Atlas - SDL_emscriptenopengles.c
Home / ext / SDL / src / video / emscripten
Lines: 1 | Size: 5201 bytes
[Download] [Show on GitHub] [Search similar files] [Raw] [Raw (proxy)] 
[FILE BEGIN]
1/*
2  Simple DirectMedia Layer
3  Copyright (C) 1997-2025 Sam Lantinga <[email protected]>
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#ifdef SDL_VIDEO_DRIVER_EMSCRIPTEN
24
25#include <emscripten/emscripten.h>
26#include <emscripten/html5_webgl.h>
27#include <GLES2/gl2.h>
28
29#include "SDL_emscriptenvideo.h"
30#include "SDL_emscriptenopengles.h"
31#include "../../main/SDL_main_callbacks.h"
32
33bool Emscripten_GLES_LoadLibrary(SDL_VideoDevice *_this, const char *path)
34{
35    return true;
36}
37
38void Emscripten_GLES_UnloadLibrary(SDL_VideoDevice *_this)
39{
40}
41
42SDL_FunctionPointer Emscripten_GLES_GetProcAddress(SDL_VideoDevice *_this, const char *proc)
43{
44    return emscripten_webgl_get_proc_address(proc);
45}
46
47bool Emscripten_GLES_SetSwapInterval(SDL_VideoDevice *_this, int interval)
48{
49    if (interval < 0) {
50        return SDL_SetError("Late swap tearing currently unsupported");
51    }
52
53    if (Emscripten_ShouldSetSwapInterval(interval)) {
54        // don't change the mainloop timing if the app is also driving a main callback with this hint,
55        //  as we assume that was the more deliberate action.
56        if (!SDL_HasMainCallbacks() || !SDL_GetHint(SDL_HINT_MAIN_CALLBACK_RATE)) {
57            if (interval == 0) {
58                emscripten_set_main_loop_timing(EM_TIMING_SETTIMEOUT, 0);
59            } else {
60                emscripten_set_main_loop_timing(EM_TIMING_RAF, interval);
61            }
62        }
63    }
64
65    return true;
66}
67
68bool Emscripten_GLES_GetSwapInterval(SDL_VideoDevice *_this, int *interval)
69{
70    int mode, value;
71
72    emscripten_get_main_loop_timing(&mode, &value);
73
74    if (mode == EM_TIMING_RAF) {
75        *interval = value;
76        return true;
77    } else {
78        *interval = 0;
79        return true;
80    }
81}
82
83SDL_GLContext Emscripten_GLES_CreateContext(SDL_VideoDevice *_this, SDL_Window *window)
84{
85    SDL_WindowData *window_data;
86
87    EmscriptenWebGLContextAttributes attribs;
88    EMSCRIPTEN_WEBGL_CONTEXT_HANDLE context;
89
90    emscripten_webgl_init_context_attributes(&attribs);
91
92    attribs.alpha = _this->gl_config.alpha_size > 0;
93    attribs.depth = _this->gl_config.depth_size > 0;
94    attribs.stencil = _this->gl_config.stencil_size > 0;
95    attribs.antialias = _this->gl_config.multisamplebuffers == 1;
96
97    if (_this->gl_config.major_version == 3)
98        attribs.majorVersion = 2; // WebGL 2.0 ~= GLES 3.0
99
100    window_data = window->internal;
101
102    if (window_data->gl_context) {
103        SDL_SetError("Cannot create multiple webgl contexts per window");
104        return NULL;
105    }
106
107    context = emscripten_webgl_create_context(window_data->canvas_id, &attribs);
108
109    if (!context) {
110        SDL_SetError("Could not create webgl context");
111        return NULL;
112    }
113
114    if (emscripten_webgl_make_context_current(context) != EMSCRIPTEN_RESULT_SUCCESS) {
115        emscripten_webgl_destroy_context(context);
116        return NULL;
117    }
118
119    window_data->gl_context = (SDL_GLContext)context;
120
121    return (SDL_GLContext)context;
122}
123
124bool Emscripten_GLES_DestroyContext(SDL_VideoDevice *_this, SDL_GLContext context)
125{
126    SDL_Window *window;
127
128    // remove the context from its window
129    for (window = _this->windows; window; window = window->next) {
130        SDL_WindowData *window_data = window->internal;
131
132        if (window_data->gl_context == context) {
133            window_data->gl_context = NULL;
134        }
135    }
136
137    emscripten_webgl_destroy_context((EMSCRIPTEN_WEBGL_CONTEXT_HANDLE)context);
138    return true;
139}
140
141bool Emscripten_GLES_SwapWindow(SDL_VideoDevice *_this, SDL_Window *window)
142{
143    if (emscripten_has_asyncify() && SDL_GetHintBoolean(SDL_HINT_EMSCRIPTEN_ASYNCIFY, true)) {
144        // give back control to browser for screen refresh
145        emscripten_sleep(0);
146    }
147    return true;
148}
149
150bool Emscripten_GLES_MakeCurrent(SDL_VideoDevice *_this, SDL_Window *window, SDL_GLContext context)
151{
152    // it isn't possible to reuse contexts across canvases
153    if (window && context) {
154        SDL_WindowData *window_data = window->internal;
155
156        if (context != window_data->gl_context) {
157            return SDL_SetError("Cannot make context current to another window");
158        }
159    }
160
161    if (emscripten_webgl_make_context_current((EMSCRIPTEN_WEBGL_CONTEXT_HANDLE)context) != EMSCRIPTEN_RESULT_SUCCESS) {
162        return SDL_SetError("Unable to make context current");
163    }
164    return true;
165}
166
167#endif // SDL_VIDEO_DRIVER_EMSCRIPTEN
168
[FILE END]
(C) 2025 0x4248
(C) 2025 4248 Media and 4248 Systems, All part of 0x4248
See LICENCE files for more information. Not all files are by 0x4248 always check Licencing.