src/video/sdl2_v.cpp

   1 /*
   2  * This file is part of OpenTTD.
   3  * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
   4  * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
   5  * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
   6  */
   7
   8 /** @file sdl2_v.cpp Implementation of the SDL2 video driver. */
   9
  10 #include "../stdafx.h"
  11 #include "../openttd.h"
  12 #include "../gfx_func.h"
  13 #include "../blitter/factory.hpp"
  14 #include "../thread.h"
  15 #include "../progress.h"
  16 #include "../core/random_func.hpp"
  17 #include "../core/math_func.hpp"
  18 #include "../core/mem_func.hpp"
  19 #include "../core/geometry_func.hpp"
  20 #include "../fileio_func.h"
  21 #include "../framerate_type.h"
  22 #include "../window_func.h"
  23 #include "sdl2_v.h"
  24 #include <SDL.h>
  25 #ifdef __EMSCRIPTEN__
  26 #       include <emscripten.h>
  27 #       include <emscripten/html5.h>
  28 #endif
  29
  30 #include "../safeguards.h"
  31
  32 void VideoDriver_SDL_Base::MakeDirty(int left, int top, int width, int height)
  33 {
  34         Rect r = {left, top, left + width, top + height};
  35         this->dirty_rect = BoundingRect(this->dirty_rect, r);
  36 }
  37
  38 void VideoDriver_SDL_Base::CheckPaletteAnim()
  39 {
  40         if (!CopyPalette(this->local_palette)) return;
  41         this->MakeDirty(0, 0, _screen.width, _screen.height);
  42 }
  43
  44 static const Dimension default_resolutions[] = {
  45         {  640,  480 },
  46         {  800,  600 },
  47         { 1024,  768 },
  48         { 1152,  864 },
  49         { 1280,  800 },
  50         { 1280,  960 },
  51         { 1280, 1024 },
  52         { 1400, 1050 },
  53         { 1600, 1200 },
  54         { 1680, 1050 },
  55         { 1920, 1200 }
  56 };
  57
  58 static void FindResolutions()
  59 {
  60         _resolutions.clear();
  61
  62         for (int display = 0; display < SDL_GetNumVideoDisplays(); display++) {
  63                 for (int i = 0; i < SDL_GetNumDisplayModes(display); i++) {
  64                         SDL_DisplayMode mode;
  65                         SDL_GetDisplayMode(display, i, &mode);
  66
  67                         if (mode.w < 640 || mode.h < 480) continue;
  68                         if (std::find(_resolutions.begin(), _resolutions.end(), Dimension(mode.w, mode.h)) != _resolutions.end()) continue;
  69                         _resolutions.emplace_back(mode.w, mode.h);
  70                 }
  71         }
  72
  73         /* We have found no resolutions, show the default list */
  74         if (_resolutions.empty()) {
  75                 _resolutions.assign(std::begin(default_resolutions), std::end(default_resolutions));
  76         }
  77
  78         SortResolutions();
  79 }
  80
  81 static void GetAvailableVideoMode(uint *w, uint *h)
  82 {
  83         /* All modes available? */
  84         if (!_fullscreen || _resolutions.empty()) return;
  85
  86         /* Is the wanted mode among the available modes? */
  87         if (std::find(_resolutions.begin(), _resolutions.end(), Dimension(*w, *h)) != _resolutions.end()) return;
  88
  89         /* Use the closest possible resolution */
  90         uint best = 0;
  91         uint delta = Delta(_resolutions[0].width, *w) * Delta(_resolutions[0].height, *h);
  92         for (uint i = 1; i != _resolutions.size(); ++i) {
  93                 uint newdelta = Delta(_resolutions[i].width, *w) * Delta(_resolutions[i].height, *h);
  94                 if (newdelta < delta) {
  95                         best = i;
  96                         delta = newdelta;
  97                 }
  98         }
  99         *w = _resolutions[best].width;
 100         *h = _resolutions[best].height;
 101 }
 102
 103 static uint FindStartupDisplay(uint startup_display)
 104 {
 105         int num_displays = SDL_GetNumVideoDisplays();
 106
 107         /* If the user indicated a valid monitor, use that. */
 108         if (IsInsideBS(startup_display, 0, num_displays)) return startup_display;
