git.sesse.net Git - nageru/blob - nageru/scene.cpp

   1 #include <assert.h>
   2 extern "C" {
   3 #include <lauxlib.h>
   4 #include <lua.hpp>
   5 }
   6
   7 #ifdef HAVE_CEF
   8 #include "cef_capture.h"
   9 #endif
  10 #include "ffmpeg_capture.h"
  11 #include "flags.h"
  12 #include "image_input.h"
  13 #include "input_state.h"
  14 #include "lua_utils.h"
  15 #include "scene.h"
  16 #include "theme.h"
  17
  18 using namespace movit;
  19 using namespace std;
  20
  21 bool display(Block *block, lua_State *L, int idx);
  22
  23 EffectType current_type(const Block *block)
  24 {
  25         return block->alternatives[block->currently_chosen_alternative]->effect_type;
  26 }
  27
  28 int find_index_of(const Block *block, EffectType val)
  29 {
  30         for (size_t idx = 0; idx < block->alternatives.size(); ++idx) {
  31                 if (block->alternatives[idx]->effect_type == val) {
  32                         return idx;
  33                 }
  34         }
  35         return -1;
  36 }
  37
  38 string get_declaration_point(lua_State *L)
  39 {
  40         lua_Debug ar;
  41         lua_getstack(L, 1, &ar);
  42         lua_getinfo(L, "nSl", &ar);
  43         char buf[256];
  44         snprintf(buf, sizeof(buf), "%s:%d", ar.source, ar.currentline);
  45         return buf;
  46 }
  47
  48 Scene::Scene(Theme *theme, float aspect_nom, float aspect_denom)
  49         : theme(theme), aspect_nom(aspect_nom), aspect_denom(aspect_denom), resource_pool(theme->get_resource_pool()) {}
  50
  51 size_t Scene::compute_chain_number(bool is_main_chain) const
  52 {
  53         assert(chains.size() > 0);
  54         assert(chains.size() % 2 == 0);
  55         bitset<256> disabled = find_disabled_blocks(size_t(-1));
  56
  57         size_t chain_number = compute_chain_number_for_block(blocks.size() - 1, disabled);
  58         assert(chain_number < chains.size() / 2);
  59         if (is_main_chain) {
  60                 chain_number += chains.size() / 2;
  61         }
  62         return chain_number;
  63 }
  64
  65 size_t Scene::compute_chain_number_for_block(size_t block_idx, const bitset<256> &disabled) const
  66 {
  67         Block *block = blocks[block_idx];
  68         size_t chain_number;
  69
  70         size_t currently_chosen_alternative;
  71         if (disabled.test(block_idx)) {
  72                 // It doesn't matter, so pick the canonical choice
  73                 // (this is the only one that is actually instantiated).
  74                 currently_chosen_alternative = block->canonical_alternative;
  75         } else {
  76                 currently_chosen_alternative = block->currently_chosen_alternative;
  77         }
  78         assert(currently_chosen_alternative < block->alternatives.size());
  79
  80         if (block_idx == 0) {
  81                 assert(block->cardinality_base == 1);
  82                 chain_number = currently_chosen_alternative;
  83         } else {
  84                 chain_number = compute_chain_number_for_block(block_idx - 1, disabled) + block->cardinality_base * currently_chosen_alternative;
  85         }
  86         return chain_number;
  87 }
  88
  89 bitset<256> Scene::find_disabled_blocks(size_t chain_idx) const
  90 {
  91         assert(blocks.size() < 256);
  92
  93         // The find_disabled_blocks() recursion logic needs only one pass by itself,
  94         // but the disabler logic is not so smart, so we just run multiple times
  95         // until it converges.
  96         bitset<256> prev, ret;
  97         do {
  98                 find_disabled_blocks(chain_idx, blocks.size() - 1, /*currently_disabled=*/false, &ret);
  99                 prev = ret;
 100
 101                 // Propagate DISABLE_IF_OTHER_DISABLED constraints (we can always do this).
 102                 for (Block *block : blocks) {
 103                         if (ret.test(block->idx)) continue;  // Already disabled.
 104
 105                         EffectType chosen_type = block->alternatives[block->chosen_alternative(chain_idx)]->effect_type;
 106                         if (chosen_type == IDENTITY_EFFECT) {
 107                                 ret.set(block->idx);
 108                                 continue;
 109                         }
 110
 111                         for (const Block::Disabler &disabler : block->disablers) {
 112                                 Block *other = blocks[disabler.block_idx];
 113                                 EffectType chosen_type = other->alternatives[other->chosen_alternative(chain_idx)]->effect_type;
 114                                 bool other_disabled = ret.test(disabler.block_idx) || chosen_type == IDENTITY_EFFECT;
 115                                 if (other_disabled && disabler.condition == Block::Disabler::DISABLE_IF_OTHER_DISABLED) {
 116                                         ret.set(block->idx);
 117                                         break;
 118                                 }
 119                         }
 120                 }
 121
 122                 // We cannot propagate DISABLE_IF_OTHER_ENABLED in all cases;
 123                 // the problem is that if A is disabled if B is enabled,
 124                 // then we cannot disable A unless we actually know for sure
 125                 // that B _is_ enabled. (E.g., imagine that B is disabled
 126                 // if C is enabled -- we couldn't disable A before we knew if
 127                 // C was enabled or not!)
