src/video/emscripten/SDL_emscriptenvideo.c - third_party/sdl - Git at Google

 /*
   Simple DirectMedia Layer
   Copyright (C) 1997-2019 Sam Lantinga <slouken@libsdl.org>

   This software is provided 'as-is', without any express or implied
   warranty.  In no event will the authors be held liable for any damages
   arising from the use of this software.

   Permission is granted to anyone to use this software for any purpose,
   including commercial applications, and to alter it and redistribute it
   freely, subject to the following restrictions:

   1. The origin of this software must not be misrepresented; you must not
      claim that you wrote the original software. If you use this software
      in a product, an acknowledgment in the product documentation would be
      appreciated but is not required.
   2. Altered source versions must be plainly marked as such, and must not be
      misrepresented as being the original software.
   3. This notice may not be removed or altered from any source distribution.
 */
 #include "../../SDL_internal.h"

 #if SDL_VIDEO_DRIVER_EMSCRIPTEN

 #include "SDL_video.h"
 #include "SDL_mouse.h"
 #include "SDL_hints.h"
 #include "../SDL_sysvideo.h"
 #include "../SDL_pixels_c.h"
 #include "../SDL_egl_c.h"
 #include "../../events/SDL_events_c.h"

 #include "SDL_emscriptenvideo.h"
 #include "SDL_emscriptenopengles.h"
 #include "SDL_emscriptenframebuffer.h"
 #include "SDL_emscriptenevents.h"
 #include "SDL_emscriptenmouse.h"

 #define EMSCRIPTENVID_DRIVER_NAME "emscripten"

 /* Initialization/Query functions */
 static int Emscripten_VideoInit(_THIS);
 static int Emscripten_SetDisplayMode(_THIS, SDL_VideoDisplay * display, SDL_DisplayMode * mode);
 static void Emscripten_VideoQuit(_THIS);

 static int Emscripten_CreateWindow(_THIS, SDL_Window * window);
 static void Emscripten_SetWindowSize(_THIS, SDL_Window * window);
 static void Emscripten_DestroyWindow(_THIS, SDL_Window * window);
 static void Emscripten_SetWindowFullscreen(_THIS, SDL_Window * window, SDL_VideoDisplay * display, SDL_bool fullscreen);
 static void Emscripten_PumpEvents(_THIS);
 static void Emscripten_SetWindowTitle(_THIS, SDL_Window * window);


 /* Emscripten driver bootstrap functions */

 static int
 Emscripten_Available(void)
 {
     return (1);
 }

 static void
 Emscripten_DeleteDevice(SDL_VideoDevice * device)
 {
     SDL_free(device);
 }

 static SDL_VideoDevice *
 Emscripten_CreateDevice(int devindex)
 {
     SDL_VideoDevice *device;

     /* Initialize all variables that we clean on shutdown */
     device = (SDL_VideoDevice *) SDL_calloc(1, sizeof(SDL_VideoDevice));
     if (!device) {
         SDL_OutOfMemory();
         return (0);
     }

     /* Firefox sends blur event which would otherwise prevent full screen
      * when the user clicks to allow full screen.
      * See https://bugzilla.mozilla.org/show_bug.cgi?id=1144964
     */
     SDL_SetHint(SDL_HINT_VIDEO_MINIMIZE_ON_FOCUS_LOSS, "0");

     /* Set the function pointers */
     device->VideoInit = Emscripten_VideoInit;
     device->VideoQuit = Emscripten_VideoQuit;
     device->SetDisplayMode = Emscripten_SetDisplayMode;


     device->PumpEvents = Emscripten_PumpEvents;

