Add checkbox to enable/disable bgrx mode through UI

app/ui.js

@@ -163,6 +163,7 @@ const UI = {
         UI.initSetting('resize', 'off');
         UI.initSetting('shared', true);
         UI.initSetting('view_only', false);
+        UI.initSetting('img_bgrx_mode', false);
         UI.initSetting('show_dot', false);
         UI.initSetting('path', 'websockify');
         UI.initSetting('repeaterID', '');
@@ -352,6 +353,8 @@ const UI = {
         UI.addSettingChangeHandler('shared');
         UI.addSettingChangeHandler('view_only');
         UI.addSettingChangeHandler('view_only', UI.updateViewOnly);
+        UI.addSettingChangeHandler('img_bgrx_mode');
+        UI.addSettingChangeHandler('img_bgrx_mode', UI.applyBGRXMode);
         UI.addSettingChangeHandler('show_dot');
         UI.addSettingChangeHandler('show_dot', UI.updateShowDotCursor);
         UI.addSettingChangeHandler('host');
@@ -1251,6 +1254,19 @@ const UI = {
         UI.rfb.resizeSession = UI.getSetting('resize') === 'remote';
     },
 
+/* ------^-------
+ *  /img_bgrx_mode
+ * ==============
+ *   BGRX mode
+ * ------v------*/
+
+    // Apply bgrx transform to images
+    applyBGRXMode() {
+        if (!UI.rfb) return;
+
+        UI.rfb.bgrxImgMode = UI.getSetting('img_bgrx_mode');
+    },
+
 /* ------^-------
  *    /RESIZE
  * ==============

core/rfb.js

@@ -282,6 +282,9 @@ export default class RFB extends EventTargetMixin {
         this._updateClip();
     }
 
+    get bgrxImgMode() { return this._display.bgrxImgMode; }
+    set bgrxImgMode(val) { this._display.bgrxImgMode = val; }
+
     get scaleViewport() { return this._scaleViewport; }
     set scaleViewport(scale) {
         this._scaleViewport = scale;

vnc.html

@@ -195,6 +195,9 @@
                     <li>
                         <label><input id="noVNC_setting_view_clip" type="checkbox"> Clip to Window</label>
                     </li>
+                    <li>
+                        <label><input id="noVNC_setting_img_bgrx_mode" type="checkbox"> BGRX mode</label>
+                    </li>
                     <li>
                         <label for="noVNC_setting_resize">Scaling Mode:</label>
                         <select id="noVNC_setting_resize" name="vncResize">