (node->effect->effect_type_id() != "GammaCompressionEffect" &&
 826                     node->effect->effect_type_id() != "GammaExpansionEffect") {
 827                         node->output_gamma_curve = gamma_curve;
 828                 }
 829         }
 830 }
 831
 832 // Propagate alpha information as far as we can in the graph.
 833 // Similar to propagate_gamma_and_color_space().
 834 void EffectChain::propagate_alpha()
 835 {
 836         // We depend on going through the nodes in order.
 837         sort_all_nodes_topologically();
 838
 839         for (unsigned i = 0; i < nodes.size(); ++i) {
 840                 Node *node = nodes[i];
 841                 if (node->disabled) {
 842                         continue;
 843                 }
 844                 assert(node->incoming_links.size() == node->effect->num_inputs());
 845                 if (node->incoming_links.size() == 0) {
 846                         assert(node->output_alpha_type != ALPHA_INVALID);
 847                         continue;
 848                 }
 849
 850                 // The alpha multiplication/division effects are special cases.
 851                 if (node->effect->effect_type_id() == "AlphaMultiplicationEffect") {
 852                         assert(node->incoming_links.size() == 1);
 853                         assert(node->incoming_links[0]->output_alpha_type == ALPHA_POSTMULTIPLIED);
 854                         node->output_alpha_type = ALPHA_PREMULTIPLIED;
 855                         continue;
 856                 }
 857                 if (node->effect->effect_type_id() == "AlphaDivisionEffect") {
 858                         assert(node->incoming_links.size() == 1);
 859                         assert(node->incoming_links[0]->output_alpha_type == ALPHA_PREMULTIPLIED);
 860                         node->output_alpha_type = ALPHA_POSTMULTIPLIED;
 861                         continue;
 862                 }
 863
 864                 // GammaCompressionEffect and GammaExpansionEffect are also a special case,
 865                 // because they are the only one that _need_ postmultiplied alpha.
 866                 if (node->effect->effect_type_id() == "GammaCompressionEffect" ||
 867                     node->effect->effect_type_id() == "GammaExpansionEffect") {
 868                         assert(node->incoming_links.size() == 1);
 869                         if (node->incoming_links[0]->output_alpha_type == ALPHA_BLANK) {
 870                                 node->output_alpha_type = ALPHA_BLANK;
 871                         } else if (node->incoming_links[0]->output_alpha_type == ALPHA_POSTMULTIPLIED) {
 872                                 node->output_alpha_type = ALPHA_POSTMULTIPLIED;
 873                         } else {
 874                                 node->output_alpha_type = ALPHA_INVALID;
 875                         }
 876                         continue;
 877                 }
 878
 879                 // Only inputs can have unconditional alpha output (OUTPUT_BLANK_ALPHA
 880                 // or OUTPUT_POSTMULTIPLIED_ALPHA), and they have already been
 881                 // taken care of above. Rationale: Even if you could imagine
 882                 // e.g. an effect that took in an image and set alpha=1.0
 883                 // unconditionally, it wouldn't make any sense to have it as
 884                 // e.g. OUTPUT_BLANK_ALPHA, since it wouldn't know whether it
 885                 // got its input pre- or postmultiplied, so it wouldn't know
 886                 // whether to divide away the old alpha or not.
 887                 Effect::AlphaHandling alpha_handling = node->effect->alpha_handling();
 888                 assert(alpha_handling == Effect::INPUT_AND_OUTPUT_PREMULTIPLIED_ALPHA ||
 889                        alpha_handling == Effect::INPUT_PREMULTIPLIED_ALPHA_KEEP_BLANK ||
 890                        alpha_handling == Effect::DONT_CARE_ALPHA_TYPE);
 891
 892                 // If the node has multiple inputs, check that they are all valid and
 893                 // the same.
 894                 bool any_invalid = false;
 895                 bool any_premultiplied = false;
 896                 bool any_postmultiplied = false;
 897
 898                 for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
 899                         switch (node->incoming_links[j]->output_alpha_type) {
 900                         case ALPHA_INVALID:
 901                                 any_invalid = true;
 902                                 break;
 903                         case ALPHA_BLANK:
 904                                 // Blank is good as both pre- and postmultiplied alpha,
 905                                 // so just ignore it.
