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 <GL/gl.h>
   8 #include <GL/glext.h>
   9
  10 #include <algorithm>
  11 #include <set>
  12
  13 #include "util.h"
  14 #include "effect_chain.h"
  15 #include "gamma_expansion_effect.h"
  16 #include "gamma_compression_effect.h"
  17 #include "lift_gamma_gain_effect.h"
  18 #include "colorspace_conversion_effect.h"
  19 #include "sandbox_effect.h"
  20 #include "saturation_effect.h"
  21 #include "mirror_effect.h"
  22 #include "vignette_effect.h"
  23 #include "blur_effect.h"
  24 #include "diffusion_effect.h"
  25
  26 EffectChain::EffectChain(unsigned width, unsigned height)
  27         : width(width),
  28           height(height),
  29           last_added_effect(NULL),
  30           use_srgb_texture_format(false),
  31           finalized(false) {}
  32
  33 void EffectChain::add_input(const ImageFormat &format)
  34 {
  35         input_format = format;
  36         output_color_space.insert(std::make_pair(static_cast<Effect *>(NULL), format.color_space));
  37         output_gamma_curve.insert(std::make_pair(static_cast<Effect *>(NULL), format.gamma_curve));
  38         effect_ids.insert(std::make_pair(static_cast<Effect *>(NULL), "src_image"));
  39 }
  40
  41 void EffectChain::add_output(const ImageFormat &format)
  42 {
  43         output_format = format;
  44 }
  45
  46 void EffectChain::add_effect_raw(Effect *effect, const std::vector<Effect *> &inputs)
  47 {
  48         char effect_id[256];
  49         sprintf(effect_id, "eff%u", (unsigned)effects.size());
  50
  51         effects.push_back(effect);
  52         effect_ids.insert(std::make_pair(effect, effect_id));
  53         assert(inputs.size() == effect->num_inputs());
  54         for (unsigned i = 0; i < inputs.size(); ++i) {
  55                 if (inputs[i] != NULL) {
  56                         assert(std::find(effects.begin(), effects.end(), inputs[i]) != effects.end());
  57                 }
  58                 outgoing_links[inputs[i]].push_back(effect);
  59         }
  60         incoming_links.insert(std::make_pair(effect, inputs));
  61         last_added_effect = effect;
  62 }
  63
  64 Effect *instantiate_effect(EffectId effect)
  65 {
  66         switch (effect) {
  67         case EFFECT_GAMMA_EXPANSION:
  68                 return new GammaExpansionEffect();
  69         case EFFECT_GAMMA_COMPRESSION:
  70                 return new GammaCompressionEffect();
  71         case EFFECT_COLOR_SPACE_CONVERSION:
  72                 return new ColorSpaceConversionEffect();
  73         case EFFECT_SANDBOX:
  74                 return new SandboxEffect();
  75         case EFFECT_LIFT_GAMMA_GAIN:
  76                 return new LiftGammaGainEffect();
  77         case EFFECT_SATURATION:
  78                 return new SaturationEffect();
  79         case EFFECT_MIRROR:
  80                 return new MirrorEffect();
  81         case EFFECT_VIGNETTE:
  82                 return new VignetteEffect();
  83         case EFFECT_BLUR:
  84                 return new BlurEffect();
  85         case EFFECT_DIFFUSION:
  86                 return new DiffusionEffect();
  87         }
  88         assert(false);
  89 }
  90
  91 Effect *EffectChain::normalize_to_linear_gamma(Effect *input)
  92 {
  93         GammaCurve current_gamma_curve = output_gamma_curve[input];
  94         if (current_gamma_curve == GAMMA_sRGB) {
  95                 // TODO: check if the extension exists
  96                 use_srgb_texture_format = true;
  97                 current_gamma_curve = GAMMA_LINEAR;
  98                 return input;
  99         } else {
 100                 GammaExpansionEffect *gamma_conversion = new GammaExpansionEffect();
 101                 gamma_conversion->set_int("source_curve", current_gamma_curve);
 102                 std::vector<Effect *> inputs;
 103                 inputs.push_back(input);
 104                 gamma_conversion->add_self_to_effect_chain(this, inputs);
 105                 current_gamma_curve = GAMMA_LINEAR;
 106                 return gamma_conversion;
 107         }
 108 }
 109
 110 Effect *EffectChain::normalize_to_srgb(Effect *input)
 111 {
 112         GammaCurve current_gamma_curve = output_gamma_curve[input];