 128                 //
 129                 // We could probably fix a fair amount of these, but the
 130                 // primary use case for DISABLE_IF_OTHER_ENABLED is really
 131                 // mutual exclusion; A must be disabled if B is enabled
 132                 // _and_ vice versa. These loops cannot be automatically
 133                 // resolved; it would depend on what A and B is. Thus,
 134                 // we simply declare this kind of constraint to be a promise
 135                 // from the user, not something that we'll solve for them.
 136         } while (prev != ret);
 137         return ret;
 138 }
 139
 140 void Scene::find_disabled_blocks(size_t chain_idx, size_t block_idx, bool currently_disabled, bitset<256> *disabled) const
 141 {
 142         if (currently_disabled) {
 143                 disabled->set(block_idx);
 144         }
 145         Block *block = blocks[block_idx];
 146         EffectType chosen_type = block->alternatives[block->chosen_alternative(chain_idx)]->effect_type;
 147         for (size_t input_idx = 0; input_idx < block->inputs.size(); ++input_idx) {
 148                 if (chosen_type == IDENTITY_EFFECT && input_idx > 0) {
 149                         // Multi-input effect that has been replaced by
 150                         // IdentityEffect, so every effect but the first are
 151                         // disabled and will not participate in the chain.
 152                         find_disabled_blocks(chain_idx, block->inputs[input_idx], /*currently_disabled=*/true, disabled);
 153                 } else {
 154                         // Just keep on recursing down.
 155                         find_disabled_blocks(chain_idx, block->inputs[input_idx], currently_disabled, disabled);
 156                 }
 157         }
 158 }
 159
 160 bool Scene::is_noncanonical_chain(size_t chain_idx) const
 161 {
 162         bitset<256> disabled = find_disabled_blocks(chain_idx);
 163         assert(blocks.size() < 256);
 164         for (size_t block_idx = 0; block_idx < blocks.size(); ++block_idx) {
 165                 Block *block = blocks[block_idx];
 166                 if (disabled.test(block_idx) && block->chosen_alternative(chain_idx) != block->canonical_alternative) {
 167                         return true;
 168                 }
 169
 170                 // Test if we're supposed to be disabled by some other block being enabled;
 171                 // the disabled bit mask does not fully capture this.
 172                 if (!disabled.test(block_idx)) {
 173                         for (const Block::Disabler &disabler : block->disablers) {
 174                                 if (disabler.condition == Block::Disabler::DISABLE_IF_OTHER_ENABLED &&
 175                                     !disabled.test(disabler.block_idx)) {
 176                                         return true;
 177                                 }
 178                         }
 179                 }
 180         }
 181         return false;
 182 }
 183
 184 int Scene::add_input(lua_State* L)
 185 {
 186         assert(lua_gettop(L) == 1 || lua_gettop(L) == 2);
 187         Scene *scene = (Scene *)luaL_checkudata(L, 1, "Scene");
 188
 189         Block *block = new Block;
 190         block->declaration_point = get_declaration_point(L);
 191         block->idx = scene->blocks.size();
 192         if (lua_gettop(L) == 1) {
 193                 // No parameter given, so a flexible input.
 194                 block->alternatives.emplace_back(new EffectBlueprint(LIVE_INPUT_YCBCR));
 195                 block->alternatives.emplace_back(new EffectBlueprint(LIVE_INPUT_YCBCR_WITH_DEINTERLACE));
 196                 block->alternatives.emplace_back(new EffectBlueprint(LIVE_INPUT_YCBCR_PLANAR));
 197                 block->alternatives.emplace_back(new EffectBlueprint(LIVE_INPUT_BGRA));
 198                 block->alternatives.emplace_back(new EffectBlueprint(IMAGE_INPUT));
 199         } else {
 200                 // Input of a given type. We'll specialize it here, plus connect the input as given.
 201                 if (lua_isnumber(L, 2)) {
 202                         block->alternatives.emplace_back(new EffectBlueprint(LIVE_INPUT_YCBCR));
 203                         block->alternatives.emplace_back(new EffectBlueprint(LIVE_INPUT_YCBCR_WITH_DEINTERLACE));
 204 #ifdef HAVE_CEF
 205                 } else if (luaL_testudata(L, 2, "HTMLInput")) {
 206                         block->alternatives.emplace_back(new EffectBlueprint(LIVE_INPUT_BGRA));
 207 #endif
 208                 } else if (luaL_testudata(L, 2, "VideoInput")) {
 209                         FFmpegCapture *capture = *(FFmpegCapture **)luaL_checkudata(L, 2, "VideoInput");
 210                         if (capture->get_current_pixel_format() == bmusb::PixelFormat_8BitYCbCrPlanar) {
 211                                 block->alternatives.emplace_back(new EffectBlueprint(LIVE_INPUT_YCBCR_PLANAR));
 212                         } else {
 213                                 assert(capture->get_current_pixel_format() == bmusb::PixelFormat_8BitBGRA);
 214                                 block->alternatives.emplace_back(new EffectBlueprint(LIVE_INPUT_BGRA));
 215                         }
 216                 } else if (luaL_testudata(L, 2, "ImageInput")) {
 217                         block->alternatives.emplace_back(new EffectBlueprint(IMAGE_INPUT));
 218                 } else {
 219                         luaL_error(L, "add_input() called with something that's not a signal (a signal number, a HTML input, or a VideoInput)");
 220                 }
 221                 bool ok = display(block, L, 2);
 222                 assert(ok);
 223         }
 224         block->is_input = true;
 225         scene->blocks.push_back(block);
 226
 227         return wrap_lua_existing_object_nonowned<Block>(L, "Block", block);
 228 }
 229
 230 void Scene::find_inputs_for_block(lua_State *L, Scene *scene, Block *block)
 231 {
 232         if (lua_gettop(L) == 2) {
 233                 // Implicitly the last added effect.
