src/video/emscripten/SDL_emscriptenvideo.c
author Ryan C. Gordon <icculus@icculus.org>
Thu, 18 Dec 2014 00:19:52 -0500
changeset 9278 8900afb78a19
child 9294 1865bd71ef12
permissions -rw-r--r--
Initial merge of Emscripten port!

With this commit, you can compile SDL2 with Emscripten
( http://emscripten.org/ ), and make your SDL-based C/C++ program
into a web app.

This port was due to the efforts of several people, including: Charlie Birks,
Sathyanarayanan Gunasekaran, Jukka Jylänki, Alon Zakai, Edward Rudd,
Bruce Mitchener, and Martin Gerhardy. (Thanks, everyone!)
     1 /*
     2   Simple DirectMedia Layer
     3   Copyright (C) 1997-2014 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_sysvideo.h"
    28 #include "../SDL_pixels_c.h"
    29 #include "../SDL_egl_c.h"
    30 #include "../../events/SDL_events_c.h"
    31 
    32 #include "SDL_emscriptenvideo.h"
    33 #include "SDL_emscriptenopengles.h"
    34 #include "SDL_emscriptenframebuffer.h"
    35 #include "SDL_emscriptenevents.h"
    36 #include "SDL_emscriptenmouse.h"
    37 
    38 #define EMSCRIPTENVID_DRIVER_NAME "emscripten"
    39 
    40 /* Initialization/Query functions */
    41 static int Emscripten_VideoInit(_THIS);
    42 static int Emscripten_SetDisplayMode(_THIS, SDL_VideoDisplay * display, SDL_DisplayMode * mode);
    43 static void Emscripten_VideoQuit(_THIS);
    44 
    45 static int Emscripten_CreateWindow(_THIS, SDL_Window * window);
    46 static void Emscripten_SetWindowSize(_THIS, SDL_Window * window);
    47 static void Emscripten_DestroyWindow(_THIS, SDL_Window * window);
    48 static void Emscripten_SetWindowFullscreen(_THIS, SDL_Window * window, SDL_VideoDisplay * display, SDL_bool fullscreen);
    49 static void Emscripten_PumpEvents(_THIS);
    50 
    51 
    52 /* Emscripten driver bootstrap functions */
    53 
    54 static int
    55 Emscripten_Available(void)
    56 {
    57     return (1);
    58 }
    59 
    60 static void
    61 Emscripten_DeleteDevice(SDL_VideoDevice * device)
    62 {
    63     SDL_free(device);
    64 }
    65 
    66 static SDL_VideoDevice *
    67 Emscripten_CreateDevice(int devindex)
    68 {
    69     SDL_VideoDevice *device;
    70 
    71     /* Initialize all variables that we clean on shutdown */
    72     device = (SDL_VideoDevice *) SDL_calloc(1, sizeof(SDL_VideoDevice));
    73     if (!device) {
    74         SDL_OutOfMemory();
    75         SDL_free(device);
    76         return (0);
    77     }
    78 
    79     /* Set the function pointers */
    80     device->VideoInit = Emscripten_VideoInit;
    81     device->VideoQuit = Emscripten_VideoQuit;
    82     device->SetDisplayMode = Emscripten_SetDisplayMode;
    83 
    84 
    85     device->PumpEvents = Emscripten_PumpEvents;
    86 
    87     device->CreateWindow = Emscripten_CreateWindow;
    88     /*device->CreateWindowFrom = Emscripten_CreateWindowFrom;
    89     device->SetWindowTitle = Emscripten_SetWindowTitle;
    90     device->SetWindowIcon = Emscripten_SetWindowIcon;
    91     device->SetWindowPosition = Emscripten_SetWindowPosition;*/
    92     device->SetWindowSize = Emscripten_SetWindowSize;
    93     /*device->ShowWindow = Emscripten_ShowWindow;
    94     device->HideWindow = Emscripten_HideWindow;
    95     device->RaiseWindow = Emscripten_RaiseWindow;
    96     device->MaximizeWindow = Emscripten_MaximizeWindow;
    97     device->MinimizeWindow = Emscripten_MinimizeWindow;
    98     device->RestoreWindow = Emscripten_RestoreWindow;
    99     device->SetWindowGrab = Emscripten_SetWindowGrab;*/
   100     device->DestroyWindow = Emscripten_DestroyWindow;
   101     device->SetWindowFullscreen = Emscripten_SetWindowFullscreen;
   102 
   103     device->CreateWindowFramebuffer = Emscripten_CreateWindowFramebuffer;
   104     device->UpdateWindowFramebuffer = Emscripten_UpdateWindowFramebuffer;