 113         ColorSpace current_color_space = output_color_space[input];
 114         assert(current_gamma_curve == GAMMA_LINEAR);
 115         ColorSpaceConversionEffect *colorspace_conversion = new ColorSpaceConversionEffect();
 116         colorspace_conversion->set_int("source_space", current_color_space);
 117         colorspace_conversion->set_int("destination_space", COLORSPACE_sRGB);
 118         std::vector<Effect *> inputs;
 119         inputs.push_back(input);
 120         colorspace_conversion->add_self_to_effect_chain(this, inputs);
 121         current_color_space = COLORSPACE_sRGB;
 122         return colorspace_conversion;
 123 }
 124
 125 Effect *EffectChain::add_effect(EffectId effect_id, const std::vector<Effect *> &inputs)
 126 {
 127         Effect *effect = instantiate_effect(effect_id);
 128
 129         assert(inputs.size() == effect->num_inputs());
 130
 131         std::vector<Effect *> normalized_inputs = inputs;
 132         for (unsigned i = 0; i < normalized_inputs.size(); ++i) {
 133                 if (effect->needs_linear_light() && output_gamma_curve[normalized_inputs[i]] != GAMMA_LINEAR) {
 134                         normalized_inputs[i] = normalize_to_linear_gamma(normalized_inputs[i]);
 135                 }
 136                 if (effect->needs_srgb_primaries() && output_color_space[normalized_inputs[i]] != COLORSPACE_sRGB) {
 137                         normalized_inputs[i] = normalize_to_srgb(normalized_inputs[i]);
 138                 }
 139         }
 140
 141         effect->add_self_to_effect_chain(this, normalized_inputs);
 142         return effect;
 143 }
 144
 145 // GLSL pre-1.30 doesn't support token pasting. Replace PREFIX(x) with <effect_id>_x.
 146 std::string replace_prefix(const std::string &text, const std::string &prefix)
 147 {
 148         std::string output;
 149         size_t start = 0;
 150
 151         while (start < text.size()) {
 152                 size_t pos = text.find("PREFIX(", start);
 153                 if (pos == std::string::npos) {
 154                         output.append(text.substr(start, std::string::npos));
 155                         break;
 156                 }
 157
 158                 output.append(text.substr(start, pos - start));
 159                 output.append(prefix);
 160                 output.append("_");
 161
 162                 pos += strlen("PREFIX(");
 163
 164                 // Output stuff until we find the matching ), which we then eat.
 165                 int depth = 1;
 166                 size_t end_arg_pos = pos;
 167                 while (end_arg_pos < text.size()) {
 168                         if (text[end_arg_pos] == '(') {
 169                                 ++depth;
 170                         } else if (text[end_arg_pos] == ')') {
 171                                 --depth;
 172                                 if (depth == 0) {
 173                                         break;
 174                                 }
 175                         }
 176                         ++end_arg_pos;
 177                 }
 178                 output.append(text.substr(pos, end_arg_pos - pos));
 179                 ++end_arg_pos;
 180                 assert(depth == 0);
 181                 start = end_arg_pos;
 182         }
 183         return output;
 184 }
 185
 186 EffectChain::Phase EffectChain::compile_glsl_program(const std::vector<Effect *> &inputs, const std::vector<Effect *> &effects)
 187 {
 188         assert(!inputs.empty());
 189         assert(!effects.empty());
 190
 191         // Figure out the true set of inputs to this phase. These are the ones
 192         // that we need somehow but don't calculate ourselves.
 193         std::set<Effect *> effect_set(effects.begin(), effects.end());
 194         std::set<Effect *> input_set(inputs.begin(), inputs.end());
 195         std::vector<Effect *> true_inputs;
 196         std::set_difference(input_set.begin(), input_set.end(),
 197                 effect_set.begin(), effect_set.end(),
 198                 std::back_inserter(true_inputs));
 199
 200         bool input_needs_mipmaps = false;
 201         std::string frag_shader = read_file("header.frag");
 202
 203         // Create functions for all the texture inputs that we need.