 234                 assert(!scene->blocks.empty());
 235                 block->inputs.push_back(scene->blocks.size() - 1);
 236                 return;
 237         }
 238
 239         for (int idx = 3; idx <= lua_gettop(L); ++idx) {
 240                 Block *input_block = nullptr;
 241                 if (luaL_testudata(L, idx, "Block")) {
 242                         input_block = *(Block **)luaL_checkudata(L, idx, "Block");
 243                 } else {
 244                         EffectBlueprint *blueprint = *(EffectBlueprint **)luaL_checkudata(L, idx, "EffectBlueprint");
 245
 246                         // Search through all the blocks to figure out which one contains this effect.
 247                         for (Block *block : scene->blocks) {
 248                                 if (find(block->alternatives.begin(), block->alternatives.end(), blueprint) != block->alternatives.end()) {
 249                                         input_block = block;
 250                                         break;
 251                                 }
 252                         }
 253                         if (input_block == nullptr) {
 254                                 luaL_error(L, "Input effect in parameter #%d has not been added to this scene", idx - 1);
 255                         }
 256                 }
 257                 block->inputs.push_back(input_block->idx);
 258         }
 259 }
 260
 261 int Scene::add_effect(lua_State* L)
 262 {
 263         assert(lua_gettop(L) >= 2);
 264         Scene *scene = (Scene *)luaL_checkudata(L, 1, "Scene");
 265
 266         Block *block = new Block;
 267         block->declaration_point = get_declaration_point(L);
 268         block->idx = scene->blocks.size();
 269
 270         if (lua_istable(L, 2)) {
 271                 size_t len = lua_objlen(L, 2);
 272                 for (size_t i = 0; i < len; ++i) {
 273                         lua_rawgeti(L, 2, i + 1);
 274                         EffectBlueprint *blueprint = *(EffectBlueprint **)luaL_checkudata(L, -1, "EffectBlueprint");
 275                         block->alternatives.push_back(blueprint);
 276                         lua_settop(L, -2);
 277                 }
 278         } else {
 279                 EffectBlueprint *blueprint = *(EffectBlueprint **)luaL_checkudata(L, 2, "EffectBlueprint");
 280                 block->alternatives.push_back(blueprint);
 281         }
 282
 283         int identity_index = find_index_of(block, IDENTITY_EFFECT);
 284         if (identity_index == -1) {
 285                 block->canonical_alternative = 0;
 286         } else {
 287                 // Pick the IdentityEffect as the canonical alternative, in case it
 288                 // helps us disable more stuff.
 289                 block->canonical_alternative = identity_index;
 290         }
 291
 292         find_inputs_for_block(L, scene, block);
 293         scene->blocks.push_back(block);
 294
 295         return wrap_lua_existing_object_nonowned<Block>(L, "Block", block);
 296 }
 297
 298 int Scene::add_optional_effect(lua_State* L)
 299 {
 300         assert(lua_gettop(L) >= 2);
 301         Scene *scene = (Scene *)luaL_checkudata(L, 1, "Scene");
 302
 303         Block *block = new Block;
 304         block->declaration_point = get_declaration_point(L);
 305         block->idx = scene->blocks.size();
 306
 307         EffectBlueprint *blueprint = *(EffectBlueprint **)luaL_checkudata(L, 2, "EffectBlueprint");
 308         block->alternatives.push_back(blueprint);
 309
 310         // An IdentityEffect will be the alternative for when the effect is disabled.
 311         block->alternatives.push_back(new EffectBlueprint(IDENTITY_EFFECT));
 312
 313         block->canonical_alternative = 1;
 314
 315         find_inputs_for_block(L, scene, block);
 316         scene->blocks.push_back(block);
 317
 318         return wrap_lua_existing_object_nonowned<Block>(L, "Block", block);
 319 }
 320
 321 Effect *Scene::instantiate_effects(const Block *block, size_t chain_idx, Scene::Instantiation *instantiation)
 322 {
 323         // Find the chosen alternative for this block in this instance.
 324         EffectType chosen_type = block->alternatives[block->chosen_alternative(chain_idx)]->effect_type;
 325
 326         vector<Effect *> inputs;
 327         for (size_t input_idx : block->inputs) {
 328                 inputs.push_back(instantiate_effects(blocks[input_idx], chain_idx, instantiation));
 329
 330                 // As a special case, we allow IdentityEffect to take only one input
 331                 // even if the other alternative (or alternatives) is multi-input.
 332                 // Thus, even if there are more than one inputs, instantiate only
 333                 // the first one.