     device->CreateSDLWindow = Emscripten_CreateWindow;
     device->SetWindowTitle = Emscripten_SetWindowTitle;
     /*device->SetWindowIcon = Emscripten_SetWindowIcon;
     device->SetWindowPosition = Emscripten_SetWindowPosition;*/
     device->SetWindowSize = Emscripten_SetWindowSize;
     /*device->ShowWindow = Emscripten_ShowWindow;
     device->HideWindow = Emscripten_HideWindow;
     device->RaiseWindow = Emscripten_RaiseWindow;
     device->MaximizeWindow = Emscripten_MaximizeWindow;
     device->MinimizeWindow = Emscripten_MinimizeWindow;
     device->RestoreWindow = Emscripten_RestoreWindow;
     device->SetWindowGrab = Emscripten_SetWindowGrab;*/
     device->DestroyWindow = Emscripten_DestroyWindow;
     device->SetWindowFullscreen = Emscripten_SetWindowFullscreen;

     device->CreateWindowFramebuffer = Emscripten_CreateWindowFramebuffer;
     device->UpdateWindowFramebuffer = Emscripten_UpdateWindowFramebuffer;
     device->DestroyWindowFramebuffer = Emscripten_DestroyWindowFramebuffer;

 #if SDL_VIDEO_OPENGL_EGL
     device->GL_LoadLibrary = Emscripten_GLES_LoadLibrary;
     device->GL_GetProcAddress = Emscripten_GLES_GetProcAddress;
     device->GL_UnloadLibrary = Emscripten_GLES_UnloadLibrary;
     device->GL_CreateContext = Emscripten_GLES_CreateContext;
     device->GL_MakeCurrent = Emscripten_GLES_MakeCurrent;
     device->GL_SetSwapInterval = Emscripten_GLES_SetSwapInterval;
     device->GL_GetSwapInterval = Emscripten_GLES_GetSwapInterval;
     device->GL_SwapWindow = Emscripten_GLES_SwapWindow;
     device->GL_DeleteContext = Emscripten_GLES_DeleteContext;
     device->GL_GetDrawableSize = Emscripten_GLES_GetDrawableSize;
 #endif

     device->free = Emscripten_DeleteDevice;

     return device;
 }

 VideoBootStrap Emscripten_bootstrap = {
     EMSCRIPTENVID_DRIVER_NAME, "SDL emscripten video driver",
     Emscripten_Available, Emscripten_CreateDevice
 };


 int
 Emscripten_VideoInit(_THIS)
 {
     SDL_DisplayMode mode;

     /* Use a fake 32-bpp desktop mode */
     mode.format = SDL_PIXELFORMAT_RGB888;

     mode.w = EM_ASM_INT_V({
         return screen.width;
     });

     mode.h = EM_ASM_INT_V({
         return screen.height;
     });

     mode.refresh_rate = 0;
     mode.driverdata = NULL;
     if (SDL_AddBasicVideoDisplay(&mode) < 0) {
         return -1;
     }

     SDL_AddDisplayMode(&_this->displays[0], &mode);

     Emscripten_InitMouse();

     /* We're done! */
     return 0;
 }

 static int
 Emscripten_SetDisplayMode(_THIS, SDL_VideoDisplay * display, SDL_DisplayMode * mode)
 {
     /* can't do this */
     return 0;
 }

 static void
 Emscripten_VideoQuit(_THIS)
 {
     Emscripten_FiniMouse();
 }

 static void
 Emscripten_PumpEvents(_THIS)
 {
     /* do nothing. */
 }

 static int
 Emscripten_CreateWindow(_THIS, SDL_Window * window)
 {
     SDL_WindowData *wdata;
     double scaled_w, scaled_h;
     double css_w, css_h;

     /* Allocate window internal data */
     wdata = (SDL_WindowData *) SDL_calloc(1, sizeof(SDL_WindowData));
     if (wdata == NULL) {
         return SDL_OutOfMemory();
     }

     if (window->flags & SDL_WINDOW_ALLOW_HIGHDPI) {
         wdata->pixel_ratio = emscripten_get_device_pixel_ratio();
     } else {
         wdata->pixel_ratio = 1.0f;
     }

     scaled_w = SDL_floor(window->w * wdata->pixel_ratio);
     scaled_h = SDL_floor(window->h * wdata->pixel_ratio);

