src/video/emscripten/SDL_emscriptenvideo.c
author Charlie Birks <charlie@daftgames.net>
Tue, 29 Jan 2019 12:14:41 +0000
changeset 12571 aa455cfe9ff3
parent 12503 806492103856
child 12574 109c919d61f6
permissions -rw-r--r--
Emscripten: use a fake size for external sizing check
The check would fail if the canvas happened to be the correct size
already. (#66, mentioned in #58)
     1 /*
     2   Simple DirectMedia Layer
     3   Copyright (C) 1997-2019 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_EMSCRIPTEN
    24 
    25 #include "SDL_video.h"
    26 #include "SDL_mouse.h"
    27 #include "SDL_hints.h"
    28 #include "../SDL_sysvideo.h"
    29 #include "../SDL_pixels_c.h"
    30 #include "../SDL_egl_c.h"
    31 #include "../../events/SDL_events_c.h"
    32 
    33 #include "SDL_emscriptenvideo.h"
    34 #include "SDL_emscriptenopengles.h"
    35 #include "SDL_emscriptenframebuffer.h"
    36 #include "SDL_emscriptenevents.h"
    37 #include "SDL_emscriptenmouse.h"
    38 
    39 #define EMSCRIPTENVID_DRIVER_NAME "emscripten"
    40 
    41 /* Initialization/Query functions */
    42 static int Emscripten_VideoInit(_THIS);
    43 static int Emscripten_SetDisplayMode(_THIS, SDL_VideoDisplay * display, SDL_DisplayMode * mode);
    44 static void Emscripten_VideoQuit(_THIS);
    45 
    46 static int Emscripten_CreateWindow(_THIS, SDL_Window * window);
    47 static void Emscripten_SetWindowSize(_THIS, SDL_Window * window);
    48 static void Emscripten_DestroyWindow(_THIS, SDL_Window * window);
    49 static void Emscripten_SetWindowFullscreen(_THIS, SDL_Window * window, SDL_VideoDisplay * display, SDL_bool fullscreen);
    50 static void Emscripten_PumpEvents(_THIS);
    51 static void Emscripten_SetWindowTitle(_THIS, SDL_Window * window);
    52 
    53 
    54 /* Emscripten driver bootstrap functions */
    55 
    56 static int
    57 Emscripten_Available(void)
    58 {
    59     return (1);
    60 }
    61 
    62 static void
    63 Emscripten_DeleteDevice(SDL_VideoDevice * device)
    64 {
    65     SDL_free(device);
    66 }
    67 
    68 static SDL_VideoDevice *
    69 Emscripten_CreateDevice(int devindex)
    70 {
    71     SDL_VideoDevice *device;
    72 
    73     /* Initialize all variables that we clean on shutdown */
    74     device = (SDL_VideoDevice *) SDL_calloc(1, sizeof(SDL_VideoDevice));
    75     if (!device) {
    76         SDL_OutOfMemory();
    77         return (0);
    78     }
    79 
    80     /* Firefox sends blur event which would otherwise prevent full screen
    81      * when the user clicks to allow full screen.