 204         for (unsigned i = 0; i < true_inputs.size(); ++i) {
 205                 Effect *effect = true_inputs[i];
 206                 assert(effect_ids.count(effect) != 0);
 207                 std::string effect_id = effect_ids[effect];
 208
 209                 frag_shader += std::string("uniform sampler2D tex_") + effect_id + ";\n";
 210                 frag_shader += std::string("vec4 ") + effect_id + "(vec2 tc) {\n";
 211                 if (effect == NULL) {
 212                         // OpenGL's origin is bottom-left, but most graphics software assumes
 213                         // a top-left origin. Thus, for inputs that come from the user,
 214                         // we flip the y coordinate. However, for FBOs, the origin
 215                         // is all correct, so don't do anything.
 216                         frag_shader += "\ttc.y = 1.0f - tc.y;\n";
 217                 }
 218                 frag_shader += "\treturn texture2D(tex_" + effect_id + ", tc);\n";
 219                 frag_shader += "}\n";
 220                 frag_shader += "\n";
 221         }
 222
 223         std::string last_effect_id;
 224         for (unsigned i = 0; i < effects.size(); ++i) {
 225                 Effect *effect = effects[i];
 226                 assert(effect != NULL);
 227                 assert(effect_ids.count(effect) != 0);
 228                 std::string effect_id = effect_ids[effect];
 229                 last_effect_id = effect_id;
 230
 231                 if (incoming_links[effect].size() == 1) {
 232                         frag_shader += std::string("#define INPUT ") + effect_ids[incoming_links[effect][0]] + "\n";
 233                 } else {
 234                         for (unsigned j = 0; j < incoming_links[effect].size(); ++j) {
 235                                 char buf[256];
 236                                 sprintf(buf, "#define INPUT%d %s\n", j + 1, effect_ids[incoming_links[effect][j]].c_str());
 237                                 frag_shader += buf;
 238                         }
 239                 }
 240
 241                 frag_shader += "\n";
 242                 frag_shader += std::string("#define FUNCNAME ") + effect_id + "\n";
 243                 frag_shader += replace_prefix(effect->output_convenience_uniforms(), effect_id);
 244                 frag_shader += replace_prefix(effect->output_fragment_shader(), effect_id);
 245                 frag_shader += "#undef PREFIX\n";
 246                 frag_shader += "#undef FUNCNAME\n";
 247                 if (incoming_links[effect].size() == 1) {
 248                         frag_shader += "#undef INPUT\n";
 249                 } else {
 250                         for (unsigned j = 0; j < incoming_links[effect].size(); ++j) {
 251                                 char buf[256];
 252                                 sprintf(buf, "#undef INPUT%d\n", j + 1);
 253                                 frag_shader += buf;
 254                         }
 255                 }
 256                 frag_shader += "\n";
 257
 258                 input_needs_mipmaps |= effect->needs_mipmaps();
 259         }
 260         assert(!last_effect_id.empty());
 261         frag_shader += std::string("#define INPUT ") + last_effect_id + "\n";
 262         frag_shader.append(read_file("footer.frag"));
 263         printf("%s\n", frag_shader.c_str());
 264
 265         GLuint glsl_program_num = glCreateProgram();
 266         GLuint vs_obj = compile_shader(read_file("vs.vert"), GL_VERTEX_SHADER);
 267         GLuint fs_obj = compile_shader(frag_shader, GL_FRAGMENT_SHADER);
 268         glAttachShader(glsl_program_num, vs_obj);
 269         check_error();
 270         glAttachShader(glsl_program_num, fs_obj);
 271         check_error();
 272         glLinkProgram(glsl_program_num);
 273         check_error();
 274
 275         Phase phase;
 276         phase.glsl_program_num = glsl_program_num;
 277         phase.input_needs_mipmaps = input_needs_mipmaps;
 278         phase.inputs = true_inputs;
 279         phase.effects = effects;
 280
 281         return phase;
 282 }
 283
 284 // Construct GLSL programs, starting at the given effect and following
 285 // the chain from there. We end a program every time we come to an effect
 286 // marked as "needs texture bounce", one that is used by multiple other
 287 // effects, and of course at the end.
 288 void EffectChain::construct_glsl_programs(Effect *start, std::set<Effect *> *completed_effects)
 289 {
 290         if (completed_effects->count(start) != 0) {
 291                 // This has already been done for us.
 292                 return;
 293         }
 294
 295         std::vector<Effect *> this_phase_inputs;  // Also includes all intermediates; these will be filtered away later.
