1 /*
2   Simple DirectMedia Layer
3   Copyright (C) 1997-2020 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_assert.h"
40 #include "SDL_system.h"
41 
42 extern "C" {
43 #include "../../thread/SDL_systhread.h"
44 #include "../SDL_sysvideo.h"
45 #include "../../events/SDL_events_c.h"
46 }
47 
48 
49 /* Forward declarations */
50 static void WINRT_YieldXAMLThread();
51 
52 
53 /* Global event management */
54 
55 void
WINRT_PumpEvents(_THIS)56 WINRT_PumpEvents(_THIS)
57 {
58     if (SDL_WinRTGlobalApp) {
59         SDL_WinRTGlobalApp->PumpEvents();
60     } else if (WINRT_XAMLWasEnabled) {
61         WINRT_YieldXAMLThread();
62     }
63 }
64 
65 
66 /* XAML Thread management */
67 
68 enum SDL_XAMLAppThreadState
69 {
70     ThreadState_NotLaunched = 0,
71     ThreadState_Running,
72     ThreadState_Yielding
73 };
74 
75 static SDL_XAMLAppThreadState _threadState = ThreadState_NotLaunched;
76 static SDL_Thread * _XAMLThread = nullptr;
77 static SDL_mutex * _mutex = nullptr;
78 static SDL_cond * _cond = nullptr;
79 
80 static void
WINRT_YieldXAMLThread()81 WINRT_YieldXAMLThread()
82 {
83     SDL_LockMutex(_mutex);
84     SDL_assert(_threadState == ThreadState_Running);
85     _threadState = ThreadState_Yielding;
86     SDL_UnlockMutex(_mutex);
87 
88     SDL_CondSignal(_cond);
89 
90     SDL_LockMutex(_mutex);
91     while (_threadState != ThreadState_Running) {
92         SDL_CondWait(_cond, _mutex);
93     }
94     SDL_UnlockMutex(_mutex);
95 }
96 
97 static int
WINRT_XAMLThreadMain(void * userdata)98 WINRT_XAMLThreadMain(void * userdata)
99 {
100     // TODO, WinRT: pass the C-style main() a reasonably realistic
101     // representation of command line arguments.
102     int argc = 0;
103     char **argv = NULL;
104     return WINRT_SDLAppEntryPoint(argc, argv);
105 }
106 
107 void
WINRT_CycleXAMLThread(void)108 WINRT_CycleXAMLThread(void)
109 {
110     switch (_threadState) {
111         case ThreadState_NotLaunched:
112         {
113             _cond = SDL_CreateCond();
114 
115             _mutex = SDL_CreateMutex();
116             _threadState = ThreadState_Running;
117             _XAMLThread = SDL_CreateThreadInternal(WINRT_XAMLThreadMain, "SDL/XAML App Thread", 0, nullptr);
118 
119             SDL_LockMutex(_mutex);
120             while (_threadState != ThreadState_Yielding) {
121                 SDL_CondWait(_cond, _mutex);
122             }
123             SDL_UnlockMutex(_mutex);
124 
125             break;
126         }
127 
128         case ThreadState_Running:
129         {
130             SDL_assert(false);
131             break;
132         }
133 
134         case ThreadState_Yielding:
135         {
136             SDL_LockMutex(_mutex);
137             SDL_assert(_threadState == ThreadState_Yielding);
138             _threadState = ThreadState_Running;
139             SDL_UnlockMutex(_mutex);
140 
141             SDL_CondSignal(_cond);
142 
143             SDL_LockMutex(_mutex);
144             while (_threadState != ThreadState_Yielding) {
145                 SDL_CondWait(_cond, _mutex);
146             }
147             SDL_UnlockMutex(_mutex);
148         }
149     }
150 }
151 
152 #endif /* SDL_VIDEO_DRIVER_WINRT */
153 
154 /* vi: set ts=4 sw=4 expandtab: */
155