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