 334                 if (chosen_type == IDENTITY_EFFECT) {
 335                         break;
 336                 }
 337         }
 338
 339         Effect *effect;
 340         switch (chosen_type) {
 341         case LIVE_INPUT_YCBCR:
 342         case LIVE_INPUT_YCBCR_WITH_DEINTERLACE:
 343         case LIVE_INPUT_YCBCR_PLANAR:
 344         case LIVE_INPUT_BGRA: {
 345                 bool deinterlace = (chosen_type == LIVE_INPUT_YCBCR_WITH_DEINTERLACE);
 346                 bool override_bounce = !deinterlace;  // For most chains, this will be fine. Reconsider if we see real problems somewhere; it's better than having the user try to understand it.
 347                 bmusb::PixelFormat pixel_format;
 348                 if (chosen_type == LIVE_INPUT_BGRA) {
 349                         pixel_format = bmusb::PixelFormat_8BitBGRA;
 350                 } else if (chosen_type == LIVE_INPUT_YCBCR_PLANAR) {
 351                         pixel_format = bmusb::PixelFormat_8BitYCbCrPlanar;
 352                 } else if (global_flags.ten_bit_input) {
 353                         pixel_format = bmusb::PixelFormat_10BitYCbCr;
 354                 } else {
 355                         pixel_format = bmusb::PixelFormat_8BitYCbCr;
 356                 }
 357                 LiveInputWrapper *input = new LiveInputWrapper(theme, instantiation->chain.get(), pixel_format, override_bounce, deinterlace, /*user_connectable=*/true);
 358                 effect = input->get_effect();  // Adds itself to the chain, so no need to call add_effect().
 359                 instantiation->inputs.emplace(block->idx, input);
 360                 break;
 361         }
 362         case IMAGE_INPUT: {
 363                 ImageInput *input = new ImageInput;
 364                 instantiation->chain->add_input(input);
 365                 instantiation->image_inputs.emplace(block->idx, input);
 366                 effect = input;
 367                 break;
 368         }
 369         default:
 370                 effect = instantiate_effect(instantiation->chain.get(), chosen_type);
 371                 instantiation->chain->add_effect(effect, inputs);
 372                 break;
 373         }
 374         instantiation->effects.emplace(block->idx, effect);
 375         return effect;
 376 }
 377
 378 int Scene::finalize(lua_State* L)
 379 {
 380         bool only_one_mode = false;
 381         bool chosen_mode = false;
 382         if (lua_gettop(L) == 2) {
 383                 only_one_mode = true;
 384                 chosen_mode = checkbool(L, 2);
 385         } else {
 386                 assert(lua_gettop(L) == 1);
 387         }
 388         Scene *scene = (Scene *)luaL_checkudata(L, 1, "Scene");
 389         Theme *theme = get_theme_updata(L);
 390
 391         size_t base = 1;
 392         for (Block *block : scene->blocks) {
 393                 block->cardinality_base = base;
 394                 base *= block->alternatives.size();
 395         }
 396
 397         const size_t cardinality = base;
 398         size_t real_cardinality = 0;
 399         for (size_t chain_idx = 0; chain_idx < cardinality; ++chain_idx) {
 400                 if (!scene->is_noncanonical_chain(chain_idx)) {
 401                         ++real_cardinality;
 402                 }
 403         }
 404         const size_t total_cardinality = real_cardinality * (only_one_mode ? 1 : 2);
 405         if (total_cardinality > 200) {
 406                 print_warning(L, "The given Scene will instantiate %zu different versions. This will take a lot of time and RAM to compile; see if you could limit some options by e.g. locking the input type in some cases (by giving a fixed input to add_input()).\n",
 407                         total_cardinality);
 408         }
 409
 410         Block *output_block = scene->blocks.back();
 411         for (bool is_main_chain : { false, true }) {
 412                 for (size_t chain_idx = 0; chain_idx < cardinality; ++chain_idx) {
 413                         if ((only_one_mode && is_main_chain != chosen_mode) ||
 414                             scene->is_noncanonical_chain(chain_idx)) {
 415                                 scene->chains.emplace_back();
 416                                 continue;
 417                         }
 418
 419                         Scene::Instantiation instantiation;
 420                         instantiation.chain.reset(new EffectChain(scene->aspect_nom, scene->aspect_denom, theme->get_resource_pool()));
 421                         scene->instantiate_effects(output_block, chain_idx, &instantiation);
 422
 423                         add_outputs_and_finalize(instantiation.chain.get(), is_main_chain);
 424                         scene->chains.emplace_back(move(instantiation));
 425                 }
 426         }
 427         return 0;
 428 }
 429
 430 int find_signal_to_connect(lua_State *L, const Block *block)
 431 {
 432         if (block->signal_type_to_connect == Block::CONNECT_SIGNAL) {
 433                 return block->signal_to_connect;
 434 #ifdef HAVE_CEF
 435         } else if (block->signal_type_to_connect == Block::CONNECT_CEF) {
 436                 return block->cef_to_connect->get_card_index();
 437 #endif
 438         } else if (block->signal_type_to_connect == Block::CONNECT_VIDEO) {
 439                 return block->video_to_connect->get_card_index();
 440         } else if (block->signal_type_to_connect == Block::CONNECT_NONE) {
 441                 luaL_error(L, "An input in a scene was not connected to anything (forgot to call display())");
 442         } else {
 443                 assert(false);
 444         }
 445         return -1;
 446 }
 447
 448 std::pair<movit::EffectChain *, std::function<void()>>
 449 Scene::get_chain(Theme *theme, lua_State *L, unsigned num, const InputState &input_state)
 450 {
 451         // For video inputs, pick the right interlaced/progressive version
 452         // based on the current state of the signals.