   105     device->DestroyWindowFramebuffer = Emscripten_DestroyWindowFramebuffer;
   106 
   107     device->GL_LoadLibrary = Emscripten_GLES_LoadLibrary;
   108     device->GL_GetProcAddress = Emscripten_GLES_GetProcAddress;
   109     device->GL_UnloadLibrary = Emscripten_GLES_UnloadLibrary;
   110     device->GL_CreateContext = Emscripten_GLES_CreateContext;
   111     device->GL_MakeCurrent = Emscripten_GLES_MakeCurrent;
   112     device->GL_SetSwapInterval = Emscripten_GLES_SetSwapInterval;
   113     device->GL_GetSwapInterval = Emscripten_GLES_GetSwapInterval;
   114     device->GL_SwapWindow = Emscripten_GLES_SwapWindow;
   115     device->GL_DeleteContext = Emscripten_GLES_DeleteContext;
   116     device->GL_GetDrawableSize = Emscripten_GLES_GetDrawableSize;
   117 
   118     device->free = Emscripten_DeleteDevice;
   119 
   120     return device;
   121 }
   122 
   123 VideoBootStrap Emscripten_bootstrap = {
   124     EMSCRIPTENVID_DRIVER_NAME, "SDL emscripten video driver",
   125     Emscripten_Available, Emscripten_CreateDevice
   126 };
   127 
   128 
   129 int
   130 Emscripten_VideoInit(_THIS)
   131 {
   132     SDL_DisplayMode mode;
   133     double css_w, css_h;
   134 
   135     /* Use a fake 32-bpp desktop mode */
   136     mode.format = SDL_PIXELFORMAT_RGB888;
   137 
   138     emscripten_get_element_css_size(NULL, &css_w, &css_h);
   139 
   140     mode.w = css_w;
   141     mode.h = css_h;
   142 
   143     mode.refresh_rate = 0;
   144     mode.driverdata = NULL;
   145     if (SDL_AddBasicVideoDisplay(&mode) < 0) {
   146         return -1;
   147     }
   148 
   149     SDL_zero(mode);
   150     SDL_AddDisplayMode(&_this->displays[0], &mode);
   151 
   152     Emscripten_InitMouse();
   153 
   154     /* We're done! */
   155     return 0;
   156 }
   157 
   158 static int
   159 Emscripten_SetDisplayMode(_THIS, SDL_VideoDisplay * display, SDL_DisplayMode * mode)
   160 {
   161     /* can't do this */
   162     return 0;
   163 }
   164 
   165 static void
   166 Emscripten_VideoQuit(_THIS)
   167 {
   168     Emscripten_FiniMouse();
   169 }
   170 
   171 static void
   172 Emscripten_PumpEvents(_THIS)
   173 {
   174     /* do nothing. */
   175 }
   176 
   177 static int
   178 Emscripten_CreateWindow(_THIS, SDL_Window * window)
   179 {
   180     SDL_WindowData *wdata;
   181     double scaled_w, scaled_h;
   182     double css_w, css_h;
   183 
   184     /* Allocate window internal data */
   185     wdata = (SDL_WindowData *) SDL_calloc(1, sizeof(SDL_WindowData));
   186     if (wdata == NULL) {
   187         return SDL_OutOfMemory();
   188     }
   189 
   190     if (window->flags & SDL_WINDOW_ALLOW_HIGHDPI) {
   191         wdata->pixel_ratio = emscripten_get_device_pixel_ratio();
   192     } else {
   193         wdata->pixel_ratio = 1.0f;
   194     }
   195 
   196     scaled_w = SDL_floor(window->w * wdata->pixel_ratio);
   197     scaled_h = SDL_floor(window->h * wdata->pixel_ratio);
   198 
   199     emscripten_set_canvas_size(scaled_w, scaled_h);
   200 
   201     emscripten_get_element_css_size(NULL, &css_w, &css_h);
   202 
   203     wdata->external_size = css_w != scaled_w || css_h != scaled_h;
   204 
   205     if ((window->flags & SDL_WINDOW_RESIZABLE) && wdata->external_size) {
   206         /* external css has resized us */
   207         scaled_w = css_w * wdata->pixel_ratio;
   208         scaled_h = css_h * wdata->pixel_ratio;
   209 
   210         emscripten_set_canvas_size(scaled_w, scaled_h);
   211         SDL_SendWindowEvent(window, SDL_WINDOWEVENT_RESIZED, css_w, css_h);
   212     }
   213 
   214     /* if the size is not being controlled by css, we need to scale down for hidpi */
   215     if (!wdata->external_size) {
   216         if (wdata->pixel_ratio != 1.0f) {
   217             /*scale canvas down*/
   218             emscripten_set_element_css_size(NULL, window->w, window->h);
