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

   1 #define GL_GLEXT_PROTOTYPES 1
   2
   3 #include <stdio.h>
   4 #include <string.h>
   5 #include <assert.h>
   6
   7 #include <algorithm>
   8 #include <set>
   9 #include <stack>
  10 #include <vector>
  11
  12 #include "util.h"
  13 #include "effect_chain.h"
  14 #include "gamma_expansion_effect.h"
  15 #include "gamma_compression_effect.h"
  16 #include "colorspace_conversion_effect.h"
  17 #include "input.h"
  18 #include "opengl.h"
  19
  20 EffectChain::EffectChain(unsigned width, unsigned height)
  21         : width(width),
  22           height(height),
  23           finalized(false) {}
  24
  25 Input *EffectChain::add_input(Input *input)
  26 {
  27         char eff_id[256];
  28         sprintf(eff_id, "src_image%u", (unsigned)inputs.size());
  29
  30         effects.push_back(input);
  31         inputs.push_back(input);
  32         output_color_space.insert(std::make_pair(input, input->get_color_space()));
  33         output_gamma_curve.insert(std::make_pair(input, input->get_gamma_curve()));
  34         effect_ids.insert(std::make_pair(input, eff_id));
  35         incoming_links.insert(std::make_pair(input, std::vector<Effect *>()));
  36         return input;
  37 }
  38
  39 void EffectChain::add_output(const ImageFormat &format)
  40 {
  41         output_format = format;
  42 }
  43
  44 void EffectChain::add_effect_raw(Effect *effect, const std::vector<Effect *> &inputs)
  45 {
  46         char effect_id[256];
  47         sprintf(effect_id, "eff%u", (unsigned)effects.size());
  48
  49         effects.push_back(effect);
  50         effect_ids.insert(std::make_pair(effect, effect_id));
  51         assert(inputs.size() == effect->num_inputs());
  52         for (unsigned i = 0; i < inputs.size(); ++i) {
  53                 assert(std::find(effects.begin(), effects.end(), inputs[i]) != effects.end());
  54                 outgoing_links[inputs[i]].push_back(effect);
  55         }
  56         incoming_links.insert(std::make_pair(effect, inputs));
  57         output_gamma_curve[effect] = output_gamma_curve[last_added_effect()];
  58         output_color_space[effect] = output_color_space[last_added_effect()];
  59 }
  60
  61 void EffectChain::find_all_nonlinear_inputs(Effect *effect,
  62                                             std::vector<Input *> *nonlinear_inputs,
  63                                             std::vector<Effect *> *intermediates)
  64 {
  65         assert(output_gamma_curve.count(effect) != 0);
  66         if (output_gamma_curve[effect] == GAMMA_LINEAR) {
  67                 return;
  68         }
  69         if (effect->num_inputs() == 0) {
  70                 nonlinear_inputs->push_back(static_cast<Input *>(effect));
  71         } else {
  72                 intermediates->push_back(effect);
  73
  74                 assert(incoming_links.count(effect) == 1);
  75                 std::vector<Effect *> deps = incoming_links[effect];
  76                 assert(effect->num_inputs() == deps.size());
  77                 for (unsigned i = 0; i < deps.size(); ++i) {
  78                         find_all_nonlinear_inputs(deps[i], nonlinear_inputs, intermediates);
  79                 }
  80         }
  81 }
  82
  83 Effect *EffectChain::normalize_to_linear_gamma(Effect *input)
  84 {
  85         // Find out if all the inputs can be set to deliver sRGB inputs.
  86         // If so, we can just ask them to do that instead of inserting a
  87         // (possibly expensive) conversion operation.
  88         //
  89         // NOTE: We assume that effects generally don't mess with the gamma
  90         // curve (except GammaCompressionEffect, which should never be
  91         // inserted into a chain when this is called), so that we can just
  92         // update the output gamma as we go.
  93         //
  94         // TODO: Setting this flag for one source might confuse a different
  95         // part of the pipeline using the same source.