 906                                 break;
 907                         case ALPHA_PREMULTIPLIED:
 908                                 any_premultiplied = true;
 909                                 break;
 910                         case ALPHA_POSTMULTIPLIED:
 911                                 any_postmultiplied = true;
 912                                 break;
 913                         default:
 914                                 assert(false);
 915                         }
 916                 }
 917
 918                 if (any_invalid) {
 919                         node->output_alpha_type = ALPHA_INVALID;
 920                         continue;
 921                 }
 922
 923                 // Inputs must be of the same type.
 924                 if (any_premultiplied && any_postmultiplied) {
 925                         node->output_alpha_type = ALPHA_INVALID;
 926                         continue;
 927                 }
 928
 929                 if (alpha_handling == Effect::INPUT_AND_OUTPUT_PREMULTIPLIED_ALPHA ||
 930                     alpha_handling == Effect::INPUT_PREMULTIPLIED_ALPHA_KEEP_BLANK) {
 931                         // If the effect has asked for premultiplied alpha, check that it has got it.
 932                         if (any_postmultiplied) {
 933                                 node->output_alpha_type = ALPHA_INVALID;
 934                         } else if (!any_premultiplied &&
 935                                    alpha_handling == Effect::INPUT_PREMULTIPLIED_ALPHA_KEEP_BLANK) {
 936                                 // Blank input alpha, and the effect preserves blank alpha.
 937                                 node->output_alpha_type = ALPHA_BLANK;
 938                         } else {
 939                                 node->output_alpha_type = ALPHA_PREMULTIPLIED;
 940                         }
 941                 } else {
 942                         // OK, all inputs are the same, and this effect is not going
 943                         // to change it.
 944                         assert(alpha_handling == Effect::DONT_CARE_ALPHA_TYPE);
 945                         if (any_premultiplied) {
 946                                 node->output_alpha_type = ALPHA_PREMULTIPLIED;
 947                         } else if (any_postmultiplied) {
 948                                 node->output_alpha_type = ALPHA_POSTMULTIPLIED;
 949                         } else {
 950                                 node->output_alpha_type = ALPHA_BLANK;
 951                         }
 952                 }
 953         }
 954 }
 955
 956 bool EffectChain::node_needs_colorspace_fix(Node *node)
 957 {
 958         if (node->disabled) {
 959                 return false;
 960         }
 961         if (node->effect->num_inputs() == 0) {
 962                 return false;
 963         }
 964
 965         // propagate_gamma_and_color_space() has already set our output
 966         // to COLORSPACE_INVALID if the inputs differ, so we can rely on that.
 967         if (node->output_color_space == COLORSPACE_INVALID) {
 968                 return true;
 969         }
 970         return (node->effect->needs_srgb_primaries() && node->output_color_space != COLORSPACE_sRGB);
 971 }
 972
 973 // Fix up color spaces so that there are no COLORSPACE_INVALID nodes left in
 974 // the graph. Our strategy is not always optimal, but quite simple:
 975 // Find an effect that's as early as possible where the inputs are of
 976 // unacceptable colorspaces (that is, either different, or, if the effect only
 977 // wants sRGB, not sRGB.) Add appropriate conversions on all its inputs,
 978 // propagate the information anew, and repeat until there are no more such
 979 // effects.
 980 void EffectChain::fix_internal_color_spaces()
 981 {
 982         unsigned colorspace_propagation_pass = 0;
 983         bool found_any;
 984         do {
 985                 found_any = false;
 986                 for (unsigned i = 0; i < nodes.size(); ++i) {
 987                         Node *node = nodes[i];
 988                         if (!node_needs_colorspace_fix(node)) {
 989                                 continue;
 990                         }
 991
 992                         // Go through each input that is not sRGB, and insert
 993                         // a colorspace conversion after it.