     /* set a fake size to check if there is any CSS sizing the canvas */
     emscripten_set_canvas_element_size(NULL, 1, 1);
     emscripten_get_element_css_size(NULL, &css_w, &css_h);

     wdata->external_size = SDL_floor(css_w) != 1 || SDL_floor(css_h) != 1;

     if ((window->flags & SDL_WINDOW_RESIZABLE) && wdata->external_size) {
         /* external css has resized us */
         scaled_w = css_w * wdata->pixel_ratio;
         scaled_h = css_h * wdata->pixel_ratio;

         SDL_SendWindowEvent(window, SDL_WINDOWEVENT_RESIZED, css_w, css_h);
     }

     emscripten_set_canvas_element_size(NULL, scaled_w, scaled_h);

     /* if the size is not being controlled by css, we need to scale down for hidpi */
     if (!wdata->external_size) {
         if (wdata->pixel_ratio != 1.0f) {
             /*scale canvas down*/
             emscripten_set_element_css_size(NULL, window->w, window->h);
         }
     }

 #if SDL_VIDEO_OPENGL_EGL
     if (window->flags & SDL_WINDOW_OPENGL) {
         if (!_this->egl_data) {
             if (SDL_GL_LoadLibrary(NULL) < 0) {
                 return -1;
             }
         }
         wdata->egl_surface = SDL_EGL_CreateSurface(_this, 0);

         if (wdata->egl_surface == EGL_NO_SURFACE) {
             return SDL_SetError("Could not create GLES window surface");
         }
     }
 #endif

     wdata->window = window;

     /* Setup driver data for this window */
     window->driverdata = wdata;

     /* One window, it always has focus */
     SDL_SetMouseFocus(window);
     SDL_SetKeyboardFocus(window);

     Emscripten_RegisterEventHandlers(wdata);

     /* Window has been successfully created */
     return 0;
 }

 static void Emscripten_SetWindowSize(_THIS, SDL_Window * window)
 {
     SDL_WindowData *data;

     if (window->driverdata) {
         data = (SDL_WindowData *) window->driverdata;
         /* update pixel ratio */
         if (window->flags & SDL_WINDOW_ALLOW_HIGHDPI) {
             data->pixel_ratio = emscripten_get_device_pixel_ratio();
         }
         emscripten_set_canvas_element_size(NULL, window->w * data->pixel_ratio, window->h * data->pixel_ratio);

         /*scale canvas down*/
         if (!data->external_size && data->pixel_ratio != 1.0f) {
             emscripten_set_element_css_size(NULL, window->w, window->h);
         }
     }
 }

 static void
 Emscripten_DestroyWindow(_THIS, SDL_Window * window)
 {
     SDL_WindowData *data;

     if(window->driverdata) {
         data = (SDL_WindowData *) window->driverdata;

         Emscripten_UnregisterEventHandlers(data);
 #if SDL_VIDEO_OPENGL_EGL
         if (data->egl_surface != EGL_NO_SURFACE) {
             SDL_EGL_DestroySurface(_this, data->egl_surface);
             data->egl_surface = EGL_NO_SURFACE;
         }
 #endif

         /* We can't destroy the canvas, so resize it to zero instead */
         emscripten_set_canvas_element_size(NULL, 0, 0);

         SDL_free(window->driverdata);
         window->driverdata = NULL;
     }
 }

 static void
 Emscripten_SetWindowFullscreen(_THIS, SDL_Window * window, SDL_VideoDisplay * display, SDL_bool fullscreen)
 {
     SDL_WindowData *data;
     if(window->driverdata) {
         data = (SDL_WindowData *) window->driverdata;

         if(fullscreen) {
             EmscriptenFullscreenStrategy strategy;
             SDL_bool is_desktop_fullscreen = (window->flags & SDL_WINDOW_FULLSCREEN_DESKTOP) == SDL_WINDOW_FULLSCREEN_DESKTOP;
             int res;

             strategy.scaleMode = is_desktop_fullscreen ? EMSCRIPTEN_FULLSCREEN_SCALE_STRETCH : EMSCRIPTEN_FULLSCREEN_SCALE_ASPECT;

