/*

   Simple DirectMedia Layer

   Copyright (C) 1997-2016 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_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);

     }

     /* Set the function pointers */

     device->VideoInit = Emscripten_VideoInit;

     device->VideoQuit = Emscripten_VideoQuit;

     device->SetDisplayMode = Emscripten_SetDisplayMode;

     device->PumpEvents = Emscripten_PumpEvents;

     device->CreateWindow = Emscripten_CreateWindow;

     /*device->CreateWindowFrom = Emscripten_CreateWindowFrom;*/

     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;

     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;

     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;

     double css_w, css_h;

     /* Use a fake 32-bpp desktop mode */

     mode.format = SDL_PIXELFORMAT_RGB888;

     emscripten_get_element_css_size(NULL, &css_w, &css_h);

     mode.w = css_w;

     mode.h = css_h;

     mode.refresh_rate = 0;

     mode.driverdata = NULL;

     if (SDL_AddBasicVideoDisplay(&mode) < 0) {

         return -1;

     }

     SDL_zero(mode);

     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);

     emscripten_set_canvas_size(scaled_w, scaled_h);

     emscripten_get_element_css_size(NULL, &css_w, &css_h);

     wdata->external_size = css_w != scaled_w || css_h != scaled_h;

     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;

         emscripten_set_canvas_size(scaled_w, scaled_h);

         SDL_SendWindowEvent(window, SDL_WINDOWEVENT_RESIZED, css_w, css_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 (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");

         }

     }

     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;

         emscripten_set_canvas_size(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 (data->egl_surface != EGL_NO_SURFACE) {

             SDL_EGL_DestroySurface(_this, data->egl_surface);

             data->egl_surface = EGL_NO_SURFACE;

         }

         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;

             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;

             /*unset the fullscreen flags as we're not actually fullscreen yet*/

             window->flags &= ~(SDL_WINDOW_FULLSCREEN_DESKTOP | SDL_WINDOW_FULLSCREEN);

             emscripten_request_fullscreen_strategy(NULL, 1, &strategy);

         }

         else

             emscripten_exit_fullscreen();

     }

 }

 static void

 Emscripten_SetWindowTitle(_THIS, SDL_Window * window) {

     EM_ASM_INT({

       if (typeof Module['setWindowTitle'] !== 'undefined') {

         Module['setWindowTitle'](Module['Pointer_stringify']($0));

       }

       return 0;

     }, window->title);

 }

 #endif /* SDL_VIDEO_DRIVER_EMSCRIPTEN */

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