player/js/utils/bez.js

function bezFunction(){

    var easingFunctions = [];
    var math = Math;

    function pointOnLine2D(x1,y1, x2,y2, x3,y3){
        var det1 = (x1*y2) + (y1*x3) + (x2*y3) - (x3*y2) - (y3*x1) - (x2*y1);
        return det1 > -0.001 && det1 < 0.001;
    }

    function pointOnLine3D(x1,y1,z1, x2,y2,z2, x3,y3,z3){
        if(z1 === 0 && z2 === 0 && z3 === 0) {
            return pointOnLine2D(x1,y1, x2,y2, x3,y3);
        }
        var dist1 = Math.sqrt(Math.pow(x2 - x1, 2) + Math.pow(y2 - y1, 2) + Math.pow(z2 - z1, 2));
        var dist2 = Math.sqrt(Math.pow(x3 - x1, 2) + Math.pow(y3 - y1, 2) + Math.pow(z3 - z1, 2));
        var dist3 = Math.sqrt(Math.pow(x3 - x2, 2) + Math.pow(y3 - y2, 2) + Math.pow(z3 - z2, 2));
        var diffDist;
        if(dist1 > dist2){
            if(dist1 > dist3){
                diffDist = dist1 - dist2 - dist3;
            } else {
                diffDist = dist3 - dist2 - dist1;
            }
        } else if(dist3 > dist2){
            diffDist = dist3 - dist2 - dist1;
        } else {
            diffDist = dist2 - dist1 - dist3;
        }
        return diffDist > -0.0001 && diffDist < 0.0001;
    }

    var getBezierLength = (function(){

        return function(pt1,pt2,pt3,pt4){
            var curveSegments = defaultCurveSegments;
            var k;
            var i, len;
            var ptCoord,perc,addedLength = 0;
            var ptDistance;
            var point = [],lastPoint = [];
            var lengthData = bezier_length_pool.newElement();
            len = pt3.length;
            for(k=0;k<curveSegments;k+=1){
                perc = k/(curveSegments-1);
                ptDistance = 0;
                for(i=0;i<len;i+=1){
                    ptCoord = bm_pow(1-perc,3)*pt1[i]+3*bm_pow(1-perc,2)*perc*pt3[i]+3*(1-perc)*bm_pow(perc,2)*pt4[i]+bm_pow(perc,3)*pt2[i];
                    point[i] = ptCoord;
                    if(lastPoint[i] !== null){
                        ptDistance += bm_pow(point[i] - lastPoint[i],2);
                    }
                    lastPoint[i] = point[i];
                }
                if(ptDistance){
                    ptDistance = bm_sqrt(ptDistance);
                    addedLength += ptDistance;
                }
                lengthData.percents[k] = perc;
                lengthData.lengths[k] = addedLength;
            }
            lengthData.addedLength = addedLength;
            return lengthData;
        };
    }());

    function getSegmentsLength(shapeData) {
        var segmentsLength = segments_length_pool.newElement();
        var closed = shapeData.c;
        var pathV = shapeData.v;
        var pathO = shapeData.o;
        var pathI = shapeData.i;
        var i, len = shapeData._length;
        var lengths = segmentsLength.lengths;
        var totalLength = 0;
        for(i=0;i<len-1;i+=1){
            lengths[i] = getBezierLength(pathV[i],pathV[i+1],pathO[i],pathI[i+1]);
            totalLength += lengths[i].addedLength;
        }
        if(closed && len){
            lengths[i] = getBezierLength(pathV[i],pathV[0],pathO[i],pathI[0]);
            totalLength += lengths[i].addedLength;
        }
        segmentsLength.totalLength = totalLength;
        return segmentsLength;
    }

    function BezierData(length){
        this.segmentLength = 0;
        this.points = new Array(length);
    }

    function PointData(partial,point){
        this.partialLength = partial;
        this.point = point;
    }

    var buildBezierData = (function(){

        var storedData = {};

        return function (keyData){
            var pt1 = keyData.s;
            var pt2 = keyData.e;
            var pt3 = keyData.to;
            var pt4 = keyData.ti;
            var bezierName = (pt1[0]+'_'+pt1[1]+'_'+pt2[0]+'_'+pt2[1]+'_'+pt3[0]+'_'+pt3[1]+'_'+pt4[0]+'_'+pt4[1]).replace(/\./g, 'p');
            if(storedData[bezierName]){
                keyData.bezierData = storedData[bezierName];
                return;
            }
            var curveSegments = defaultCurveSegments;
            var k, i, len;
            var ptCoord,perc,addedLength = 0;
            var ptDistance;
            var point,lastPoint = null;
            if (pt1.length === 2 && (pt1[0] != pt2[0] || pt1[1] != pt2[1]) && pointOnLine2D(pt1[0],pt1[1],pt2[0],pt2[1],pt1[0]+pt3[0],pt1[1]+pt3[1]) && pointOnLine2D(pt1[0],pt1[1],pt2[0],pt2[1],pt2[0]+pt4[0],pt2[1]+pt4[1])){
                curveSegments = 2;
            }
            var bezierData = new BezierData(curveSegments);
            len = pt3.length;
            for (k = 0; k < curveSegments; k += 1) {
                point = createSizedArray(len);
                perc = k / (curveSegments - 1);
                ptDistance = 0;
                for (i = 0; i < len; i += 1){
                    ptCoord = bm_pow(1-perc,3)*pt1[i]+3*bm_pow(1-perc,2)*perc*(pt1[i] + pt3[i])+3*(1-perc)*bm_pow(perc,2)*(pt2[i] + pt4[i])+bm_pow(perc,3)*pt2[i];
                    point[i] = ptCoord;
                    if(lastPoint !== null){
                        ptDistance += bm_pow(point[i] - lastPoint[i],2);
                    }
                }
                ptDistance = bm_sqrt(ptDistance);
                addedLength += ptDistance;
                bezierData.points[k] = new PointData(ptDistance, point);
                lastPoint = point;
            }
            bezierData.segmentLength = addedLength;
            keyData.bezierData = bezierData;
            storedData[bezierName] = bezierData;
        };
    }());

