From 5a079a2d114f96d4847d1ee305d5b7c16eeec50e Mon Sep 17 00:00:00 2001 From: 3gg <3gg@shellblade.net> Date: Sat, 27 Dec 2025 12:03:39 -0800 Subject: Initial commit --- .../video/emscripten/SDL_emscriptenframebuffer.c | 161 +++++++++++++++++++++ 1 file changed, 161 insertions(+) create mode 100644 contrib/SDL-3.2.8/src/video/emscripten/SDL_emscriptenframebuffer.c (limited to 'contrib/SDL-3.2.8/src/video/emscripten/SDL_emscriptenframebuffer.c') diff --git a/contrib/SDL-3.2.8/src/video/emscripten/SDL_emscriptenframebuffer.c b/contrib/SDL-3.2.8/src/video/emscripten/SDL_emscriptenframebuffer.c new file mode 100644 index 0000000..503fac6 --- /dev/null +++ b/contrib/SDL-3.2.8/src/video/emscripten/SDL_emscriptenframebuffer.c @@ -0,0 +1,161 @@ +/* + Simple DirectMedia Layer + Copyright (C) 1997-2025 Sam Lantinga + + 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" + +#ifdef SDL_VIDEO_DRIVER_EMSCRIPTEN + +#include "SDL_emscriptenvideo.h" +#include "SDL_emscriptenframebuffer.h" + +#include + +bool Emscripten_CreateWindowFramebuffer(SDL_VideoDevice *_this, SDL_Window *window, SDL_PixelFormat *format, void **pixels, int *pitch) +{ + SDL_Surface *surface; + const SDL_PixelFormat surface_format = SDL_PIXELFORMAT_XBGR8888; + int w, h; + + // Free the old framebuffer surface + SDL_WindowData *data = window->internal; + surface = data->surface; + SDL_DestroySurface(surface); + + // Create a new one + SDL_GetWindowSizeInPixels(window, &w, &h); + + surface = SDL_CreateSurface(w, h, surface_format); + if (!surface) { + return false; + } + + // Save the info and return! + data->surface = surface; + *format = surface_format; + *pixels = surface->pixels; + *pitch = surface->pitch; + return true; +} + +bool Emscripten_UpdateWindowFramebuffer(SDL_VideoDevice *_this, SDL_Window *window, const SDL_Rect *rects, int numrects) +{ + SDL_Surface *surface; + + SDL_WindowData *data = window->internal; + surface = data->surface; + if (!surface) { + return SDL_SetError("Couldn't find framebuffer surface for window"); + } + + // Send the data to the display + + /* *INDENT-OFF* */ // clang-format off + MAIN_THREAD_EM_ASM({ + var w = $0; + var h = $1; + var pixels = $2; + var canvasId = UTF8ToString($3); + var canvas = document.querySelector(canvasId); + + //TODO: this should store a context per canvas + if (!Module['SDL3']) Module['SDL3'] = {}; + var SDL3 = Module['SDL3']; + if (SDL3.ctxCanvas !== canvas) { + SDL3.ctx = Module['createContext'](canvas, false, true); + SDL3.ctxCanvas = canvas; + } + if (SDL3.w !== w || SDL3.h !== h || SDL3.imageCtx !== SDL3.ctx) { + SDL3.image = SDL3.ctx.createImageData(w, h); + SDL3.w = w; + SDL3.h = h; + SDL3.imageCtx = SDL3.ctx; + } + var data = SDL3.image.data; + var src = pixels / 4; + var dst = 0; + var num; + + if (SDL3.data32Data !== data) { + SDL3.data32 = new Int32Array(data.buffer); + SDL3.data8 = new Uint8Array(data.buffer); + SDL3.data32Data = data; + } + var data32 = SDL3.data32; + num = data32.length; + // logically we need to do + // while (dst < num) { + // data32[dst++] = HEAP32[src++] | 0xff000000 + // } + // the following code is faster though, because + // .set() is almost free - easily 10x faster due to + // native SDL_memcpy efficiencies, and the remaining loop + // just stores, not load + store, so it is faster + data32.set(HEAP32.subarray(src, src + num)); + var data8 = SDL3.data8; + var i = 3; + var j = i + 4*num; + if (num % 8 == 0) { + // unrolling gives big speedups + while (i < j) { + data8[i] = 0xff; + i = i + 4 | 0; + data8[i] = 0xff; + i = i + 4 | 0; + data8[i] = 0xff; + i = i + 4 | 0; + data8[i] = 0xff; + i = i + 4 | 0; + data8[i] = 0xff; + i = i + 4 | 0; + data8[i] = 0xff; + i = i + 4 | 0; + data8[i] = 0xff; + i = i + 4 | 0; + data8[i] = 0xff; + i = i + 4 | 0; + } + } else { + while (i < j) { + data8[i] = 0xff; + i = i + 4 | 0; + } + } + + SDL3.ctx.putImageData(SDL3.image, 0, 0); + }, surface->w, surface->h, surface->pixels, data->canvas_id); + /* *INDENT-ON* */ // clang-format on + + if (emscripten_has_asyncify() && SDL_GetHintBoolean(SDL_HINT_EMSCRIPTEN_ASYNCIFY, true)) { + // give back control to browser for screen refresh + emscripten_sleep(0); + } + + return true; +} + +void Emscripten_DestroyWindowFramebuffer(SDL_VideoDevice *_this, SDL_Window *window) +{ + SDL_WindowData *data = window->internal; + + SDL_DestroySurface(data->surface); + data->surface = NULL; +} + +#endif // SDL_VIDEO_DRIVER_EMSCRIPTEN -- cgit v1.2.3