 296         std::vector<Effect *> this_phase_effects;
 297         Effect *node = start;
 298         for ( ;; ) {  // Termination condition within loop.
 299                 if (node == NULL) {
 300                         this_phase_inputs.push_back(node);
 301                 } else {
 302                         // Check that we have all the inputs we need for this effect.
 303                         // If not, we end the phase here right away; the other side
 304                         // of the input chain will eventually come and pick the effect up.
 305                         assert(incoming_links.count(node) != 0);
 306                         std::vector<Effect *> deps = incoming_links[node];
 307                         assert(!deps.empty());
 308                         bool have_all_deps = true;
 309                         for (unsigned i = 0; i < deps.size(); ++i) {
 310                                 if (completed_effects->count(deps[i]) == 0) {
 311                                         have_all_deps = false;
 312                                         break;
 313                                 }
 314                         }
 315
 316                         if (!have_all_deps) {
 317                                 if (!this_phase_effects.empty()) {
 318                                         phases.push_back(compile_glsl_program(this_phase_inputs, this_phase_effects));
 319                                 }
 320                                 return;
 321                         }
 322                         this_phase_inputs.insert(this_phase_inputs.end(), deps.begin(), deps.end());
 323                         this_phase_effects.push_back(node);
 324                 }
 325                 completed_effects->insert(node);
 326
 327                 // Find all the effects that use this one as a direct input.
 328                 if (outgoing_links.count(node) == 0) {
 329                         // End of the line; output.
 330                         phases.push_back(compile_glsl_program(this_phase_inputs, this_phase_effects));
 331                         return;
 332                 }
 333
 334                 std::vector<Effect *> next = outgoing_links[node];
 335                 assert(!next.empty());
 336                 if (next.size() > 1) {
 337                         // More than one effect uses this as the input.
 338                         // The easiest thing to do (and probably also the safest
 339                         // performance-wise in most cases) is to bounce it to a texture
 340                         // and then let the next passes read from that.
 341                         if (node != NULL) {
 342                                 phases.push_back(compile_glsl_program(this_phase_inputs, this_phase_effects));
 343                         }
 344
 345                         // Start phases for all the effects that need us (in arbitrary order).
 346                         for (unsigned i = 0; i < next.size(); ++i) {
 347                                 construct_glsl_programs(next[i], completed_effects);
 348                         }
 349                         return;
 350                 }
 351
 352                 // OK, only one effect uses this as the input. Keep iterating,
 353                 // but first see if it requires a texture bounce; if so, give it
 354                 // one by starting a new phase.
 355                 node = next[0];
 356                 if (node->needs_texture_bounce()) {
 357                         phases.push_back(compile_glsl_program(this_phase_inputs, this_phase_effects));
 358                         this_phase_inputs.clear();
 359                         this_phase_effects.clear();
 360                 }
 361         }
 362 }
 363
 364 void EffectChain::finalize()
 365 {
 366         // Add normalizers to get the output format right.
 367         GammaCurve current_gamma_curve = output_gamma_curve[last_added_effect];  // FIXME
 368         ColorSpace current_color_space = output_color_space[last_added_effect];  // FIXME
 369         if (current_color_space != output_format.color_space) {
 370                 ColorSpaceConversionEffect *colorspace_conversion = new ColorSpaceConversionEffect();
 371                 colorspace_conversion->set_int("source_space", current_color_space);
 372                 colorspace_conversion->set_int("destination_space", output_format.color_space);
 373                 effects.push_back(colorspace_conversion);
 374                 current_color_space = output_format.color_space;
 375         }
 376         if (current_gamma_curve != output_format.gamma_curve) {
 377                 if (current_gamma_curve != GAMMA_LINEAR) {
 378                         normalize_to_linear_gamma(last_added_effect);  // FIXME
 379                 }
 380                 assert(current_gamma_curve == GAMMA_LINEAR);
 381                 GammaCompressionEffect *gamma_conversion = new GammaCompressionEffect();
 382                 gamma_conversion->set_int("destination_curve", output_format.gamma_curve);
 383                 effects.push_back(gamma_conversion);
 384                 current_gamma_curve = output_format.gamma_curve;
 385         }
 386
 387         // Construct all needed GLSL programs, starting at the input.