 109
 110         /* Mouse position decides which display to use. */
 111         int mx, my;
 112         SDL_GetGlobalMouseState(&mx, &my);
 113         for (int display = 0; display < num_displays; ++display) {
 114                 SDL_Rect r;
 115                 if (SDL_GetDisplayBounds(display, &r) == 0 && IsInsideBS(mx, r.x, r.w) && IsInsideBS(my, r.y, r.h)) {
 116                         Debug(driver, 1, "SDL2: Mouse is at ({}, {}), use display {} ({}, {}, {}, {})", mx, my, display, r.x, r.y, r.w, r.h);
 117                         return display;
 118                 }
 119         }
 120
 121         return 0;
 122 }
 123
 124 void VideoDriver_SDL_Base::ClientSizeChanged(int w, int h, bool force)
 125 {
 126         /* Allocate backing store of the new size. */
 127         if (this->AllocateBackingStore(w, h, force)) {
 128                 CopyPalette(this->local_palette, true);
 129
 130                 BlitterFactory::GetCurrentBlitter()->PostResize();
 131
 132                 GameSizeChanged();
 133         }
 134 }
 135
 136 bool VideoDriver_SDL_Base::CreateMainWindow(uint w, uint h, uint flags)
 137 {
 138         if (this->sdl_window != nullptr) return true;
 139
 140         flags |= SDL_WINDOW_SHOWN | SDL_WINDOW_RESIZABLE;
 141
 142         if (_fullscreen) {
 143                 flags |= SDL_WINDOW_FULLSCREEN;
 144         }
 145
 146         int x = SDL_WINDOWPOS_UNDEFINED, y = SDL_WINDOWPOS_UNDEFINED;
 147         SDL_Rect r;
 148         if (SDL_GetDisplayBounds(this->startup_display, &r) == 0) {
 149                 x = r.x + std::max(0, r.w - static_cast<int>(w)) / 2;
 150                 y = r.y + std::max(0, r.h - static_cast<int>(h)) / 4; // decent desktops have taskbars at the bottom
 151         }
 152
 153         std::string caption = VideoDriver::GetCaption();
 154         this->sdl_window = SDL_CreateWindow(
 155                 caption.c_str(),
 156                 x, y,
 157                 w, h,
 158                 flags);
 159
 160         if (this->sdl_window == nullptr) {
 161                 Debug(driver, 0, "SDL2: Couldn't allocate a window to draw on: {}", SDL_GetError());
 162                 return false;
 163         }
 164
 165         std::string icon_path = FioFindFullPath(BASESET_DIR, "openttd.32.bmp");
 166         if (!icon_path.empty()) {
 167                 /* Give the application an icon */
 168                 SDL_Surface *icon = SDL_LoadBMP(icon_path.c_str());
 169                 if (icon != nullptr) {
 170                         /* Get the colourkey, which will be magenta */
 171                         uint32_t rgbmap = SDL_MapRGB(icon->format, 255, 0, 255);
 172
 173                         SDL_SetColorKey(icon, SDL_TRUE, rgbmap);
 174                         SDL_SetWindowIcon(this->sdl_window, icon);
 175                         SDL_FreeSurface(icon);
 176                 }
 177         }
 178
 179         return true;
 180 }
 181
 182 bool VideoDriver_SDL_Base::CreateMainSurface(uint w, uint h, bool resize)
 183 {
 184         GetAvailableVideoMode(&w, &h);
 185         Debug(driver, 1, "SDL2: using mode {}x{}", w, h);
 186
 187         if (!this->CreateMainWindow(w, h)) return false;
 188         if (resize) SDL_SetWindowSize(this->sdl_window, w, h);
 189         this->ClientSizeChanged(w, h, true);
 190
 191         /* When in full screen, we will always have the mouse cursor
 192          * within the window, even though SDL does not give us the
 193          * appropriate event to know this. */
 194         if (_fullscreen) _cursor.in_window = true;
 195
 196         return true;
 197 }
 198
 199 bool VideoDriver_SDL_Base::ClaimMousePointer()
 200 {
 201         /* Emscripten never claims the pointer, so we do not need to change the cursor visibility. */
 202 #ifndef __EMSCRIPTEN__
 203         SDL_ShowCursor(0);
 204 #endif
 205         return true;
 206 }
 207
 208 /**
 209  * This is called to indicate that an edit box has gained focus, text input mode should be enabled.