    82      * See https://bugzilla.mozilla.org/show_bug.cgi?id=1144964
    83     */
    84     SDL_SetHint(SDL_HINT_VIDEO_MINIMIZE_ON_FOCUS_LOSS, "0");
    85 
    86     /* Set the function pointers */
    87     device->VideoInit = Emscripten_VideoInit;
    88     device->VideoQuit = Emscripten_VideoQuit;
    89     device->SetDisplayMode = Emscripten_SetDisplayMode;
    90 
    91 
    92     device->PumpEvents = Emscripten_PumpEvents;
    93 
    94     device->CreateSDLWindow = Emscripten_CreateWindow;
    95     device->SetWindowTitle = Emscripten_SetWindowTitle;
    96     /*device->SetWindowIcon = Emscripten_SetWindowIcon;
    97     device->SetWindowPosition = Emscripten_SetWindowPosition;*/
    98     device->SetWindowSize = Emscripten_SetWindowSize;
    99     /*device->ShowWindow = Emscripten_ShowWindow;
   100     device->HideWindow = Emscripten_HideWindow;
   101     device->RaiseWindow = Emscripten_RaiseWindow;
   102     device->MaximizeWindow = Emscripten_MaximizeWindow;
   103     device->MinimizeWindow = Emscripten_MinimizeWindow;
   104     device->RestoreWindow = Emscripten_RestoreWindow;
   105     device->SetWindowGrab = Emscripten_SetWindowGrab;*/
   106     device->DestroyWindow = Emscripten_DestroyWindow;
   107     device->SetWindowFullscreen = Emscripten_SetWindowFullscreen;
   108 
   109     device->CreateWindowFramebuffer = Emscripten_CreateWindowFramebuffer;
   110     device->UpdateWindowFramebuffer = Emscripten_UpdateWindowFramebuffer;
   111     device->DestroyWindowFramebuffer = Emscripten_DestroyWindowFramebuffer;
   112 
   113 #if SDL_VIDEO_OPENGL_EGL
   114     device->GL_LoadLibrary = Emscripten_GLES_LoadLibrary;
   115     device->GL_GetProcAddress = Emscripten_GLES_GetProcAddress;
   116     device->GL_UnloadLibrary = Emscripten_GLES_UnloadLibrary;
   117     device->GL_CreateContext = Emscripten_GLES_CreateContext;
   118     device->GL_MakeCurrent = Emscripten_GLES_MakeCurrent;
   119     device->GL_SetSwapInterval = Emscripten_GLES_SetSwapInterval;
   120     device->GL_GetSwapInterval = Emscripten_GLES_GetSwapInterval;
   121     device->GL_SwapWindow = Emscripten_GLES_SwapWindow;
   122     device->GL_DeleteContext = Emscripten_GLES_DeleteContext;
   123     device->GL_GetDrawableSize = Emscripten_GLES_GetDrawableSize;
   124 #endif
   125 
   126     device->free = Emscripten_DeleteDevice;
   127 
   128     return device;
   129 }
   130 
   131 VideoBootStrap Emscripten_bootstrap = {
   132     EMSCRIPTENVID_DRIVER_NAME, "SDL emscripten video driver",
   133     Emscripten_Available, Emscripten_CreateDevice
   134 };
   135 
   136 
   137 int
   138 Emscripten_VideoInit(_THIS)
   139 {
   140     SDL_DisplayMode mode;
   141 
   142     /* Use a fake 32-bpp desktop mode */
   143     mode.format = SDL_PIXELFORMAT_RGB888;
   144 
   145     mode.w = EM_ASM_INT_V({
   146         return screen.width;
   147     });
   148 
   149     mode.h = EM_ASM_INT_V({
   150         return screen.height;
   151     });
   152 
   153     mode.refresh_rate = 0;
   154     mode.driverdata = NULL;
   155     if (SDL_AddBasicVideoDisplay(&mode) < 0) {
   156         return -1;
   157     }
   158 
   159     SDL_zero(mode);
   160     SDL_AddDisplayMode(&_this->displays[0], &mode);
   161 
   162     Emscripten_InitMouse();
   163 
   164     /* We're done! */
   165     return 0;
   166 }
   167 
   168 static int
   169 Emscripten_SetDisplayMode(_THIS, SDL_VideoDisplay * display, SDL_DisplayMode * mode)
