summaryrefslogtreecommitdiff
path: root/src/video/sdl2_v.cpp
blob: 33c2b96b18e7eec89bb7a62a2e25399d91d1dae6 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
/*
 * This file is part of OpenTTD.
 * 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.
 * 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.
 * 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/>.
 */

/** @file sdl2_v.cpp Implementation of the SDL2 video driver. */

#include "../stdafx.h"
#include "../openttd.h"
#include "../gfx_func.h"
#include "../rev.h"
#include "../blitter/factory.hpp"
#include "../network/network.h"
#include "../thread.h"
#include "../progress.h"
#include "../core/random_func.hpp"
#include "../core/math_func.hpp"
#include "../fileio_func.h"
#include "../framerate_type.h"
#include "../window_func.h"
#include "sdl2_v.h"
#include <SDL.h>
#include <mutex>
#include <condition_variable>
#ifdef __EMSCRIPTEN__
#	include <emscripten.h>
#	include <emscripten/html5.h>
#endif

#include "../safeguards.h"

static FVideoDriver_SDL iFVideoDriver_SDL;

static SDL_Window *_sdl_window;
static SDL_Surface *_sdl_surface;
static SDL_Surface *_sdl_realscreen;

/** Whether the drawing is/may be done in a separate thread. */
static bool _draw_threaded;
/** Mutex to keep the access to the shared memory controlled. */
static std::recursive_mutex *_draw_mutex = nullptr;
/** Signal to draw the next frame. */
static std::condition_variable_any *_draw_signal = nullptr;
/** Should we keep continue drawing? */
static volatile bool _draw_continue;
static Palette _local_palette;
static SDL_Palette *_sdl_palette;

#ifdef __EMSCRIPTEN__
/** Whether we just had a window-enter event. */
static bool _cursor_new_in_window = false;
#endif

#define MAX_DIRTY_RECTS 100
static SDL_Rect _dirty_rects[MAX_DIRTY_RECTS];
static int _num_dirty_rects;

/* Size of window */
static int _window_size_w;
static int _window_size_h;

void VideoDriver_SDL::MakeDirty(int left, int top, int width, int height)
{
	if (_num_dirty_rects < MAX_DIRTY_RECTS) {
		_dirty_rects[_num_dirty_rects].x = left;
		_dirty_rects[_num_dirty_rects].y = top;
		_dirty_rects[_num_dirty_rects].w = width;
		_dirty_rects[_num_dirty_rects].h = height;
	}
	_num_dirty_rects++;
}

static void UpdatePalette(bool init = false)
{
	SDL_Color pal[256];

	for (int i = 0; i != _local_palette.count_dirty; i++) {
		pal[i].r = _local_palette.palette[_local_palette.first_dirty + i].r;
		pal[i].g = _local_palette.palette[_local_palette.first_dirty + i].g;
		pal[i].b = _local_palette.palette[_local_palette.first_dirty + i].b;
		pal[i].a = 0;
	}

	SDL_SetPaletteColors(_sdl_palette, pal, _local_palette.first_dirty, _local_palette.count_dirty);
	SDL_SetSurfacePalette(_sdl_surface, _sdl_palette);

	if (_sdl_surface != _sdl_realscreen && init) {
		/* When using a shadow surface, also set our palette on the real screen. This lets SDL
		 * allocate as many colors (or approximations) as
		 * possible, instead of using only the default SDL
		 * palette. This allows us to get more colors exactly
		 * right and might allow using better approximations for
		 * other colors.
		 *
		 * Note that colors allocations are tried in-order, so
		 * this favors colors further up into the palette. Also
		 * note that if two colors from the same animation
		 * sequence are approximated using the same color, that
		 * animation will stop working.
		 *
		 * Since changing the system palette causes the colours
		 * to change right away, and allocations might
		 * drastically change, we can't use this for animation,
		 * since that could cause weird coloring between the
		 * palette change and the blitting below, so we only set
		 * the real palette during initialisation.
		 */
		SDL_SetSurfacePalette(_sdl_realscreen, _sdl_palette);
	}

	if (_sdl_surface != _sdl_realscreen && !init) {
		/* We're not using real hardware palette, but are letting SDL
		 * approximate the palette during shadow -> screen copy. To
		 * change the palette, we need to recopy the entire screen.
		 *
		 * Note that this operation can slow down the rendering
		 * considerably, especially since changing the shadow
		 * palette will need the next blit to re-detect the
		 * best mapping of shadow palette colors to real palette
		 * colors from scratch.
		 */
		SDL_BlitSurface(_sdl_surface, nullptr, _sdl_realscreen, nullptr);
		SDL_UpdateWindowSurface(_sdl_window);
	}
}

