src/video/android/SDL_androidevents.c
author Gabriel Jacobo <gabomdq@gmail.com>
Thu, 10 Oct 2013 00:30:03 -0300
changeset 7795 6acc7df4a175
parent 7677 871d43c6968a
child 7910 261addaa47d0
permissions -rw-r--r--
Fixes Bug 2134 - [Android] Black screen after resume (sometimes)
     1 /*
     2   Simple DirectMedia Layer
     3   Copyright (C) 1997-2013 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_config.h"
    22 
    23 #if SDL_VIDEO_DRIVER_ANDROID
    24 
    25 /* We're going to do this by default */
    26 #define SDL_ANDROID_BLOCK_ON_PAUSE  1
    27 
    28 #include "SDL_androidevents.h"
    29 #include "SDL_events.h"
    30 #include "SDL_androidwindow.h"
    31 
    32 void android_egl_context_backup();
    33 void android_egl_context_restore();
    34 
    35 void 
    36 android_egl_context_restore() 
    37 {
    38     SDL_WindowData *data = (SDL_WindowData *) Android_Window->driverdata;
    39     if (SDL_GL_MakeCurrent(Android_Window, (SDL_GLContext) data->egl_context) < 0) {
    40         /* The context is no longer valid, create a new one */
    41         /* FIXME: Notify the user that the context changed and textures need to be re created */
    42         data->egl_context = (EGLContext) SDL_GL_CreateContext(Android_Window);
    43         SDL_GL_MakeCurrent(Android_Window, (SDL_GLContext) data->egl_context);
    44     }
    45 }
    46 
    47 void 
    48 android_egl_context_backup() 
    49 {
    50     /* Keep a copy of the EGL Context so we can try to restore it when we resume */
    51     SDL_WindowData *data = (SDL_WindowData *) Android_Window->driverdata;
    52     data->egl_context = SDL_GL_GetCurrentContext();
    53     /* We need to do this so the EGLSurface can be freed */
    54     SDL_GL_MakeCurrent(Android_Window, NULL);
    55 }
    56 
    57 void
    58 Android_PumpEvents(_THIS)
    59 {
    60     static int isPaused = 0;
    61 #if SDL_ANDROID_BLOCK_ON_PAUSE
    62     static int isPausing = 0;
    63 #endif
    64     /* No polling necessary */
    65 
    66     /*
    67      * Android_ResumeSem and Android_PauseSem are signaled from Java_org_libsdl_app_SDLActivity_nativePause and Java_org_libsdl_app_SDLActivity_nativeResume
    68      * When the pause semaphore is signaled, if SDL_ANDROID_BLOCK_ON_PAUSE is defined the event loop will block until the resume signal is emitted.
    69      * When the resume semaphore is signaled, SDL_GL_CreateContext is called which in turn calls Java code
    70      * SDLActivity::createGLContext -> SDLActivity:: initEGL -> SDLActivity::createEGLSurface -> SDLActivity::createEGLContext
    71      */
    72 
    73 #if SDL_ANDROID_BLOCK_ON_PAUSE
    74     if (isPaused && !isPausing) {
    75         /* Make sure this is the last thing we do before pausing */
    76         android_egl_context_backup();
    77         if(SDL_SemWait(Android_ResumeSem) == 0) {
    78 #else
    79     if (isPaused) {
    80         if(SDL_SemTryWait(Android_ResumeSem) == 0) {
    81 #endif
    82             isPaused = 0;
    83             
    84             /* Restore the GL Context from here, as this operation is thread dependent */
    85             android_egl_context_restore();
    86         }
    87     }
    88     else {
    89 #if SDL_ANDROID_BLOCK_ON_PAUSE
    90         if( isPausing || SDL_SemTryWait(Android_PauseSem) == 0 ) {
    91             /* We've been signaled to pause, but before we block ourselves, 
    92             we need to make sure that certain key events have reached the app */
    93             if (SDL_HasEvent(SDL_WINDOWEVENT) || SDL_HasEvent(SDL_APP_WILLENTERBACKGROUND) || SDL_HasEvent(SDL_APP_DIDENTERBACKGROUND) ) {
    94                 isPausing = 1;
    95             }
    96             else {
    97                 isPausing = 0;
    98                 isPaused = 1;
    99             }
   100         }
   101 #else
   102         if(SDL_SemTryWait(Android_PauseSem) == 0) {
   103             android_egl_context_backup();
   104             isPaused = 1;
   105         }
   106 #endif
   107     }
   108 }
   109 
   110 #endif /* SDL_VIDEO_DRIVER_ANDROID */
   111 
   112 /* vi: set ts=4 sw=4 expandtab: */