 453         InputStateInfo info(input_state);
 454         for (Block *block : blocks) {
 455                 if (block->is_input && block->signal_type_to_connect == Block::CONNECT_SIGNAL) {
 456                         EffectType chosen_type = current_type(block);
 457                         assert(chosen_type == LIVE_INPUT_YCBCR || chosen_type == LIVE_INPUT_YCBCR_WITH_DEINTERLACE);
 458                         if (info.last_interlaced[block->signal_to_connect]) {
 459                                 block->currently_chosen_alternative = find_index_of(block, LIVE_INPUT_YCBCR_WITH_DEINTERLACE);
 460                         } else {
 461                                 block->currently_chosen_alternative = find_index_of(block, LIVE_INPUT_YCBCR);
 462                         }
 463                 }
 464         }
 465
 466         // Pick out the right chain based on the current selections,
 467         // and snapshot all the set variables so that we can set them
 468         // in the prepare function even if they're being changed by
 469         // the Lua code later.
 470         bool is_main_chain = (num == 0);
 471         size_t chain_idx = compute_chain_number(is_main_chain);
 472         if (is_noncanonical_chain(chain_idx)) {
 473                 // This should be due to promise_to_disable_if_enabled(). Find out what
 474                 // happened, to give the user some help.
 475                 bitset<256> disabled = find_disabled_blocks(chain_idx);
 476                 for (size_t block_idx = 0; block_idx < blocks.size(); ++block_idx) {
 477                         Block *block = blocks[block_idx];
 478                         if (disabled.test(block_idx)) continue;
 479                         for (const Block::Disabler &disabler : block->disablers) {
 480                                 if (disabler.condition == Block::Disabler::DISABLE_IF_OTHER_ENABLED &&
 481                                     !disabled.test(disabler.block_idx)) {
 482                                         fprintf(stderr, "Promise declared at %s violated.\n", disabler.declaration_point.c_str());
 483                                         abort();
 484                                 }
 485                         }
 486                 }
 487                 assert(false);  // Something else happened, seemingly.
 488         }
 489         const Scene::Instantiation &instantiation = chains[chain_idx];
 490         EffectChain *effect_chain = instantiation.chain.get();
 491
 492         map<LiveInputWrapper *, int> signals_to_connect;
 493         map<ImageInput *, string> images_to_select;
 494         map<pair<Effect *, string>, int> int_to_set;
 495         map<pair<Effect *, string>, float> float_to_set;
 496         map<pair<Effect *, string>, array<float, 3>> vec3_to_set;
 497         map<pair<Effect *, string>, array<float, 4>> vec4_to_set;
 498         for (const auto &index_and_input : instantiation.inputs) {
 499                 Block *block = blocks[index_and_input.first];
 500                 EffectType chosen_type = current_type(block);
 501                 if (chosen_type == LIVE_INPUT_YCBCR ||
 502                     chosen_type == LIVE_INPUT_YCBCR_WITH_DEINTERLACE ||
 503                     chosen_type == LIVE_INPUT_YCBCR_PLANAR ||
 504                     chosen_type == LIVE_INPUT_BGRA) {
 505                         LiveInputWrapper *input = index_and_input.second;
 506                         signals_to_connect.emplace(input, find_signal_to_connect(L, block));
 507                 }
 508         }
 509         for (const auto &index_and_input : instantiation.image_inputs) {
 510                 Block *block = blocks[index_and_input.first];
 511                 ImageInput *input = index_and_input.second;
 512                 if (current_type(block) == IMAGE_INPUT) {
 513                         images_to_select.emplace(input, block->pathname);
 514                 }
 515         }
 516         for (const auto &index_and_effect : instantiation.effects) {
 517                 Block *block = blocks[index_and_effect.first];
 518                 Effect *effect = index_and_effect.second;
 519
 520                 bool missing_width = (current_type(block) == RESIZE_EFFECT ||
 521                         current_type(block) == RESAMPLE_EFFECT ||
 522                         current_type(block) == PADDING_EFFECT);
 523                 bool missing_height = missing_width;
 524
 525                 // Get the effects currently set on the block.
 526                 if (current_type(block) != IDENTITY_EFFECT) {  // Ignore settings on optional effects.
 527                         if (block->int_parameters.count("width") && block->int_parameters["width"] > 0) {
 528                                 missing_width = false;
 529                         }
 530                         if (block->int_parameters.count("height") && block->int_parameters["height"] > 0) {
 531                                 missing_height = false;
 532                         }
 533                         for (const auto &key_and_tuple : block->int_parameters) {
 534                                 int_to_set.emplace(make_pair(effect, key_and_tuple.first), key_and_tuple.second);
 535                         }
 536                         for (const auto &key_and_tuple : block->float_parameters) {
 537                                 float_to_set.emplace(make_pair(effect, key_and_tuple.first), key_and_tuple.second);
 538                         }
 539                         for (const auto &key_and_tuple : block->vec3_parameters) {
 540                                 vec3_to_set.emplace(make_pair(effect, key_and_tuple.first), key_and_tuple.second);
 541                         }
 542                         for (const auto &key_and_tuple : block->vec4_parameters) {
 543                                 vec4_to_set.emplace(make_pair(effect, key_and_tuple.first), key_and_tuple.second);
 544                         }
 545                 }
 546
 547                 // Parameters set on the blueprint itself override those that are set for the block,
 548                 // so they are set afterwards.