static void InitPalette()
{
	_cur_palette.first_dirty = 0;
	_cur_palette.count_dirty = 256;
	_local_palette = _cur_palette;
	UpdatePalette(true);
}

static void CheckPaletteAnim()
{
	if (_cur_palette.count_dirty != 0) {
		Blitter *blitter = BlitterFactory::GetCurrentBlitter();

		switch (blitter->UsePaletteAnimation()) {
			case Blitter::PALETTE_ANIMATION_VIDEO_BACKEND:
				UpdatePalette();
				break;

			case Blitter::PALETTE_ANIMATION_BLITTER:
				blitter->PaletteAnimate(_local_palette);
				break;

			case Blitter::PALETTE_ANIMATION_NONE:
				break;

			default:
				NOT_REACHED();
		}
		_cur_palette.count_dirty = 0;
	}
}

static void DrawSurfaceToScreen()
{
	PerformanceMeasurer framerate(PFE_VIDEO);

	int n = _num_dirty_rects;
	if (n == 0) return;

	_num_dirty_rects = 0;

	if (n > MAX_DIRTY_RECTS) {
		if (_sdl_surface != _sdl_realscreen) {
			SDL_BlitSurface(_sdl_surface, nullptr, _sdl_realscreen, nullptr);
		}

		SDL_UpdateWindowSurface(_sdl_window);
	} else {
		if (_sdl_surface != _sdl_realscreen) {
			for (int i = 0; i < n; i++) {
				SDL_BlitSurface(_sdl_surface, &_dirty_rects[i], _sdl_realscreen, &_dirty_rects[i]);
			}
		}

		SDL_UpdateWindowSurfaceRects(_sdl_window, _dirty_rects, n);
	}
}

static void DrawSurfaceToScreenThread()
{
	/* First tell the main thread we're started */
	std::unique_lock<std::recursive_mutex> lock(*_draw_mutex);
	_draw_signal->notify_one();

	/* Now wait for the first thing to draw! */
	_draw_signal->wait(*_draw_mutex);

	while (_draw_continue) {
		CheckPaletteAnim();
		/* Then just draw and wait till we stop */
		DrawSurfaceToScreen();
		_draw_signal->wait(lock);
	}
}

static const Dimension default_resolutions[] = {
	{  640,  480 },
	{  800,  600 },
	{ 1024,  768 },
	{ 1152,  864 },
	{ 1280,  800 },
	{ 1280,  960 },
	{ 1280, 1024 },
	{ 1400, 1050 },
	{ 1600, 1200 },
	{ 1680, 1050 },
	{ 1920, 1200 }
};

static void FindResolutions()
{
	_resolutions.clear();

	for (int i = 0; i < SDL_GetNumDisplayModes(0); i++) {
		SDL_DisplayMode mode;
		SDL_GetDisplayMode(0, i, &mode);

		if (mode.w < 640 || mode.h < 480) continue;
		if (std::find(_resolutions.begin(), _resolutions.end(), Dimension(mode.w, mode.h)) != _resolutions.end()) continue;
		_resolutions.emplace_back(mode.w, mode.h);
	}

	/* We have found no resolutions, show the default list */
	if (_resolutions.empty()) {
		_resolutions.assign(std::begin(default_resolutions), std::end(default_resolutions));
	}

	SortResolutions();
}

static void GetAvailableVideoMode(uint *w, uint *h)
{
	/* All modes available? */
	if (!_fullscreen || _resolutions.empty()) return;

	/* Is the wanted mode among the available modes? */
	if (std::find(_resolutions.begin(), _resolutions.end(), Dimension(*w, *h)) != _resolutions.end()) return;

	/* Use the closest possible resolution */
	uint best = 0;
	uint delta = Delta(_resolutions[0].width, *w) * Delta(_resolutions[0].height, *h);
	for (uint i = 1; i != _resolutions.size(); ++i) {
		uint newdelta = Delta(_resolutions[i].width, *w) * Delta(_resolutions[i].height, *h);
		if (newdelta < delta) {
			best = i;
			delta = newdelta;
		}
	}
	*w = _resolutions[best].width;
	*h = _resolutions[best].height;
}

static uint FindStartupDisplay(uint startup_display)
{
	int num_displays = SDL_GetNumVideoDisplays();