 388         std::set<Effect *> completed_effects;
 389         construct_glsl_programs(NULL, &completed_effects);
 390
 391         // If we have more than one phase, we need intermediate render-to-texture.
 392         // Construct an FBO, and then as many textures as we need.
 393         // We choose the simplest option of having one texture per output,
 394         // since otherwise this turns into an (albeit simple)
 395         // register allocation problem.
 396         if (phases.size() > 1) {
 397                 glGenFramebuffers(1, &fbo);
 398
 399                 for (unsigned i = 0; i < phases.size() - 1; ++i) {
 400                         Effect *output_effect = phases[i].effects.back();
 401                         GLuint temp_texture;
 402                         glGenTextures(1, &temp_texture);
 403                         check_error();
 404                         glBindTexture(GL_TEXTURE_2D, temp_texture);
 405                         check_error();
 406                         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
 407                         check_error();
 408                         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
 409                         check_error();
 410                         glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA16F_ARB, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
 411                         check_error();
 412                         effect_output_textures.insert(std::make_pair(output_effect, temp_texture));
 413                 }
 414         }
 415
 416         // Translate the input format to OpenGL's enums.
 417         GLenum internal_format;
 418         if (use_srgb_texture_format) {
 419                 internal_format = GL_SRGB8;
 420         } else {
 421                 internal_format = GL_RGBA8;
 422         }
 423         if (input_format.pixel_format == FORMAT_RGB) {
 424                 format = GL_RGB;
 425                 bytes_per_pixel = 3;
 426         } else if (input_format.pixel_format == FORMAT_RGBA) {
 427                 format = GL_RGBA;
 428                 bytes_per_pixel = 4;
 429         } else if (input_format.pixel_format == FORMAT_BGR) {
 430                 format = GL_BGR;
 431                 bytes_per_pixel = 3;
 432         } else if (input_format.pixel_format == FORMAT_BGRA) {
 433                 format = GL_BGRA;
 434                 bytes_per_pixel = 4;
 435         } else {
 436                 assert(false);
 437         }
 438
 439         // Create PBO to hold the texture holding the input image, and then the texture itself.
 440         glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, 2);
 441         check_error();
 442         glBufferData(GL_PIXEL_UNPACK_BUFFER_ARB, width * height * bytes_per_pixel, NULL, GL_STREAM_DRAW);
 443         check_error();
 444         glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, 0);
 445         check_error();
 446
 447         glGenTextures(1, &source_image_num);
 448         check_error();
 449         glBindTexture(GL_TEXTURE_2D, source_image_num);
 450         check_error();
 451         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
 452         check_error();
 453         // Intel/Mesa seems to have a broken glGenerateMipmap() for non-FBO textures, so do it here.
 454         glTexParameteri(GL_TEXTURE_2D, GL_GENERATE_MIPMAP, phases[0].input_needs_mipmaps ? GL_TRUE : GL_FALSE);
 455         check_error();
 456         glTexImage2D(GL_TEXTURE_2D, 0, internal_format, width, height, 0, format, GL_UNSIGNED_BYTE, NULL);
 457         check_error();
 458
 459         finalized = true;
 460 }
 461
 462 void EffectChain::render_to_screen(unsigned char *src)
 463 {
 464         assert(finalized);
 465
 466         // Copy the pixel data into the PBO.
 467         glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, 2);
 468         check_error();
 469         void *mapped_pbo = glMapBufferARB(GL_PIXEL_UNPACK_BUFFER_ARB, GL_WRITE_ONLY);
 470         memcpy(mapped_pbo, src, width * height * bytes_per_pixel);
 471         glUnmapBufferARB(GL_PIXEL_UNPACK_BUFFER_ARB);
 472         check_error();
 473
 474         // Re-upload the texture from the PBO.
 475         glActiveTexture(GL_TEXTURE0);
 476         check_error();
 477         glBindTexture(GL_TEXTURE_2D, source_image_num);
 478         check_error();
 479         glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, width, height, format, GL_UNSIGNED_BYTE, BUFFER_OFFSET(0));
 480         check_error();
 481         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
 482         check_error();
 483         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
 484         check_error();
 485         glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, 0);
 486         check_error();
 487
 488         // Basic state.