             if(!is_desktop_fullscreen) {
                 strategy.canvasResolutionScaleMode = EMSCRIPTEN_FULLSCREEN_CANVAS_SCALE_NONE;
             } else if(window->flags & SDL_WINDOW_ALLOW_HIGHDPI) {
                 strategy.canvasResolutionScaleMode = EMSCRIPTEN_FULLSCREEN_CANVAS_SCALE_HIDEF;
             } else {
                 strategy.canvasResolutionScaleMode = EMSCRIPTEN_FULLSCREEN_CANVAS_SCALE_STDDEF;
             }

             strategy.filteringMode = EMSCRIPTEN_FULLSCREEN_FILTERING_DEFAULT;

             strategy.canvasResizedCallback = Emscripten_HandleCanvasResize;
             strategy.canvasResizedCallbackUserData = data;

             data->requested_fullscreen_mode = window->flags & (SDL_WINDOW_FULLSCREEN_DESKTOP | SDL_WINDOW_FULLSCREEN);
             data->fullscreen_resize = is_desktop_fullscreen;

             res = emscripten_request_fullscreen_strategy(NULL, 1, &strategy);
             if(res != EMSCRIPTEN_RESULT_SUCCESS && res != EMSCRIPTEN_RESULT_DEFERRED) {
                 /* unset flags, fullscreen failed */
                 window->flags &= ~(SDL_WINDOW_FULLSCREEN_DESKTOP | SDL_WINDOW_FULLSCREEN);
             }
         }
         else
             emscripten_exit_fullscreen();
     }
 }

 static void
 Emscripten_SetWindowTitle(_THIS, SDL_Window * window) {
     EM_ASM_INT({
       if (typeof Module['setWindowTitle'] !== 'undefined') {
         Module['setWindowTitle'](UTF8ToString($0));
       }
       return 0;
     }, window->title);
 }

 #endif /* SDL_VIDEO_DRIVER_EMSCRIPTEN */

 /* vi: set ts=4 sw=4 expandtab: */
	/*
	Simple DirectMedia Layer
	Copyright (C) 1997-2019 Sam Lantinga <slouken@libsdl.org>

	This software is provided 'as-is', without any express or implied
	warranty. In no event will the authors be held liable for any damages
	arising from the use of this software.

	Permission is granted to anyone to use this software for any purpose,
	including commercial applications, and to alter it and redistribute it
	freely, subject to the following restrictions:

	1. The origin of this software must not be misrepresented; you must not
	claim that you wrote the original software. If you use this software
	in a product, an acknowledgment in the product documentation would be
	appreciated but is not required.
	2. Altered source versions must be plainly marked as such, and must not be
	misrepresented as being the original software.
	3. This notice may not be removed or altered from any source distribution.
	*/
	#include "../../SDL_internal.h"

	#if SDL_VIDEO_DRIVER_EMSCRIPTEN

	#include "SDL_video.h"
	#include "SDL_mouse.h"
	#include "SDL_hints.h"
	#include "../SDL_sysvideo.h"
	#include "../SDL_pixels_c.h"
	#include "../SDL_egl_c.h"
	#include "../../events/SDL_events_c.h"

	#include "SDL_emscriptenvideo.h"
	#include "SDL_emscriptenopengles.h"
	#include "SDL_emscriptenframebuffer.h"
	#include "SDL_emscriptenevents.h"
	#include "SDL_emscriptenmouse.h"

	#define EMSCRIPTENVID_DRIVER_NAME "emscripten"

	/* Initialization/Query functions */
	static int Emscripten_VideoInit(_THIS);
	static int Emscripten_SetDisplayMode(_THIS, SDL_VideoDisplay * display, SDL_DisplayMode * mode);
	static void Emscripten_VideoQuit(_THIS);

	static int Emscripten_CreateWindow(_THIS, SDL_Window * window);
	static void Emscripten_SetWindowSize(_THIS, SDL_Window * window);
	static void Emscripten_DestroyWindow(_THIS, SDL_Window * window);
	static void Emscripten_SetWindowFullscreen(_THIS, SDL_Window * window, SDL_VideoDisplay * display, SDL_bool fullscreen);
	static void Emscripten_PumpEvents(_THIS);
	static void Emscripten_SetWindowTitle(_THIS, SDL_Window * window);