 210  */
 211 void VideoDriver_SDL_Base::EditBoxGainedFocus()
 212 {
 213         if (!this->edit_box_focused) {
 214                 SDL_StartTextInput();
 215                 this->edit_box_focused = true;
 216         }
 217 }
 218
 219 /**
 220  * This is called to indicate that an edit box has lost focus, text input mode should be disabled.
 221  */
 222 void VideoDriver_SDL_Base::EditBoxLostFocus()
 223 {
 224         if (this->edit_box_focused) {
 225                 SDL_StopTextInput();
 226                 this->edit_box_focused = false;
 227         }
 228 }
 229
 230 std::vector<int> VideoDriver_SDL_Base::GetListOfMonitorRefreshRates()
 231 {
 232         std::vector<int> rates = {};
 233         for (int i = 0; i < SDL_GetNumVideoDisplays(); i++) {
 234                 SDL_DisplayMode mode = {};
 235                 if (SDL_GetDisplayMode(i, 0, &mode) != 0) continue;
 236                 if (mode.refresh_rate != 0) rates.push_back(mode.refresh_rate);
 237         }
 238         return rates;
 239 }
 240
 241
 242 struct SDLVkMapping {
 243         SDL_Keycode vk_from;
 244         byte vk_count;
 245         byte map_to;
 246         bool unprintable;
 247 };
 248
 249 #define AS(x, z) {x, 0, z, false}
 250 #define AM(x, y, z, w) {x, (byte)(y - x), z, false}
 251 #define AS_UP(x, z) {x, 0, z, true}
 252 #define AM_UP(x, y, z, w) {x, (byte)(y - x), z, true}
 253
 254 static const SDLVkMapping _vk_mapping[] = {
 255         /* Pageup stuff + up/down */
 256         AS_UP(SDLK_PAGEUP,   WKC_PAGEUP),
 257         AS_UP(SDLK_PAGEDOWN, WKC_PAGEDOWN),
 258         AS_UP(SDLK_UP,     WKC_UP),
 259         AS_UP(SDLK_DOWN,   WKC_DOWN),
 260         AS_UP(SDLK_LEFT,   WKC_LEFT),
 261         AS_UP(SDLK_RIGHT,  WKC_RIGHT),
 262
 263         AS_UP(SDLK_HOME,   WKC_HOME),
 264         AS_UP(SDLK_END,    WKC_END),
 265
 266         AS_UP(SDLK_INSERT, WKC_INSERT),
 267         AS_UP(SDLK_DELETE, WKC_DELETE),
 268
 269         /* Map letters & digits */
 270         AM(SDLK_a, SDLK_z, 'A', 'Z'),
 271         AM(SDLK_0, SDLK_9, '0', '9'),
 272
 273         AS_UP(SDLK_ESCAPE,    WKC_ESC),
 274         AS_UP(SDLK_PAUSE,     WKC_PAUSE),
 275         AS_UP(SDLK_BACKSPACE, WKC_BACKSPACE),
 276
 277         AS(SDLK_SPACE,     WKC_SPACE),
 278         AS(SDLK_RETURN,    WKC_RETURN),
 279         AS(SDLK_TAB,       WKC_TAB),
 280
 281         /* Function keys */
 282         AM_UP(SDLK_F1, SDLK_F12, WKC_F1, WKC_F12),
 283
