ardetector.js

"use strict";

define(['settings','JSARToolKit.min'],function(settings) {
    var create = function(sourceCanvas) {
        var JSARRaster = new NyARRgbRaster_Canvas2D(sourceCanvas.getElement());
        var JSARParameters = new FLARParam(sourceCanvas.getWidth(), sourceCanvas.getHeight());
        var JSARDetector = new FLARMultiIdMarkerDetector(JSARParameters, 120);
        JSARDetector.setContinueMode(true);

        var getMarkerNumber = function(idx) {
            var data = JSARDetector.getIdMarkerData(idx);
            if (data.packetLength > 4) {
                return -1;
            } 
            
            var result=0;
            for (var i = 0; i < data.packetLength; i++ ) {
                result = (result << 8) | data.getPacketData(i);
            }

            return result;
        };

        var getTransformMatrix = function(idx) {
            var mat = new NyARTransMatResult();
            JSARDetector.getTransformMatrix(idx, mat);

            var cm = new Float32Array(16);
            cm[0] = mat.m00;
            cm[1] = -mat.m10;
            cm[2] = mat.m20;
            cm[3] = 0;
            cm[4] = mat.m01;
            cm[5] = -mat.m11;
            cm[6] = mat.m21;
            cm[7] = 0;
            cm[8] = -mat.m02;
            cm[9] = mat.m12;
            cm[10] = -mat.m22;
            cm[11] = 0;
            cm[12] = mat.m03;
            cm[13] = -mat.m13;
            cm[14] = mat.m23;
            cm[15] = 1;

            return cm;
        };

        var getCameraMatrix = function(zNear, zFar) {
            var result = new Float32Array(16);
            JSARParameters.copyCameraMatrix(result, zNear, zFar);
            return result;
        };

        var newMarker = function(id, matrix) {
            return {
                id: id,
                matrix: matrix,
                age: settings.arMarkerPersist,
            };
        };

        var markers = {};
        var detect = function( onCreate, onUpdate, onDestroy ) {
            if( !sourceCanvas.getElement().changed ) {
                return;
            }
            var markerCount = JSARDetector.detectMarkerLite(JSARRaster, settings.arThreshold); 
            var marker;
            for( var index = 0; index < markerCount; index++ ) {
                var id = getMarkerNumber(index);
                marker = markers[id];
                if( marker === undefined ) {
                    marker = newMarker(id, getTransformMatrix(index));
                    markers[id] = marker;
                    onCreate( marker );
                }
                else {
                    marker.matrix = getTransformMatrix(index);
                    marker.age = settings.arMarkerPersist;
                    onUpdate( marker );
                }
            }

            for( var id in markers ) {
                marker = markers[id];
                if( marker ) {
                    if( marker.age-- === 0 ) {
                        onDestroy( marker );
                        delete markers[id];
                    }
                }
            }
        };

        function reset() {
            markers = {};
        }

        return {
            detect: detect,
            reset: reset,
            getCameraMatrix: getCameraMatrix,
        };
    };

    return {
        create: create,
    };
});