	/* If the user indicated a valid monitor, use that. */
	if (IsInsideBS(startup_display, 0, num_displays)) return startup_display;

	/* Mouse position decides which display to use. */
	int mx, my;
	SDL_GetGlobalMouseState(&mx, &my);
	for (int display = 0; display < num_displays; ++display) {
		SDL_Rect r;
		if (SDL_GetDisplayBounds(display, &r) == 0 && IsInsideBS(mx, r.x, r.w) && IsInsideBS(my, r.y, r.h)) {
			DEBUG(driver, 1, "SDL2: Mouse is at (%d, %d), use display %d (%d, %d, %d, %d)", mx, my, display, r.x, r.y, r.w, r.h);
			return display;
		}
	}

	return 0;
}

bool VideoDriver_SDL::CreateMainSurface(uint w, uint h, bool resize)
{
	SDL_Surface *newscreen;
	int bpp = BlitterFactory::GetCurrentBlitter()->GetScreenDepth();

	GetAvailableVideoMode(&w, &h);

	DEBUG(driver, 1, "SDL2: using mode %ux%ux%d", w, h, bpp);

	/* Free any previously allocated shadow surface */
	if (_sdl_surface != nullptr && _sdl_surface != _sdl_realscreen) SDL_FreeSurface(_sdl_surface);

	if (_sdl_window == nullptr) {
		Uint32 flags = SDL_WINDOW_SHOWN | SDL_WINDOW_RESIZABLE;

		if (_fullscreen) {
			flags |= SDL_WINDOW_FULLSCREEN;
		}

		int x = SDL_WINDOWPOS_UNDEFINED, y = SDL_WINDOWPOS_UNDEFINED;
		SDL_Rect r;
		if (SDL_GetDisplayBounds(this->startup_display, &r) == 0) {
			x = r.x + std::max(0, r.w - static_cast<int>(w)) / 2;
			y = r.y + std::max(0, r.h - static_cast<int>(h)) / 4; // decent desktops have taskbars at the bottom
		}

		char caption[50];
		seprintf(caption, lastof(caption), "OpenTTD %s", _openttd_revision);
		_sdl_window = SDL_CreateWindow(
			caption,
			x, y,
			w, h,
			flags);

		if (_sdl_window == nullptr) {
			DEBUG(driver, 0, "SDL2: Couldn't allocate a window to draw on");
			return false;
		}

		std::string icon_path = FioFindFullPath(BASESET_DIR, "openttd.32.bmp");
		if (!icon_path.empty()) {
			/* Give the application an icon */
			SDL_Surface *icon = SDL_LoadBMP(icon_path.c_str());
			if (icon != nullptr) {
				/* Get the colourkey, which will be magenta */
				uint32 rgbmap = SDL_MapRGB(icon->format, 255, 0, 255);

				SDL_SetColorKey(icon, SDL_TRUE, rgbmap);
				SDL_SetWindowIcon(_sdl_window, icon);
				SDL_FreeSurface(icon);
			}
		}
	}

	if (resize) SDL_SetWindowSize(_sdl_window, w, h);

	newscreen = SDL_GetWindowSurface(_sdl_window);
	if (newscreen == NULL) {
		DEBUG(driver, 0, "SDL2: Couldn't get window surface: %s", SDL_GetError());
		return false;
	}

	_sdl_realscreen = newscreen;

	if (bpp == 8) {
		newscreen = SDL_CreateRGBSurface(0, w, h, 8, 0, 0, 0, 0);

		if (newscreen == nullptr) {
			DEBUG(driver, 0, "SDL2: Couldn't allocate shadow surface: %s", SDL_GetError());
			return false;
		}
	}

	if (_sdl_palette == nullptr) {
		_sdl_palette = SDL_AllocPalette(256);
	}

	if (_sdl_palette == nullptr) {
		DEBUG(driver, 0, "SDL_AllocPalette() failed: %s", SDL_GetError());
		return false;
	}

	/* Delay drawing for this cycle; the next cycle will redraw the whole screen */
	_num_dirty_rects = 0;

	_screen.width = newscreen->w;
	_screen.height = newscreen->h;
	_screen.pitch = newscreen->pitch / (bpp / 8);
	_screen.dst_ptr = newscreen->pixels;
	_sdl_surface = newscreen;

	/* When in full screen, we will always have the mouse cursor
	 * within the window, even though SDL does not give us the
	 * appropriate event to know this. */
	if (_fullscreen) _cursor.in_window = true;

	BlitterFactory::GetCurrentBlitter()->PostResize();