 284         /* Numeric part. */
 285         AM(SDLK_KP_0, SDLK_KP_9, '0', '9'),
 286         AS(SDLK_KP_DIVIDE,   WKC_NUM_DIV),
 287         AS(SDLK_KP_MULTIPLY, WKC_NUM_MUL),
 288         AS(SDLK_KP_MINUS,    WKC_NUM_MINUS),
 289         AS(SDLK_KP_PLUS,     WKC_NUM_PLUS),
 290         AS(SDLK_KP_ENTER,    WKC_NUM_ENTER),
 291         AS(SDLK_KP_PERIOD,   WKC_NUM_DECIMAL),
 292
 293         /* Other non-letter keys */
 294         AS(SDLK_SLASH,        WKC_SLASH),
 295         AS(SDLK_SEMICOLON,    WKC_SEMICOLON),
 296         AS(SDLK_EQUALS,       WKC_EQUALS),
 297         AS(SDLK_LEFTBRACKET,  WKC_L_BRACKET),
 298         AS(SDLK_BACKSLASH,    WKC_BACKSLASH),
 299         AS(SDLK_RIGHTBRACKET, WKC_R_BRACKET),
 300
 301         AS(SDLK_QUOTE,   WKC_SINGLEQUOTE),
 302         AS(SDLK_COMMA,   WKC_COMMA),
 303         AS(SDLK_MINUS,   WKC_MINUS),
 304         AS(SDLK_PERIOD,  WKC_PERIOD)
 305 };
 306
 307 static uint ConvertSdlKeyIntoMy(SDL_Keysym *sym, char32_t *character)
 308 {
 309         const SDLVkMapping *map;
 310         uint key = 0;
 311         bool unprintable = false;
 312
 313         for (map = _vk_mapping; map != endof(_vk_mapping); ++map) {
 314                 if ((uint)(sym->sym - map->vk_from) <= map->vk_count) {
 315                         key = sym->sym - map->vk_from + map->map_to;
 316                         unprintable = map->unprintable;
 317                         break;
 318                 }
 319         }
 320
 321         /* check scancode for BACKQUOTE key, because we want the key left of "1", not anything else (on non-US keyboards) */
 322         if (sym->scancode == SDL_SCANCODE_GRAVE) key = WKC_BACKQUOTE;
 323
 324         /* META are the command keys on mac */
 325         if (sym->mod & KMOD_GUI)   key |= WKC_META;
 326         if (sym->mod & KMOD_SHIFT) key |= WKC_SHIFT;
 327         if (sym->mod & KMOD_CTRL)  key |= WKC_CTRL;
 328         if (sym->mod & KMOD_ALT)   key |= WKC_ALT;
 329
 330         /* The mod keys have no character. Prevent '?' */
 331         if (sym->mod & KMOD_GUI ||
 332                 sym->mod & KMOD_CTRL ||
 333                 sym->mod & KMOD_ALT ||
 334                 unprintable) {
 335                 *character = WKC_NONE;
 336         } else {
 337                 *character = sym->sym;
 338         }
 339
 340         return key;
 341 }
 342
 343 /**
 344  * Like ConvertSdlKeyIntoMy(), but takes an SDL_Keycode as input
 345  * instead of an SDL_Keysym.
