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

   1 #define GL_GLEXT_PROTOTYPES 1
   2
   3 #include <stdio.h>
   4 #include <math.h>
   5 #include <string.h>
   6 #include <locale.h>
   7 #include <assert.h>
   8 #include <GL/glew.h>
   9
  10 #include <algorithm>
  11 #include <set>
  12 #include <stack>
  13 #include <vector>
  14
  15 #include "util.h"
  16 #include "effect_chain.h"
  17 #include "gamma_expansion_effect.h"
  18 #include "gamma_compression_effect.h"
  19 #include "colorspace_conversion_effect.h"
  20 #include "alpha_multiplication_effect.h"
  21 #include "alpha_division_effect.h"
  22 #include "dither_effect.h"
  23 #include "input.h"
  24 #include "init.h"
  25
  26 EffectChain::EffectChain(float aspect_nom, float aspect_denom)
  27         : aspect_nom(aspect_nom),
  28           aspect_denom(aspect_denom),
  29           dither_effect(NULL),
  30           fbo(0),
  31           num_dither_bits(0),
  32           finalized(false) {}
  33
  34 EffectChain::~EffectChain()
  35 {
  36         for (unsigned i = 0; i < nodes.size(); ++i) {
  37                 if (nodes[i]->output_texture != 0) {
  38                         glDeleteTextures(1, &nodes[i]->output_texture);
  39                 }
  40                 delete nodes[i]->effect;
  41                 delete nodes[i];
  42         }
  43         for (unsigned i = 0; i < phases.size(); ++i) {
  44                 glDeleteProgram(phases[i]->glsl_program_num);
  45                 glDeleteShader(phases[i]->vertex_shader);
  46                 glDeleteShader(phases[i]->fragment_shader);
  47                 delete phases[i];
  48         }
  49         if (fbo != 0) {
  50                 glDeleteFramebuffers(1, &fbo);
  51         }
  52 }
  53
  54 Input *EffectChain::add_input(Input *input)
  55 {
  56         inputs.push_back(input);
  57         add_node(input);
  58         return input;
  59 }
  60
  61 void EffectChain::add_output(const ImageFormat &format, OutputAlphaFormat alpha_format)
  62 {
  63         output_format = format;
  64         output_alpha_format = alpha_format;
  65 }
  66
  67 Node *EffectChain::add_node(Effect *effect)
  68 {
  69         char effect_id[256];
  70         sprintf(effect_id, "eff%u", (unsigned)nodes.size());
  71
  72         Node *node = new Node;
  73         node->effect = effect;
  74         node->disabled = false;
  75         node->effect_id = effect_id;
  76         node->output_color_space = COLORSPACE_INVALID;
  77         node->output_gamma_curve = GAMMA_INVALID;
  78         node->output_alpha_type = ALPHA_INVALID;
  79         node->output_texture = 0;
  80
  81         nodes.push_back(node);
  82         node_map[effect] = node;
  83         return node;
  84 }
  85
  86 void EffectChain::connect_nodes(Node *sender, Node *receiver)
  87 {
  88         sender->outgoing_links.push_back(receiver);
  89         receiver->incoming_links.push_back(sender);
  90 }
  91
  92 void EffectChain::replace_receiver(Node *old_receiver, Node *new_receiver)
  93 {
  94         new_receiver->incoming_links = old_receiver->incoming_links;
  95         old_receiver->incoming_links.clear();
  96
  97         for (unsigned i = 0; i < new_receiver->incoming_links.size(); ++i) {
  98                 Node *sender = new_receiver->incoming_links[i];
  99                 for (unsigned j = 0; j < sender->outgoing_links.size(); ++j) {
 100                         if (sender->outgoing_links[j] == old_receiver) {
 101                                 sender->outgoing_links[j] = new_receiver;
 102                         }
 103                 }
 104         }
 105 }
 106
 107 void EffectChain::replace_sender(Node *old_sender, Node *new_sender)
 108 {
 109         new_sender->outgoing_links = old_sender->outgoing_links;
 110         old_sender->outgoing_links.clear();
 111
 112         for (unsigned i = 0; i < new_sender->outgoing_links.size(); ++i) {
 113                 Node *receiver = new_sender->outgoing_links[i];
 114                 for (unsigned j = 0; j < receiver->incoming_links.size(); ++j) {
 115                         if (receiver->incoming_links[j] == old_sender) {
 116                                 receiver->incoming_links[j] = new_sender;
 117                         }
 118                 }
 119         }
 120 }
 121
 122 void EffectChain::insert_node_between(Node *sender, Node *middle, Node *receiver)
 123 {
 124         for (unsigned i = 0; i < sender->outgoing_links.size(); ++i) {
 125                 if (sender->outgoing_links[i] == receiver) {
 126                         sender->outgoing_links[i] = middle;
 127                         middle->incoming_links.push_back(sender);
 128                 }
 129         }
 130         for (unsigned i = 0; i < receiver->incoming_links.size(); ++i) {
 131                 if (receiver->incoming_links[i] == sender) {
 132                         receiver->incoming_links[i] = middle;
 133                         middle->outgoing_links.push_back(receiver);
 134                 }
 135         }
 136
 137         assert(middle->incoming_links.size() == middle->effect->num_inputs());
 138 }
 139
 140 void EffectChain::find_all_nonlinear_inputs(Node *node, std::vector<Node *> *nonlinear_inputs)
 141 {
 142         if (node->output_gamma_curve == GAMMA_LINEAR &&
 143             node->effect->effect_type_id() != "GammaCompressionEffect") {
 144                 return;
 145         }
 146         if (node->effect->num_inputs() == 0) {
 147                 nonlinear_inputs->push_back(node);
 148         } else {
 149                 assert(node->effect->num_inputs() == node->incoming_links.size());
 150                 for (unsigned i = 0; i < node->incoming_links.size(); ++i) {
 151                         find_all_nonlinear_inputs(node->incoming_links[i], nonlinear_inputs);
 152                 }
 153         }
 154 }
 155
 156 Effect *EffectChain::add_effect(Effect *effect, const std::vector<Effect *> &inputs)
 157 {
 158         assert(inputs.size() == effect->num_inputs());
 159         Node *node = add_node(effect);
 160         for (unsigned i = 0; i < inputs.size(); ++i) {
 161                 assert(node_map.count(inputs[i]) != 0);
 162                 connect_nodes(node_map[inputs[i]], node);
 163         }
 164         return effect;
 165 }
 166
 167 // GLSL pre-1.30 doesn't support token pasting. Replace PREFIX(x) with <effect_id>_x.
 168 std::string replace_prefix(const std::string &text, const std::string &prefix)
 169 {
 170         std::string output;
 171         size_t start = 0;
 172
 173         while (start < text.size()) {
 174                 size_t pos = text.find("PREFIX(", start);
 175                 if (pos == std::string::npos) {
 176                         output.append(text.substr(start, std::string::npos));
 177                         break;
 178                 }
 179
 180                 output.append(text.substr(start, pos - start));
 181                 output.append(prefix);
 182                 output.append("_");
 183
 184                 pos += strlen("PREFIX(");
 185
 186                 // Output stuff until we find the matching ), which we then eat.
 187                 int depth = 1;
 188                 size_t end_arg_pos = pos;
 189                 while (end_arg_pos < text.size()) {
 190                         if (text[end_arg_pos] == '(') {
 191                                 ++depth;
 192                         } else if (text[end_arg_pos] == ')') {
 193                                 --depth;
 194                                 if (depth == 0) {
 195                                         break;
 196                                 }
 197                         }
 198                         ++end_arg_pos;
 199                 }
 200                 output.append(text.substr(pos, end_arg_pos - pos));
 201                 ++end_arg_pos;
 202                 assert(depth == 0);
 203                 start = end_arg_pos;
 204         }
 205         return output;
 206 }
 207
 208 Phase *EffectChain::compile_glsl_program(
 209         const std::vector<Node *> &inputs,
 210         const std::vector<Node *> &effects)
 211 {
 212         assert(!effects.empty());
 213
 214         // Deduplicate the inputs.