	InitPalette();
	GameSizeChanged();
	return true;
}

bool VideoDriver_SDL::ClaimMousePointer()
{
	SDL_ShowCursor(0);
#ifdef __EMSCRIPTEN__
	SDL_SetRelativeMouseMode(SDL_TRUE);
#endif
	return true;
}

/**
 * This is called to indicate that an edit box has gained focus, text input mode should be enabled.
 */
void VideoDriver_SDL::EditBoxGainedFocus()
{
	if (!this->edit_box_focused) {
		SDL_StartTextInput();
		this->edit_box_focused = true;
	}
}

/**
 * This is called to indicate that an edit box has lost focus, text input mode should be disabled.
 */
void VideoDriver_SDL::EditBoxLostFocus()
{
	if (this->edit_box_focused) {
		SDL_StopTextInput();
		this->edit_box_focused = false;
	}
}


struct VkMapping {
	SDL_Keycode vk_from;
	byte vk_count;
	byte map_to;
	bool unprintable;
};

#define AS(x, z) {x, 0, z, false}
#define AM(x, y, z, w) {x, (byte)(y - x), z, false}
#define AS_UP(x, z) {x, 0, z, true}
#define AM_UP(x, y, z, w) {x, (byte)(y - x), z, true}

static const VkMapping _vk_mapping[] = {
	/* Pageup stuff + up/down */
	AS_UP(SDLK_PAGEUP,   WKC_PAGEUP),
	AS_UP(SDLK_PAGEDOWN, WKC_PAGEDOWN),
	AS_UP(SDLK_UP,     WKC_UP),
	AS_UP(SDLK_DOWN,   WKC_DOWN),
	AS_UP(SDLK_LEFT,   WKC_LEFT),
	AS_UP(SDLK_RIGHT,  WKC_RIGHT),

	AS_UP(SDLK_HOME,   WKC_HOME),
	AS_UP(SDLK_END,    WKC_END),

	AS_UP(SDLK_INSERT, WKC_INSERT),
	AS_UP(SDLK_DELETE, WKC_DELETE),

	/* Map letters & digits */
	AM(SDLK_a, SDLK_z, 'A', 'Z'),
	AM(SDLK_0, SDLK_9, '0', '9'),

	AS_UP(SDLK_ESCAPE,    WKC_ESC),
	AS_UP(SDLK_PAUSE,     WKC_PAUSE),
	AS_UP(SDLK_BACKSPACE, WKC_BACKSPACE),

	AS(SDLK_SPACE,     WKC_SPACE),
	AS(SDLK_RETURN,    WKC_RETURN),
	AS(SDLK_TAB,       WKC_TAB),

	/* Function keys */
	AM_UP(SDLK_F1, SDLK_F12, WKC_F1, WKC_F12),

	/* Numeric part. */
	AM(SDLK_KP_0, SDLK_KP_9, '0', '9'),
	AS(SDLK_KP_DIVIDE,   WKC_NUM_DIV),
	AS(SDLK_KP_MULTIPLY, WKC_NUM_MUL),
	AS(SDLK_KP_MINUS,    WKC_NUM_MINUS),
	AS(SDLK_KP_PLUS,     WKC_NUM_PLUS),
	AS(SDLK_KP_ENTER,    WKC_NUM_ENTER),
	AS(SDLK_KP_PERIOD,   WKC_NUM_DECIMAL),

	/* Other non-letter keys */
	AS(SDLK_SLASH,        WKC_SLASH),
	AS(SDLK_SEMICOLON,    WKC_SEMICOLON),
	AS(SDLK_EQUALS,       WKC_EQUALS),
	AS(SDLK_LEFTBRACKET,  WKC_L_BRACKET),
	AS(SDLK_BACKSLASH,    WKC_BACKSLASH),
	AS(SDLK_RIGHTBRACKET, WKC_R_BRACKET),

	AS(SDLK_QUOTE,   WKC_SINGLEQUOTE),
	AS(SDLK_COMMA,   WKC_COMMA),
	AS(SDLK_MINUS,   WKC_MINUS),
	AS(SDLK_PERIOD,  WKC_PERIOD)
};

static uint ConvertSdlKeyIntoMy(SDL_Keysym *sym, WChar *character)
{
	const VkMapping *map;
	uint key = 0;
	bool unprintable = false;

	for (map = _vk_mapping; map != endof(_vk_mapping); ++map) {
		if ((uint)(sym->sym - map->vk_from) <= map->vk_count) {
			key = sym->sym - map->vk_from + map->map_to;
			unprintable = map->unprintable;
			break;
		}
	}

