src/video/emscripten/SDL_emscriptenframebuffer.c
author Sam Lantinga
Sat, 02 Jan 2016 10:10:34 -0800
changeset 9998 f67cf37e9cd4
parent 9619 b94b6d0bff0f
child 10323 abfc071013af
permissions -rw-r--r--
Updated copyright to 2016
     1 /*
     2   Simple DirectMedia Layer
     3   Copyright (C) 1997-2016 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
    24 
    25 #include "SDL_emscriptenvideo.h"
    26 #include "SDL_emscriptenframebuffer.h"
    27 
    28 
    29 int Emscripten_CreateWindowFramebuffer(_THIS, SDL_Window * window, Uint32 * format, void ** pixels, int *pitch)
    30 {
    31     SDL_Surface *surface;
    32     const Uint32 surface_format = SDL_PIXELFORMAT_BGR888;
    33     int w, h;
    34     int bpp;
    35     Uint32 Rmask, Gmask, Bmask, Amask;
    36 
    37     /* Free the old framebuffer surface */
    38     SDL_WindowData *data = (SDL_WindowData *) window->driverdata;
    39     surface = data->surface;
    40     SDL_FreeSurface(surface);
    41 
    42     /* Create a new one */
    43     SDL_PixelFormatEnumToMasks(surface_format, &bpp, &Rmask, &Gmask, &Bmask, &Amask);
    44     SDL_GetWindowSize(window, &w, &h);
    45 
    46     surface = SDL_CreateRGBSurface(0, w, h, bpp, Rmask, Gmask, Bmask, Amask);
    47     if (!surface) {
    48         return -1;
    49     }
    50 
    51     /* Save the info and return! */
    52     data->surface = surface;
    53     *format = surface_format;
    54     *pixels = surface->pixels;
    55     *pitch = surface->pitch;
    56     return 0;
    57 }
    58 
    59 int Emscripten_UpdateWindowFramebuffer(_THIS, SDL_Window * window, const SDL_Rect * rects, int numrects)
    60 {
    61     SDL_Surface *surface;
    62 
    63     SDL_WindowData *data = (SDL_WindowData *) window->driverdata;
    64     surface = data->surface;
    65     if (!surface) {
    66         return SDL_SetError("Couldn't find framebuffer surface for window");
    67     }
    68 
    69     /* Send the data to the display */
    70 
    71     EM_ASM_INT({
    72         //TODO: don't create context every update
    73         var ctx = Module['canvas'].getContext('2d');
    74 
    75         //library_sdl.js SDL_UnlockSurface
    76         var image = ctx.createImageData($0, $1);
    77         var data = image.data;
    78         var src = $2 >> 2;
    79         var dst = 0;
    80         var isScreen = true;
    81         var num;
    82         if (typeof CanvasPixelArray !== 'undefined' && data instanceof CanvasPixelArray) {
    83             // IE10/IE11: ImageData objects are backed by the deprecated CanvasPixelArray,
    84             // not UInt8ClampedArray. These don't have buffers, so we need to revert
    85             // to copying a byte at a time. We do the undefined check because modern
    86             // browsers do not define CanvasPixelArray anymore.
    87             num = data.length;
    88             while (dst < num) {
    89                 var val = HEAP32[src]; // This is optimized. Instead, we could do {{{ makeGetValue('buffer', 'dst', 'i32') }}};
    90                 data[dst  ] = val & 0xff;
    91                 data[dst+1] = (val >> 8) & 0xff;
    92                 data[dst+2] = (val >> 16) & 0xff;
    93                 data[dst+3] = isScreen ? 0xff : ((val >> 24) & 0xff);
    94                 src++;
    95                 dst += 4;
    96             }
    97         } else {
    98             var data32 = new Uint32Array(data.buffer);
    99             num = data32.length;
   100             if (isScreen) {
   101                 while (dst < num) {
   102                     // HEAP32[src++] is an optimization. Instead, we could do {{{ makeGetValue('buffer', 'dst', 'i32') }}};
   103                     data32[dst++] = HEAP32[src++] | 0xff000000;
   104                 }
   105             } else {
   106                 while (dst < num) {
   107                     data32[dst++] = HEAP32[src++];
   108                 }
   109             }
   110         }
   111 
   112         ctx.putImageData(image, 0, 0);
   113         return 0;
   114     }, surface->w, surface->h, surface->pixels);
   115 
   116     /*if (SDL_getenv("SDL_VIDEO_Emscripten_SAVE_FRAMES")) {
   117         static int frame_number = 0;
   118         char file[128];
   119         SDL_snprintf(file, sizeof(file), "SDL_window%d-%8.8d.bmp",
   120                      SDL_GetWindowID(window), ++frame_number);
   121         SDL_SaveBMP(surface, file);
   122     }*/
   123     return 0;
   124 }
   125 
   126 void Emscripten_DestroyWindowFramebuffer(_THIS, SDL_Window * window)
   127 {
   128     SDL_WindowData *data = (SDL_WindowData *) window->driverdata;
   129 
   130     SDL_FreeSurface(data->surface);
   131     data->surface = NULL;
   132 }
   133 
   134 #endif /* SDL_VIDEO_DRIVER_EMSCRIPTEN */
   135 
   136 /* vi: set ts=4 sw=4 expandtab: */