 549                 if (!block->alternatives.empty()) {
 550                         EffectBlueprint *blueprint = block->alternatives[block->currently_chosen_alternative];
 551                         if (blueprint->int_parameters.count("width") && blueprint->int_parameters["width"] > 0) {
 552                                 missing_width = false;
 553                         }
 554                         if (blueprint->int_parameters.count("height") && blueprint->int_parameters["height"] > 0) {
 555                                 missing_height = false;
 556                         }
 557                         for (const auto &key_and_tuple : blueprint->int_parameters) {
 558                                 int_to_set[make_pair(effect, key_and_tuple.first)] = key_and_tuple.second;
 559                         }
 560                         for (const auto &key_and_tuple : blueprint->float_parameters) {
 561                                 float_to_set[make_pair(effect, key_and_tuple.first)] = key_and_tuple.second;
 562                         }
 563                         for (const auto &key_and_tuple : blueprint->vec3_parameters) {
 564                                 vec3_to_set[make_pair(effect, key_and_tuple.first)] = key_and_tuple.second;
 565                         }
 566                         for (const auto &key_and_tuple : blueprint->vec4_parameters) {
 567                                 vec4_to_set[make_pair(effect, key_and_tuple.first)] = key_and_tuple.second;
 568                         }
 569                 }
 570
 571                 if (missing_width || missing_height) {
 572                         fprintf(stderr, "WARNING: Unset or nonpositive width/height for effect declared at %s "
 573                                 "when getting scene for signal %u; setting to 1x1 to avoid crash.\n",
 574                                 block->declaration_point.c_str(), num);
 575                         int_to_set[make_pair(effect, "width")] = 1;
 576                         int_to_set[make_pair(effect, "height")] = 1;
 577                 }
 578         }
 579
 580         lua_pop(L, 1);
 581
 582         auto setup_chain = [L, theme, signals_to_connect, images_to_select, int_to_set, float_to_set, vec3_to_set, vec4_to_set, input_state]{
 583                 lock_guard<mutex> lock(theme->m);
 584
 585                 // Set up state, including connecting signals.
 586                 for (const auto &input_and_signal : signals_to_connect) {
 587                         LiveInputWrapper *input = input_and_signal.first;
 588                         input->connect_signal_raw(input_and_signal.second, input_state);
 589                 }
 590                 for (const auto &input_and_filename : images_to_select) {
 591                         input_and_filename.first->switch_image(input_and_filename.second);
 592                 }
 593                 for (const auto &effect_and_key_and_value : int_to_set) {
 594                         Effect *effect = effect_and_key_and_value.first.first;
 595                         const string &key = effect_and_key_and_value.first.second;
 596                         const int value = effect_and_key_and_value.second;
 597                         if (!effect->set_int(key, value)) {
 598                                 luaL_error(L, "Effect refused set_int(\"%s\", %d) (invalid key?)", key.c_str(), value);
 599                         }
 600                 }
 601                 for (const auto &effect_and_key_and_value : float_to_set) {
 602                         Effect *effect = effect_and_key_and_value.first.first;
 603                         const string &key = effect_and_key_and_value.first.second;
 604                         const float value = effect_and_key_and_value.second;
 605                         if (!effect->set_float(key, value)) {
 606                                 luaL_error(L, "Effect refused set_float(\"%s\", %f) (invalid key?)", key.c_str(), value);
 607                         }
 608                 }
 609                 for (const auto &effect_and_key_and_value : vec3_to_set) {
 610                         Effect *effect = effect_and_key_and_value.first.first;
 611                         const string &key = effect_and_key_and_value.first.second;
 612                         const float *value = effect_and_key_and_value.second.data();
 613                         if (!effect->set_vec3(key, value)) {
 614                                 luaL_error(L, "Effect refused set_vec3(\"%s\", %f, %f, %f) (invalid key?)", key.c_str(),
 615                                                 value[0], value[1], value[2]);
 616                         }
 617                 }
 618                 for (const auto &effect_and_key_and_value : vec4_to_set) {
 619                         Effect *effect = effect_and_key_and_value.first.first;
 620                         const string &key = effect_and_key_and_value.first.second;
 621                         const float *value = effect_and_key_and_value.second.data();
 622                         if (!effect->set_vec4(key, value)) {
 623                                 luaL_error(L, "Effect refused set_vec4(\"%s\", %f, %f, %f, %f) (invalid key?)", key.c_str(),
 624                                                 value[0], value[1], value[2], value[3]);
 625                         }
 626                 }
 627         };
 628         return make_pair(effect_chain, move(setup_chain));
 629 }
 630
 631 bool display(Block *block, lua_State *L, int idx)
 632 {
 633         if (lua_isnumber(L, idx)) {
 634                 Theme *theme = get_theme_updata(L);
 635                 int signal_idx = luaL_checknumber(L, idx);
 636                 block->signal_type_to_connect = Block::CONNECT_SIGNAL;
 637                 block->signal_to_connect = theme->map_signal(signal_idx);
 638                 block->currently_chosen_alternative = find_index_of(block, LIVE_INPUT_YCBCR);  // Will be changed to deinterlaced at get_chain() time if needed.