 215         std::vector<Node *> true_inputs = inputs;
 216         std::sort(true_inputs.begin(), true_inputs.end());
 217         true_inputs.erase(std::unique(true_inputs.begin(), true_inputs.end()), true_inputs.end());
 218
 219         bool input_needs_mipmaps = false;
 220         std::string frag_shader = read_file("header.frag");
 221
 222         // Create functions for all the texture inputs that we need.
 223         for (unsigned i = 0; i < true_inputs.size(); ++i) {
 224                 Node *input = true_inputs[i];
 225
 226                 frag_shader += std::string("uniform sampler2D tex_") + input->effect_id + ";\n";
 227                 frag_shader += std::string("vec4 ") + input->effect_id + "(vec2 tc) {\n";
 228                 frag_shader += "\treturn texture2D(tex_" + input->effect_id + ", tc);\n";
 229                 frag_shader += "}\n";
 230                 frag_shader += "\n";
 231         }
 232
 233         std::vector<Node *> sorted_effects = topological_sort(effects);
 234
 235         for (unsigned i = 0; i < sorted_effects.size(); ++i) {
 236                 Node *node = sorted_effects[i];
 237
 238                 if (node->incoming_links.size() == 1) {
 239                         frag_shader += std::string("#define INPUT ") + node->incoming_links[0]->effect_id + "\n";
 240                 } else {
 241                         for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
 242                                 char buf[256];
 243                                 sprintf(buf, "#define INPUT%d %s\n", j + 1, node->incoming_links[j]->effect_id.c_str());
 244                                 frag_shader += buf;
 245                         }
 246                 }
 247
 248                 frag_shader += "\n";
 249                 frag_shader += std::string("#define FUNCNAME ") + node->effect_id + "\n";
 250                 frag_shader += replace_prefix(node->effect->output_convenience_uniforms(), node->effect_id);
 251                 frag_shader += replace_prefix(node->effect->output_fragment_shader(), node->effect_id);
 252                 frag_shader += "#undef PREFIX\n";
 253                 frag_shader += "#undef FUNCNAME\n";
 254                 if (node->incoming_links.size() == 1) {
 255                         frag_shader += "#undef INPUT\n";
 256                 } else {
 257                         for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
 258                                 char buf[256];
 259                                 sprintf(buf, "#undef INPUT%d\n", j + 1);
 260                                 frag_shader += buf;
 261                         }
 262                 }
 263                 frag_shader += "\n";
 264
 265                 input_needs_mipmaps |= node->effect->needs_mipmaps();
 266         }
 267         for (unsigned i = 0; i < sorted_effects.size(); ++i) {
 268                 Node *node = sorted_effects[i];
 269                 if (node->effect->num_inputs() == 0) {
 270                         CHECK(node->effect->set_int("needs_mipmaps", input_needs_mipmaps));
 271                 }
 272         }
 273         frag_shader += std::string("#define INPUT ") + sorted_effects.back()->effect_id + "\n";
 274         frag_shader.append(read_file("footer.frag"));
 275
 276         if (movit_debug_level == MOVIT_DEBUG_ON) {
 277                 // Output shader to a temporary file, for easier debugging.
 278                 static int compiled_shader_num = 0;
 279                 char filename[256];
 280                 sprintf(filename, "chain-%03d.frag", compiled_shader_num++);
 281                 FILE *fp = fopen(filename, "w");
 282                 if (fp == NULL) {
 283                         perror(filename);
 284                         exit(1);
 285                 }
 286                 fprintf(fp, "%s\n", frag_shader.c_str());
 287                 fclose(fp);
 288         }
 289
 290         GLuint glsl_program_num = glCreateProgram();
 291         GLuint vs_obj = compile_shader(read_file("vs.vert"), GL_VERTEX_SHADER);
 292         GLuint fs_obj = compile_shader(frag_shader, GL_FRAGMENT_SHADER);
 293         glAttachShader(glsl_program_num, vs_obj);
 294         check_error();
 295         glAttachShader(glsl_program_num, fs_obj);
 296         check_error();
 297         glLinkProgram(glsl_program_num);
 298         check_error();
 299
 300         Phase *phase = new Phase;
 301         phase->glsl_program_num = glsl_program_num;
 302         phase->vertex_shader = vs_obj;
 303         phase->fragment_shader = fs_obj;
 304         phase->input_needs_mipmaps = input_needs_mipmaps;
 305         phase->inputs = true_inputs;
 306         phase->effects = sorted_effects;
 307
 308         return phase;
 309 }
 310
 311 // Construct GLSL programs, starting at the given effect and following
 312 // the chain from there. We end a program every time we come to an effect
 313 // marked as "needs texture bounce", one that is used by multiple other
 314 // effects, every time an effect wants to change the output size,
 315 // and of course at the end.
 316 //
 317 // We follow a quite simple depth-first search from the output, although
 318 // without any explicit recursion.
 319 void EffectChain::construct_glsl_programs(Node *output)
 320 {
 321         // Which effects have already been completed?
 322         // We need to keep track of it, as an effect with multiple outputs
 323         // could otherwise be calculated multiple times.
 324         std::set<Node *> completed_effects;
 325
 326         // Effects in the current phase, as well as inputs (outputs from other phases
 327         // that we depend on). Note that since we start iterating from the end,
 328         // the effect list will be in the reverse order.
 329         std::vector<Node *> this_phase_inputs;
 330         std::vector<Node *> this_phase_effects;
 331
 332         // Effects that we have yet to calculate, but that we know should
 333         // be in the current phase.
 334         std::stack<Node *> effects_todo_this_phase;
 335
 336         // Effects that we have yet to calculate, but that come from other phases.
 337         // We delay these until we have this phase done in its entirety,
 338         // at which point we pick any of them and start a new phase from that.
 339         std::stack<Node *> effects_todo_other_phases;
 340
 341         effects_todo_this_phase.push(output);
 342
 343         for ( ;; ) {  // Termination condition within loop.
 344                 if (!effects_todo_this_phase.empty()) {
 345                         // OK, we have more to do this phase.
 346                         Node *node = effects_todo_this_phase.top();
 347                         effects_todo_this_phase.pop();
 348
 349                         // This should currently only happen for effects that are inputs
 350                         // (either true inputs or phase outputs). We special-case inputs,
 351                         // and then deduplicate phase outputs in compile_glsl_program().
 352                         if (node->effect->num_inputs() == 0) {
 353                                 if (find(this_phase_effects.begin(), this_phase_effects.end(), node) != this_phase_effects.end()) {
 354                                         continue;
 355                                 }
 356                         } else {
 357                                 assert(completed_effects.count(node) == 0);
 358                         }
 359
 360                         this_phase_effects.push_back(node);
 361                         completed_effects.insert(node);
 362
 363                         // Find all the dependencies of this effect, and add them to the stack.
 364                         std::vector<Node *> deps = node->incoming_links;
 365                         assert(node->effect->num_inputs() == deps.size());
 366                         for (unsigned i = 0; i < deps.size(); ++i) {
 367                                 bool start_new_phase = false;
 368
 369                                 // FIXME: If we sample directly from a texture, we won't need this.
 370                                 if (node->effect->needs_texture_bounce()) {
 371                                         start_new_phase = true;
 372                                 }
 373
 374                                 if (deps[i]->outgoing_links.size() > 1) {
 375                                         if (deps[i]->effect->num_inputs() > 0) {
 376                                                 // More than one effect uses this as the input,
 377                                                 // and it is not a texture itself.
 378                                                 // The easiest thing to do (and probably also the safest
 379                                                 // performance-wise in most cases) is to bounce it to a texture
 380                                                 // and then let the next passes read from that.
 381                                                 start_new_phase = true;
 382                                         } else {
 383                                                 // For textures, we try to be slightly more clever;
 384                                                 // if none of our outputs need a bounce, we don't bounce
 385                                                 // but instead simply use the effect many times.
 386                                                 //
 387                                                 // Strictly speaking, we could bounce it for some outputs
 388                                                 // and use it directly for others, but the processing becomes
 389                                                 // somewhat simpler if the effect is only used in one such way.