	/* check scancode for BACKQUOTE key, because we want the key left of "1", not anything else (on non-US keyboards) */
	if (sym->scancode == SDL_SCANCODE_GRAVE) key = WKC_BACKQUOTE;

	/* META are the command keys on mac */
	if (sym->mod & KMOD_GUI)   key |= WKC_META;
	if (sym->mod & KMOD_SHIFT) key |= WKC_SHIFT;
	if (sym->mod & KMOD_CTRL)  key |= WKC_CTRL;
	if (sym->mod & KMOD_ALT)   key |= WKC_ALT;

	/* The mod keys have no character. Prevent '?' */
	if (sym->mod & KMOD_GUI ||
		sym->mod & KMOD_CTRL ||
		sym->mod & KMOD_ALT ||
		unprintable) {
		*character = WKC_NONE;
	} else {
		*character = sym->sym;
	}

	return key;
}

/**
 * Like ConvertSdlKeyIntoMy(), but takes an SDL_Keycode as input
 * instead of an SDL_Keysym.
 */
static uint ConvertSdlKeycodeIntoMy(SDL_Keycode kc)
{
	const VkMapping *map;
	uint key = 0;

	for (map = _vk_mapping; map != endof(_vk_mapping); ++map) {
		if ((uint)(kc - map->vk_from) <= map->vk_count) {
			key = kc - map->vk_from + map->map_to;
			break;
		}
	}

	/* check scancode for BACKQUOTE key, because we want the key left
	   of "1", not anything else (on non-US keyboards) */
	SDL_Scancode sc = SDL_GetScancodeFromKey(kc);
	if (sc == SDL_SCANCODE_GRAVE) key = WKC_BACKQUOTE;

	return key;
}

int VideoDriver_SDL::PollEvent()
{
	SDL_Event ev;

	if (!SDL_PollEvent(&ev)) return -2;

	switch (ev.type) {
		case SDL_MOUSEMOTION:
#ifdef __EMSCRIPTEN__
			if (_cursor_new_in_window) {
				/* The cursor just moved into the window; this means we don't
				* know the absolutely position yet to move relative from.
				* Before this time, SDL didn't know it either, and this is
				* why we postpone it till now. Update the absolute position
				* for this once, and work relative after. */
				_cursor.pos.x = ev.motion.x;
				_cursor.pos.y = ev.motion.y;
				_cursor.dirty = true;

				_cursor_new_in_window = false;
				SDL_SetRelativeMouseMode(SDL_TRUE);
			} else {
				_cursor.UpdateCursorPositionRelative(ev.motion.xrel, ev.motion.yrel);
			}
#else
			if (_cursor.UpdateCursorPosition(ev.motion.x, ev.motion.y, true)) {
				SDL_WarpMouseInWindow(_sdl_window, _cursor.pos.x, _cursor.pos.y);
			}
#endif
			HandleMouseEvents();
			break;

		case SDL_MOUSEWHEEL:
			if (ev.wheel.y > 0) {
				_cursor.wheel--;
			} else if (ev.wheel.y < 0) {
				_cursor.wheel++;
			}
			break;

		case SDL_MOUSEBUTTONDOWN:
			if (_rightclick_emulate && SDL_GetModState() & KMOD_CTRL) {
				ev.button.button = SDL_BUTTON_RIGHT;
			}

			switch (ev.button.button) {
				case SDL_BUTTON_LEFT:
					_left_button_down = true;
					break;

				case SDL_BUTTON_RIGHT:
					_right_button_down = true;
					_right_button_clicked = true;
					break;

				default: break;
			}
			HandleMouseEvents();
			break;

		case SDL_MOUSEBUTTONUP:
			if (_rightclick_emulate) {
				_right_button_down = false;
				_left_button_down = false;
				_left_button_clicked = false;
			} else if (ev.button.button == SDL_BUTTON_LEFT) {
				_left_button_down = false;
				_left_button_clicked = false;
			} else if (ev.button.button == SDL_BUTTON_RIGHT) {
				_right_button_down = false;
			}
			HandleMouseEvents();
			break;

		case SDL_QUIT:
			HandleExitGameRequest();
			break;

		case SDL_KEYDOWN: // Toggle full-screen on ALT + ENTER/F
			if ((ev.key.keysym.mod & (KMOD_ALT | KMOD_GUI)) &&
					(ev.key.keysym.sym == SDLK_RETURN || ev.key.keysym.sym == SDLK_f)) {
				if (ev.key.repeat == 0) ToggleFullScreen(!_fullscreen);
			} else {
				WChar character;

