1 /*
2   Simple DirectMedia Layer
3   Copyright (C) 1997-2020 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 && SDL_VIDEO_OPENGL_EGL
24 
25 #include <emscripten/emscripten.h>
26 #include <GLES2/gl2.h>
27 
28 #include "SDL_emscriptenvideo.h"
29 #include "SDL_emscriptenopengles.h"
30 #include "SDL_hints.h"
31 
32 #define LOAD_FUNC(NAME) _this->egl_data->NAME = NAME;
33 
34 /* EGL implementation of SDL OpenGL support */
35 
36 int
Emscripten_GLES_LoadLibrary(_THIS,const char * path)37 Emscripten_GLES_LoadLibrary(_THIS, const char *path) {
38     /*we can't load EGL dynamically*/
39     _this->egl_data = (struct SDL_EGL_VideoData *) SDL_calloc(1, sizeof(SDL_EGL_VideoData));
40     if (!_this->egl_data) {
41         return SDL_OutOfMemory();
42     }
43 
44     /* Emscripten forces you to manually cast eglGetProcAddress to the real
45        function type; grep for "__eglMustCastToProperFunctionPointerType" in
46        Emscripten's egl.h for details. */
47     _this->egl_data->eglGetProcAddress = (void *(EGLAPIENTRY *)(const char *)) eglGetProcAddress;
48 
49     LOAD_FUNC(eglGetDisplay);
50     LOAD_FUNC(eglInitialize);
51     LOAD_FUNC(eglTerminate);
52     LOAD_FUNC(eglChooseConfig);
53     LOAD_FUNC(eglGetConfigAttrib);
54     LOAD_FUNC(eglCreateContext);
55     LOAD_FUNC(eglDestroyContext);
56     LOAD_FUNC(eglCreateWindowSurface);
57     LOAD_FUNC(eglDestroySurface);
58     LOAD_FUNC(eglMakeCurrent);
59     LOAD_FUNC(eglSwapBuffers);
60     LOAD_FUNC(eglSwapInterval);
61     LOAD_FUNC(eglWaitNative);
62     LOAD_FUNC(eglWaitGL);
63     LOAD_FUNC(eglBindAPI);
64     LOAD_FUNC(eglQueryString);
65     LOAD_FUNC(eglGetError);
66 
67     _this->egl_data->egl_display = _this->egl_data->eglGetDisplay(EGL_DEFAULT_DISPLAY);
68     if (!_this->egl_data->egl_display) {
69         return SDL_SetError("Could not get EGL display");
70     }
71 
72     if (_this->egl_data->eglInitialize(_this->egl_data->egl_display, NULL, NULL) != EGL_TRUE) {
73         return SDL_SetError("Could not initialize EGL");
74     }
75 
76     if (path) {
77         SDL_strlcpy(_this->gl_config.driver_path, path, sizeof(_this->gl_config.driver_path) - 1);
78     } else {
79         *_this->gl_config.driver_path = '\0';
80     }
81 
82     return 0;
83 }
84 
85 SDL_EGL_CreateContext_impl(Emscripten)
SDL_EGL_MakeCurrent_impl(Emscripten)86 SDL_EGL_MakeCurrent_impl(Emscripten)
87 
88 int
89 Emscripten_GLES_SwapWindow(_THIS, SDL_Window * window)
90 {
91     EGLBoolean ret = SDL_EGL_SwapBuffers(_this, ((SDL_WindowData *) window->driverdata)->egl_surface);
92     if (emscripten_has_asyncify() && SDL_GetHintBoolean(SDL_HINT_EMSCRIPTEN_ASYNCIFY, SDL_TRUE)) {
93         /* give back control to browser for screen refresh */
94         emscripten_sleep(0);
95     }
96     return ret;
97 }
98 
99 void
Emscripten_GLES_GetDrawableSize(_THIS,SDL_Window * window,int * w,int * h)100 Emscripten_GLES_GetDrawableSize(_THIS, SDL_Window * window, int * w, int * h)
101 {
102     SDL_WindowData *data;
103     if (window->driverdata) {
104         data = (SDL_WindowData *) window->driverdata;
105 
106         if (w) {
107             *w = window->w * data->pixel_ratio;
108         }
109 
110         if (h) {
111             *h = window->h * data->pixel_ratio;
112         }
113     }
114 }
115 
116 #endif /* SDL_VIDEO_DRIVER_EMSCRIPTEN && SDL_VIDEO_OPENGL_EGL */
117 
118 /* vi: set ts=4 sw=4 expandtab: */
119 
120