Atlas - SDL_emscriptenframebuffer.c
Home / ext / SDL / src / video / emscripten
Lines: 1 | Size: 4094 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 "SDL_emscriptenvideo.h"
26#include "SDL_emscriptenframebuffer.h"
27
28#include <emscripten/threading.h>
29
30bool Emscripten_CreateWindowFramebuffer(SDL_VideoDevice *_this, SDL_Window *window, SDL_PixelFormat *format, void **pixels, int *pitch)
31{
32    SDL_Surface *surface;
33    const SDL_PixelFormat surface_format = SDL_PIXELFORMAT_RGBA32;
34    int w, h;
35
36    // Free the old framebuffer surface
37    SDL_WindowData *data = window->internal;
38    surface = data->surface;
39    SDL_DestroySurface(surface);
40
41    // Create a new one
42    SDL_GetWindowSizeInPixels(window, &w, &h);
43
44    surface = SDL_CreateSurface(w, h, surface_format);
45    if (!surface) {
46        return false;
47    }
48
49    // Save the info and return!
50    data->surface = surface;
51    *format = surface_format;
52    *pixels = surface->pixels;
53    *pitch = surface->pitch;
54    return true;
55}
56
57bool Emscripten_UpdateWindowFramebuffer(SDL_VideoDevice *_this, SDL_Window *window, const SDL_Rect *rects, int numrects)
58{
59    SDL_Surface *surface;
60
61    SDL_WindowData *data = window->internal;
62    surface = data->surface;
63    if (!surface) {
64        return SDL_SetError("Couldn't find framebuffer surface for window");
65    }
66
67    // Send the data to the display
68
69    /* *INDENT-OFF* */ // clang-format off
70    int updated = MAIN_THREAD_EM_ASM_INT({
71        var w = $0;
72        var h = $1;
73        var pixels = $2;
74        var canvasId = UTF8ToString($3);
75        var canvas = document.querySelector(canvasId);
76
77        //TODO: this should store a context per canvas
78        if (!Module['SDL3']) Module['SDL3'] = {};
79        var SDL3 = Module['SDL3'];
80        if (SDL3.ctxCanvas !== canvas) {
81            SDL3.ctx = Browser.createContext(canvas, false, true);
82            if (!SDL3.ctx) {
83                return false;
84            }
85            SDL3.ctxCanvas = canvas;
86        }
87        if (SDL3.w !== w || SDL3.h !== h || SDL3.imageCtx !== SDL3.ctx) {
88            SDL3.image = SDL3.ctx.createImageData(w, h);
89            SDL3.w = w;
90            SDL3.h = h;
91            SDL3.imageCtx = SDL3.ctx;
92        }
93        var data = SDL3.image.data;
94        var src = pixels / 4;
95
96        if (SDL3.data32Data !== data) {
97            SDL3.data32 = new Int32Array(data.buffer);
98            SDL3.data32Data = data;
99        }
100        var data32 = SDL3.data32;
101        data32.set(HEAP32.subarray(src, src + data32.length));
102
103        SDL3.ctx.putImageData(SDL3.image, 0, 0);
104        return true;
105    }, surface->w, surface->h, surface->pixels, data->canvas_id);
106    /* *INDENT-ON* */ // clang-format on
107
108    if (!updated) {
109        return SDL_SetError("Couldn't create context for canvas update");
110    }
111
112    if (emscripten_has_asyncify() && SDL_GetHintBoolean(SDL_HINT_EMSCRIPTEN_ASYNCIFY, true)) {
113        // give back control to browser for screen refresh
114        emscripten_sleep(0);
115    }
116
117    return true;
118}
119
120void Emscripten_DestroyWindowFramebuffer(SDL_VideoDevice *_this, SDL_Window *window)
121{
122    SDL_WindowData *data = window->internal;
123
124    SDL_DestroySurface(data->surface);
125    data->surface = NULL;
126}
127
128#endif // SDL_VIDEO_DRIVER_EMSCRIPTEN
129
[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.