				uint keycode = ConvertSdlKeyIntoMy(&ev.key.keysym, &character);
				// Only handle non-text keys here. Text is handled in
				// SDL_TEXTINPUT below.
				if (!this->edit_box_focused ||
					keycode == WKC_DELETE ||
					keycode == WKC_NUM_ENTER ||
					keycode == WKC_LEFT ||
					keycode == WKC_RIGHT ||
					keycode == WKC_UP ||
					keycode == WKC_DOWN ||
					keycode == WKC_HOME ||
					keycode == WKC_END ||
					keycode & WKC_META ||
					keycode & WKC_CTRL ||
					keycode & WKC_ALT ||
					(keycode >= WKC_F1 && keycode <= WKC_F12) ||
					!IsValidChar(character, CS_ALPHANUMERAL)) {
					HandleKeypress(keycode, character);
				}
			}
			break;

		case SDL_TEXTINPUT: {
			if (!this->edit_box_focused) break;
			SDL_Keycode kc = SDL_GetKeyFromName(ev.text.text);
			uint keycode = ConvertSdlKeycodeIntoMy(kc);

			if (keycode == WKC_BACKQUOTE && FocusedWindowIsConsole()) {
				WChar character;
				Utf8Decode(&character, ev.text.text);
				HandleKeypress(keycode, character);
			} else {
				HandleTextInput(ev.text.text);
			}
			break;
		}
		case SDL_WINDOWEVENT: {
			if (ev.window.event == SDL_WINDOWEVENT_EXPOSED) {
				// Force a redraw of the entire screen.
				_num_dirty_rects = MAX_DIRTY_RECTS + 1;
			} else if (ev.window.event == SDL_WINDOWEVENT_SIZE_CHANGED) {
				int w = std::max(ev.window.data1, 64);
				int h = std::max(ev.window.data2, 64);
				CreateMainSurface(w, h, w != ev.window.data1 || h != ev.window.data2);
			} else if (ev.window.event == SDL_WINDOWEVENT_ENTER) {
				// mouse entered the window, enable cursor
				_cursor.in_window = true;
#ifdef __EMSCRIPTEN__
				/* Disable relative mouse mode for the first mouse motion,
				 * so we can pick up the absolutely position again. */
				_cursor_new_in_window = true;
				SDL_SetRelativeMouseMode(SDL_FALSE);
#endif
			} else if (ev.window.event == SDL_WINDOWEVENT_LEAVE) {
				// mouse left the window, undraw cursor
				UndrawMouseCursor();
				_cursor.in_window = false;
			}
			break;
		}
	}
	return -1;
}

const char *VideoDriver_SDL::Start(const StringList &parm)
{
	if (BlitterFactory::GetCurrentBlitter()->GetScreenDepth() == 0) return "Only real blitters supported";

	/* Explicitly disable hardware acceleration. Enabling this causes
	 * UpdateWindowSurface() to update the window's texture instead of
	 * its surface. */
	SDL_SetHint(SDL_HINT_FRAMEBUFFER_ACCELERATION, "0");
	SDL_SetHint(SDL_HINT_MOUSE_RELATIVE_MODE_WARP, "1");

	/* Just on the offchance the audio subsystem started before the video system,
	 * check whether any part of SDL has been initialised before getting here.
	 * Slightly duplicated with sound/sdl_s.cpp */
	int ret_code = 0;
	if (SDL_WasInit(SDL_INIT_VIDEO) == 0) {
		ret_code = SDL_InitSubSystem(SDL_INIT_VIDEO);
	}
	if (ret_code < 0) return SDL_GetError();

	this->UpdateAutoResolution();

	FindResolutions();

	this->startup_display = FindStartupDisplay(GetDriverParamInt(parm, "display", -1));

	if (!CreateMainSurface(_cur_resolution.width, _cur_resolution.height, false)) {
		return SDL_GetError();
	}

	const char *dname = SDL_GetCurrentVideoDriver();
	DEBUG(driver, 1, "SDL2: using driver '%s'", dname);

	MarkWholeScreenDirty();

	_draw_threaded = !GetDriverParamBool(parm, "no_threads") && !GetDriverParamBool(parm, "no_thread");