 390                                                 for (unsigned j = 0; j < deps[i]->outgoing_links.size(); ++j) {
 391                                                         Node *rdep = deps[i]->outgoing_links[j];
 392                                                         start_new_phase |= rdep->effect->needs_texture_bounce();
 393                                                 }
 394                                         }
 395                                 }
 396
 397                                 if (deps[i]->effect->changes_output_size()) {
 398                                         start_new_phase = true;
 399                                 }
 400
 401                                 if (start_new_phase) {
 402                                         effects_todo_other_phases.push(deps[i]);
 403                                         this_phase_inputs.push_back(deps[i]);
 404                                 } else {
 405                                         effects_todo_this_phase.push(deps[i]);
 406                                 }
 407                         }
 408                         continue;
 409                 }
 410
 411                 // No more effects to do this phase. Take all the ones we have,
 412                 // and create a GLSL program for it.
 413                 if (!this_phase_effects.empty()) {
 414                         reverse(this_phase_effects.begin(), this_phase_effects.end());
 415                         phases.push_back(compile_glsl_program(this_phase_inputs, this_phase_effects));
 416                         this_phase_effects.back()->phase = phases.back();
 417                         this_phase_inputs.clear();
 418                         this_phase_effects.clear();
 419                 }
 420                 assert(this_phase_inputs.empty());
 421                 assert(this_phase_effects.empty());
 422
 423                 // If we have no effects left, exit.
 424                 if (effects_todo_other_phases.empty()) {
 425                         break;
 426                 }
 427
 428                 Node *node = effects_todo_other_phases.top();
 429                 effects_todo_other_phases.pop();
 430
 431                 if (completed_effects.count(node) == 0) {
 432                         // Start a new phase, calculating from this effect.
 433                         effects_todo_this_phase.push(node);
 434                 }
 435         }
 436
 437         // Finally, since the phases are found from the output but must be executed
 438         // from the input(s), reverse them, too.
 439         std::reverse(phases.begin(), phases.end());
 440 }
 441
 442 void EffectChain::output_dot(const char *filename)
 443 {
 444         if (movit_debug_level != MOVIT_DEBUG_ON) {
 445                 return;
 446         }
 447
 448         FILE *fp = fopen(filename, "w");
 449         if (fp == NULL) {
 450                 perror(filename);
 451                 exit(1);
 452         }
 453
 454         fprintf(fp, "digraph G {\n");
 455         fprintf(fp, "  output [shape=box label=\"(output)\"];\n");
 456         for (unsigned i = 0; i < nodes.size(); ++i) {
 457                 // Find out which phase this event belongs to.
 458                 std::vector<int> in_phases;
 459                 for (unsigned j = 0; j < phases.size(); ++j) {
 460                         const Phase* p = phases[j];
 461                         if (std::find(p->effects.begin(), p->effects.end(), nodes[i]) != p->effects.end()) {
 462                                 in_phases.push_back(j);
 463                         }
 464                 }
 465
 466                 if (in_phases.empty()) {
 467                         fprintf(fp, "  n%ld [label=\"%s\"];\n", (long)nodes[i], nodes[i]->effect->effect_type_id().c_str());
 468                 } else if (in_phases.size() == 1) {
 469                         fprintf(fp, "  n%ld [label=\"%s\" style=\"filled\" fillcolor=\"/accent8/%d\"];\n",
 470                                 (long)nodes[i], nodes[i]->effect->effect_type_id().c_str(),
 471                                 (in_phases[0] % 8) + 1);
 472                 } else {
 473                         // If we had new enough Graphviz, style="wedged" would probably be ideal here.
 474                         // But alas.
 475                         fprintf(fp, "  n%ld [label=\"%s [in multiple phases]\" style=\"filled\" fillcolor=\"/accent8/%d\"];\n",
 476                                 (long)nodes[i], nodes[i]->effect->effect_type_id().c_str(),
 477                                 (in_phases[0] % 8) + 1);
 478                 }
 479
 480                 char from_node_id[256];
 481                 snprintf(from_node_id, 256, "n%ld", (long)nodes[i]);
 482
 483                 for (unsigned j = 0; j < nodes[i]->outgoing_links.size(); ++j) {
 484                         char to_node_id[256];
 485                         snprintf(to_node_id, 256, "n%ld", (long)nodes[i]->outgoing_links[j]);
 486
 487                         std::vector<std::string> labels = get_labels_for_edge(nodes[i], nodes[i]->outgoing_links[j]);
 488                         output_dot_edge(fp, from_node_id, to_node_id, labels);
 489                 }
 490
 491                 if (nodes[i]->outgoing_links.empty() && !nodes[i]->disabled) {
 492                         // Output node.
 493                         std::vector<std::string> labels = get_labels_for_edge(nodes[i], NULL);
 494                         output_dot_edge(fp, from_node_id, "output", labels);
 495                 }
 496         }
 497         fprintf(fp, "}\n");
 498
 499         fclose(fp);
 500 }
 501
 502 std::vector<std::string> EffectChain::get_labels_for_edge(const Node *from, const Node *to)
 503 {
 504         std::vector<std::string> labels;
 505
 506         if (to != NULL && to->effect->needs_texture_bounce()) {
 507                 labels.push_back("needs_bounce");
 508         }
 509         if (from->effect->changes_output_size()) {
 510                 labels.push_back("resize");
 511         }
 512
 513         switch (from->output_color_space) {
 514         case COLORSPACE_INVALID:
 515                 labels.push_back("spc[invalid]");
 516                 break;
 517         case COLORSPACE_REC_601_525:
 518                 labels.push_back("spc[rec601-525]");
 519                 break;
 520         case COLORSPACE_REC_601_625:
 521                 labels.push_back("spc[rec601-625]");
 522                 break;
 523         default:
 524                 break;
 525         }
 526
 527         switch (from->output_gamma_curve) {
 528         case GAMMA_INVALID:
 529                 labels.push_back("gamma[invalid]");
 530                 break;
 531         case GAMMA_sRGB:
 532                 labels.push_back("gamma[sRGB]");
 533                 break;
 534         case GAMMA_REC_601:  // and GAMMA_REC_709
 535                 labels.push_back("gamma[rec601/709]");
 536                 break;
 537         default:
 538                 break;
 539         }
 540
 541         switch (from->output_alpha_type) {
 542         case ALPHA_INVALID:
 543                 labels.push_back("alpha[invalid]");
 544                 break;
 545         case ALPHA_BLANK:
 546                 labels.push_back("alpha[blank]");
 547                 break;
 548         case ALPHA_POSTMULTIPLIED:
 549                 labels.push_back("alpha[postmult]");
 550                 break;
 551         default:
 552                 break;
 553         }
 554
 555         return labels;
 556 }
 557
 558 void EffectChain::output_dot_edge(FILE *fp,
 559                                   const std::string &from_node_id,
 560                                   const std::string &to_node_id,
 561                                   const std::vector<std::string> &labels)
 562 {
 563         if (labels.empty()) {
 564                 fprintf(fp, "  %s -> %s;\n", from_node_id.c_str(), to_node_id.c_str());
 565         } else {
 566                 std::string label = labels[0];
 567                 for (unsigned k = 1; k < labels.size(); ++k) {
 568                         label += ", " + labels[k];
 569                 }
 570                 fprintf(fp, "  %s -> %s [label=\"%s\"];\n", from_node_id.c_str(), to_node_id.c_str(), label.c_str());
 571         }
 572 }
 573
 574 unsigned EffectChain::fit_rectangle_to_aspect(unsigned width, unsigned height)
 575 {
 576         if (float(width) * aspect_denom >= float(height) * aspect_nom) {
 577                 // Same aspect, or W/H > aspect (image is wider than the frame).
 578                 // In either case, keep width.
 579                 return width;
 580         } else {
 581                 // W/H < aspect (image is taller than the frame), so keep height,
 582                 // and adjust width correspondingly.
 583                 return lrintf(height * aspect_nom / aspect_denom);
 584         }
 585 }
 586
 587 // Propagate input texture sizes throughout, and inform effects downstream.
 588 // (Like a lot of other code, we depend on effects being in topological order.)