   170 {
   171     /* can't do this */
   172     return 0;
   173 }
   174 
   175 static void
   176 Emscripten_VideoQuit(_THIS)
   177 {
   178     Emscripten_FiniMouse();
   179 }
   180 
   181 static void
   182 Emscripten_PumpEvents(_THIS)
   183 {
   184     /* do nothing. */
   185 }
   186 
   187 static int
   188 Emscripten_CreateWindow(_THIS, SDL_Window * window)
   189 {
   190     SDL_WindowData *wdata;
   191     double scaled_w, scaled_h;
   192     double css_w, css_h;
   193 
   194     /* Allocate window internal data */
   195     wdata = (SDL_WindowData *) SDL_calloc(1, sizeof(SDL_WindowData));
   196     if (wdata == NULL) {
   197         return SDL_OutOfMemory();
   198     }
   199 
   200     if (window->flags & SDL_WINDOW_ALLOW_HIGHDPI) {
   201         wdata->pixel_ratio = emscripten_get_device_pixel_ratio();
   202     } else {
   203         wdata->pixel_ratio = 1.0f;
   204     }
   205 
   206     scaled_w = SDL_floor(window->w * wdata->pixel_ratio);
   207     scaled_h = SDL_floor(window->h * wdata->pixel_ratio);
   208 
   209     /* set a fake size to check if there is any CSS sizing the canvas */
   210     emscripten_set_canvas_size(1, 1);
   211     emscripten_get_element_css_size(NULL, &css_w, &css_h);
   212 
   213     wdata->external_size = SDL_floor(css_w) != 1 || SDL_floor(css_h) != 1;
   214 
   215     if ((window->flags & SDL_WINDOW_RESIZABLE) && wdata->external_size) {
   216         /* external css has resized us */
   217         scaled_w = css_w * wdata->pixel_ratio;
   218         scaled_h = css_h * wdata->pixel_ratio;
   219 
   220         SDL_SendWindowEvent(window, SDL_WINDOWEVENT_RESIZED, css_w, css_h);
   221     }
   222 
   223     emscripten_set_canvas_size(scaled_w, scaled_h);
   224 
   225     /* if the size is not being controlled by css, we need to scale down for hidpi */
   226     if (!wdata->external_size) {
   227         if (wdata->pixel_ratio != 1.0f) {
   228             /*scale canvas down*/
   229             emscripten_set_element_css_size(NULL, window->w, window->h);
   230         }
   231     }
   232 
   233 #if SDL_VIDEO_OPENGL_EGL
   234     if (window->flags & SDL_WINDOW_OPENGL) {
   235         if (!_this->egl_data) {
   236             if (SDL_GL_LoadLibrary(NULL) < 0) {
   237                 return -1;
   238             }
   239         }
   240         wdata->egl_surface = SDL_EGL_CreateSurface(_this, 0);
   241 
   242         if (wdata->egl_surface == EGL_NO_SURFACE) {
   243             return SDL_SetError("Could not create GLES window surface");
   244         }
   245     }
   246 #endif
   247 
   248     wdata->window = window;
   249 
   250     /* Setup driver data for this window */
   251     window->driverdata = wdata;
   252 
   253     /* One window, it always has focus */
   254     SDL_SetMouseFocus(window);
   255     SDL_SetKeyboardFocus(window);
   256 
   257     Emscripten_RegisterEventHandlers(wdata);
   258 
   259     /* Window has been successfully created */
   260     return 0;
   261 }
   262 
   263 static void Emscripten_SetWindowSize(_THIS, SDL_Window * window)
   264 {
   265     SDL_WindowData *data;
   266 
   267     if (window->driverdata) {
   268         data = (SDL_WindowData *) window->driverdata;
   269         /* update pixel ratio */
   270         if (window->flags & SDL_WINDOW_ALLOW_HIGHDPI) {
   271             data->pixel_ratio = emscripten_get_device_pixel_ratio();
   272         }