 639                 return true;
 640 #ifdef HAVE_CEF
 641         } else if (luaL_testudata(L, idx, "HTMLInput")) {
 642                 CEFCapture *capture = *(CEFCapture **)luaL_checkudata(L, idx, "HTMLInput");
 643                 block->signal_type_to_connect = Block::CONNECT_CEF;
 644                 block->cef_to_connect = capture;
 645                 block->currently_chosen_alternative = find_index_of(block, LIVE_INPUT_BGRA);
 646                 assert(capture->get_current_pixel_format() == bmusb::PixelFormat_8BitBGRA);
 647                 return true;
 648 #endif
 649         } else if (luaL_testudata(L, idx, "VideoInput")) {
 650                 FFmpegCapture *capture = *(FFmpegCapture **)luaL_checkudata(L, idx, "VideoInput");
 651                 block->signal_type_to_connect = Block::CONNECT_VIDEO;
 652                 block->video_to_connect = capture;
 653                 if (capture->get_current_pixel_format() == bmusb::PixelFormat_8BitYCbCrPlanar) {
 654                         block->currently_chosen_alternative = find_index_of(block, LIVE_INPUT_YCBCR_PLANAR);
 655                 } else {
 656                         assert(capture->get_current_pixel_format() == bmusb::PixelFormat_8BitBGRA);
 657                         block->currently_chosen_alternative = find_index_of(block, LIVE_INPUT_BGRA);
 658                 }
 659                 return true;
 660         } else if (luaL_testudata(L, idx, "ImageInput")) {
 661                 ImageInput *image = *(ImageInput **)luaL_checkudata(L, idx, "ImageInput");
 662                 block->signal_type_to_connect = Block::CONNECT_NONE;
 663                 block->currently_chosen_alternative = find_index_of(block, IMAGE_INPUT);
 664                 block->pathname = image->get_pathname();
 665                 return true;
 666         } else {
 667                 return false;
 668         }
 669 }
 670
 671 int Block_display(lua_State* L)
 672 {
 673         assert(lua_gettop(L) == 2);
 674         Block *block = *(Block **)luaL_checkudata(L, 1, "Block");
 675         if (!block->is_input) {
 676                 luaL_error(L, "display() called on something that isn't an input");
 677         }
 678
 679         bool ok = display(block, L, 2);
 680         if (!ok) {
 681                 luaL_error(L, "display() called with something that's not a signal (a signal number, a HTML input, or a VideoInput)");
 682         }
 683
 684         if (block->currently_chosen_alternative == -1) {
 685                 luaL_error(L, "display() called on an input whose type was fixed at construction time, with a signal of different type");
 686         }
 687
 688         return 0;
 689 }
 690
 691 int Block_choose(lua_State* L)
 692 {
 693         assert(lua_gettop(L) == 2);
 694         Block *block = *(Block **)luaL_checkudata(L, 1, "Block");
 695         int alternative_idx = -1;
 696         if (lua_isnumber(L, 2)) {
 697                 alternative_idx = luaL_checknumber(L, 2);
 698         } else if (lua_istable(L, 2)) {
 699                 // See if it's an Effect metatable (e.g. foo:choose(ResampleEffect))
 700                 lua_getfield(L, 2, "__effect_type_id");
 701                 if (lua_isnumber(L, -1)) {
 702                         EffectType effect_type = EffectType(luaL_checknumber(L, -1));
 703                         alternative_idx = find_index_of(block, effect_type);
 704                 }
 705                 lua_pop(L, 1);
 706         }
 707
 708         if (alternative_idx == -1) {
 709                 luaL_error(L, "choose() called with something that was not an index or an effect type (e.g. ResampleEffect) that was part of the alternatives");
 710         }
 711
 712         assert(alternative_idx >= 0);
 713         assert(size_t(alternative_idx) < block->alternatives.size());
 714         block->currently_chosen_alternative = alternative_idx;
 715
 716         return wrap_lua_existing_object_nonowned<EffectBlueprint>(L, "EffectBlueprint", block->alternatives[alternative_idx]);
 717 }
 718
 719 int Block_enable(lua_State *L)
 720 {
 721         assert(lua_gettop(L) == 1);
 722         Block *block = *(Block **)luaL_checkudata(L, 1, "Block");
 723
 724         if (block->alternatives.size() != 2 ||
 725             block->alternatives[1]->effect_type != IDENTITY_EFFECT) {
 726                 luaL_error(L, "enable() called on something that wasn't added with add_optional_effect()");
 727         }
 728         block->currently_chosen_alternative = 0;  // The actual effect.
