// Copyright (c) 2015-2017 The Regents of the University of California.
// All rights reserved.
//
// Permission is hereby granted, without written agreement and without
// license or royalty fees, to use, copy, modify, and distribute this
// software and its documentation for any purpose, provided that the above
// copyright notice and the following two paragraphs appear in all copies
// of this software.
//
// IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY
// FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
// ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF
// THE UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF
// SUCH DAMAGE.
//
// THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES,
// INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE
// PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND THE UNIVERSITY OF
// CALIFORNIA HAS NO OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES,
// ENHANCEMENTS, OR MODIFICATIONS.
//
//
// Ptolemy II includes the work of others, to see those copyrights, follow
// the copyright link on the splash page or see copyright.htm.
/**
* Module to access camera hardware on the host.
*
* This implementation uses the opencv npm module by
* Peter Braden, see https://github.com/peterbraden/node-opencv
*
* @module @accessors-modules/cameras
* @author Christopher Brooks, based on the Cape Code cameras module by Edward A. Lee
* @version $$Id$$
*/
// Stop extra messages from jslint. Note that there should be no
// space between the / and the * and global.
/*globals actor, Java, exports, require, util */
/*jshint globalstrict: true*/
"use strict";
// We use installIfMissingThenRequire(), which is defined in
// nodeHost.js to install certain packages if they are missing.
// To replicate, use:
// rm -rf node_modules/opencv
// (cd $PTII/org/terraswarm/accessor/accessors/web/net/test/auto; node ../../../hosts/node/nodeHostInvoke.js net/test/auto/SerialLoopbackNumber)
var nodeHost = require('@accessors-hosts/node');
var cv;
var EventEmitter = require('events').EventEmitter;
var util = require('util');
try {
cv = nodeHost.installIfMissingThenRequire('opencv');
} catch (error) {
console.error("Failed to require the opencv module. See http://accessors.org/accessors/wiki/Notes/OpenCV: " + error)
}
////////////////////////////////////////////////////////////
//// Functions provided in this module.
/** Return an array of camera names for cameras currently available
* on the current host. This array includes a special name "default camera",
* which represents the system default camera, if there is one.
* @return An array of names, or null if there are no cameras.
*/
exports.cameras = function () {
// As of April, 2017, OpenCV does not support iterating cameras, see
// https://github.com/opencv/opencv/issues/4269
return [0];
};
/** Return the name of the default camera on the current host, or null
* if there is none.
* @return A camera name.
*/
exports.defaultCamera = function () {
try {
var camera = new cv.VideoCapture(0);
cv.release();
return 0;
} catch (error) {
return null;
}
};
////////////////////////////////////////////////////////////
//// Classes provided in this module.
/** Construct an instance of an Camera object type. To capture an image from
* the default camera, you can do this:
* <pre>
* var cameras = require("cameras");
* var camera = new cameras.Camera();
* camera.open();
* var image = camera.snapshot();
* camera.close();
* </pre>
* The image will be a binary object. This object can be sent to an output
* port displayed or otherwise further processed. To capture every image
* from the camera, you can do this:
* <pre>
* var cameras = require("cameras");
* var camera = new cameras.Camera();
* camera.on('image', function(image) { ... handle the image ... });
* camera.open();
* ...
* camera.close();
* </pre>
* An instance of this object type implements the following functions:
* <ul>
* <li> close(): Close the camera.
* <li> getViewSize(): Return the current view size for this camera as a JSON string, as in {"width":176, "height":144}.
* <li> on(event, handler): Specify an event handler for the camera.
* <li> open(): Open the camera.
* <li> setViewSize(size): Set the current view size for this camera. The argument can either be a JSON string or an object with a width and height field, as in for example {"width":176, "height":144}.
* <li> snapshot(): Return the last image recorded by the camera.
* <li> viewSizes(): Return an array of view sizes supported by this camera, each given as a JSON string of the form '{"width":176, "height":144}', for example.
* </ul>
* An instance of this object emits the following events:
* <ul>
* <li> "opened": The camera has been opened.
* <li> "image": A new image has been obtained.
* <li> "closed": The camera has been closed.
* </ul>
* @param name The camera name, or null to use the default camera.
*/
exports.Camera = function (name) {
if (name !== '0') {
console.log('node cameras.js: Camera(' + name + ') defaulting to camera 0');
name = 0;
}
this.helper = new cv.VideoCapture(name);
};
// FIXME: Not sure if we need this:
util.inherits(exports.Camera, EventEmitter);
/** Close the camera, stopping any image acquisition.
*/
exports.Camera.prototype.close = function () {
this.helper.release();
};
/** Return the current view size for this camera, a JSON string
* as in {"width":176, "height":144}.
* @return A JSON string representing the current view size.
*/
exports.Camera.prototype.getViewSize = function () {
// FIXME: Can't get the frame size.
return {"width":-1, "height":-1};
};
/** Open the camera, initiating emission of the 'image' event each
* time the camera obtains a new image.
*/
exports.Camera.prototype.open = function () {
//this.helper.open();
};
/** Set the current view size for this camera.
* The argument can either be a JSON string or an object with a width and
* height field, as in for example {"width":176, "height":144}.
* @param size A view size.
*/
exports.Camera.prototype.setViewSize = function (size) {
if (typeof size === 'string') {
size = JSON.parse(size);
}
this.helper.setWidth(size.width);
this.helper.setHeight(size.height);
};
/** Take a snapshot and emit an event with the image.
*/
exports.Camera.prototype.snapshot = function () {
this.emit('snapshot', this.helper.ReadSync());
};
/** Return an array of view sizes supported by this camera,
* each given as a JSON string of the form '{"width":176, "height":144}', for example.
* @return An array of strings representing available view sizes.
*/
exports.Camera.prototype.viewSizes = function () {
return {"width":-1, "height":-1};
};