1 /*
2   Simple DirectMedia Layer
3   Copyright (C) 1997-2021 Sam Lantinga <slouken@libsdl.org>
4 
5   This software is provided 'as-is', without any express or implied
6   warranty.  In no event will the authors be held liable for any damages
7   arising from the use of this software.
8 
9   Permission is granted to anyone to use this software for any purpose,
10   including commercial applications, and to alter it and redistribute it
11   freely, subject to the following restrictions:
12 
13   1. The origin of this software must not be misrepresented; you must not
14      claim that you wrote the original software. If you use this software
15      in a product, an acknowledgment in the product documentation would be
16      appreciated but is not required.
17   2. Altered source versions must be plainly marked as such, and must not be
18      misrepresented as being the original software.
19   3. This notice may not be removed or altered from any source distribution.
20 */
21 #include "../../SDL_internal.h"
22 
23 #if SDL_VIDEO_DRIVER_WINRT
24 
25 /*
26  * Windows includes:
27  */
28 #include <Windows.h>
29 using namespace Windows::UI::Core;
30 using Windows::UI::Core::CoreCursor;
31 
32 /*
33  * SDL includes:
34  */
35 #include "SDL_winrtevents_c.h"
36 #include "../../core/winrt/SDL_winrtapp_common.h"
37 #include "../../core/winrt/SDL_winrtapp_direct3d.h"
38 #include "../../core/winrt/SDL_winrtapp_xaml.h"
39 #include "SDL_system.h"
40 
41 extern "C" {
42 #include "../../thread/SDL_systhread.h"
43 #include "../SDL_sysvideo.h"
44 #include "../../events/SDL_events_c.h"
45 }
46 
47 
48 /* Forward declarations */
49 static void WINRT_YieldXAMLThread();
50 
51 
52 /* Global event management */
53 
54 void
WINRT_PumpEvents(_THIS)55 WINRT_PumpEvents(_THIS)
56 {
57     if (SDL_WinRTGlobalApp) {
58         SDL_WinRTGlobalApp->PumpEvents();
59     } else if (WINRT_XAMLWasEnabled) {
60         WINRT_YieldXAMLThread();
61     }
62 }
63 
64 
65 /* XAML Thread management */
66 
67 enum SDL_XAMLAppThreadState
68 {
69     ThreadState_NotLaunched = 0,
70     ThreadState_Running,
71     ThreadState_Yielding
72 };
73 
74 static SDL_XAMLAppThreadState _threadState = ThreadState_NotLaunched;
75 static SDL_Thread * _XAMLThread = nullptr;
76 static SDL_mutex * _mutex = nullptr;
77 static SDL_cond * _cond = nullptr;
78 
79 static void
WINRT_YieldXAMLThread()80 WINRT_YieldXAMLThread()
81 {
82     SDL_LockMutex(_mutex);
83     SDL_assert(_threadState == ThreadState_Running);
84     _threadState = ThreadState_Yielding;
85     SDL_UnlockMutex(_mutex);
86 
87     SDL_CondSignal(_cond);
88 
89     SDL_LockMutex(_mutex);
90     while (_threadState != ThreadState_Running) {
91         SDL_CondWait(_cond, _mutex);
92     }
93     SDL_UnlockMutex(_mutex);
94 }
95 
96 static int
WINRT_XAMLThreadMain(void * userdata)97 WINRT_XAMLThreadMain(void * userdata)
98 {
99     // TODO, WinRT: pass the C-style main() a reasonably realistic
100     // representation of command line arguments.
101     int argc = 0;
102     char **argv = NULL;
103     return WINRT_SDLAppEntryPoint(argc, argv);
104 }
105 
106 void
WINRT_CycleXAMLThread(void)107 WINRT_CycleXAMLThread(void)
108 {
109     switch (_threadState) {
110         case ThreadState_NotLaunched:
111         {
112             _cond = SDL_CreateCond();
113 
114             _mutex = SDL_CreateMutex();
115             _threadState = ThreadState_Running;
116             _XAMLThread = SDL_CreateThreadInternal(WINRT_XAMLThreadMain, "SDL/XAML App Thread", 0, nullptr);
117 
118             SDL_LockMutex(_mutex);
119             while (_threadState != ThreadState_Yielding) {
120                 SDL_CondWait(_cond, _mutex);
121             }
122             SDL_UnlockMutex(_mutex);
123 
124             break;
125         }
126 
127         case ThreadState_Running:
128         {
129             SDL_assert(false);
130             break;
131         }
132 
133         case ThreadState_Yielding:
134         {
135             SDL_LockMutex(_mutex);
136             SDL_assert(_threadState == ThreadState_Yielding);
137             _threadState = ThreadState_Running;
138             SDL_UnlockMutex(_mutex);
139 
140             SDL_CondSignal(_cond);
141 
142             SDL_LockMutex(_mutex);
143             while (_threadState != ThreadState_Yielding) {
144                 SDL_CondWait(_cond, _mutex);
145             }
146             SDL_UnlockMutex(_mutex);
147         }
148     }
149 }
150 
151 #endif /* SDL_VIDEO_DRIVER_WINRT */
152 
153 /* vi: set ts=4 sw=4 expandtab: */
154