 346  */
 347 static uint ConvertSdlKeycodeIntoMy(SDL_Keycode kc)
 348 {
 349         const SDLVkMapping *map;
 350         uint key = 0;
 351
 352         for (map = _vk_mapping; map != endof(_vk_mapping); ++map) {
 353                 if ((uint)(kc - map->vk_from) <= map->vk_count) {
 354                         key = kc - map->vk_from + map->map_to;
 355                         break;
 356                 }
 357         }
 358
 359         /* check scancode for BACKQUOTE key, because we want the key left
 360          * of "1", not anything else (on non-US keyboards) */
 361         SDL_Scancode sc = SDL_GetScancodeFromKey(kc);
 362         if (sc == SDL_SCANCODE_GRAVE) key = WKC_BACKQUOTE;
 363
 364         return key;
 365 }
 366
 367 bool VideoDriver_SDL_Base::PollEvent()
 368 {
 369         SDL_Event ev;
 370
 371         if (!SDL_PollEvent(&ev)) return false;
 372
 373         switch (ev.type) {
 374                 case SDL_MOUSEMOTION: {
 375                         int32_t x = ev.motion.x;
 376                         int32_t y = ev.motion.y;
 377
 378                         if (_cursor.fix_at) {
 379                                 /* Get all queued mouse events now in case we have to warp the cursor. In the
 380                                  * end, we only care about the current mouse position and not bygone events. */
 381                                 while (SDL_PeepEvents(&ev, 1, SDL_GETEVENT, SDL_MOUSEMOTION, SDL_MOUSEMOTION)) {
 382                                         x = ev.motion.x;
 383                                         y = ev.motion.y;
 384                                 }
 385                         }
 386
 387                         if (_cursor.UpdateCursorPosition(x, y)) {
 388                                 SDL_WarpMouseInWindow(this->sdl_window, _cursor.pos.x, _cursor.pos.y);
 389                         }
 390                         HandleMouseEvents();
 391                         break;
 392                 }
 393
 394                 case SDL_MOUSEWHEEL:
 395                         if (ev.wheel.y > 0) {
 396                                 _cursor.wheel--;
 397                         } else if (ev.wheel.y < 0) {
 398                                 _cursor.wheel++;
 399                         }
 400                         break;
 401
 402                 case SDL_MOUSEBUTTONDOWN:
 403                         if (_rightclick_emulate && SDL_GetModState() & KMOD_CTRL) {
 404                                 ev.button.button = SDL_BUTTON_RIGHT;
 405                         }
 406
 407                         switch (ev.button.button) {
 408                                 case SDL_BUTTON_LEFT:
 409                                         _left_button_down = true;
 410                                         break;
 411
 412                                 case SDL_BUTTON_RIGHT:
 413                                         _right_button_down = true;
 414                                         _right_button_clicked = true;
 415                                         break;
 416
 417                                 default: break;
 418                         }
 419                         HandleMouseEvents();
 420                         break;
 421
 422                 case SDL_MOUSEBUTTONUP:
 423                         if (_rightclick_emulate) {
 424                                 _right_button_down = false;
 425                                 _left_button_down = false;
 426                                 _left_button_clicked = false;
 427                         } else if (ev.button.button == SDL_BUTTON_LEFT) {
 428                                 _left_button_down = false;
 429                                 _left_button_clicked = false;
 430                         } else if (ev.button.button == SDL_BUTTON_RIGHT) {
 431                                 _right_button_down = false;
 432                         }
 433                         HandleMouseEvents();
 434                         break;
 435
 436                 case SDL_QUIT:
 437                         HandleExitGameRequest();
 438                         break;
 439
 440                 case SDL_KEYDOWN: // Toggle full-screen on ALT + ENTER/F
 441                         if ((ev.key.keysym.mod & (KMOD_ALT | KMOD_GUI)) &&
 442                                         (ev.key.keysym.sym == SDLK_RETURN || ev.key.keysym.sym == SDLK_f)) {
 443                                 if (ev.key.repeat == 0) ToggleFullScreen(!_fullscreen);
 444                         } else {
 445                                 char32_t character;
 446
 447                                 uint keycode = ConvertSdlKeyIntoMy(&ev.key.keysym, &character);
 448                                 // Only handle non-text keys here. Text is handled in
 449                                 // SDL_TEXTINPUT below.