 589 void EffectChain::inform_input_sizes(Phase *phase)
 590 {
 591         // All effects that have a defined size (inputs and RTT inputs)
 592         // get that. Reset all others.
 593         for (unsigned i = 0; i < phase->effects.size(); ++i) {
 594                 Node *node = phase->effects[i];
 595                 if (node->effect->num_inputs() == 0) {
 596                         Input *input = static_cast<Input *>(node->effect);
 597                         node->output_width = input->get_width();
 598                         node->output_height = input->get_height();
 599                         assert(node->output_width != 0);
 600                         assert(node->output_height != 0);
 601                 } else {
 602                         node->output_width = node->output_height = 0;
 603                 }
 604         }
 605         for (unsigned i = 0; i < phase->inputs.size(); ++i) {
 606                 Node *input = phase->inputs[i];
 607                 input->output_width = input->phase->output_width;
 608                 input->output_height = input->phase->output_height;
 609                 assert(input->output_width != 0);
 610                 assert(input->output_height != 0);
 611         }
 612
 613         // Now propagate from the inputs towards the end, and inform as we go.
 614         // The rules are simple:
 615         //
 616         //   1. Don't touch effects that already have given sizes (ie., inputs).
 617         //   2. If all of your inputs have the same size, that will be your output size.
 618         //   3. Otherwise, your output size is 0x0.
 619         for (unsigned i = 0; i < phase->effects.size(); ++i) {
 620                 Node *node = phase->effects[i];
 621                 if (node->effect->num_inputs() == 0) {
 622                         continue;
 623                 }
 624                 unsigned this_output_width = 0;
 625                 unsigned this_output_height = 0;
 626                 for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
 627                         Node *input = node->incoming_links[j];
 628                         node->effect->inform_input_size(j, input->output_width, input->output_height);
 629                         if (j == 0) {
 630                                 this_output_width = input->output_width;
 631                                 this_output_height = input->output_height;
 632                         } else if (input->output_width != this_output_width || input->output_height != this_output_height) {
 633                                 // Inputs disagree.
 634                                 this_output_width = 0;
 635                                 this_output_height = 0;
 636                         }
 637                 }
 638                 node->output_width = this_output_width;
 639                 node->output_height = this_output_height;
 640         }
 641 }
 642
 643 // Note: You should call inform_input_sizes() before this, as the last effect's
 644 // desired output size might change based on the inputs.
 645 void EffectChain::find_output_size(Phase *phase)
 646 {
 647         Node *output_node = phase->effects.back();
 648
 649         // If the last effect explicitly sets an output size, use that.
 650         if (output_node->effect->changes_output_size()) {
 651                 output_node->effect->get_output_size(&phase->output_width, &phase->output_height);
 652                 return;
 653         }
 654
 655         // If not, look at the input phases and textures.
 656         // We select the largest one (by fit into the current aspect).
 657         unsigned best_width = 0;
 658         for (unsigned i = 0; i < phase->inputs.size(); ++i) {
 659                 Node *input = phase->inputs[i];
 660                 assert(input->phase->output_width != 0);
 661                 assert(input->phase->output_height != 0);
 662                 unsigned width = fit_rectangle_to_aspect(input->phase->output_width, input->phase->output_height);
 663                 if (width > best_width) {
 664                         best_width = width;
 665                 }
 666         }
 667         for (unsigned i = 0; i < phase->effects.size(); ++i) {
 668                 Effect *effect = phase->effects[i]->effect;
 669                 if (effect->num_inputs() != 0) {
 670                         continue;
 671                 }
 672
 673                 Input *input = static_cast<Input *>(effect);
 674                 unsigned width = fit_rectangle_to_aspect(input->get_width(), input->get_height());
 675                 if (width > best_width) {
 676                         best_width = width;
 677                 }
 678         }
 679         assert(best_width != 0);
 680         phase->output_width = best_width;
 681         phase->output_height = best_width * aspect_denom / aspect_nom;
 682 }
 683
 684 void EffectChain::sort_all_nodes_topologically()
 685 {
 686         nodes = topological_sort(nodes);
 687 }
 688
 689 std::vector<Node *> EffectChain::topological_sort(const std::vector<Node *> &nodes)
 690 {
 691         std::set<Node *> nodes_left_to_visit(nodes.begin(), nodes.end());
 692         std::vector<Node *> sorted_list;
 693         for (unsigned i = 0; i < nodes.size(); ++i) {
 694                 topological_sort_visit_node(nodes[i], &nodes_left_to_visit, &sorted_list);
 695         }
 696         reverse(sorted_list.begin(), sorted_list.end());
 697         return sorted_list;
 698 }
 699
 700 void EffectChain::topological_sort_visit_node(Node *node, std::set<Node *> *nodes_left_to_visit, std::vector<Node *> *sorted_list)
 701 {
 702         if (nodes_left_to_visit->count(node) == 0) {
 703                 return;
 704         }
 705         nodes_left_to_visit->erase(node);
 706         for (unsigned i = 0; i < node->outgoing_links.size(); ++i) {
 707                 topological_sort_visit_node(node->outgoing_links[i], nodes_left_to_visit, sorted_list);
 708         }
 709         sorted_list->push_back(node);
 710 }
 711
 712 void EffectChain::find_color_spaces_for_inputs()
 713 {
 714         for (unsigned i = 0; i < nodes.size(); ++i) {
 715                 Node *node = nodes[i];
 716                 if (node->disabled) {
 717                         continue;
 718                 }
 719                 if (node->incoming_links.size() == 0) {
 720                         Input *input = static_cast<Input *>(node->effect);
 721                         node->output_color_space = input->get_color_space();
 722                         node->output_gamma_curve = input->get_gamma_curve();
 723
 724                         Effect::AlphaHandling alpha_handling = input->alpha_handling();
 725                         switch (alpha_handling) {
 726                         case Effect::OUTPUT_BLANK_ALPHA:
 727                                 node->output_alpha_type = ALPHA_BLANK;
 728                                 break;
 729                         case Effect::INPUT_AND_OUTPUT_ALPHA_PREMULTIPLIED:
 730                                 node->output_alpha_type = ALPHA_PREMULTIPLIED;
 731                                 break;
 732                         case Effect::OUTPUT_ALPHA_POSTMULTIPLIED:
 733                                 node->output_alpha_type = ALPHA_POSTMULTIPLIED;
 734                                 break;
 735                         case Effect::DONT_CARE_ALPHA_TYPE:
 736                         default:
 737                                 assert(false);
 738                         }
 739
 740                         if (node->output_alpha_type == ALPHA_PREMULTIPLIED) {
 741                                 assert(node->output_gamma_curve == GAMMA_LINEAR);
 742                         }
 743                 }
 744         }
 745 }
 746
 747 // Propagate gamma and color space information as far as we can in the graph.
 748 // The rules are simple: Anything where all the inputs agree, get that as
 749 // output as well. Anything else keeps having *_INVALID.
 750 void EffectChain::propagate_gamma_and_color_space()
 751 {
 752         // We depend on going through the nodes in order.
 753         sort_all_nodes_topologically();
 754
 755         for (unsigned i = 0; i < nodes.size(); ++i) {
 756                 Node *node = nodes[i];
 757                 if (node->disabled) {
 758                         continue;
 759                 }
 760                 assert(node->incoming_links.size() == node->effect->num_inputs());
 761                 if (node->incoming_links.size() == 0) {
 762                         assert(node->output_color_space != COLORSPACE_INVALID);
 763                         assert(node->output_gamma_curve != GAMMA_INVALID);
 764                         continue;
 765                 }
 766
 767                 Colorspace color_space = node->incoming_links[0]->output_color_space;
 768                 GammaCurve gamma_curve = node->incoming_links[0]->output_gamma_curve;
 769                 for (unsigned j = 1; j < node->incoming_links.size(); ++j) {
 770                         if (node->incoming_links[j]->output_color_space != color_space) {
 771                                 color_space = COLORSPACE_INVALID;
 772                         }
 773                         if (node->incoming_links[j]->output_gamma_curve != gamma_curve) {
 774                                 gamma_curve = GAMMA_INVALID;
 775                         }
 776                 }
 777
 778                 // The conversion effects already have their outputs set correctly,
 779                 // so leave them alone.