	/* Emscripten driver bootstrap functions */

	static int
	Emscripten_Available(void)
	{
	return (1);
	}

	static void
	Emscripten_DeleteDevice(SDL_VideoDevice * device)
	{
	SDL_free(device);
	}

	static SDL_VideoDevice *
	Emscripten_CreateDevice(int devindex)
	{
	SDL_VideoDevice *device;

	/* Initialize all variables that we clean on shutdown */
	device = (SDL_VideoDevice *) SDL_calloc(1, sizeof(SDL_VideoDevice));
	if (!device) {
	SDL_OutOfMemory();
	return (0);
	}

	/* Firefox sends blur event which would otherwise prevent full screen
	* when the user clicks to allow full screen.
	* See https://bugzilla.mozilla.org/show_bug.cgi?id=1144964
	*/
	SDL_SetHint(SDL_HINT_VIDEO_MINIMIZE_ON_FOCUS_LOSS, "0");

	/* Set the function pointers */
	device->VideoInit = Emscripten_VideoInit;
	device->VideoQuit = Emscripten_VideoQuit;
	device->SetDisplayMode = Emscripten_SetDisplayMode;


	device->PumpEvents = Emscripten_PumpEvents;

	device->CreateSDLWindow = Emscripten_CreateWindow;
	device->SetWindowTitle = Emscripten_SetWindowTitle;
	/*device->SetWindowIcon = Emscripten_SetWindowIcon;
	device->SetWindowPosition = Emscripten_SetWindowPosition;*/
	device->SetWindowSize = Emscripten_SetWindowSize;
	/*device->ShowWindow = Emscripten_ShowWindow;
	device->HideWindow = Emscripten_HideWindow;
	device->RaiseWindow = Emscripten_RaiseWindow;
	device->MaximizeWindow = Emscripten_MaximizeWindow;
	device->MinimizeWindow = Emscripten_MinimizeWindow;
	device->RestoreWindow = Emscripten_RestoreWindow;
	device->SetWindowGrab = Emscripten_SetWindowGrab;*/
	device->DestroyWindow = Emscripten_DestroyWindow;
	device->SetWindowFullscreen = Emscripten_SetWindowFullscreen;

	device->CreateWindowFramebuffer = Emscripten_CreateWindowFramebuffer;
	device->UpdateWindowFramebuffer = Emscripten_UpdateWindowFramebuffer;
	device->DestroyWindowFramebuffer = Emscripten_DestroyWindowFramebuffer;

	#if SDL_VIDEO_OPENGL_EGL
	device->GL_LoadLibrary = Emscripten_GLES_LoadLibrary;
	device->GL_GetProcAddress = Emscripten_GLES_GetProcAddress;
	device->GL_UnloadLibrary = Emscripten_GLES_UnloadLibrary;
	device->GL_CreateContext = Emscripten_GLES_CreateContext;
	device->GL_MakeCurrent = Emscripten_GLES_MakeCurrent;
	device->GL_SetSwapInterval = Emscripten_GLES_SetSwapInterval;
	device->GL_GetSwapInterval = Emscripten_GLES_GetSwapInterval;
	device->GL_SwapWindow = Emscripten_GLES_SwapWindow;
	device->GL_DeleteContext = Emscripten_GLES_DeleteContext;
	device->GL_GetDrawableSize = Emscripten_GLES_GetDrawableSize;
	#endif

	device->free = Emscripten_DeleteDevice;

	return device;
	}

	VideoBootStrap Emscripten_bootstrap = {
	EMSCRIPTENVID_DRIVER_NAME, "SDL emscripten video driver",
	Emscripten_Available, Emscripten_CreateDevice
	};


	int
	Emscripten_VideoInit(_THIS)
	{
	SDL_DisplayMode mode;

