src/video/emscripten/SDL_emscriptenmouse.c
author Charlie Birks <charlie@daftgames.net>
Tue, 29 Jan 2019 12:19:03 +0000
changeset 12576 8d61748ac590
parent 12503 806492103856
permissions -rw-r--r--
Emscripten: use UTF8ToString instead of Pointer_stringify
     1 /*
     2   Simple DirectMedia Layer
     3   Copyright (C) 1997-2019 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 
    22 
    23 #include "../../SDL_internal.h"
    24 
    25 #if SDL_VIDEO_DRIVER_EMSCRIPTEN
    26 
    27 #include <emscripten/emscripten.h>
    28 #include <emscripten/html5.h>
    29 
    30 #include "SDL_emscriptenmouse.h"
    31 
    32 #include "../../events/SDL_mouse_c.h"
    33 #include "SDL_assert.h"
    34 
    35 static SDL_Cursor*
    36 Emscripten_CreateCursorFromString(const char* cursor_str, SDL_bool is_custom)
    37 {
    38     SDL_Cursor* cursor;
    39     Emscripten_CursorData *curdata;
    40 
    41     cursor = SDL_calloc(1, sizeof(SDL_Cursor));
    42     if (cursor) {
    43         curdata = (Emscripten_CursorData *) SDL_calloc(1, sizeof(*curdata));
    44         if (!curdata) {
    45             SDL_OutOfMemory();
    46             SDL_free(cursor);
    47             return NULL;
    48         }
    49 
    50         curdata->system_cursor = cursor_str;
    51         curdata->is_custom = is_custom;
    52         cursor->driverdata = curdata;
    53     }
    54     else {
    55         SDL_OutOfMemory();
    56     }
    57 
    58     return cursor;
    59 }
    60 
    61 static SDL_Cursor*
    62 Emscripten_CreateDefaultCursor()
    63 {
    64     return Emscripten_CreateCursorFromString("default", SDL_FALSE);
    65 }
    66 
    67 static SDL_Cursor*
    68 Emscripten_CreateCursor(SDL_Surface* surface, int hot_x, int hot_y)
    69 {
    70     const char *cursor_url = NULL;
    71     SDL_Surface *conv_surf;
    72 
    73     conv_surf = SDL_ConvertSurfaceFormat(surface, SDL_PIXELFORMAT_ABGR8888, 0);
    74 
    75     if (!conv_surf) {
    76         return NULL;
    77     }
    78 
    79     cursor_url = (const char *)EM_ASM_INT({
    80         var w = $0;
    81         var h = $1;
    82         var hot_x = $2;
    83         var hot_y = $3;
    84         var pixels = $4;
    85 
    86         var canvas = document.createElement("canvas");
    87         canvas.width = w;
    88         canvas.height = h;
    89 
    90         var ctx = canvas.getContext("2d");
    91 
    92         var image = ctx.createImageData(w, h);
    93         var data = image.data;
    94         var src = pixels >> 2;
    95         var dst = 0;
    96         var num;
    97         if (typeof CanvasPixelArray !== 'undefined' && data instanceof CanvasPixelArray) {
    98             // IE10/IE11: ImageData objects are backed by the deprecated CanvasPixelArray,
    99             // not UInt8ClampedArray. These don't have buffers, so we need to revert
   100             // to copying a byte at a time. We do the undefined check because modern
   101             // browsers do not define CanvasPixelArray anymore.
   102             num = data.length;
   103             while (dst < num) {
   104                 var val = HEAP32[src]; // This is optimized. Instead, we could do {{{ makeGetValue('buffer', 'dst', 'i32') }}};
   105                 data[dst  ] = val & 0xff;
   106                 data[dst+1] = (val >> 8) & 0xff;
   107                 data[dst+2] = (val >> 16) & 0xff;
   108                 data[dst+3] = (val >> 24) & 0xff;
   109                 src++;
   110                 dst += 4;
   111             }
   112         } else {
   113             var data32 = new Int32Array(data.buffer);
   114             num = data32.length;
   115             data32.set(HEAP32.subarray(src, src + num));
   116         }
   117 
   118         ctx.putImageData(image, 0, 0);
   119         var url = hot_x === 0 && hot_y === 0
   120             ? "url(" + canvas.toDataURL() + "), auto"
   121             : "url(" + canvas.toDataURL() + ") " + hot_x + " " + hot_y + ", auto";
   122 
   123         var urlBuf = _malloc(url.length + 1);
   124         stringToUTF8(url, urlBuf, url.length + 1);
   125 
   126         return urlBuf;
   127     }, surface->w, surface->h, hot_x, hot_y, conv_surf->pixels);
   128 
   129     SDL_FreeSurface(conv_surf);
   130 
   131     return Emscripten_CreateCursorFromString(cursor_url, SDL_TRUE);
   132 }
   133 
   134 static SDL_Cursor*
   135 Emscripten_CreateSystemCursor(SDL_SystemCursor id)
   136 {
   137     const char *cursor_name = NULL;