 780                 if (node->effect->effect_type_id() != "ColorspaceConversionEffect") {
 781                         node->output_color_space = color_space;
 782                 }
 783                 if (node->effect->effect_type_id() != "GammaCompressionEffect" &&
 784                     node->effect->effect_type_id() != "GammaExpansionEffect") {
 785                         node->output_gamma_curve = gamma_curve;
 786                 }
 787         }
 788 }
 789
 790 // Propagate alpha information as far as we can in the graph.
 791 // Similar to propagate_gamma_and_color_space().
 792 void EffectChain::propagate_alpha()
 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_alpha_type != ALPHA_INVALID);
 805                         continue;
 806                 }
 807
 808                 // The alpha multiplication/division effects are special cases.
 809                 if (node->effect->effect_type_id() == "AlphaMultiplicationEffect") {
 810                         assert(node->incoming_links.size() == 1);
 811                         assert(node->incoming_links[0]->output_alpha_type == ALPHA_POSTMULTIPLIED);
 812                         node->output_alpha_type = ALPHA_PREMULTIPLIED;
 813                         continue;
 814                 }
 815                 if (node->effect->effect_type_id() == "AlphaDivisionEffect") {
 816                         assert(node->incoming_links.size() == 1);
 817                         assert(node->incoming_links[0]->output_alpha_type == ALPHA_PREMULTIPLIED);
 818                         node->output_alpha_type = ALPHA_POSTMULTIPLIED;
 819                         continue;
 820                 }
 821
 822                 // GammaCompressionEffect and GammaExpansionEffect are also a special case,
 823                 // because they are the only one that _need_ postmultiplied alpha.
 824                 if (node->effect->effect_type_id() == "GammaCompressionEffect" ||
 825                     node->effect->effect_type_id() == "GammaExpansionEffect") {
 826                         assert(node->incoming_links.size() == 1);
 827                         if (node->incoming_links[0]->output_alpha_type == ALPHA_BLANK) {
 828                                 node->output_alpha_type = ALPHA_BLANK;
 829                         } else if (node->incoming_links[0]->output_alpha_type == ALPHA_POSTMULTIPLIED) {
 830                                 node->output_alpha_type = ALPHA_POSTMULTIPLIED;
 831                         } else {
 832                                 node->output_alpha_type = ALPHA_INVALID;
 833                         }
 834                         continue;
 835                 }
 836
 837                 // Only inputs can have unconditional alpha output (OUTPUT_BLANK_ALPHA
 838                 // or OUTPUT_ALPHA_POSTMULTIPLIED), and they have already been
 839                 // taken care of above. Rationale: Even if you could imagine
 840                 // e.g. an effect that took in an image and set alpha=1.0
 841                 // unconditionally, it wouldn't make any sense to have it as
 842                 // e.g. OUTPUT_BLANK_ALPHA, since it wouldn't know whether it
 843                 // got its input pre- or postmultiplied, so it wouldn't know
 844                 // whether to divide away the old alpha or not.
 845                 Effect::AlphaHandling alpha_handling = node->effect->alpha_handling();
 846                 assert(alpha_handling == Effect::INPUT_AND_OUTPUT_ALPHA_PREMULTIPLIED ||
 847                        alpha_handling == Effect::DONT_CARE_ALPHA_TYPE);
 848
 849                 // If the node has multiple inputs, check that they are all valid and
 850                 // the same.
 851                 bool any_invalid = false;
 852                 bool any_premultiplied = false;
 853                 bool any_postmultiplied = false;
 854
 855                 for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
 856                         switch (node->incoming_links[j]->output_alpha_type) {
 857                         case ALPHA_INVALID:
 858                                 any_invalid = true;
 859                                 break;
 860                         case ALPHA_BLANK:
 861                                 // Blank is good as both pre- and postmultiplied alpha,
 862                                 // so just ignore it.
 863                                 break;
 864                         case ALPHA_PREMULTIPLIED:
 865                                 any_premultiplied = true;
 866                                 break;
 867                         case ALPHA_POSTMULTIPLIED:
 868                                 any_postmultiplied = true;
 869                                 break;
 870                         default:
 871                                 assert(false);
 872                         }
 873                 }
 874
 875                 if (any_invalid) {
 876                         node->output_alpha_type = ALPHA_INVALID;
 877                         continue;
 878                 }
 879
 880                 // Inputs must be of the same type.
 881                 if (any_premultiplied && any_postmultiplied) {
 882                         node->output_alpha_type = ALPHA_INVALID;
 883                         continue;
 884                 }
 885
 886                 if (alpha_handling == Effect::INPUT_AND_OUTPUT_ALPHA_PREMULTIPLIED) {
 887                         // If the effect has asked for premultiplied alpha, check that it has got it.
 888                         if (any_postmultiplied) {
 889                                 node->output_alpha_type = ALPHA_INVALID;
 890                         } else {
 891                                 // In some rare cases, it might be advantageous to say
 892                                 // that blank input alpha yields blank output alpha.
 893                                 // However, this would cause a more complex Effect interface
 894                                 // an effect would need to guarantee that it doesn't mess with
 895                                 // blank alpha), so this is the simplest.
 896                                 node->output_alpha_type = ALPHA_PREMULTIPLIED;
 897                         }
 898                 } else {
 899                         // OK, all inputs are the same, and this effect is not going
 900                         // to change it.
 901                         assert(alpha_handling == Effect::DONT_CARE_ALPHA_TYPE);
 902                         if (any_premultiplied) {
 903                                 node->output_alpha_type = ALPHA_PREMULTIPLIED;
 904                         } else if (any_postmultiplied) {
 905                                 node->output_alpha_type = ALPHA_POSTMULTIPLIED;
 906                         } else {
 907                                 node->output_alpha_type = ALPHA_BLANK;
 908                         }
 909                 }
 910         }
 911 }
 912
 913 bool EffectChain::node_needs_colorspace_fix(Node *node)
 914 {
 915         if (node->disabled) {
 916                 return false;
 917         }
 918         if (node->effect->num_inputs() == 0) {
 919                 return false;
 920         }
 921
 922         // propagate_gamma_and_color_space() has already set our output
 923         // to COLORSPACE_INVALID if the inputs differ, so we can rely on that.
 924         if (node->output_color_space == COLORSPACE_INVALID) {
 925                 return true;
 926         }
 927         return (node->effect->needs_srgb_primaries() && node->output_color_space != COLORSPACE_sRGB);
 928 }
 929
 930 // Fix up color spaces so that there are no COLORSPACE_INVALID nodes left in
 931 // the graph. Our strategy is not always optimal, but quite simple:
 932 // Find an effect that's as early as possible where the inputs are of
 933 // unacceptable colorspaces (that is, either different, or, if the effect only
 934 // wants sRGB, not sRGB.) Add appropriate conversions on all its inputs,
 935 // propagate the information anew, and repeat until there are no more such
 936 // effects.
 937 void EffectChain::fix_internal_color_spaces()
 938 {
 939         unsigned colorspace_propagation_pass = 0;
 940         bool found_any;
 941         do {
 942                 found_any = false;
 943                 for (unsigned i = 0; i < nodes.size(); ++i) {
 944                         Node *node = nodes[i];
 945                         if (!node_needs_colorspace_fix(node)) {
 946                                 continue;
 947                         }
 948
 949                         // Go through each input that is not sRGB, and insert
 950                         // a colorspace conversion after it.
 951                         for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
 952                                 Node *input = node->incoming_links[j];
 953                                 assert(input->output_color_space != COLORSPACE_INVALID);
 954                                 if (input->output_color_space == COLORSPACE_sRGB) {
 955                                         continue;
 956                                 }
 957                                 Node *conversion = add_node(new ColorspaceConversionEffect());
 958                                 CHECK(conversion->effect->set_int("source_space", input->output_color_space));
 959                                 CHECK(conversion->effect->set_int("destination_space", COLORSPACE_sRGB));
 960                                 conversion->output_color_space = COLORSPACE_sRGB;
 961                                 replace_sender(input, conversion);
 962                                 connect_nodes(input, conversion);
 963                         }
 964
 965                         // Re-sort topologically, and propagate the new information.