 450                                 if (!this->edit_box_focused ||
 451                                         keycode == WKC_DELETE ||
 452                                         keycode == WKC_NUM_ENTER ||
 453                                         keycode == WKC_LEFT ||
 454                                         keycode == WKC_RIGHT ||
 455                                         keycode == WKC_UP ||
 456                                         keycode == WKC_DOWN ||
 457                                         keycode == WKC_HOME ||
 458                                         keycode == WKC_END ||
 459                                         keycode & WKC_META ||
 460                                         keycode & WKC_CTRL ||
 461                                         keycode & WKC_ALT ||
 462                                         (keycode >= WKC_F1 && keycode <= WKC_F12) ||
 463                                         !IsValidChar(character, CS_ALPHANUMERAL)) {
 464                                         HandleKeypress(keycode, character);
 465                                 }
 466                         }
 467                         break;
 468
 469                 case SDL_TEXTINPUT: {
 470                         if (!this->edit_box_focused) break;
 471                         SDL_Keycode kc = SDL_GetKeyFromName(ev.text.text);
 472                         uint keycode = ConvertSdlKeycodeIntoMy(kc);
 473
 474                         if (keycode == WKC_BACKQUOTE && FocusedWindowIsConsole()) {
 475                                 char32_t character;
 476                                 Utf8Decode(&character, ev.text.text);
 477                                 HandleKeypress(keycode, character);
 478                         } else {
 479                                 HandleTextInput(ev.text.text);
 480                         }
 481                         break;
 482                 }
 483                 case SDL_WINDOWEVENT: {
 484                         if (ev.window.event == SDL_WINDOWEVENT_EXPOSED) {
 485                                 // Force a redraw of the entire screen.
 486                                 this->MakeDirty(0, 0, _screen.width, _screen.height);
 487                         } else if (ev.window.event == SDL_WINDOWEVENT_SIZE_CHANGED) {
 488                                 int w = std::max(ev.window.data1, 64);
 489                                 int h = std::max(ev.window.data2, 64);
 490                                 CreateMainSurface(w, h, w != ev.window.data1 || h != ev.window.data2);
 491                         } else if (ev.window.event == SDL_WINDOWEVENT_ENTER) {
 492                                 // mouse entered the window, enable cursor
 493                                 _cursor.in_window = true;
 494                                 /* Ensure pointer lock will not occur. */
 495                                 SDL_SetRelativeMouseMode(SDL_FALSE);
 496                         } else if (ev.window.event == SDL_WINDOWEVENT_LEAVE) {
 497                                 // mouse left the window, undraw cursor
 498                                 UndrawMouseCursor();
 499                                 _cursor.in_window = false;
 500                         }
 501                         break;
 502                 }
 503         }
 504
 505         return true;
 506 }
 507
 508 static const char *InitializeSDL()
 509 {
 510         /* Check if the video-driver is already initialized. */