	/* Use a fake 32-bpp desktop mode */
	mode.format = SDL_PIXELFORMAT_RGB888;

	mode.w = EM_ASM_INT_V({
	return screen.width;
	});

	mode.h = EM_ASM_INT_V({
	return screen.height;
	});

	mode.refresh_rate = 0;
	mode.driverdata = NULL;
	if (SDL_AddBasicVideoDisplay(&mode) < 0) {
	return -1;
	}

	SDL_AddDisplayMode(&_this->displays[0], &mode);

	Emscripten_InitMouse();

	/* We're done! */
	return 0;
	}

	static int
	Emscripten_SetDisplayMode(_THIS, SDL_VideoDisplay * display, SDL_DisplayMode * mode)
	{
	/* can't do this */
	return 0;
	}

	static void
	Emscripten_VideoQuit(_THIS)
	{
	Emscripten_FiniMouse();
	}

	static void
	Emscripten_PumpEvents(_THIS)
	{
	/* do nothing. */
	}

	static int
	Emscripten_CreateWindow(_THIS, SDL_Window * window)
	{
	SDL_WindowData *wdata;
	double scaled_w, scaled_h;
	double css_w, css_h;

	/* Allocate window internal data */
	wdata = (SDL_WindowData *) SDL_calloc(1, sizeof(SDL_WindowData));
	if (wdata == NULL) {
	return SDL_OutOfMemory();
	}

	if (window->flags & SDL_WINDOW_ALLOW_HIGHDPI) {
	wdata->pixel_ratio = emscripten_get_device_pixel_ratio();
	} else {
	wdata->pixel_ratio = 1.0f;
	}

	scaled_w = SDL_floor(window->w * wdata->pixel_ratio);
	scaled_h = SDL_floor(window->h * wdata->pixel_ratio);

	/* set a fake size to check if there is any CSS sizing the canvas */
	emscripten_set_canvas_element_size(NULL, 1, 1);
	emscripten_get_element_css_size(NULL, &css_w, &css_h);

	wdata->external_size = SDL_floor(css_w) != 1 \|\| SDL_floor(css_h) != 1;

	if ((window->flags & SDL_WINDOW_RESIZABLE) && wdata->external_size) {
	/* external css has resized us */
	scaled_w = css_w * wdata->pixel_ratio;
	scaled_h = css_h * wdata->pixel_ratio;

	SDL_SendWindowEvent(window, SDL_WINDOWEVENT_RESIZED, css_w, css_h);
	}

	emscripten_set_canvas_element_size(NULL, scaled_w, scaled_h);

	/* if the size is not being controlled by css, we need to scale down for hidpi */
	if (!wdata->external_size) {
	if (wdata->pixel_ratio != 1.0f) {
	/scale canvas down/
	emscripten_set_element_css_size(NULL, window->w, window->h);
	}
	}

	#if SDL_VIDEO_OPENGL_EGL
	if (window->flags & SDL_WINDOW_OPENGL) {
	if (!_this->egl_data) {
	if (SDL_GL_LoadLibrary(NULL) < 0) {
	return -1;
	}
	}
	wdata->egl_surface = SDL_EGL_CreateSurface(_this, 0);

	if (wdata->egl_surface == EGL_NO_SURFACE) {
	return SDL_SetError("Could not create GLES window surface");
	}
	}
	#endif

	wdata->window = window;

	/* Setup driver data for this window */
	window->driverdata = wdata;

	/* One window, it always has focus */
	SDL_SetMouseFocus(window);
	SDL_SetKeyboardFocus(window);

	Emscripten_RegisterEventHandlers(wdata);

	/* Window has been successfully created */
	return 0;
	}

	static void Emscripten_SetWindowSize(_THIS, SDL_Window * window)
	{
	SDL_WindowData *data;

	if (window->driverdata) {
	data = (SDL_WindowData *) window->driverdata;
	/* update pixel ratio */
	if (window->flags & SDL_WINDOW_ALLOW_HIGHDPI) {
	data->pixel_ratio = emscripten_get_device_pixel_ratio();
	}
	emscripten_set_canvas_element_size(NULL, window->w * data->pixel_ratio, window->h * data->pixel_ratio);