 966                         propagate_gamma_and_color_space();
 967
 968                         found_any = true;
 969                         break;
 970                 }
 971
 972                 char filename[256];
 973                 sprintf(filename, "step5-colorspacefix-iter%u.dot", ++colorspace_propagation_pass);
 974                 output_dot(filename);
 975                 assert(colorspace_propagation_pass < 100);
 976         } while (found_any);
 977
 978         for (unsigned i = 0; i < nodes.size(); ++i) {
 979                 Node *node = nodes[i];
 980                 if (node->disabled) {
 981                         continue;
 982                 }
 983                 assert(node->output_color_space != COLORSPACE_INVALID);
 984         }
 985 }
 986
 987 bool EffectChain::node_needs_alpha_fix(Node *node)
 988 {
 989         if (node->disabled) {
 990                 return false;
 991         }
 992
 993         // propagate_alpha() has already set our output to ALPHA_INVALID if the
 994         // inputs differ or we are otherwise in mismatch, so we can rely on that.
 995         return (node->output_alpha_type == ALPHA_INVALID);
 996 }
 997
 998 // Fix up alpha so that there are no ALPHA_INVALID nodes left in
 999 // the graph. Similar to fix_internal_color_spaces().
1000 void EffectChain::fix_internal_alpha(unsigned step)
1001 {
1002         unsigned alpha_propagation_pass = 0;
1003         bool found_any;
1004         do {
1005                 found_any = false;
1006                 for (unsigned i = 0; i < nodes.size(); ++i) {
1007                         Node *node = nodes[i];
1008                         if (!node_needs_alpha_fix(node)) {
1009                                 continue;
1010                         }
1011
1012                         // If we need to fix up GammaExpansionEffect, then clearly something
1013                         // is wrong, since the combination of premultiplied alpha and nonlinear inputs
1014                         // is meaningless.
1015                         assert(node->effect->effect_type_id() != "GammaExpansionEffect");
1016
1017                         AlphaType desired_type = ALPHA_PREMULTIPLIED;
1018
1019                         // GammaCompressionEffect is special; it needs postmultiplied alpha.
1020                         if (node->effect->effect_type_id() == "GammaCompressionEffect") {
1021                                 assert(node->incoming_links.size() == 1);
1022                                 assert(node->incoming_links[0]->output_alpha_type == ALPHA_PREMULTIPLIED);
1023                                 desired_type = ALPHA_POSTMULTIPLIED;
1024                         }
1025
1026                         // Go through each input that is not premultiplied alpha, and insert
1027                         // a conversion before it.
1028                         for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
1029                                 Node *input = node->incoming_links[j];
1030                                 assert(input->output_alpha_type != ALPHA_INVALID);
1031                                 if (input->output_alpha_type == desired_type ||
1032                                     input->output_alpha_type == ALPHA_BLANK) {
1033                                         continue;
1034                                 }
1035                                 Node *conversion;
1036                                 if (desired_type == ALPHA_PREMULTIPLIED) {
1037                                         conversion = add_node(new AlphaMultiplicationEffect());
1038                                 } else {
1039                                         conversion = add_node(new AlphaDivisionEffect());
1040                                 }
1041                                 conversion->output_alpha_type = desired_type;
1042                                 replace_sender(input, conversion);
1043                                 connect_nodes(input, conversion);
1044                         }
1045
1046                         // Re-sort topologically, and propagate the new information.
1047                         propagate_gamma_and_color_space();
1048                         propagate_alpha();
1049
1050                         found_any = true;
1051                         break;
1052                 }
1053
1054                 char filename[256];
1055                 sprintf(filename, "step%u-alphafix-iter%u.dot", step, ++alpha_propagation_pass);
1056                 output_dot(filename);
1057                 assert(alpha_propagation_pass < 100);
1058         } while (found_any);
1059
1060         for (unsigned i = 0; i < nodes.size(); ++i) {
1061                 Node *node = nodes[i];
1062                 if (node->disabled) {
1063                         continue;
1064                 }
1065                 assert(node->output_alpha_type != ALPHA_INVALID);
1066         }
1067 }
1068
1069 // Make so that the output is in the desired color space.
1070 void EffectChain::fix_output_color_space()
1071 {
1072         Node *output = find_output_node();
1073         if (output->output_color_space != output_format.color_space) {
1074                 Node *conversion = add_node(new ColorspaceConversionEffect());
1075                 CHECK(conversion->effect->set_int("source_space", output->output_color_space));
1076                 CHECK(conversion->effect->set_int("destination_space", output_format.color_space));
1077                 conversion->output_color_space = output_format.color_space;
1078                 connect_nodes(output, conversion);
1079                 propagate_alpha();
1080                 propagate_gamma_and_color_space();
1081         }
1082 }
1083
1084 // Make so that the output is in the desired pre-/postmultiplication alpha state.
1085 void EffectChain::fix_output_alpha()
1086 {
1087         Node *output = find_output_node();
1088         assert(output->output_alpha_type != ALPHA_INVALID);
1089         if (output->output_alpha_type == ALPHA_BLANK) {
1090                 // No alpha output, so we don't care.
1091                 return;
1092         }
1093         if (output->output_alpha_type == ALPHA_PREMULTIPLIED &&
1094             output_alpha_format == OUTPUT_ALPHA_POSTMULTIPLIED) {
1095                 Node *conversion = add_node(new AlphaDivisionEffect());
1096                 connect_nodes(output, conversion);
1097                 propagate_alpha();
1098                 propagate_gamma_and_color_space();
1099         }
1100         if (output->output_alpha_type == ALPHA_POSTMULTIPLIED &&
1101             output_alpha_format == OUTPUT_ALPHA_PREMULTIPLIED) {
1102                 Node *conversion = add_node(new AlphaMultiplicationEffect());
1103                 connect_nodes(output, conversion);
1104                 propagate_alpha();
1105                 propagate_gamma_and_color_space();
1106         }
1107 }
1108
1109 bool EffectChain::node_needs_gamma_fix(Node *node)
1110 {
1111         if (node->disabled) {
1112                 return false;
1113         }
1114
1115         // Small hack since the output is not an explicit node:
1116         // If we are the last node and our output is in the wrong
1117         // space compared to EffectChain's output, we need to fix it.
1118         // This will only take us to linear, but fix_output_gamma()
1119         // will come and take us to the desired output gamma
1120         // if it is needed.
1121         //
1122         // This needs to be before everything else, since it could
1123         // even apply to inputs (if they are the only effect).
1124         if (node->outgoing_links.empty() &&
1125             node->output_gamma_curve != output_format.gamma_curve &&
1126             node->output_gamma_curve != GAMMA_LINEAR) {
1127                 return true;
1128         }
1129
1130         if (node->effect->num_inputs() == 0) {
1131                 return false;
1132         }
1133
1134         // propagate_gamma_and_color_space() has already set our output
1135         // to GAMMA_INVALID if the inputs differ, so we can rely on that,
1136         // except for GammaCompressionEffect.
1137         if (node->output_gamma_curve == GAMMA_INVALID) {
1138                 return true;
1139         }
1140         if (node->effect->effect_type_id() == "GammaCompressionEffect") {
1141                 assert(node->incoming_links.size() == 1);
1142                 return node->incoming_links[0]->output_gamma_curve != GAMMA_LINEAR;
1143         }
1144
1145         return (node->effect->needs_linear_light() && node->output_gamma_curve != GAMMA_LINEAR);
1146 }
1147
1148 // Very similar to fix_internal_color_spaces(), but for gamma.
1149 // There is one difference, though; before we start adding conversion nodes,
1150 // we see if we can get anything out of asking the sources to deliver
1151 // linear gamma directly. fix_internal_gamma_by_asking_inputs()
1152 // does that part, while fix_internal_gamma_by_inserting_nodes()
1153 // inserts nodes as needed afterwards.