  96         std::vector<Input *> nonlinear_inputs;
  97         std::vector<Effect *> intermediates;
  98         find_all_nonlinear_inputs(input, &nonlinear_inputs, &intermediates);
  99
 100         bool all_ok = true;
 101         for (unsigned i = 0; i < nonlinear_inputs.size(); ++i) {
 102                 all_ok &= nonlinear_inputs[i]->can_output_linear_gamma();
 103         }
 104
 105         if (all_ok) {
 106                 for (unsigned i = 0; i < nonlinear_inputs.size(); ++i) {
 107                         bool ok = nonlinear_inputs[i]->set_int("output_linear_gamma", 1);
 108                         assert(ok);
 109                         output_gamma_curve[nonlinear_inputs[i]] = GAMMA_LINEAR;
 110                 }
 111                 for (unsigned i = 0; i < intermediates.size(); ++i) {
 112                         output_gamma_curve[intermediates[i]] = GAMMA_LINEAR;
 113                 }
 114                 return input;
 115         }
 116
 117         // OK, that didn't work. Insert a conversion effect.
 118         GammaExpansionEffect *gamma_conversion = new GammaExpansionEffect();
 119         gamma_conversion->set_int("source_curve", output_gamma_curve[input]);
 120         std::vector<Effect *> inputs;
 121         inputs.push_back(input);
 122         gamma_conversion->add_self_to_effect_chain(this, inputs);
 123         output_gamma_curve[gamma_conversion] = GAMMA_LINEAR;
 124         return gamma_conversion;
 125 }
 126
 127 Effect *EffectChain::normalize_to_srgb(Effect *input)
 128 {
 129         assert(output_gamma_curve.count(input) != 0);
 130         assert(output_color_space.count(input) != 0);
 131         assert(output_gamma_curve[input] == GAMMA_LINEAR);
 132         ColorSpaceConversionEffect *colorspace_conversion = new ColorSpaceConversionEffect();
 133         colorspace_conversion->set_int("source_space", output_color_space[input]);
 134         colorspace_conversion->set_int("destination_space", COLORSPACE_sRGB);
 135         std::vector<Effect *> inputs;
 136         inputs.push_back(input);
 137         colorspace_conversion->add_self_to_effect_chain(this, inputs);
 138         output_color_space[colorspace_conversion] = COLORSPACE_sRGB;
 139         return colorspace_conversion;
 140 }
 141
 142 Effect *EffectChain::add_effect(Effect *effect, const std::vector<Effect *> &inputs)
 143 {
 144         assert(inputs.size() == effect->num_inputs());
 145
 146         std::vector<Effect *> normalized_inputs = inputs;
 147         for (unsigned i = 0; i < normalized_inputs.size(); ++i) {
 148                 assert(output_gamma_curve.count(normalized_inputs[i]) != 0);
 149                 if (effect->needs_linear_light() && output_gamma_curve[normalized_inputs[i]] != GAMMA_LINEAR) {
 150                         normalized_inputs[i] = normalize_to_linear_gamma(normalized_inputs[i]);
 151                 }
 152                 assert(output_color_space.count(normalized_inputs[i]) != 0);
 153                 if (effect->needs_srgb_primaries() && output_color_space[normalized_inputs[i]] != COLORSPACE_sRGB) {
 154                         normalized_inputs[i] = normalize_to_srgb(normalized_inputs[i]);
 155                 }
 156         }
 157
 158         effect->add_self_to_effect_chain(this, normalized_inputs);
 159         return effect;
 160 }
 161
 162 // GLSL pre-1.30 doesn't support token pasting. Replace PREFIX(x) with <effect_id>_x.
 163 std::string replace_prefix(const std::string &text, const std::string &prefix)
 164 {
 165         std::string output;
 166         size_t start = 0;
 167
 168         while (start < text.size()) {
 169                 size_t pos = text.find("PREFIX(", start);
 170                 if (pos == std::string::npos) {
 171                         output.append(text.substr(start, std::string::npos));
 172                         break;
 173                 }
 174
 175                 output.append(text.substr(start, pos - start));
 176                 output.append(prefix);
 177                 output.append("_");
 178
 179                 pos += strlen("PREFIX(");
 180
 181                 // Output stuff until we find the matching ), which we then eat.