   219         }
   220     }
   221 
   222     wdata->windowed_width = scaled_w;
   223     wdata->windowed_height = scaled_h;
   224 
   225     if (window->flags & SDL_WINDOW_OPENGL) {
   226         if (!_this->egl_data) {
   227             if (SDL_GL_LoadLibrary(NULL) < 0) {
   228                 return -1;
   229             }
   230         }
   231         wdata->egl_surface = SDL_EGL_CreateSurface(_this, NULL);
   232 
   233         if (wdata->egl_surface == EGL_NO_SURFACE) {
   234             return SDL_SetError("Could not create GLES window surface");
   235         }
   236     }
   237 
   238     wdata->window = window;
   239 
   240     /* Setup driver data for this window */
   241     window->driverdata = wdata;
   242 
   243     /* One window, it always has focus */
   244     SDL_SetMouseFocus(window);
   245     SDL_SetKeyboardFocus(window);
   246 
   247     Emscripten_RegisterEventHandlers(wdata);
   248 
   249     /* Window has been successfully created */
   250     return 0;
   251 }
   252 
   253 static void Emscripten_SetWindowSize(_THIS, SDL_Window * window)
   254 {
   255     SDL_WindowData *data;
   256 
   257     if (window->driverdata) {
   258         data = (SDL_WindowData *) window->driverdata;
   259         emscripten_set_canvas_size(window->w * data->pixel_ratio, window->h * data->pixel_ratio);
   260 
   261         /*scale canvas down*/
   262         if (!data->external_size && data->pixel_ratio != 1.0f) {
   263             emscripten_set_element_css_size(NULL, window->w, window->h);
   264         }
   265     }
   266 }
   267 
   268 static void
   269 Emscripten_DestroyWindow(_THIS, SDL_Window * window)
   270 {
   271     SDL_WindowData *data;
   272 
   273     if(window->driverdata) {
   274         data = (SDL_WindowData *) window->driverdata;
   275 
   276         Emscripten_UnregisterEventHandlers(data);
   277         if (data->egl_surface != EGL_NO_SURFACE) {
   278             SDL_EGL_DestroySurface(_this, data->egl_surface);
   279             data->egl_surface = EGL_NO_SURFACE;
   280         }
   281         SDL_free(window->driverdata);
   282         window->driverdata = NULL;
   283     }
   284 }
   285 
   286 static void
   287 Emscripten_SetWindowFullscreen(_THIS, SDL_Window * window, SDL_VideoDisplay * display, SDL_bool fullscreen)
   288 {
   289     SDL_WindowData *data;
   290     if(window->driverdata) {
   291         data = (SDL_WindowData *) window->driverdata;
   292 
   293         if(fullscreen) {
   294             data->requested_fullscreen_mode = window->flags & (SDL_WINDOW_FULLSCREEN_DESKTOP | SDL_WINDOW_FULLSCREEN);
   295             /*unset the fullscreen flags as we're not actually fullscreen yet*/
   296             window->flags &= ~(SDL_WINDOW_FULLSCREEN_DESKTOP | SDL_WINDOW_FULLSCREEN);
   297 
   298             EM_ASM({
   299                 //reparent canvas (similar to Module.requestFullscreen)
   300                 var canvas = Module['canvas'];
   301                 if(canvas.parentNode.id != "SDLFullscreenElement") {
   302                     var canvasContainer = document.createElement("div");
   303                     canvasContainer.id = "SDLFullscreenElement";
   304                     canvas.parentNode.insertBefore(canvasContainer, canvas);
   305                     canvasContainer.appendChild(canvas);
   306                 }
   307             });
   308 
   309             int is_fullscreen;
   310             emscripten_get_canvas_size(&data->windowed_width, &data->windowed_height, &is_fullscreen);
   311             emscripten_request_fullscreen("SDLFullscreenElement", 1);
   312         }
   313         else
   314             emscripten_exit_fullscreen();
   315     }
   316 }
   317 
   318 #endif /* SDL_VIDEO_DRIVER_EMSCRIPTEN */
   319 
   320 /* vi: set ts=4 sw=4 expandtab: */