   273         emscripten_set_canvas_size(window->w * data->pixel_ratio, window->h * data->pixel_ratio);
   274 
   275         /*scale canvas down*/
   276         if (!data->external_size && data->pixel_ratio != 1.0f) {
   277             emscripten_set_element_css_size(NULL, window->w, window->h);
   278         }
   279     }
   280 }
   281 
   282 static void
   283 Emscripten_DestroyWindow(_THIS, SDL_Window * window)
   284 {
   285     SDL_WindowData *data;
   286 
   287     if(window->driverdata) {
   288         data = (SDL_WindowData *) window->driverdata;
   289 
   290         Emscripten_UnregisterEventHandlers(data);
   291 #if SDL_VIDEO_OPENGL_EGL
   292         if (data->egl_surface != EGL_NO_SURFACE) {
   293             SDL_EGL_DestroySurface(_this, data->egl_surface);
   294             data->egl_surface = EGL_NO_SURFACE;
   295         }
   296 #endif
   297         SDL_free(window->driverdata);
   298         window->driverdata = NULL;
   299     }
   300 }
   301 
   302 static void
   303 Emscripten_SetWindowFullscreen(_THIS, SDL_Window * window, SDL_VideoDisplay * display, SDL_bool fullscreen)
   304 {
   305     SDL_WindowData *data;
   306     if(window->driverdata) {
   307         data = (SDL_WindowData *) window->driverdata;
   308 
   309         if(fullscreen) {
   310             EmscriptenFullscreenStrategy strategy;
   311             SDL_bool is_desktop_fullscreen = (window->flags & SDL_WINDOW_FULLSCREEN_DESKTOP) == SDL_WINDOW_FULLSCREEN_DESKTOP;
   312             int res;
   313 
   314             strategy.scaleMode = is_desktop_fullscreen ? EMSCRIPTEN_FULLSCREEN_SCALE_STRETCH : EMSCRIPTEN_FULLSCREEN_SCALE_ASPECT;
   315 
   316             if(!is_desktop_fullscreen) {
   317                 strategy.canvasResolutionScaleMode = EMSCRIPTEN_FULLSCREEN_CANVAS_SCALE_NONE;
   318             } else if(window->flags & SDL_WINDOW_ALLOW_HIGHDPI) {
   319                 strategy.canvasResolutionScaleMode = EMSCRIPTEN_FULLSCREEN_CANVAS_SCALE_HIDEF;
   320             } else {
   321                 strategy.canvasResolutionScaleMode = EMSCRIPTEN_FULLSCREEN_CANVAS_SCALE_STDDEF;
   322             }
   323 
   324             strategy.filteringMode = EMSCRIPTEN_FULLSCREEN_FILTERING_DEFAULT;
   325 
   326             strategy.canvasResizedCallback = Emscripten_HandleCanvasResize;
   327             strategy.canvasResizedCallbackUserData = data;
   328 
   329             data->requested_fullscreen_mode = window->flags & (SDL_WINDOW_FULLSCREEN_DESKTOP | SDL_WINDOW_FULLSCREEN);
   330             data->fullscreen_resize = is_desktop_fullscreen;
   331 
   332             res = emscripten_request_fullscreen_strategy(NULL, 1, &strategy);
   333             if(res != EMSCRIPTEN_RESULT_SUCCESS && res != EMSCRIPTEN_RESULT_DEFERRED) {
   334                 /* unset flags, fullscreen failed */
   335                 window->flags &= ~(SDL_WINDOW_FULLSCREEN_DESKTOP | SDL_WINDOW_FULLSCREEN);
   336             }
   337         }
   338         else
   339             emscripten_exit_fullscreen();
   340     }
   341 }
   342 
   343 static void
   344 Emscripten_SetWindowTitle(_THIS, SDL_Window * window) {
   345     EM_ASM_INT({
   346       if (typeof Module['setWindowTitle'] !== 'undefined') {
   347         Module['setWindowTitle'](Module['Pointer_stringify']($0));
   348       }
   349       return 0;
   350     }, window->title);
   351 }
   352 
   353 #endif /* SDL_VIDEO_DRIVER_EMSCRIPTEN */
   354 
   355 /* vi: set ts=4 sw=4 expandtab: */