 994                         for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
 995                                 Node *input = node->incoming_links[j];
 996                                 assert(input->output_color_space != COLORSPACE_INVALID);
 997                                 if (input->output_color_space == COLORSPACE_sRGB) {
 998                                         continue;
 999                                 }
1000                                 Node *conversion = add_node(new ColorspaceConversionEffect());
1001                                 CHECK(conversion->effect->set_int("source_space", input->output_color_space));
1002                                 CHECK(conversion->effect->set_int("destination_space", COLORSPACE_sRGB));
1003                                 conversion->output_color_space = COLORSPACE_sRGB;
1004                                 replace_sender(input, conversion);
1005                                 connect_nodes(input, conversion);
1006                         }
1007
1008                         // Re-sort topologically, and propagate the new information.
1009                         propagate_gamma_and_color_space();
1010
1011                         found_any = true;
1012                         break;
1013                 }
1014
1015                 char filename[256];
1016                 sprintf(filename, "step5-colorspacefix-iter%u.dot", ++colorspace_propagation_pass);
1017                 output_dot(filename);
1018                 assert(colorspace_propagation_pass < 100);
1019         } while (found_any);
1020
1021         for (unsigned i = 0; i < nodes.size(); ++i) {
1022                 Node *node = nodes[i];
1023                 if (node->disabled) {
1024                         continue;
1025                 }
1026                 assert(node->output_color_space != COLORSPACE_INVALID);
1027         }
1028 }
1029
1030 bool EffectChain::node_needs_alpha_fix(Node *node)
1031 {
1032         if (node->disabled) {
1033                 return false;
1034         }
1035
1036         // propagate_alpha() has already set our output to ALPHA_INVALID if the
1037         // inputs differ or we are otherwise in mismatch, so we can rely on that.
1038         return (node->output_alpha_type == ALPHA_INVALID);
1039 }
1040
1041 // Fix up alpha so that there are no ALPHA_INVALID nodes left in
1042 // the graph. Similar to fix_internal_color_spaces().
1043 void EffectChain::fix_internal_alpha(unsigned step)
1044 {
1045         unsigned alpha_propagation_pass = 0;
1046         bool found_any;
1047         do {
1048                 found_any = false;
1049                 for (unsigned i = 0; i < nodes.size(); ++i) {
1050                         Node *node = nodes[i];
1051                         if (!node_needs_alpha_fix(node)) {
1052                                 continue;
1053                         }
1054
1055                         // If we need to fix up GammaExpansionEffect, then clearly something
1056                         // is wrong, since the combination of premultiplied alpha and nonlinear inputs
1057                         // is meaningless.
1058                         assert(node->effect->effect_type_id() != "GammaExpansionEffect");
1059
1060                         AlphaType desired_type = ALPHA_PREMULTIPLIED;
1061
1062                         // GammaCompressionEffect is special; it needs postmultiplied alpha.
1063                         if (node->effect->effect_type_id() == "GammaCompressionEffect") {
1064                                 assert(node->incoming_links.size() == 1);
1065                                 assert(node->incoming_links[0]->output_alpha_type == ALPHA_PREMULTIPLIED);
1066                                 desired_type = ALPHA_POSTMULTIPLIED;
1067                         }
1068
1069                         // Go through each input that is not premultiplied alpha, and insert
1070                         // a conversion before it.
1071                         for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
1072                                 Node *input = node->incoming_links[j];
1073                                 assert(input->output_alpha_type != ALPHA_INVALID);
1074                                 if (input->output_alpha_type == desired_type ||
1075                                     input->output_alpha_type == ALPHA_BLANK) {
1076                                         continue;
1077                                 }
1078                                 Node *conversion;
1079                                 if (desired_type == ALPHA_PREMULTIPLIED) {
1080                                         conversion = add_node(new AlphaMultiplicationEffect());
1081                                 } else {
1082                                         conversion = add_node(new AlphaDivisionEffect());
1083                                 }
1084                                 conversion->output_alpha_type = desired_type;
1085                                 replace_sender(input, conversion);
1086                                 connect_nodes(input, conversion);
1087                         }
1088
1089                         // Re-sort topologically, and propagate the new information.