 182                 int depth = 1;
 183                 size_t end_arg_pos = pos;
 184                 while (end_arg_pos < text.size()) {
 185                         if (text[end_arg_pos] == '(') {
 186                                 ++depth;
 187                         } else if (text[end_arg_pos] == ')') {
 188                                 --depth;
 189                                 if (depth == 0) {
 190                                         break;
 191                                 }
 192                         }
 193                         ++end_arg_pos;
 194                 }
 195                 output.append(text.substr(pos, end_arg_pos - pos));
 196                 ++end_arg_pos;
 197                 assert(depth == 0);
 198                 start = end_arg_pos;
 199         }
 200         return output;
 201 }
 202
 203 EffectChain::Phase *EffectChain::compile_glsl_program(const std::vector<Effect *> &inputs, const std::vector<Effect *> &effects)
 204 {
 205         assert(!effects.empty());
 206
 207         // Deduplicate the inputs.
 208         std::vector<Effect *> true_inputs = inputs;
 209         std::sort(true_inputs.begin(), true_inputs.end());
 210         true_inputs.erase(std::unique(true_inputs.begin(), true_inputs.end()), true_inputs.end());
 211
 212         bool input_needs_mipmaps = false;
 213         std::string frag_shader = read_file("header.frag");
 214
 215         // Create functions for all the texture inputs that we need.
 216         for (unsigned i = 0; i < true_inputs.size(); ++i) {
 217                 Effect *effect = true_inputs[i];
 218                 assert(effect_ids.count(effect) != 0);
 219                 std::string effect_id = effect_ids[effect];
 220
 221                 frag_shader += std::string("uniform sampler2D tex_") + effect_id + ";\n";
 222                 frag_shader += std::string("vec4 ") + effect_id + "(vec2 tc) {\n";
 223                 if (effect->num_inputs() == 0) {
 224                         // OpenGL's origin is bottom-left, but most graphics software assumes
 225                         // a top-left origin. Thus, for inputs that come from the user,
 226                         // we flip the y coordinate. However, for FBOs, the origin
 227                         // is all correct, so don't do anything.
 228                         frag_shader += "\ttc.y = 1.0f - tc.y;\n";
 229                 }
 230                 frag_shader += "\treturn texture2D(tex_" + effect_id + ", tc);\n";
 231                 frag_shader += "}\n";
 232                 frag_shader += "\n";
 233         }
 234
 235         std::string last_effect_id;
 236         for (unsigned i = 0; i < effects.size(); ++i) {
 237                 Effect *effect = effects[i];
 238                 assert(effect != NULL);
 239                 assert(effect_ids.count(effect) != 0);
 240                 std::string effect_id = effect_ids[effect];
 241                 last_effect_id = effect_id;
 242
 243                 if (incoming_links[effect].size() == 1) {
 244                         frag_shader += std::string("#define INPUT ") + effect_ids[incoming_links[effect][0]] + "\n";
 245                 } else {
 246                         for (unsigned j = 0; j < incoming_links[effect].size(); ++j) {
 247                                 char buf[256];
 248                                 sprintf(buf, "#define INPUT%d %s\n", j + 1, effect_ids[incoming_links[effect][j]].c_str());
 249                                 frag_shader += buf;
 250                         }
 251                 }
 252
 253                 frag_shader += "\n";
 254                 frag_shader += std::string("#define FUNCNAME ") + effect_id + "\n";
 255                 frag_shader += replace_prefix(effect->output_convenience_uniforms(), effect_id);
 256                 frag_shader += replace_prefix(effect->output_fragment_shader(), effect_id);
 257                 frag_shader += "#undef PREFIX\n";
 258                 frag_shader += "#undef FUNCNAME\n";
 259                 if (incoming_links[effect].size() == 1) {
 260                         frag_shader += "#undef INPUT\n";
 261                 } else {
 262                         for (unsigned j = 0; j < incoming_links[effect].size(); ++j) {
 263                                 char buf[256];
 264                                 sprintf(buf, "#undef INPUT%d\n", j + 1);
 265                                 frag_shader += buf;
 266                         }
 267                 }
 268                 frag_shader += "\n";
 269
 270                 input_needs_mipmaps |= effect->needs_mipmaps();
 271         }
 272         for (unsigned i = 0; i < effects.size(); ++i) {
 273                 Effect *effect = effects[i];