	/scale canvas down/
	if (!data->external_size && data->pixel_ratio != 1.0f) {
	emscripten_set_element_css_size(NULL, window->w, window->h);
	}
	}
	}

	static void
	Emscripten_DestroyWindow(_THIS, SDL_Window * window)
	{
	SDL_WindowData *data;

	if(window->driverdata) {
	data = (SDL_WindowData *) window->driverdata;

	Emscripten_UnregisterEventHandlers(data);
	#if SDL_VIDEO_OPENGL_EGL
	if (data->egl_surface != EGL_NO_SURFACE) {
	SDL_EGL_DestroySurface(_this, data->egl_surface);
	data->egl_surface = EGL_NO_SURFACE;
	}
	#endif

	/* We can't destroy the canvas, so resize it to zero instead */
	emscripten_set_canvas_element_size(NULL, 0, 0);

	SDL_free(window->driverdata);
	window->driverdata = NULL;
	}
	}

	static void
	Emscripten_SetWindowFullscreen(_THIS, SDL_Window * window, SDL_VideoDisplay * display, SDL_bool fullscreen)
	{
	SDL_WindowData *data;
	if(window->driverdata) {
	data = (SDL_WindowData *) window->driverdata;

	if(fullscreen) {
	EmscriptenFullscreenStrategy strategy;
	SDL_bool is_desktop_fullscreen = (window->flags & SDL_WINDOW_FULLSCREEN_DESKTOP) == SDL_WINDOW_FULLSCREEN_DESKTOP;
	int res;

	strategy.scaleMode = is_desktop_fullscreen ? EMSCRIPTEN_FULLSCREEN_SCALE_STRETCH : EMSCRIPTEN_FULLSCREEN_SCALE_ASPECT;

	if(!is_desktop_fullscreen) {
	strategy.canvasResolutionScaleMode = EMSCRIPTEN_FULLSCREEN_CANVAS_SCALE_NONE;
	} else if(window->flags & SDL_WINDOW_ALLOW_HIGHDPI) {
	strategy.canvasResolutionScaleMode = EMSCRIPTEN_FULLSCREEN_CANVAS_SCALE_HIDEF;
	} else {
	strategy.canvasResolutionScaleMode = EMSCRIPTEN_FULLSCREEN_CANVAS_SCALE_STDDEF;
	}

	strategy.filteringMode = EMSCRIPTEN_FULLSCREEN_FILTERING_DEFAULT;

	strategy.canvasResizedCallback = Emscripten_HandleCanvasResize;
	strategy.canvasResizedCallbackUserData = data;

	data->requested_fullscreen_mode = window->flags & (SDL_WINDOW_FULLSCREEN_DESKTOP \| SDL_WINDOW_FULLSCREEN);
	data->fullscreen_resize = is_desktop_fullscreen;

	res = emscripten_request_fullscreen_strategy(NULL, 1, &strategy);
	if(res != EMSCRIPTEN_RESULT_SUCCESS && res != EMSCRIPTEN_RESULT_DEFERRED) {
	/* unset flags, fullscreen failed */
	window->flags &= ~(SDL_WINDOW_FULLSCREEN_DESKTOP \| SDL_WINDOW_FULLSCREEN);
	}
	}
	else
	emscripten_exit_fullscreen();
	}
	}

	static void
	Emscripten_SetWindowTitle(_THIS, SDL_Window * window) {
	EM_ASM_INT({
	if (typeof Module['setWindowTitle'] !== 'undefined') {
	Module['setWindowTitle'](UTF8ToString($0));
	}
	return 0;
	}, window->title);
	}

	#endif /* SDL_VIDEO_DRIVER_EMSCRIPTEN */

	/* vi: set ts=4 sw=4 expandtab: */