1090                         propagate_gamma_and_color_space();
1091                         propagate_alpha();
1092
1093                         found_any = true;
1094                         break;
1095                 }
1096
1097                 char filename[256];
1098                 sprintf(filename, "step%u-alphafix-iter%u.dot", step, ++alpha_propagation_pass);
1099                 output_dot(filename);
1100                 assert(alpha_propagation_pass < 100);
1101         } while (found_any);
1102
1103         for (unsigned i = 0; i < nodes.size(); ++i) {
1104                 Node *node = nodes[i];
1105                 if (node->disabled) {
1106                         continue;
1107                 }
1108                 assert(node->output_alpha_type != ALPHA_INVALID);
1109         }
1110 }
1111
1112 // Make so that the output is in the desired color space.
1113 void EffectChain::fix_output_color_space()
1114 {
1115         Node *output = find_output_node();
1116         if (output->output_color_space != output_format.color_space) {
1117                 Node *conversion = add_node(new ColorspaceConversionEffect());
1118                 CHECK(conversion->effect->set_int("source_space", output->output_color_space));
1119                 CHECK(conversion->effect->set_int("destination_space", output_format.color_space));
1120                 conversion->output_color_space = output_format.color_space;
1121                 connect_nodes(output, conversion);
1122                 propagate_alpha();
1123                 propagate_gamma_and_color_space();
1124         }
1125 }
1126
1127 // Make so that the output is in the desired pre-/postmultiplication alpha state.
1128 void EffectChain::fix_output_alpha()
1129 {
1130         Node *output = find_output_node();
1131         assert(output->output_alpha_type != ALPHA_INVALID);
1132         if (output->output_alpha_type == ALPHA_BLANK) {
1133                 // No alpha output, so we don't care.
1134                 return;
1135         }
1136         if (output->output_alpha_type == ALPHA_PREMULTIPLIED &&
1137             output_alpha_format == OUTPUT_ALPHA_FORMAT_POSTMULTIPLIED) {
1138                 Node *conversion = add_node(new AlphaDivisionEffect());
1139                 connect_nodes(output, conversion);
1140                 propagate_alpha();
1141                 propagate_gamma_and_color_space();
1142         }
1143         if (output->output_alpha_type == ALPHA_POSTMULTIPLIED &&
1144             output_alpha_format == OUTPUT_ALPHA_FORMAT_PREMULTIPLIED) {
1145                 Node *conversion = add_node(new AlphaMultiplicationEffect());
1146                 connect_nodes(output, conversion);
1147                 propagate_alpha();
1148                 propagate_gamma_and_color_space();
1149         }
1150 }
1151
1152 bool EffectChain::node_needs_gamma_fix(Node *node)
1153 {
1154         if (node->disabled) {
1155                 return false;
1156         }
1157
1158         // Small hack since the output is not an explicit node:
1159         // If we are the last node and our output is in the wrong
1160         // space compared to EffectChain's output, we need to fix it.
1161         // This will only take us to linear, but fix_output_gamma()
1162         // will come and take us to the desired output gamma
1163         // if it is needed.
1164         //
1165         // This needs to be before everything else, since it could
1166         // even apply to inputs (if they are the only effect).
1167         if (node->outgoing_links.empty() &&
1168             node->output_gamma_curve != output_format.gamma_curve &&
1169             node->output_gamma_curve != GAMMA_LINEAR) {
1170                 return true;
1171         }
1172
1173         if (node->effect->num_inputs() == 0) {
1174                 return false;
1175         }
1176
1177         // propagate_gamma_and_color_space() has already set our output
1178         // to GAMMA_INVALID if the inputs differ, so we can rely on that,
1179         // except for GammaCompressionEffect.
1180         if (node->output_gamma_curve == GAMMA_INVALID) {
1181                 return true;
1182         }
1183         if (node->effect->effect_type_id() == "GammaCompressionEffect") {
1184                 assert(node->incoming_links.size() == 1);
1185                 return node->incoming_links[0]->output_gamma_curve != GAMMA_LINEAR;
1186         }
1187
1188         return (node->effect->needs_linear_light() && node->output_gamma_curve != GAMMA_LINEAR);
1189 }
1190
1191 // Very similar to fix_internal_color_spaces(), but for gamma.