 274                 if (effect->num_inputs() == 0) {
 275                         effect->set_int("needs_mipmaps", input_needs_mipmaps);
 276                 }
 277         }
 278         assert(!last_effect_id.empty());
 279         frag_shader += std::string("#define INPUT ") + last_effect_id + "\n";
 280         frag_shader.append(read_file("footer.frag"));
 281         printf("%s\n", frag_shader.c_str());
 282
 283         GLuint glsl_program_num = glCreateProgram();
 284         GLuint vs_obj = compile_shader(read_file("vs.vert"), GL_VERTEX_SHADER);
 285         GLuint fs_obj = compile_shader(frag_shader, GL_FRAGMENT_SHADER);
 286         glAttachShader(glsl_program_num, vs_obj);
 287         check_error();
 288         glAttachShader(glsl_program_num, fs_obj);
 289         check_error();
 290         glLinkProgram(glsl_program_num);
 291         check_error();
 292
 293         Phase *phase = new Phase;
 294         phase->glsl_program_num = glsl_program_num;
 295         phase->input_needs_mipmaps = input_needs_mipmaps;
 296         phase->inputs = true_inputs;
 297         phase->effects = 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(Effect *output)
 311 {
 312         // Which effects have already been completed in this phase?
 313         // We need to keep track of it, as an effect with multiple outputs
 314         // could otherwise be calculate multiple times.
 315         std::set<Effect *> 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         std::vector<Effect *> this_phase_inputs;
 321         std::vector<Effect *> this_phase_effects;
 322
 323         // Effects that we have yet to calculate, but that we know should
 324         // be in the current phase.
 325         std::stack<Effect *> 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         std::stack<Effect *> 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                         Effect *effect = effects_todo_this_phase.top();
 338                         effects_todo_this_phase.pop();
 339
 340                         // This should currently only happen for effects that are phase outputs,
 341                         // and we throw those out separately below.
 342                         assert(completed_effects.count(effect) == 0);
 343
 344                         this_phase_effects.push_back(effect);
 345                         completed_effects.insert(effect);
 346
 347                         // Find all the dependencies of this effect, and add them to the stack.
 348                         assert(incoming_links.count(effect) == 1);
 349                         std::vector<Effect *> deps = incoming_links[effect];
 350                         assert(effect->num_inputs() == deps.size());
 351                         for (unsigned i = 0; i < deps.size(); ++i) {
 352                                 bool start_new_phase = false;
 353
 354                                 // FIXME: If we sample directly from a texture, we won't need this.
 355                                 if (effect->needs_texture_bounce()) {
 356                                         start_new_phase = true;
 357                                 }
 358
 359                                 assert(outgoing_links.count(deps[i]) == 1);
 360                                 if (outgoing_links[deps[i]].size() > 1 && deps[i]->num_inputs() > 0) {
 361                                         // More than one effect uses this as the input,
 362                                         // and it is not a texture itself.
 363                                         // The easiest thing to do (and probably also the safest
 364                                         // performance-wise in most cases) is to bounce it to a texture
 365                                         // and then let the next passes read from that.
 366                                         start_new_phase = true;
 367                                 }
 368
 369                                 if (deps[i]->changes_output_size()) {
 370                                         start_new_phase = true;
 371                                 }
 372
 373                                 if (start_new_phase) {
 374                                         effects_todo_other_phases.push(deps[i]);
 375                                         this_phase_inputs.push_back(deps[i]);
 376                                 } else {
 377                                         effects_todo_this_phase.push(deps[i]);
 378                                 }
 379                         }
 380                         continue;
 381                 }
 382
 383                 // No more effects to do this phase. Take all the ones we have,
 384                 // and create a GLSL program for it.