1154 void EffectChain::fix_internal_gamma_by_asking_inputs(unsigned step)
1155 {
1156         unsigned gamma_propagation_pass = 0;
1157         bool found_any;
1158         do {
1159                 found_any = false;
1160                 for (unsigned i = 0; i < nodes.size(); ++i) {
1161                         Node *node = nodes[i];
1162                         if (!node_needs_gamma_fix(node)) {
1163                                 continue;
1164                         }
1165
1166                         // See if all inputs can give us linear gamma. If not, leave it.
1167                         std::vector<Node *> nonlinear_inputs;
1168                         find_all_nonlinear_inputs(node, &nonlinear_inputs);
1169                         assert(!nonlinear_inputs.empty());
1170
1171                         bool all_ok = true;
1172                         for (unsigned i = 0; i < nonlinear_inputs.size(); ++i) {
1173                                 Input *input = static_cast<Input *>(nonlinear_inputs[i]->effect);
1174                                 all_ok &= input->can_output_linear_gamma();
1175                         }
1176
1177                         if (!all_ok) {
1178                                 continue;
1179                         }
1180
1181                         for (unsigned i = 0; i < nonlinear_inputs.size(); ++i) {
1182                                 CHECK(nonlinear_inputs[i]->effect->set_int("output_linear_gamma", 1));
1183                                 nonlinear_inputs[i]->output_gamma_curve = GAMMA_LINEAR;
1184                         }
1185
1186                         // Re-sort topologically, and propagate the new information.
1187                         propagate_gamma_and_color_space();
1188
1189                         found_any = true;
1190                         break;
1191                 }
1192
1193                 char filename[256];
1194                 sprintf(filename, "step%u-gammafix-iter%u.dot", step, ++gamma_propagation_pass);
1195                 output_dot(filename);
1196                 assert(gamma_propagation_pass < 100);
1197         } while (found_any);
1198 }
1199
1200 void EffectChain::fix_internal_gamma_by_inserting_nodes(unsigned step)
1201 {
1202         unsigned gamma_propagation_pass = 0;
1203         bool found_any;
1204         do {
1205                 found_any = false;
1206                 for (unsigned i = 0; i < nodes.size(); ++i) {
1207                         Node *node = nodes[i];
1208                         if (!node_needs_gamma_fix(node)) {
1209                                 continue;
1210                         }
1211
1212                         // Special case: We could be an input and still be asked to
1213                         // fix our gamma; if so, we should be the only node
1214                         // (as node_needs_gamma_fix() would only return true in
1215                         // for an input in that case). That means we should insert
1216                         // a conversion node _after_ ourselves.
1217                         if (node->incoming_links.empty()) {
1218                                 assert(node->outgoing_links.empty());
1219                                 Node *conversion = add_node(new GammaExpansionEffect());
1220                                 CHECK(conversion->effect->set_int("source_curve", node->output_gamma_curve));
1221                                 conversion->output_gamma_curve = GAMMA_LINEAR;
1222                                 connect_nodes(node, conversion);
1223                         }
1224
1225                         // If not, go through each input that is not linear gamma,
1226                         // and insert a gamma conversion after it.
1227                         for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
1228                                 Node *input = node->incoming_links[j];
1229                                 assert(input->output_gamma_curve != GAMMA_INVALID);
1230                                 if (input->output_gamma_curve == GAMMA_LINEAR) {
1231                                         continue;
1232                                 }
1233                                 Node *conversion = add_node(new GammaExpansionEffect());
1234                                 CHECK(conversion->effect->set_int("source_curve", input->output_gamma_curve));
1235                                 conversion->output_gamma_curve = GAMMA_LINEAR;
1236                                 replace_sender(input, conversion);
1237                                 connect_nodes(input, conversion);
1238                         }
1239
1240                         // Re-sort topologically, and propagate the new information.
1241                         propagate_alpha();
1242                         propagate_gamma_and_color_space();
1243
1244                         found_any = true;
1245                         break;
1246                 }
1247
1248                 char filename[256];
1249                 sprintf(filename, "step%u-gammafix-iter%u.dot", step, ++gamma_propagation_pass);
1250                 output_dot(filename);
1251                 assert(gamma_propagation_pass < 100);
1252         } while (found_any);
1253
1254         for (unsigned i = 0; i < nodes.size(); ++i) {
1255                 Node *node = nodes[i];
1256                 if (node->disabled) {
1257                         continue;
1258                 }
1259                 assert(node->output_gamma_curve != GAMMA_INVALID);
1260         }
1261 }
1262
1263 // Make so that the output is in the desired gamma.
1264 // Note that this assumes linear input gamma, so it might create the need
1265 // for another pass of fix_internal_gamma().
1266 void EffectChain::fix_output_gamma()
1267 {
1268         Node *output = find_output_node();
1269         if (output->output_gamma_curve != output_format.gamma_curve) {
1270                 Node *conversion = add_node(new GammaCompressionEffect());
1271                 CHECK(conversion->effect->set_int("destination_curve", output_format.gamma_curve));
1272                 conversion->output_gamma_curve = output_format.gamma_curve;
1273                 connect_nodes(output, conversion);
1274         }
1275 }
1276
1277 // If the user has requested dither, add a DitherEffect right at the end
1278 // (after GammaCompressionEffect etc.). This needs to be done after everything else,
1279 // since dither is about the only effect that can _not_ be done in linear space.
1280 void EffectChain::add_dither_if_needed()
1281 {
1282         if (num_dither_bits == 0) {
1283                 return;
1284         }
1285         Node *output = find_output_node();
1286         Node *dither = add_node(new DitherEffect());
1287         CHECK(dither->effect->set_int("num_bits", num_dither_bits));
1288         connect_nodes(output, dither);
1289
1290         dither_effect = dither->effect;
1291 }
1292
1293 // Find the output node. This is, simply, one that has no outgoing links.
1294 // If there are multiple ones, the graph is malformed (we do not support
1295 // multiple outputs right now).
1296 Node *EffectChain::find_output_node()
1297 {
1298         std::vector<Node *> output_nodes;
1299         for (unsigned i = 0; i < nodes.size(); ++i) {
1300                 Node *node = nodes[i];
1301                 if (node->disabled) {
1302                         continue;
1303                 }
1304                 if (node->outgoing_links.empty()) {
1305                         output_nodes.push_back(node);
1306                 }
1307         }
1308         assert(output_nodes.size() == 1);
1309         return output_nodes[0];
1310 }
1311
1312 void EffectChain::finalize()
1313 {
1314         // Save the current locale, and set it to C, so that we can output decimal
1315         // numbers with printf and be sure to get them in the format mandated by GLSL.
1316         char *saved_locale = setlocale(LC_NUMERIC, "C");
1317
1318         // Output the graph as it is before we do any conversions on it.
1319         output_dot("step0-start.dot");
1320
1321         // Give each effect in turn a chance to rewrite its own part of the graph.
1322         // Note that if more effects are added as part of this, they will be
1323         // picked up as part of the same for loop, since they are added at the end.
1324         for (unsigned i = 0; i < nodes.size(); ++i) {
1325                 nodes[i]->effect->rewrite_graph(this, nodes[i]);
1326         }
1327         output_dot("step1-rewritten.dot");
1328
1329         find_color_spaces_for_inputs();
1330         output_dot("step2-input-colorspace.dot");
1331
1332         propagate_alpha();
1333         output_dot("step3-propagated-alpha.dot");
1334
1335         propagate_gamma_and_color_space();
1336         output_dot("step4-propagated-all.dot");
1337
1338         fix_internal_color_spaces();
1339         fix_internal_alpha(6);
1340         fix_output_color_space();
1341         output_dot("step7-output-colorspacefix.dot");
1342         fix_output_alpha();
1343         output_dot("step8-output-alphafix.dot");
1344
1345         // Note that we need to fix gamma after colorspace conversion,
1346         // because colorspace conversions might create needs for gamma conversions.
1347         // Also, we need to run an extra pass of fix_internal_gamma() after
1348         // fixing the output gamma, as we only have conversions to/from linear,
1349         // and fix_internal_alpha() since GammaCompressionEffect needs
1350         // postmultiplied input.