1192 // There is one difference, though; before we start adding conversion nodes,
1193 // we see if we can get anything out of asking the sources to deliver
1194 // linear gamma directly. fix_internal_gamma_by_asking_inputs()
1195 // does that part, while fix_internal_gamma_by_inserting_nodes()
1196 // inserts nodes as needed afterwards.
1197 void EffectChain::fix_internal_gamma_by_asking_inputs(unsigned step)
1198 {
1199         unsigned gamma_propagation_pass = 0;
1200         bool found_any;
1201         do {
1202                 found_any = false;
1203                 for (unsigned i = 0; i < nodes.size(); ++i) {
1204                         Node *node = nodes[i];
1205                         if (!node_needs_gamma_fix(node)) {
1206                                 continue;
1207                         }
1208
1209                         // See if all inputs can give us linear gamma. If not, leave it.
1210                         vector<Node *> nonlinear_inputs;
1211                         find_all_nonlinear_inputs(node, &nonlinear_inputs);
1212                         assert(!nonlinear_inputs.empty());
1213
1214                         bool all_ok = true;
1215                         for (unsigned i = 0; i < nonlinear_inputs.size(); ++i) {
1216                                 Input *input = static_cast<Input *>(nonlinear_inputs[i]->effect);
1217                                 all_ok &= input->can_output_linear_gamma();
1218                         }
1219
1220                         if (!all_ok) {
1221                                 continue;
1222                         }
1223
1224                         for (unsigned i = 0; i < nonlinear_inputs.size(); ++i) {
1225                                 CHECK(nonlinear_inputs[i]->effect->set_int("output_linear_gamma", 1));
1226                                 nonlinear_inputs[i]->output_gamma_curve = GAMMA_LINEAR;
1227                         }
1228
1229                         // Re-sort topologically, and propagate the new information.
1230                         propagate_gamma_and_color_space();
1231
1232                         found_any = true;
1233                         break;
1234                 }
1235
1236                 char filename[256];
1237                 sprintf(filename, "step%u-gammafix-iter%u.dot", step, ++gamma_propagation_pass);
1238                 output_dot(filename);
1239                 assert(gamma_propagation_pass < 100);
1240         } while (found_any);
1241 }
1242
1243 void EffectChain::fix_internal_gamma_by_inserting_nodes(unsigned step)
1244 {
1245         unsigned gamma_propagation_pass = 0;
1246         bool found_any;
1247         do {
1248                 found_any = false;
1249                 for (unsigned i = 0; i < nodes.size(); ++i) {
1250                         Node *node = nodes[i];
1251                         if (!node_needs_gamma_fix(node)) {
1252                                 continue;
1253                         }
1254
1255                         // Special case: We could be an input and still be asked to
1256                         // fix our gamma; if so, we should be the only node
1257                         // (as node_needs_gamma_fix() would only return true in
1258                         // for an input in that case). That means we should insert
1259                         // a conversion node _after_ ourselves.
1260                         if (node->incoming_links.empty()) {
1261                                 assert(node->outgoing_links.empty());
1262                                 Node *conversion = add_node(new GammaExpansionEffect());
1263                                 CHECK(conversion->effect->set_int("source_curve", node->output_gamma_curve));
1264                                 conversion->output_gamma_curve = GAMMA_LINEAR;
1265                                 connect_nodes(node, conversion);
1266                         }
1267
1268                         // If not, go through each input that is not linear gamma,
1269                         // and insert a gamma conversion after it.
1270                         for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
1271                                 Node *input = node->incoming_links[j];
1272                                 assert(input->output_gamma_curve != GAMMA_INVALID);
1273                                 if (input->output_gamma_curve == GAMMA_LINEAR) {
1274                                         continue;
1275                                 }
1276                                 Node *conversion = add_node(new GammaExpansionEffect());
1277                                 CHECK(conversion->effect->set_int("source_curve", input->output_gamma_curve));
1278                                 conversion->output_gamma_curve = GAMMA_LINEAR;
1279                                 replace_sender(input, conversion);
1280                                 connect_nodes(input, conversion);
1281                         }
1282
1283                         // Re-sort topologically, and propagate the new information.