 489         glDisable(GL_BLEND);
 490         check_error();
 491         glDisable(GL_DEPTH_TEST);
 492         check_error();
 493         glDepthMask(GL_FALSE);
 494         check_error();
 495
 496         glMatrixMode(GL_PROJECTION);
 497         glLoadIdentity();
 498         glOrtho(0.0, 1.0, 0.0, 1.0, 0.0, 1.0);
 499
 500         glMatrixMode(GL_MODELVIEW);
 501         glLoadIdentity();
 502
 503         if (phases.size() > 1) {
 504                 glBindFramebuffer(GL_FRAMEBUFFER, fbo);
 505                 check_error();
 506         }
 507
 508         std::set<Effect *> generated_mipmaps;
 509         generated_mipmaps.insert(NULL);  // Already done further up.
 510
 511         for (unsigned phase = 0; phase < phases.size(); ++phase) {
 512                 glUseProgram(phases[phase].glsl_program_num);
 513                 check_error();
 514
 515                 // Set up inputs for this phase.
 516                 assert(!phases[phase].inputs.empty());
 517                 for (unsigned sampler = 0; sampler < phases[phase].inputs.size(); ++sampler) {
 518                         glActiveTexture(GL_TEXTURE0 + sampler);
 519                         Effect *input = phases[phase].inputs[sampler];
 520                         if (input == NULL) {
 521                                 glBindTexture(GL_TEXTURE_2D, source_image_num);
 522                                 check_error();
 523                         } else {
 524                                 assert(effect_output_textures.count(input) != 0);
 525                                 glBindTexture(GL_TEXTURE_2D, effect_output_textures[input]);
 526                                 check_error();
 527                         }
 528                         if (phases[phase].input_needs_mipmaps) {
 529                                 if (generated_mipmaps.count(input) == 0) {
 530                                         glGenerateMipmap(GL_TEXTURE_2D);
 531                                         check_error();
 532                                         generated_mipmaps.insert(input);
 533                                 }
 534                                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_NEAREST);
 535                                 check_error();
 536                         } else {
 537                                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
 538                                 check_error();
 539                         }
 540
 541                         assert(effect_ids.count(input));
 542                         std::string texture_name = std::string("tex_") + effect_ids[input];
 543                         glUniform1i(glGetUniformLocation(phases[phase].glsl_program_num, texture_name.c_str()), sampler);
 544                         check_error();
 545                 }
 546
 547                 // And now the output.
 548                 if (phase == phases.size() - 1) {
 549                         // Last phase goes directly to the screen.
 550                         glBindFramebuffer(GL_FRAMEBUFFER, 0);
 551                         check_error();
 552                 } else {
 553                         Effect *last_effect = phases[phase].effects.back();
 554                         assert(effect_output_textures.count(last_effect) != 0);
 555                         glFramebufferTexture2D(
 556                                 GL_FRAMEBUFFER,
 557                                 GL_COLOR_ATTACHMENT0,
 558                                 GL_TEXTURE_2D,
 559                                 effect_output_textures[last_effect],
 560                                 0);
 561                         check_error();
 562                 }
 563
 564                 // Give the required parameters to all the effects.
 565                 unsigned sampler_num = phases[phase].inputs.size();
 566                 for (unsigned i = 0; i < phases[phase].effects.size(); ++i) {
 567                         Effect *effect = phases[phase].effects[i];
 568                         effect->set_uniforms(phases[phase].glsl_program_num, effect_ids[effect], &sampler_num);
 569                 }
 570
 571                 // Now draw!
 572                 glBegin(GL_QUADS);
 573
 574                 glTexCoord2f(0.0f, 0.0f);
 575                 glVertex2f(0.0f, 0.0f);
 576
 577                 glTexCoord2f(1.0f, 0.0f);
 578                 glVertex2f(1.0f, 0.0f);
 579
 580                 glTexCoord2f(1.0f, 1.0f);
 581                 glVertex2f(1.0f, 1.0f);
 582
 583                 glTexCoord2f(0.0f, 1.0f);
 584                 glVertex2f(0.0f, 1.0f);
 585
 586                 glEnd();
 587                 check_error();
 588
 589                 // HACK
 590                 glActiveTexture(GL_TEXTURE0);
 591                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_BASE_LEVEL, 0);
 592                 check_error();
 593                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAX_LEVEL, 1000);
 594                 check_error();
 595         }
 596 }