 511         if (SDL_WasInit(SDL_INIT_VIDEO) != 0) return nullptr;
 512
 513         if (SDL_InitSubSystem(SDL_INIT_VIDEO) < 0) return SDL_GetError();
 514         return nullptr;
 515 }
 516
 517 const char *VideoDriver_SDL_Base::Initialize()
 518 {
 519         this->UpdateAutoResolution();
 520
 521         const char *error = InitializeSDL();
 522         if (error != nullptr) return error;
 523
 524         FindResolutions();
 525         Debug(driver, 2, "Resolution for display: {}x{}", _cur_resolution.width, _cur_resolution.height);
 526
 527         return nullptr;
 528 }
 529
 530 const char *VideoDriver_SDL_Base::Start(const StringList &param)
 531 {
 532         if (BlitterFactory::GetCurrentBlitter()->GetScreenDepth() == 0) return "Only real blitters supported";
 533
 534         const char *error = this->Initialize();
 535         if (error != nullptr) return error;
 536
 537         this->startup_display = FindStartupDisplay(GetDriverParamInt(param, "display", -1));
 538
 539         if (!CreateMainSurface(_cur_resolution.width, _cur_resolution.height, false)) {
 540                 return SDL_GetError();
 541         }
 542
 543         const char *dname = SDL_GetCurrentVideoDriver();
 544         Debug(driver, 1, "SDL2: using driver '{}'", dname);
 545
 546         this->driver_info = this->GetName();
 547         this->driver_info += " (";
 548         this->driver_info += dname;
 549         this->driver_info += ")";
 550
 551         MarkWholeScreenDirty();
 552
 553         SDL_StopTextInput();
 554         this->edit_box_focused = false;
 555
 556 #ifdef __EMSCRIPTEN__
 557         this->is_game_threaded = false;
 558 #else
 559         this->is_game_threaded = !GetDriverParamBool(param, "no_threads") && !GetDriverParamBool(param, "no_thread");
 560 #endif
 561
 562         return nullptr;
 563 }
 564
 565 void VideoDriver_SDL_Base::Stop()
 566 {
 567         SDL_QuitSubSystem(SDL_INIT_VIDEO);
 568         if (SDL_WasInit(SDL_INIT_EVERYTHING) == 0) {
 569                 SDL_Quit(); // If there's nothing left, quit SDL
 570         }
 571 }
 572
 573 void VideoDriver_SDL_Base::InputLoop()
 574 {
 575         uint32_t mod = SDL_GetModState();
 576         const Uint8 *keys = SDL_GetKeyboardState(nullptr);
 577
 578         bool old_ctrl_pressed = _ctrl_pressed;
 579
 580         _ctrl_pressed  = !!(mod & KMOD_CTRL);
 581         _shift_pressed = !!(mod & KMOD_SHIFT);
 582
 583         /* Speedup when pressing tab, except when using ALT+TAB
 584          * to switch to another application. */
 585         this->fast_forward_key_pressed = keys[SDL_SCANCODE_TAB] && (mod & KMOD_ALT) == 0;
 586
 587         /* Determine which directional keys are down. */
 588         _dirkeys =
 589                 (keys[SDL_SCANCODE_LEFT]  ? 1 : 0) |
 590                 (keys[SDL_SCANCODE_UP]    ? 2 : 0) |
 591                 (keys[SDL_SCANCODE_RIGHT] ? 4 : 0) |
 592                 (keys[SDL_SCANCODE_DOWN]  ? 8 : 0);
 593
 594         if (old_ctrl_pressed != _ctrl_pressed) HandleCtrlChanged();
 595 }
 596
 597 void VideoDriver_SDL_Base::LoopOnce()
 598 {
 599         if (_exit_game) {
 600 #ifdef __EMSCRIPTEN__
 601                 /* Emscripten is event-driven, and as such the main loop is inside
 602                  * the browser. So if _exit_game goes true, the main loop ends (the
 603                  * cancel call), but we still have to call the cleanup that is
 604                  * normally done at the end of the main loop for non-Emscripten.
