webgl webcam test driver

doesn't work on firefox, see https://bugzilla.mozilla.org/show_bug.cgi?id=917314

Makefile.emscripten

@@ -59,7 +59,7 @@ libretro = libretro_emscripten.bc
 
 LIBS = -lm
 DEFINES = -DHAVE_SCREENSHOTS -DHAVE_NULLAUDIO -DHAVE_BSV_MOVIE
-LDFLAGS = -L. -s TOTAL_MEMORY=$(MEMORY) --js-library emscripten/library_rwebaudio.js --js-library emscripten/library_rwebinput.js
+LDFLAGS = -L. -s TOTAL_MEMORY=$(MEMORY) --js-library emscripten/library_rwebaudio.js --js-library emscripten/library_rwebinput.js --js-library emscripten/library_rwebcam.js
 
 ifeq ($(PERF_TEST), 1)
    DEFINES += -DPERF_TEST

emscripten/library_rwebcam.js

@@ -0,0 +1,70 @@
+//"use strict";
+
+var LibraryRWebCam = {
+   $RWC: {
+      /*
+      run modes:
+      0: not running
+      1: waiting for user to confirm webcam
+      2: running
+      */
+      runMode: 0,
+      videoElement: null
+   },
+
+   RWebCamInit: function() {
+      RWC.runMode = 0;
+
+      if (!navigator) return 0;
+
+      navigator.getMedia = navigator.getUserMedia ||
+                           navigator.webkitGetUserMedia ||
+                           navigator.mozGetUserMedia ||
+                           navigator.msGetUserMedia;
+
+      if (!navigator.getMedia) return 0;
+
+      RWC.videoElement = document.createElement("video");
+
+      RWC.runMode = 1;
+
+      navigator.getMedia({video: true, audio: false}, function(stream) {
+         RWC.videoElement.autoplay = true;
+         RWC.videoElement.src = URL.createObjectURL(stream);
+         RWC.runMode = 2;
+      }, function (err) {
+         console.log("webcam request failed", err);
+         RWC.runMode = 0;
+      });
+
+      return 1;
+   },
+
+   RWebCamTexImage2D: function(width, height) {
+      if (RWC.runMode != 2 || RWC.videoElement.paused) return 0;
+
+      Module.ctx.texImage2D(Module.ctx.TEXTURE_2D, 0, Module.ctx.RGB, Module.ctx.RGB, Module.ctx.UNSIGNED_BYTE, RWC.videoElement);
+
+      if (width)  {{{ makeSetValue('width',  '0', 'RWC.videoElement.videoWidth',  'i32') }}};
+      if (height) {{{ makeSetValue('height', '0', 'RWC.videoElement.videoHeight', 'i32') }}};
+   },
+
+   RWebCamTexSubImage2D: function(x, y) {
+      if (RWC.runMode != 2 || RWC.videoElement.paused) return 0;
+
+      Module.ctx.texSubImage2D(Module.ctx.TEXTURE_2D, 0, x, y, Module.ctx.RGB, Module.ctx.UNSIGNED_BYTE, RWC.videoElement);
+   },
+
+   RWebCamReady: function() {
+      return RWC.runMode == 2 ? 1 : 0;
+   },
+
+   RWebCamFree: function() {
+      RWC.videoElement.pause();
+      RWC.videoElement = null;
+      RWC.runMode = 0;
+   }
+};
+
+autoAddDeps(LibraryRWebCam, '$RWC');
+mergeInto(LibraryManager.library, LibraryRWebCam);