 385                 if (!this_phase_effects.empty()) {
 386                         reverse(this_phase_effects.begin(), this_phase_effects.end());
 387                         phases.push_back(compile_glsl_program(this_phase_inputs, this_phase_effects));
 388                         output_effects_to_phase.insert(std::make_pair(this_phase_effects.back(), phases.back()));
 389                         this_phase_inputs.clear();
 390                         this_phase_effects.clear();
 391                 }
 392                 assert(this_phase_inputs.empty());
 393                 assert(this_phase_effects.empty());
 394
 395                 // If we have no effects left, exit.
 396                 if (effects_todo_other_phases.empty()) {
 397                         break;
 398                 }
 399
 400                 Effect *effect = effects_todo_other_phases.top();
 401                 effects_todo_other_phases.pop();
 402
 403                 if (completed_effects.count(effect) == 0) {
 404                         // Start a new phase, calculating from this effect.
 405                         effects_todo_this_phase.push(effect);
 406                 }
 407         }
 408
 409         // Finally, since the phases are found from the output but must be executed
 410         // from the input(s), reverse them, too.
 411         std::reverse(phases.begin(), phases.end());
 412 }
 413
 414 void EffectChain::find_output_size(EffectChain::Phase *phase)
 415 {
 416         Effect *output_effect = phase->effects.back();
 417
 418         // If the last effect explicitly sets an output size,
 419         // use that.
 420         if (output_effect->changes_output_size()) {
 421                 output_effect->get_output_size(&phase->output_width, &phase->output_height);
 422                 return;
 423         }
 424
 425         // If not, look at the input phases, if any. We select the largest one
 426         // (really assuming they all have the same aspect currently), by pixel count.
 427         if (!phase->inputs.empty()) {
 428                 unsigned best_width = 0, best_height = 0;
 429                 for (unsigned i = 0; i < phase->inputs.size(); ++i) {
 430                         Effect *input = phase->inputs[i];
 431                         assert(output_effects_to_phase.count(input) != 0);
 432                         const Phase *input_phase = output_effects_to_phase[input];
 433                         assert(input_phase->output_width != 0);
 434                         assert(input_phase->output_height != 0);
 435                         if (input_phase->output_width * input_phase->output_height > best_width * best_height) {
 436                                 best_width = input_phase->output_width;
 437                                 best_height = input_phase->output_height;
 438                         }
 439                 }
 440                 assert(best_width != 0);
 441                 assert(best_height != 0);
 442                 phase->output_width = best_width;
 443                 phase->output_height = best_height;
 444                 return;
 445         }
 446
 447         // OK, no inputs. Just use the global width/height.
 448         // TODO: We probably want to use the texture's size eventually.
 449         phase->output_width = width;
 450         phase->output_height = height;
 451 }
 452
 453 void EffectChain::finalize()
 454 {
 455         // Find the output effect. This is, simply, one that has no outgoing links.
 456         // If there are multiple ones, the graph is malformed (we do not support
 457         // multiple outputs right now).
 458         std::vector<Effect *> output_effects;
 459         for (unsigned i = 0; i < effects.size(); ++i) {
 460                 Effect *effect = effects[i];
 461                 if (outgoing_links.count(effect) == 0 || outgoing_links[effect].size() == 0) {
 462                         output_effects.push_back(effect);
 463                 }
 464         }
 465         assert(output_effects.size() == 1);
 466         Effect *output_effect = output_effects[0];
 467
 468         // Add normalizers to get the output format right.