 729         return 0;
 730 }
 731
 732 int Block_enable_if(lua_State *L)
 733 {
 734         assert(lua_gettop(L) == 2);
 735         Block *block = *(Block **)luaL_checkudata(L, 1, "Block");
 736
 737         if (block->alternatives.size() != 2 ||
 738             block->alternatives[1]->effect_type != IDENTITY_EFFECT) {
 739                 luaL_error(L, "enable_if() called on something that wasn't added with add_optional_effect()");
 740         }
 741         bool enabled = checkbool(L, 2);
 742         block->currently_chosen_alternative = enabled ? 0 : 1;
 743         return 0;
 744 }
 745
 746 int Block_disable(lua_State *L)
 747 {
 748         assert(lua_gettop(L) == 1);
 749         Block *block = *(Block **)luaL_checkudata(L, 1, "Block");
 750
 751         block->currently_chosen_alternative = find_index_of(block, IDENTITY_EFFECT);
 752         if (block->currently_chosen_alternative == -1) {
 753                 luaL_error(L, "disable() called on something that didn't have an IdentityEffect fallback (try add_optional_effect())");
 754         }
 755         assert(block->currently_chosen_alternative != -1);
 756         return 0;
 757 }
 758
 759 int Block_always_disable_if_disabled(lua_State *L)
 760 {
 761         assert(lua_gettop(L) == 2);
 762         Block *block = *(Block **)luaL_checkudata(L, 1, "Block");
 763         Block *disabler_block = *(Block **)luaL_checkudata(L, 2, "Block");
 764
 765         int my_alternative = find_index_of(block, IDENTITY_EFFECT);
 766         int their_alternative = find_index_of(disabler_block, IDENTITY_EFFECT);
 767         if (my_alternative == -1) {
 768                 luaL_error(L, "always_disable_if_disabled() called on something that didn't have an IdentityEffect fallback (try add_optional_effect())");
 769         }
 770         if (their_alternative == -1) {
 771                 luaL_error(L, "always_disable_if_disabled() with an argument that didn't have an IdentityEffect fallback (try add_optional_effect())");
 772         }
 773
 774         // The declaration point isn't actually used, but it's nice for completeness.
 775         block->disablers.push_back(Block::Disabler{ disabler_block->idx, Block::Disabler::DISABLE_IF_OTHER_DISABLED, get_declaration_point(L) });
 776
 777         lua_pop(L, 2);
 778         return 0;
 779 }
 780
 781 int Block_promise_to_disable_if_enabled(lua_State *L)
 782 {
 783         assert(lua_gettop(L) == 2);
 784         Block *block = *(Block **)luaL_checkudata(L, 1, "Block");
 785         Block *disabler_block = *(Block **)luaL_checkudata(L, 2, "Block");
 786
 787         int my_alternative = find_index_of(block, IDENTITY_EFFECT);
 788         int their_alternative = find_index_of(disabler_block, IDENTITY_EFFECT);
 789         if (my_alternative == -1) {
 790                 luaL_error(L, "promise_to_disable_if_enabled() called on something that didn't have an IdentityEffect fallback (try add_optional_effect())");
 791         }
 792         if (their_alternative == -1) {
 793                 luaL_error(L, "promise_to_disable_if_enabled() with an argument that didn't have an IdentityEffect fallback (try add_optional_effect())");
 794         }
 795
 796         block->disablers.push_back(Block::Disabler{ disabler_block->idx, Block::Disabler::DISABLE_IF_OTHER_ENABLED, get_declaration_point(L) });
 797
 798         lua_pop(L, 2);
 799         return 0;
 800 }
 801
 802 int Block_set_int(lua_State *L)
 803 {
 804         assert(lua_gettop(L) == 3);
 805         Block *block = *(Block **)luaL_checkudata(L, 1, "Block");
 806         string key = checkstdstring(L, 2);
 807         float value = luaL_checknumber(L, 3);
 808
 809         // TODO: check validity already here, if possible?
 810         block->int_parameters[key] = value;
 811
 812         return 0;
 813 }
 814
 815 int Block_set_float(lua_State *L)
 816 {
 817         assert(lua_gettop(L) == 3);
 818         Block *block = *(Block **)luaL_checkudata(L, 1, "Block");
 819         string key = checkstdstring(L, 2);
 820         float value = luaL_checknumber(L, 3);
 821
 822         // TODO: check validity already here, if possible?
 823         block->float_parameters[key] = value;
 824
 825         return 0;
 826 }
 827
 828 int Block_set_vec3(lua_State *L)
 829 {
 830         assert(lua_gettop(L) == 5);
 831         Block *block = *(Block **)luaL_checkudata(L, 1, "Block");
 832         string key = checkstdstring(L, 2);
 833         array<float, 3> v;
 834         v[0] = luaL_checknumber(L, 3);
 835         v[1] = luaL_checknumber(L, 4);
 836         v[2] = luaL_checknumber(L, 5);
 837
 838         // TODO: check validity already here, if possible?
 839         block->vec3_parameters[key] = v;
 840
 841         return 0;
 842 }
 843
 844 int Block_set_vec4(lua_State *L)
 845 {
 846         assert(lua_gettop(L) == 6);
 847         Block *block = *(Block **)luaL_checkudata(L, 1, "Block");
 848         string key = checkstdstring(L, 2);
 849         array<float, 4> v;
 850         v[0] = luaL_checknumber(L, 3);
 851         v[1] = luaL_checknumber(L, 4);
 852         v[2] = luaL_checknumber(L, 5);
 853         v[3] = luaL_checknumber(L, 6);
 854
 855         // TODO: check validity already here, if possible?
 856         block->vec4_parameters[key] = v;
 857
 858         return 0;
 859 }
 860