	SDL_StopTextInput();
	this->edit_box_focused = false;

	return nullptr;
}

void VideoDriver_SDL::Stop()
{
	SDL_QuitSubSystem(SDL_INIT_VIDEO);
	if (SDL_WasInit(SDL_INIT_EVERYTHING) == 0) {
		SDL_Quit(); // If there's nothing left, quit SDL
	}
}

void VideoDriver_SDL::LoopOnce()
{
	uint32 mod;
	int numkeys;
	const Uint8 *keys;
	uint32 prev_cur_ticks = cur_ticks; // to check for wrapping
	InteractiveRandom(); // randomness

	while (PollEvent() == -1) {}
	if (_exit_game) {
#ifdef __EMSCRIPTEN__
		/* Emscripten is event-driven, and as such the main loop is inside
		 * the browser. So if _exit_game goes true, the main loop ends (the
		 * cancel call), but we still have to call the cleanup that is
		 * normally done at the end of the main loop for non-Emscripten.
		 * After that, Emscripten just halts, and the HTML shows a nice
		 * "bye, see you next time" message. */
		emscripten_cancel_main_loop();
		MainLoopCleanup();
#endif
		return;
	}

	mod = SDL_GetModState();
	keys = SDL_GetKeyboardState(&numkeys);

#if defined(_DEBUG)
	if (_shift_pressed)
#else
	/* Speedup when pressing tab, except when using ALT+TAB
	 * to switch to another application */
	if (keys[SDL_SCANCODE_TAB] && (mod & KMOD_ALT) == 0)
#endif /* defined(_DEBUG) */
	{
		if (!_networking && _game_mode != GM_MENU) _fast_forward |= 2;
	} else if (_fast_forward & 2) {
		_fast_forward = 0;
	}

	cur_ticks = SDL_GetTicks();
	if (SDL_TICKS_PASSED(cur_ticks, next_tick) || (_fast_forward && !_pause_mode) || cur_ticks < prev_cur_ticks) {
		_realtime_tick += cur_ticks - last_cur_ticks;
		last_cur_ticks = cur_ticks;
		next_tick = cur_ticks + MILLISECONDS_PER_TICK;

		bool old_ctrl_pressed = _ctrl_pressed;

		_ctrl_pressed  = !!(mod & KMOD_CTRL);
		_shift_pressed = !!(mod & KMOD_SHIFT);

		/* determine which directional keys are down */
		_dirkeys =
			(keys[SDL_SCANCODE_LEFT]  ? 1 : 0) |
			(keys[SDL_SCANCODE_UP]    ? 2 : 0) |
			(keys[SDL_SCANCODE_RIGHT] ? 4 : 0) |
			(keys[SDL_SCANCODE_DOWN]  ? 8 : 0);
		if (old_ctrl_pressed != _ctrl_pressed) HandleCtrlChanged();

		/* The gameloop is the part that can run asynchronously. The rest
		 * except sleeping can't. */
		if (_draw_mutex != nullptr) draw_lock.unlock();

		GameLoop();

		if (_draw_mutex != nullptr) draw_lock.lock();

		UpdateWindows();
		_local_palette = _cur_palette;
	} else {
		/* Release the thread while sleeping */
		if (_draw_mutex != nullptr) {
			draw_lock.unlock();
			CSleep(1);
			draw_lock.lock();
		} else {
/* Emscripten is running an event-based mainloop; there is already some
 * downtime between each iteration, so no need to sleep. */
#ifndef __EMSCRIPTEN__
			CSleep(1);
#endif
		}

		NetworkDrawChatMessage();
		DrawMouseCursor();
	}

	/* End of the critical part. */
	if (_draw_mutex != nullptr && !HasModalProgress()) {
		_draw_signal->notify_one();
	} else {
		/* Oh, we didn't have threads, then just draw unthreaded */
		CheckPaletteAnim();
		DrawSurfaceToScreen();
	}
}

void VideoDriver_SDL::MainLoop()
{
	cur_ticks = SDL_GetTicks();
	last_cur_ticks = cur_ticks;
	next_tick = cur_ticks + MILLISECONDS_PER_TICK;

	CheckPaletteAnim();

	if (_draw_threaded) {
		/* Initialise the mutex first, because that's the thing we *need*
		 * directly in the newly created thread. */
		_draw_mutex = new std::recursive_mutex();
		if (_draw_mutex == nullptr) {
			_draw_threaded = false;
		} else {
			draw_lock = std::unique_lock<std::recursive_mutex>(*_draw_mutex);
			_draw_signal = new std::condition_variable_any();
			_draw_continue = true;

			_draw_threaded = StartNewThread(&draw_thread, "ottd:draw-sdl", &DrawSurfaceToScreenThread);