 469         assert(output_gamma_curve.count(output_effect) != 0);
 470         assert(output_color_space.count(output_effect) != 0);
 471         ColorSpace current_color_space = output_color_space[output_effect];
 472         if (current_color_space != output_format.color_space) {
 473                 ColorSpaceConversionEffect *colorspace_conversion = new ColorSpaceConversionEffect();
 474                 colorspace_conversion->set_int("source_space", current_color_space);
 475                 colorspace_conversion->set_int("destination_space", output_format.color_space);
 476                 std::vector<Effect *> inputs;
 477                 inputs.push_back(output_effect);
 478                 colorspace_conversion->add_self_to_effect_chain(this, inputs);
 479                 output_color_space[colorspace_conversion] = output_format.color_space;
 480                 output_effect = colorspace_conversion;
 481         }
 482         GammaCurve current_gamma_curve = output_gamma_curve[output_effect];
 483         if (current_gamma_curve != output_format.gamma_curve) {
 484                 if (current_gamma_curve != GAMMA_LINEAR) {
 485                         output_effect = normalize_to_linear_gamma(output_effect);
 486                         current_gamma_curve = GAMMA_LINEAR;
 487                 }
 488                 GammaCompressionEffect *gamma_conversion = new GammaCompressionEffect();
 489                 gamma_conversion->set_int("destination_curve", output_format.gamma_curve);
 490                 std::vector<Effect *> inputs;
 491                 inputs.push_back(output_effect);
 492                 gamma_conversion->add_self_to_effect_chain(this, inputs);
 493                 output_gamma_curve[gamma_conversion] = output_format.gamma_curve;
 494                 output_effect = gamma_conversion;
 495         }
 496
 497         // Construct all needed GLSL programs, starting at the output.
 498         construct_glsl_programs(output_effect);
 499
 500         // If we have more than one phase, we need intermediate render-to-texture.
 501         // Construct an FBO, and then as many textures as we need.
 502         // We choose the simplest option of having one texture per output,
 503         // since otherwise this turns into an (albeit simple)
 504         // register allocation problem.
 505         if (phases.size() > 1) {
 506                 glGenFramebuffers(1, &fbo);
 507
 508                 for (unsigned i = 0; i < phases.size() - 1; ++i) {
 509                         find_output_size(phases[i]);
 510
 511                         Effect *output_effect = phases[i]->effects.back();
 512                         GLuint temp_texture;
 513                         glGenTextures(1, &temp_texture);
 514                         check_error();
 515                         glBindTexture(GL_TEXTURE_2D, temp_texture);
 516                         check_error();
 517                         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
 518                         check_error();
 519                         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
 520                         check_error();
 521                         glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA16F_ARB, phases[i]->output_width, phases[i]->output_height, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
 522                         check_error();
 523                         effect_output_textures.insert(std::make_pair(output_effect, temp_texture));
 524                         effect_output_texture_sizes.insert(std::make_pair(output_effect, std::make_pair(phases[i]->output_width, phases[i]->output_height)));
 525                 }
 526         }
 527
 528         for (unsigned i = 0; i < inputs.size(); ++i) {
 529                 inputs[i]->finalize();
 530         }
 531
 532         assert(phases[0]->inputs.empty());
 533
 534         finalized = true;
 535 }
 536
 537 void EffectChain::render_to_screen()
 538 {
 539         assert(finalized);
 540
 541         // Basic state.
 542         glDisable(GL_BLEND);
 543         check_error();
 544         glDisable(GL_DEPTH_TEST);
 545         check_error();
 546         glDepthMask(GL_FALSE);
 547         check_error();
 548
 549         glMatrixMode(GL_PROJECTION);
 550         glLoadIdentity();
 551         glOrtho(0.0, 1.0, 0.0, 1.0, 0.0, 1.0);
 552
 553         glMatrixMode(GL_MODELVIEW);
 554         glLoadIdentity();
 555
 556         if (phases.size() > 1) {
 557                 glBindFramebuffer(GL_FRAMEBUFFER, fbo);
 558                 check_error();
 559         }
 560
 561         std::set<Effect *> generated_mipmaps;
 562
 563         for (unsigned phase = 0; phase < phases.size(); ++phase) {
 564                 // See if the requested output size has changed. If so, we need to recreate
 565                 // the texture (and before we start setting up inputs).