1284                         propagate_alpha();
1285                         propagate_gamma_and_color_space();
1286
1287                         found_any = true;
1288                         break;
1289                 }
1290
1291                 char filename[256];
1292                 sprintf(filename, "step%u-gammafix-iter%u.dot", step, ++gamma_propagation_pass);
1293                 output_dot(filename);
1294                 assert(gamma_propagation_pass < 100);
1295         } while (found_any);
1296
1297         for (unsigned i = 0; i < nodes.size(); ++i) {
1298                 Node *node = nodes[i];
1299                 if (node->disabled) {
1300                         continue;
1301                 }
1302                 assert(node->output_gamma_curve != GAMMA_INVALID);
1303         }
1304 }
1305
1306 // Make so that the output is in the desired gamma.
1307 // Note that this assumes linear input gamma, so it might create the need
1308 // for another pass of fix_internal_gamma().
1309 void EffectChain::fix_output_gamma()
1310 {
1311         Node *output = find_output_node();
1312         if (output->output_gamma_curve != output_format.gamma_curve) {
1313                 Node *conversion = add_node(new GammaCompressionEffect());
1314                 CHECK(conversion->effect->set_int("destination_curve", output_format.gamma_curve));
1315                 conversion->output_gamma_curve = output_format.gamma_curve;
1316                 connect_nodes(output, conversion);
1317         }
1318 }
1319
1320 // If the user has requested dither, add a DitherEffect right at the end
1321 // (after GammaCompressionEffect etc.). This needs to be done after everything else,
1322 // since dither is about the only effect that can _not_ be done in linear space.
1323 void EffectChain::add_dither_if_needed()
1324 {
1325         if (num_dither_bits == 0) {
1326                 return;
1327         }
1328         Node *output = find_output_node();
1329         Node *dither = add_node(new DitherEffect());
1330         CHECK(dither->effect->set_int("num_bits", num_dither_bits));
1331         connect_nodes(output, dither);
1332
1333         dither_effect = dither->effect;
1334 }
1335
1336 // Find the output node. This is, simply, one that has no outgoing links.
1337 // If there are multiple ones, the graph is malformed (we do not support
1338 // multiple outputs right now).
1339 Node *EffectChain::find_output_node()
1340 {
1341         vector<Node *> output_nodes;
1342         for (unsigned i = 0; i < nodes.size(); ++i) {
1343                 Node *node = nodes[i];
1344                 if (node->disabled) {
1345                         continue;
1346                 }
1347                 if (node->outgoing_links.empty()) {
1348                         output_nodes.push_back(node);
1349                 }
1350         }
1351         assert(output_nodes.size() == 1);
1352         return output_nodes[0];
1353 }
1354
1355 void EffectChain::finalize()
1356 {
1357         // Save the current locale, and set it to C, so that we can output decimal
1358         // numbers with printf and be sure to get them in the format mandated by GLSL.
1359         char *saved_locale = setlocale(LC_NUMERIC, "C");
1360
1361         // Output the graph as it is before we do any conversions on it.
1362         output_dot("step0-start.dot");
1363
1364         // Give each effect in turn a chance to rewrite its own part of the graph.
1365         // Note that if more effects are added as part of this, they will be
1366         // picked up as part of the same for loop, since they are added at the end.
1367         for (unsigned i = 0; i < nodes.size(); ++i) {
1368                 nodes[i]->effect->rewrite_graph(this, nodes[i]);
1369         }
1370         output_dot("step1-rewritten.dot");
1371
1372         find_color_spaces_for_inputs();
1373         output_dot("step2-input-colorspace.dot");
1374
1375         propagate_alpha();
1376         output_dot("step3-propagated-alpha.dot");
1377
1378         propagate_gamma_and_color_space();
1379         output_dot("step4-propagated-all.dot");
1380
1381         fix_internal_color_spaces();
1382         fix_internal_alpha(6);
1383         fix_output_color_space();
1384         output_dot("step7-output-colorspacefix.dot");
1385         fix_output_alpha();
1386         output_dot("step8-output-alphafix.dot");
1387
1388         // Note that we need to fix gamma after colorspace conversion,
1389         // because colorspace conversions might create needs for gamma conversions.