			/* Free the mutex if we won't be able to use it. */
			if (!_draw_threaded) {
				draw_lock.unlock();
				draw_lock.release();
				delete _draw_mutex;
				delete _draw_signal;
				_draw_mutex = nullptr;
				_draw_signal = nullptr;
			} else {
				/* Wait till the draw mutex has started itself. */
				_draw_signal->wait(*_draw_mutex);
			}
		}
	}

	DEBUG(driver, 1, "SDL2: using %sthreads", _draw_threaded ? "" : "no ");

#ifdef __EMSCRIPTEN__
	/* Run the main loop event-driven, based on RequestAnimationFrame. */
	emscripten_set_main_loop_arg(&this->EmscriptenLoop, this, 0, 1);
#else
	while (!_exit_game) {
		LoopOnce();
	}

	MainLoopCleanup();
#endif
}

void VideoDriver_SDL::MainLoopCleanup()
{
	if (_draw_mutex != nullptr) {
		_draw_continue = false;
		/* Sending signal if there is no thread blocked
		 * is very valid and results in noop */
		_draw_signal->notify_one();
		if (draw_lock.owns_lock()) draw_lock.unlock();
		draw_lock.release();
		draw_thread.join();

		delete _draw_mutex;
		delete _draw_signal;

		_draw_mutex = nullptr;
		_draw_signal = nullptr;
	}

#ifdef __EMSCRIPTEN__
	emscripten_exit_pointerlock();
	/* In effect, the game ends here. As emscripten_set_main_loop() caused
	 * the stack to be unwound, the code after MainLoop() in
	 * openttd_main() is never executed. */
	EM_ASM(if (window["openttd_syncfs"]) openttd_syncfs());
	EM_ASM(if (window["openttd_exit"]) openttd_exit());
#endif
}

bool VideoDriver_SDL::ChangeResolution(int w, int h)
{
	std::unique_lock<std::recursive_mutex> lock;
	if (_draw_mutex != nullptr) lock = std::unique_lock<std::recursive_mutex>(*_draw_mutex);

	return CreateMainSurface(w, h, true);
}

bool VideoDriver_SDL::ToggleFullscreen(bool fullscreen)
{
	std::unique_lock<std::recursive_mutex> lock;
	if (_draw_mutex != nullptr) lock = std::unique_lock<std::recursive_mutex>(*_draw_mutex);

	/* Remember current window size */
	if (fullscreen) {
		SDL_GetWindowSize(_sdl_window, &_window_size_w, &_window_size_h);

		/* Find fullscreen window size */
		SDL_DisplayMode dm;
		if (SDL_GetCurrentDisplayMode(0, &dm) < 0) {
			DEBUG(driver, 0, "SDL_GetCurrentDisplayMode() failed: %s", SDL_GetError());
		} else {
			SDL_SetWindowSize(_sdl_window, dm.w, dm.h);
		}
	}

	DEBUG(driver, 1, "SDL2: Setting %s", fullscreen ? "fullscreen" : "windowed");
	int ret = SDL_SetWindowFullscreen(_sdl_window, fullscreen ? SDL_WINDOW_FULLSCREEN : 0);
	if (ret == 0) {
		/* Switching resolution succeeded, set fullscreen value of window. */
		_fullscreen = fullscreen;
		if (!fullscreen) SDL_SetWindowSize(_sdl_window, _window_size_w, _window_size_h);
	} else {
		DEBUG(driver, 0, "SDL_SetWindowFullscreen() failed: %s", SDL_GetError());
	}

	return ret == 0;
}

bool VideoDriver_SDL::AfterBlitterChange()
{
	assert(BlitterFactory::GetCurrentBlitter()->GetScreenDepth() != 0);
	int w, h;
	SDL_GetWindowSize(_sdl_window, &w, &h);
	return CreateMainSurface(w, h, false);
}

void VideoDriver_SDL::AcquireBlitterLock()
{
	if (_draw_mutex != nullptr) _draw_mutex->lock();
}

void VideoDriver_SDL::ReleaseBlitterLock()
{
	if (_draw_mutex != nullptr) _draw_mutex->unlock();
}

Dimension VideoDriver_SDL::GetScreenSize() const
{
	SDL_DisplayMode mode;
	if (SDL_GetCurrentDisplayMode(this->startup_display, &mode) != 0) return VideoDriver::GetScreenSize();

	return { static_cast<uint>(mode.w), static_cast<uint>(mode.h) };
}