   138 
   139     switch(id) {
   140         case SDL_SYSTEM_CURSOR_ARROW:
   141             cursor_name = "default";
   142             break;
   143         case SDL_SYSTEM_CURSOR_IBEAM:
   144             cursor_name = "text";
   145             break;
   146         case SDL_SYSTEM_CURSOR_WAIT:
   147             cursor_name = "wait";
   148             break;
   149         case SDL_SYSTEM_CURSOR_CROSSHAIR:
   150             cursor_name = "crosshair";
   151             break;
   152         case SDL_SYSTEM_CURSOR_WAITARROW:
   153             cursor_name = "progress";
   154             break;
   155         case SDL_SYSTEM_CURSOR_SIZENWSE:
   156             cursor_name = "nwse-resize";
   157             break;
   158         case SDL_SYSTEM_CURSOR_SIZENESW:
   159             cursor_name = "nesw-resize";
   160             break;
   161         case SDL_SYSTEM_CURSOR_SIZEWE:
   162             cursor_name = "ew-resize";
   163             break;
   164         case SDL_SYSTEM_CURSOR_SIZENS:
   165             cursor_name = "ns-resize";
   166             break;
   167         case SDL_SYSTEM_CURSOR_SIZEALL:
   168             cursor_name = "move";
   169             break;
   170         case SDL_SYSTEM_CURSOR_NO:
   171             cursor_name = "not-allowed";
   172             break;
   173         case SDL_SYSTEM_CURSOR_HAND:
   174             cursor_name = "pointer";
   175             break;
   176         default:
   177             SDL_assert(0);
   178             return NULL;
   179     }
   180 
   181     return Emscripten_CreateCursorFromString(cursor_name, SDL_FALSE);
   182 }
   183 
   184 static void
   185 Emscripten_FreeCursor(SDL_Cursor* cursor)
   186 {
   187     Emscripten_CursorData *curdata;
   188     if (cursor) {
   189         curdata = (Emscripten_CursorData *) cursor->driverdata;
   190 
   191         if (curdata != NULL) {
   192             if (curdata->is_custom) {
   193                 SDL_free((char *)curdata->system_cursor);
   194             }
   195             SDL_free(cursor->driverdata);
   196         }
   197 
   198         SDL_free(cursor);
   199     }
   200 }
   201 
   202 static int
   203 Emscripten_ShowCursor(SDL_Cursor* cursor)
   204 {
   205     Emscripten_CursorData *curdata;
   206     if (SDL_GetMouseFocus() != NULL) {
   207         if(cursor && cursor->driverdata) {
   208             curdata = (Emscripten_CursorData *) cursor->driverdata;
   209 
   210             if(curdata->system_cursor) {
   211                 EM_ASM_INT({
   212                     if (Module['canvas']) {
   213                         Module['canvas'].style['cursor'] = UTF8ToString($0);
   214                     }
   215                     return 0;
   216                 }, curdata->system_cursor);
   217             }
   218         }
   219         else {
   220             EM_ASM(
   221                 if (Module['canvas']) {
   222                     Module['canvas'].style['cursor'] = 'none';
   223                 }
   224             );
   225         }
   226     }
   227     return 0;
   228 }
   229 
   230 static void
   231 Emscripten_WarpMouse(SDL_Window* window, int x, int y)
   232 {
   233     SDL_Unsupported();
   234 }
   235 
   236 static int
   237 Emscripten_SetRelativeMouseMode(SDL_bool enabled)
   238 {
   239     /* TODO: pointer lock isn't actually enabled yet */
   240     if(enabled) {
   241         if(emscripten_request_pointerlock(NULL, 1) >= EMSCRIPTEN_RESULT_SUCCESS) {
   242             return 0;
   243         }
   244     } else {
   245         if(emscripten_exit_pointerlock() >= EMSCRIPTEN_RESULT_SUCCESS) {
   246             return 0;
   247         }
   248     }
   249     return -1;
   250 }
   251 
   252 void
   253 Emscripten_InitMouse()
   254 {
   255     SDL_Mouse* mouse = SDL_GetMouse();
   256 
   257     mouse->CreateCursor         = Emscripten_CreateCursor;
   258     mouse->ShowCursor           = Emscripten_ShowCursor;
   259     mouse->FreeCursor           = Emscripten_FreeCursor;
   260     mouse->WarpMouse            = Emscripten_WarpMouse;
   261     mouse->CreateSystemCursor   = Emscripten_CreateSystemCursor;
   262     mouse->SetRelativeMouseMode = Emscripten_SetRelativeMouseMode;
   263 
   264     SDL_SetDefaultCursor(Emscripten_CreateDefaultCursor());
   265 }
   266 
   267 void
   268 Emscripten_FiniMouse()
   269 {
   270 }
   271 
   272 #endif /* SDL_VIDEO_DRIVER_EMSCRIPTEN */
   273 
   274 /* vi: set ts=4 sw=4 expandtab: */
   275