 605                  * After that, Emscripten just halts, and the HTML shows a nice
 606                  * "bye, see you next time" message. */
 607                 extern void PostMainLoop();
 608                 PostMainLoop();
 609
 610                 emscripten_cancel_main_loop();
 611                 emscripten_exit_pointerlock();
 612                 /* In effect, the game ends here. As emscripten_set_main_loop() caused
 613                  * the stack to be unwound, the code after MainLoop() in
 614                  * openttd_main() is never executed. */
 615                 if (_game_mode == GM_BOOTSTRAP) {
 616                         EM_ASM(if (window["openttd_bootstrap_reload"]) openttd_bootstrap_reload());
 617                 } else {
 618                         EM_ASM(if (window["openttd_exit"]) openttd_exit());
 619                 }
 620 #endif
 621                 return;
 622         }
 623
 624         this->Tick();
 625
 626 /* Emscripten is running an event-based mainloop; there is already some
 627  * downtime between each iteration, so no need to sleep. */
 628 #ifndef __EMSCRIPTEN__
 629         this->SleepTillNextTick();
 630 #endif
 631 }
 632
 633 void VideoDriver_SDL_Base::MainLoop()
 634 {
 635 #ifdef __EMSCRIPTEN__
 636         /* Run the main loop event-driven, based on RequestAnimationFrame. */
 637         emscripten_set_main_loop_arg(&this->EmscriptenLoop, this, 0, 1);
 638 #else
 639         this->StartGameThread();
 640
 641         while (!_exit_game) {
 642                 LoopOnce();
 643         }
 644
 645         this->StopGameThread();
 646 #endif
 647 }
 648
 649 bool VideoDriver_SDL_Base::ChangeResolution(int w, int h)
 650 {
 651         return CreateMainSurface(w, h, true);
 652 }
 653
 654 bool VideoDriver_SDL_Base::ToggleFullscreen(bool fullscreen)
 655 {
 656         /* Remember current window size */
 657         int w, h;
 658         SDL_GetWindowSize(this->sdl_window, &w, &h);
 659
 660         if (fullscreen) {
 661                 /* Find fullscreen window size */
 662                 SDL_DisplayMode dm;
 663                 if (SDL_GetCurrentDisplayMode(SDL_GetWindowDisplayIndex(this->sdl_window), &dm) < 0) {
 664                         Debug(driver, 0, "SDL_GetCurrentDisplayMode() failed: {}", SDL_GetError());
 665                 } else {
 666                         SDL_SetWindowSize(this->sdl_window, dm.w, dm.h);
 667                 }
 668         }
 669
 670         Debug(driver, 1, "SDL2: Setting {}", fullscreen ? "fullscreen" : "windowed");
 671         int ret = SDL_SetWindowFullscreen(this->sdl_window, fullscreen ? SDL_WINDOW_FULLSCREEN : 0);
 672         if (ret == 0) {
 673                 /* Switching resolution succeeded, set fullscreen value of window. */
 674                 _fullscreen = fullscreen;
 675                 if (!fullscreen) SDL_SetWindowSize(this->sdl_window, w, h);
 676         } else {
 677                 Debug(driver, 0, "SDL_SetWindowFullscreen() failed: {}", SDL_GetError());
 678         }
 679
 680         InvalidateWindowClassesData(WC_GAME_OPTIONS, 3);
 681         return ret == 0;
 682 }
 683
 684 bool VideoDriver_SDL_Base::AfterBlitterChange()
 685 {
 686         assert(BlitterFactory::GetCurrentBlitter()->GetScreenDepth() != 0);
 687         int w, h;
 688         SDL_GetWindowSize(this->sdl_window, &w, &h);
 689         return CreateMainSurface(w, h, false);
 690 }
 691
 692 Dimension VideoDriver_SDL_Base::GetScreenSize() const
 693 {
 694         SDL_DisplayMode mode;
 695         if (SDL_GetCurrentDisplayMode(this->startup_display, &mode) != 0) return VideoDriver::GetScreenSize();
 696
 697         return { static_cast<uint>(mode.w), static_cast<uint>(mode.h) };
 698 }
 699
 700 bool VideoDriver_SDL_Base::LockVideoBuffer()
 701 {
 702         if (this->buffer_locked) return false;
 703         this->buffer_locked = true;
 704
 705         _screen.dst_ptr = this->GetVideoPointer();
 706         assert(_screen.dst_ptr != nullptr);
 707
 708         return true;
 709 }
 710
 711 void VideoDriver_SDL_Base::UnlockVideoBuffer()
 712 {
 713         if (_screen.dst_ptr != nullptr) {
 714                 /* Hand video buffer back to the drawing backend. */
 715                 this->ReleaseVideoPointer();
 716                 _screen.dst_ptr = nullptr;
 717         }
 718
 719         this->buffer_locked = false;
 720 }