1351         fix_internal_gamma_by_asking_inputs(9);
1352         fix_internal_gamma_by_inserting_nodes(10);
1353         fix_output_gamma();
1354         output_dot("step11-output-gammafix.dot");
1355         propagate_alpha();
1356         output_dot("step12-output-alpha-propagated.dot");
1357         fix_internal_alpha(13);
1358         output_dot("step14-output-alpha-fixed.dot");
1359         fix_internal_gamma_by_asking_inputs(15);
1360         fix_internal_gamma_by_inserting_nodes(16);
1361
1362         output_dot("step17-before-dither.dot");
1363
1364         add_dither_if_needed();
1365
1366         output_dot("step18-final.dot");
1367
1368         // Construct all needed GLSL programs, starting at the output.
1369         construct_glsl_programs(find_output_node());
1370
1371         output_dot("step19-split-to-phases.dot");
1372
1373         // If we have more than one phase, we need intermediate render-to-texture.
1374         // Construct an FBO, and then as many textures as we need.
1375         // We choose the simplest option of having one texture per output,
1376         // since otherwise this turns into an (albeit simple)
1377         // register allocation problem.
1378         if (phases.size() > 1) {
1379                 glGenFramebuffers(1, &fbo);
1380
1381                 for (unsigned i = 0; i < phases.size() - 1; ++i) {
1382                         inform_input_sizes(phases[i]);
1383                         find_output_size(phases[i]);
1384
1385                         Node *output_node = phases[i]->effects.back();
1386                         glGenTextures(1, &output_node->output_texture);
1387                         check_error();
1388                         glBindTexture(GL_TEXTURE_2D, output_node->output_texture);
1389                         check_error();
1390                         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
1391                         check_error();
1392                         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
1393                         check_error();
1394                         glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA16F_ARB, phases[i]->output_width, phases[i]->output_height, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
1395                         check_error();
1396
1397                         output_node->output_texture_width = phases[i]->output_width;
1398                         output_node->output_texture_height = phases[i]->output_height;
1399                 }
1400                 inform_input_sizes(phases.back());
1401         }
1402
1403         for (unsigned i = 0; i < inputs.size(); ++i) {
1404                 inputs[i]->finalize();
1405         }
1406
1407         assert(phases[0]->inputs.empty());
1408
1409         finalized = true;
1410         setlocale(LC_NUMERIC, saved_locale);
1411 }
1412
1413 void EffectChain::render_to_fbo(GLuint dest_fbo, unsigned width, unsigned height)
1414 {
1415         assert(finalized);
1416
1417         // Save original viewport.
1418         GLuint x = 0, y = 0;
1419
1420         if (width == 0 && height == 0) {
1421                 GLint viewport[4];
1422                 glGetIntegerv(GL_VIEWPORT, viewport);
1423                 x = viewport[0];
1424                 y = viewport[1];
1425                 width = viewport[2];
1426                 height = viewport[3];
1427         }
1428
1429         // Basic state.
1430         glDisable(GL_BLEND);
1431         check_error();
1432         glDisable(GL_DEPTH_TEST);
1433         check_error();
1434         glDepthMask(GL_FALSE);
1435         check_error();
1436
1437         glMatrixMode(GL_PROJECTION);
1438         glLoadIdentity();
1439         glOrtho(0.0, 1.0, 0.0, 1.0, 0.0, 1.0);
1440
1441         glMatrixMode(GL_MODELVIEW);
1442         glLoadIdentity();
1443
1444         if (phases.size() > 1) {
1445                 glBindFramebuffer(GL_FRAMEBUFFER, fbo);
1446                 check_error();
1447         }
1448
1449         std::set<Node *> generated_mipmaps;
1450
1451         for (unsigned phase = 0; phase < phases.size(); ++phase) {
1452                 // See if the requested output size has changed. If so, we need to recreate
1453                 // the texture (and before we start setting up inputs).
1454                 inform_input_sizes(phases[phase]);
1455                 if (phase != phases.size() - 1) {
1456                         find_output_size(phases[phase]);
1457
1458                         Node *output_node = phases[phase]->effects.back();
1459
1460                         if (output_node->output_texture_width != phases[phase]->output_width ||
1461                             output_node->output_texture_height != phases[phase]->output_height) {
1462                                 glActiveTexture(GL_TEXTURE0);
1463                                 check_error();
1464                                 glBindTexture(GL_TEXTURE_2D, output_node->output_texture);
1465                                 check_error();
1466                                 glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA16F_ARB, phases[phase]->output_width, phases[phase]->output_height, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
1467                                 check_error();
1468                                 glBindTexture(GL_TEXTURE_2D, 0);
1469                                 check_error();
1470
1471                                 output_node->output_texture_width = phases[phase]->output_width;
1472                                 output_node->output_texture_height = phases[phase]->output_height;
1473                         }
1474                 }
1475
1476                 glUseProgram(phases[phase]->glsl_program_num);
1477                 check_error();
1478
1479                 // Set up RTT inputs for this phase.
1480                 for (unsigned sampler = 0; sampler < phases[phase]->inputs.size(); ++sampler) {
1481                         glActiveTexture(GL_TEXTURE0 + sampler);
1482                         Node *input = phases[phase]->inputs[sampler];
1483                         glBindTexture(GL_TEXTURE_2D, input->output_texture);
1484                         check_error();
1485                         if (phases[phase]->input_needs_mipmaps) {
1486                                 if (generated_mipmaps.count(input) == 0) {
1487                                         glGenerateMipmap(GL_TEXTURE_2D);
1488                                         check_error();
1489                                         generated_mipmaps.insert(input);
1490                                 }
1491                                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_NEAREST);
1492                                 check_error();
1493                         } else {
1494                                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
1495                                 check_error();
1496                         }
1497
1498                         std::string texture_name = std::string("tex_") + input->effect_id;
1499                         glUniform1i(glGetUniformLocation(phases[phase]->glsl_program_num, texture_name.c_str()), sampler);
1500                         check_error();
1501                 }
1502
1503                 // And now the output.
1504                 if (phase == phases.size() - 1) {
1505                         // Last phase goes to the output the user specified.
1506                         glBindFramebuffer(GL_FRAMEBUFFER, dest_fbo);
1507                         check_error();
1508                         glViewport(x, y, width, height);
1509                         if (dither_effect != NULL) {
1510                                 CHECK(dither_effect->set_int("output_width", width));
1511                                 CHECK(dither_effect->set_int("output_height", height));
1512                         }
1513                 } else {
1514                         Node *output_node = phases[phase]->effects.back();
1515                         glFramebufferTexture2D(
1516                                 GL_FRAMEBUFFER,
1517                                 GL_COLOR_ATTACHMENT0,
1518                                 GL_TEXTURE_2D,
1519                                 output_node->output_texture,
1520                                 0);
1521                         check_error();
1522                         glViewport(0, 0, phases[phase]->output_width, phases[phase]->output_height);
1523                 }
1524
1525                 // Give the required parameters to all the effects.
1526                 unsigned sampler_num = phases[phase]->inputs.size();
1527                 for (unsigned i = 0; i < phases[phase]->effects.size(); ++i) {
1528                         Node *node = phases[phase]->effects[i];
1529                         node->effect->set_gl_state(phases[phase]->glsl_program_num, node->effect_id, &sampler_num);
1530                         check_error();
1531                 }
1532
1533                 // Now draw!
1534                 glBegin(GL_QUADS);
1535
1536                 glTexCoord2f(0.0f, 0.0f);
1537                 glVertex2f(0.0f, 0.0f);
1538
1539                 glTexCoord2f(1.0f, 0.0f);
1540                 glVertex2f(1.0f, 0.0f);
1541
1542                 glTexCoord2f(1.0f, 1.0f);
1543                 glVertex2f(1.0f, 1.0f);
1544
1545                 glTexCoord2f(0.0f, 1.0f);
1546                 glVertex2f(0.0f, 1.0f);
1547
1548                 glEnd();
1549                 check_error();
1550
1551                 for (unsigned i = 0; i < phases[phase]->effects.size(); ++i) {
1552                         Node *node = phases[phase]->effects[i];
1553                         node->effect->clear_gl_state();
1554                 }
1555         }
1556 }