    function getDistancePerc(perc,bezierData){
        var percents = bezierData.percents;
        var lengths = bezierData.lengths;
        var len = percents.length;
        var initPos = bm_floor((len-1)*perc);
        var lengthPos = perc*bezierData.addedLength;
        var lPerc = 0;
        if(initPos === len - 1 || initPos === 0 || lengthPos === lengths[initPos]){
            return percents[initPos];
        }else{
            var dir = lengths[initPos] > lengthPos ? -1 : 1;
            var flag = true;
            while(flag){
                if(lengths[initPos] <= lengthPos && lengths[initPos+1] > lengthPos){
                    lPerc = (lengthPos - lengths[initPos]) / (lengths[initPos+1] - lengths[initPos]);
                    flag = false;
                }else{
                    initPos += dir;
                }
                if(initPos < 0 || initPos >= len - 1){
                    //FIX for TypedArrays that don't store floating point values with enough accuracy
                    if(initPos === len - 1) {
                        return percents[initPos];
                    }
                    flag = false;
                }
            }
            return percents[initPos] + (percents[initPos+1] - percents[initPos])*lPerc;
        }
    }

    function getPointInSegment(pt1, pt2, pt3, pt4, percent, bezierData) {
        var t1 = getDistancePerc(percent,bezierData);
        var u0 = 1;
        var u1 = 1 - t1;
        var ptX = Math.round((u1*u1*u1* pt1[0] + (t1*u1*u1 + u1*t1*u1 + u1*u1*t1)* pt3[0] + (t1*t1*u1 + u1*t1*t1 + t1*u1*t1)*pt4[0] + t1*t1*t1* pt2[0])* 1000) / 1000;
        var ptY = Math.round((u1*u1*u1* pt1[1] + (t1*u1*u1 + u1*t1*u1 + u1*u1*t1)* pt3[1] + (t1*t1*u1 + u1*t1*t1 + t1*u1*t1)*pt4[1] + t1*t1*t1* pt2[1])* 1000) / 1000;
        return [ptX, ptY];
    }

    function getSegmentArray() {

    }

    var bezier_segment_points = createTypedArray('float32', 8);

    function getNewSegment(pt1,pt2,pt3,pt4,startPerc,endPerc, bezierData){

        startPerc = startPerc < 0 ? 0 : startPerc > 1 ? 1 : startPerc;
        var t0 = getDistancePerc(startPerc,bezierData);
        endPerc = endPerc > 1 ? 1 : endPerc;
        var t1 = getDistancePerc(endPerc,bezierData);
        var i, len = pt1.length;
        var u0 = 1 - t0;
        var u1 = 1 - t1;
        var u0u0u0 = u0*u0*u0;
        var t0u0u0_3 = t0*u0*u0*3;
        var t0t0u0_3 = t0*t0*u0*3;
        var t0t0t0 = t0*t0*t0;
        //
        var u0u0u1 = u0*u0*u1;
        var t0u0u1_3 = t0*u0*u1 + u0*t0*u1 + u0*u0*t1;
        var t0t0u1_3 = t0*t0*u1 + u0*t0*t1 + t0*u0*t1;
        var t0t0t1 = t0*t0*t1;
        //
        var u0u1u1 = u0*u1*u1;
        var t0u1u1_3 = t0*u1*u1 + u0*t1*u1 + u0*u1*t1;
        var t0t1u1_3 = t0*t1*u1 + u0*t1*t1 + t0*u1*t1;
        var t0t1t1 = t0*t1*t1;
        //
        var u1u1u1 = u1*u1*u1;
        var t1u1u1_3 = t1*u1*u1 + u1*t1*u1 + u1*u1*t1;
        var t1t1u1_3 = t1*t1*u1 + u1*t1*t1 + t1*u1*t1;
        var t1t1t1 = t1*t1*t1;
        for(i=0;i<len;i+=1){
            bezier_segment_points[i * 4] = Math.round((u0u0u0 * pt1[i] + t0u0u0_3 * pt3[i] + t0t0u0_3 * pt4[i] + t0t0t0 * pt2[i]) * 1000) / 1000;
            bezier_segment_points[i * 4 + 1] = Math.round((u0u0u1 * pt1[i] + t0u0u1_3 * pt3[i] + t0t0u1_3 * pt4[i] + t0t0t1 * pt2[i]) * 1000) / 1000;
            bezier_segment_points[i * 4 + 2] = Math.round((u0u1u1 * pt1[i] + t0u1u1_3 * pt3[i] + t0t1u1_3 * pt4[i] + t0t1t1 * pt2[i]) * 1000) / 1000;
            bezier_segment_points[i * 4 + 3] = Math.round((u1u1u1 * pt1[i] + t1u1u1_3 * pt3[i] + t1t1u1_3 * pt4[i] + t1t1t1 * pt2[i]) * 1000) / 1000;
        }

        return bezier_segment_points;
    }

    return {
        getSegmentsLength : getSegmentsLength,
        getNewSegment : getNewSegment,
        getPointInSegment : getPointInSegment,
        buildBezierData : buildBezierData,
        pointOnLine2D : pointOnLine2D,
        pointOnLine3D : pointOnLine3D
    };
}

var bez = bezFunction();