 566                 if (phase != phases.size() - 1) {
 567                         find_output_size(phases[phase]);
 568
 569                         Effect *output_effect = phases[phase]->effects.back();
 570                         assert(effect_output_texture_sizes.count(output_effect) != 0);
 571                         std::pair<GLuint, GLuint> old_size = effect_output_texture_sizes[output_effect];
 572
 573                         if (old_size.first != phases[phase]->output_width ||
 574                             old_size.second != phases[phase]->output_height) {
 575                                 glActiveTexture(GL_TEXTURE0);
 576                                 check_error();
 577                                 assert(effect_output_textures.count(output_effect) != 0);
 578                                 glBindTexture(GL_TEXTURE_2D, effect_output_textures[output_effect]);
 579                                 check_error();
 580                                 glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA16F_ARB, phases[phase]->output_width, phases[phase]->output_height, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
 581                                 check_error();
 582                                 effect_output_texture_sizes[output_effect] = std::make_pair(phases[phase]->output_width, phases[phase]->output_height);
 583                                 glBindTexture(GL_TEXTURE_2D, 0);
 584                                 check_error();
 585                         }
 586                 }
 587
 588                 glUseProgram(phases[phase]->glsl_program_num);
 589                 check_error();
 590
 591                 // Set up RTT inputs for this phase.
 592                 for (unsigned sampler = 0; sampler < phases[phase]->inputs.size(); ++sampler) {
 593                         glActiveTexture(GL_TEXTURE0 + sampler);
 594                         Effect *input = phases[phase]->inputs[sampler];
 595                         assert(effect_output_textures.count(input) != 0);
 596                         glBindTexture(GL_TEXTURE_2D, effect_output_textures[input]);
 597                         check_error();
 598                         if (phases[phase]->input_needs_mipmaps) {
 599                                 if (generated_mipmaps.count(input) == 0) {
 600                                         glGenerateMipmap(GL_TEXTURE_2D);
 601                                         check_error();
 602                                         generated_mipmaps.insert(input);
 603                                 }
 604                                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_NEAREST);
 605                                 check_error();
 606                         } else {
 607                                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
 608                                 check_error();
 609                         }
 610
 611                         assert(effect_ids.count(input));
 612                         std::string texture_name = std::string("tex_") + effect_ids[input];
 613                         glUniform1i(glGetUniformLocation(phases[phase]->glsl_program_num, texture_name.c_str()), sampler);
 614                         check_error();
 615                 }
 616
 617                 // And now the output.
 618                 if (phase == phases.size() - 1) {
 619                         // Last phase goes directly to the screen.
 620                         glBindFramebuffer(GL_FRAMEBUFFER, 0);
 621                         check_error();
 622                         glViewport(0, 0, width, height);
 623                 } else {
 624                         Effect *output_effect = phases[phase]->effects.back();
 625                         assert(effect_output_textures.count(output_effect) != 0);
 626                         glFramebufferTexture2D(
 627                                 GL_FRAMEBUFFER,
 628                                 GL_COLOR_ATTACHMENT0,
 629                                 GL_TEXTURE_2D,
 630                                 effect_output_textures[output_effect],
 631                                 0);
 632                         check_error();
 633                         glViewport(0, 0, phases[phase]->output_width, phases[phase]->output_height);
 634                 }
 635
 636                 // Give the required parameters to all the effects.
 637                 unsigned sampler_num = phases[phase]->inputs.size();
 638                 for (unsigned i = 0; i < phases[phase]->effects.size(); ++i) {
 639                         Effect *effect = phases[phase]->effects[i];
 640                         effect->set_gl_state(phases[phase]->glsl_program_num, effect_ids[effect], &sampler_num);
 641                         check_error();
 642                 }
 643
 644                 // Now draw!
 645                 glBegin(GL_QUADS);
 646
 647                 glTexCoord2f(0.0f, 0.0f);
 648                 glVertex2f(0.0f, 0.0f);
 649
 650                 glTexCoord2f(1.0f, 0.0f);
 651                 glVertex2f(1.0f, 0.0f);
 652
 653                 glTexCoord2f(1.0f, 1.0f);
 654                 glVertex2f(1.0f, 1.0f);
 655
 656                 glTexCoord2f(0.0f, 1.0f);
 657                 glVertex2f(0.0f, 1.0f);
 658
 659                 glEnd();
 660                 check_error();
 661
 662                 for (unsigned i = 0; i < phases[phase]->effects.size(); ++i) {
 663                         Effect *effect = phases[phase]->effects[i];
 664                         effect->clear_gl_state();
 665                 }
 666         }
 667 }