1390         // Also, we need to run an extra pass of fix_internal_gamma() after
1391         // fixing the output gamma, as we only have conversions to/from linear,
1392         // and fix_internal_alpha() since GammaCompressionEffect needs
1393         // postmultiplied input.
1394         fix_internal_gamma_by_asking_inputs(9);
1395         fix_internal_gamma_by_inserting_nodes(10);
1396         fix_output_gamma();
1397         output_dot("step11-output-gammafix.dot");
1398         propagate_alpha();
1399         output_dot("step12-output-alpha-propagated.dot");
1400         fix_internal_alpha(13);
1401         output_dot("step14-output-alpha-fixed.dot");
1402         fix_internal_gamma_by_asking_inputs(15);
1403         fix_internal_gamma_by_inserting_nodes(16);
1404
1405         output_dot("step17-before-dither.dot");
1406
1407         add_dither_if_needed();
1408
1409         output_dot("step18-final.dot");
1410
1411         // Construct all needed GLSL programs, starting at the output.
1412         construct_glsl_programs(find_output_node());
1413
1414         output_dot("step19-split-to-phases.dot");
1415
1416         for (unsigned i = 0; i < inputs.size(); ++i) {
1417                 inputs[i]->finalize();
1418         }
1419
1420         assert(phases[0]->inputs.empty());
1421
1422         finalized = true;
1423         setlocale(LC_NUMERIC, saved_locale);
1424 }
1425
1426 void EffectChain::render_to_fbo(GLuint dest_fbo, unsigned width, unsigned height)
1427 {
1428         assert(finalized);
1429
1430         // Save original viewport.
1431         GLuint x = 0, y = 0;
1432         GLuint fbo = 0;
1433
1434         if (width == 0 && height == 0) {
1435                 GLint viewport[4];
1436                 glGetIntegerv(GL_VIEWPORT, viewport);
1437                 x = viewport[0];
1438                 y = viewport[1];
1439                 width = viewport[2];
1440                 height = viewport[3];
1441         }
1442
1443         // Basic state.
1444         glDisable(GL_BLEND);
1445         check_error();
1446         glDisable(GL_DEPTH_TEST);
1447         check_error();
1448         glDepthMask(GL_FALSE);
1449         check_error();
1450
1451         glMatrixMode(GL_PROJECTION);
1452         glLoadIdentity();
1453         glOrtho(0.0, 1.0, 0.0, 1.0, 0.0, 1.0);
1454
1455         glMatrixMode(GL_MODELVIEW);
1456         glLoadIdentity();
1457
1458         if (phases.size() > 1) {
1459                 glGenFramebuffers(1, &fbo);
1460                 check_error();
1461                 glBindFramebuffer(GL_FRAMEBUFFER, fbo);
1462                 check_error();
1463         }
1464
1465         set<Node *> generated_mipmaps;
1466
1467         // We choose the simplest option of having one texture per output,
1468         // since otherwise this turns into an (albeit simple) register allocation problem.
1469         map<Phase *, GLuint> output_textures;
1470
1471         for (unsigned phase = 0; phase < phases.size(); ++phase) {
1472                 // Find a texture for this phase.
1473                 inform_input_sizes(phases[phase]);
1474                 if (phase != phases.size() - 1) {
1475                         find_output_size(phases[phase]);
1476
1477                         GLuint tex_num = resource_pool->create_2d_texture(GL_RGBA16F_ARB, phases[phase]->output_width, phases[phase]->output_height);
1478                         output_textures.insert(make_pair(phases[phase], tex_num));
1479                 }
1480
1481                 glUseProgram(phases[phase]->glsl_program_num);
1482                 check_error();
1483
1484                 // Set up RTT inputs for this phase.
1485                 for (unsigned sampler = 0; sampler < phases[phase]->inputs.size(); ++sampler) {
1486                         glActiveTexture(GL_TEXTURE0 + sampler);
1487                         Node *input = phases[phase]->inputs[sampler];
1488                         glBindTexture(GL_TEXTURE_2D, output_textures[input->phase]);
1489                         check_error();
1490                         if (phases[phase]->input_needs_mipmaps) {
1491                                 if (generated_mipmaps.count(input) == 0) {
1492                                         glGenerateMipmap(GL_TEXTURE_2D);
1493                                         check_error();
1494                                         generated_mipmaps.insert(input);
1495                                 }
1496                                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_NEAREST);
1497                                 check_error();
1498                         } else {
1499                                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
1500                                 check_error();
1501                         }
1502                         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
1503                         check_error();
1504                         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
1505                         check_error();
1506
1507                         string texture_name = string("tex_") + phases[phase]->effect_ids[input];
1508                         glUniform1i(glGetUniformLocation(phases[phase]->glsl_program_num, texture_name.c_str()), sampler);
1509                         check_error();
1510                 }
1511
1512                 // And now the output.
1513                 if (phase == phases.size() - 1) {
1514                         // Last phase goes to the output the user specified.
1515                         glBindFramebuffer(GL_FRAMEBUFFER, dest_fbo);
1516                         check_error();
1517                         GLenum status = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);
1518                         assert(status == GL_FRAMEBUFFER_COMPLETE);
1519                         glViewport(x, y, width, height);
1520                         if (dither_effect != NULL) {
1521                                 CHECK(dither_effect->set_int("output_width", width));
1522                                 CHECK(dither_effect->set_int("output_height", height));
1523                         }
1524                 } else {
1525                         glFramebufferTexture2D(
1526                                 GL_FRAMEBUFFER,
1527                                 GL_COLOR_ATTACHMENT0,
1528                                 GL_TEXTURE_2D,
1529                                 output_textures[phases[phase]],
1530                                 0);
1531                         check_error();
1532                         GLenum status = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);
1533                         assert(status == GL_FRAMEBUFFER_COMPLETE);
1534                         glViewport(0, 0, phases[phase]->output_width, phases[phase]->output_height);
1535                 }
1536
1537                 // Give the required parameters to all the effects.
1538                 unsigned sampler_num = phases[phase]->inputs.size();
1539                 for (unsigned i = 0; i < phases[phase]->effects.size(); ++i) {
1540                         Node *node = phases[phase]->effects[i];
1541                         node->effect->set_gl_state(phases[phase]->glsl_program_num, phases[phase]->effect_ids[node], &sampler_num);
1542                         check_error();
1543                 }
1544
1545                 // Now draw!
1546                 glBegin(GL_QUADS);
1547
1548                 glTexCoord2f(0.0f, 0.0f);
1549                 glVertex2f(0.0f, 0.0f);
1550
1551                 glTexCoord2f(1.0f, 0.0f);
1552                 glVertex2f(1.0f, 0.0f);
1553
1554                 glTexCoord2f(1.0f, 1.0f);
1555                 glVertex2f(1.0f, 1.0f);
1556
1557                 glTexCoord2f(0.0f, 1.0f);
1558                 glVertex2f(0.0f, 1.0f);
1559
1560                 glEnd();
1561                 check_error();
1562
1563                 for (unsigned i = 0; i < phases[phase]->effects.size(); ++i) {
1564                         Node *node = phases[phase]->effects[i];
1565                         node->effect->clear_gl_state();
1566                 }
1567         }
1568
1569         for (map<Phase *, GLuint>::const_iterator texture_it = output_textures.begin();
1570              texture_it != output_textures.end();
1571              ++texture_it) {
1572                 resource_pool->release_2d_texture(texture_it->second);
1573         }
1574
1575         glBindFramebuffer(GL_FRAMEBUFFER, 0);
1576         check_error();
1577
1578         if (fbo != 0) {
1579                 glDeleteFramebuffers(1, &fbo);
1580                 check_error();
1581         }
1582 }