iHealth-app-demo/html/mine/js/transform.js

/* transformjs
 * By dntzhang
 */
;(function () {

    var Matrix3D = function (n11, n12, n13, n14, n21, n22, n23, n24, n31, n32, n33, n34, n41, n42, n43, n44) {
        this.elements =window.Float32Array ? new Float32Array(16) : [];
        var te = this.elements;
        te[0] = (n11 !== undefined) ? n11 : 1; te[4] = n12 || 0; te[8] = n13 || 0; te[12] = n14 || 0;
        te[1] = n21 || 0; te[5] = (n22 !== undefined) ? n22 : 1; te[9] = n23 || 0; te[13] = n24 || 0;
        te[2] = n31 || 0; te[6] = n32 || 0; te[10] = (n33 !== undefined) ? n33 : 1; te[14] = n34 || 0;
        te[3] = n41 || 0; te[7] = n42 || 0; te[11] = n43 || 0; te[15] = (n44 !== undefined) ? n44 : 1;
    };

    Matrix3D.DEG_TO_RAD = Math.PI / 180;

    Matrix3D.prototype = {
        set: function (n11, n12, n13, n14, n21, n22, n23, n24, n31, n32, n33, n34, n41, n42, n43, n44) {
            var te = this.elements;
            te[0] = n11; te[4] = n12; te[8] = n13; te[12] = n14;
            te[1] = n21; te[5] = n22; te[9] = n23; te[13] = n24;
            te[2] = n31; te[6] = n32; te[10] = n33; te[14] = n34;
            te[3] = n41; te[7] = n42; te[11] = n43; te[15] = n44;
            return this;
        },
        identity: function () {
            this.set(
                1, 0, 0, 0,
                0, 1, 0, 0,
                0, 0, 1, 0,
                0, 0, 0, 1
            );
            return this;
        },
        multiplyMatrices: function (a, be) {

            var ae = a.elements;
            var te = this.elements;
            var a11 = ae[0], a12 = ae[4], a13 = ae[8], a14 = ae[12];
            var a21 = ae[1], a22 = ae[5], a23 = ae[9], a24 = ae[13];
            var a31 = ae[2], a32 = ae[6], a33 = ae[10], a34 = ae[14];
            var a41 = ae[3], a42 = ae[7], a43 = ae[11], a44 = ae[15];

            var b11 = be[0], b12 = be[1], b13 = be[2], b14 = be[3];
            var b21 = be[4], b22 = be[5], b23 = be[6], b24 = be[7];
            var b31 = be[8], b32 = be[9], b33 = be[10], b34 = be[11];
            var b41 = be[12], b42 = be[13], b43 = be[14], b44 = be[15];

            te[0] = a11 * b11 + a12 * b21 + a13 * b31 + a14 * b41;
            te[4] = a11 * b12 + a12 * b22 + a13 * b32 + a14 * b42;
            te[8] = a11 * b13 + a12 * b23 + a13 * b33 + a14 * b43;
            te[12] = a11 * b14 + a12 * b24 + a13 * b34 + a14 * b44;

            te[1] = a21 * b11 + a22 * b21 + a23 * b31 + a24 * b41;
            te[5] = a21 * b12 + a22 * b22 + a23 * b32 + a24 * b42;
            te[9] = a21 * b13 + a22 * b23 + a23 * b33 + a24 * b43;
            te[13] = a21 * b14 + a22 * b24 + a23 * b34 + a24 * b44;

            te[2] = a31 * b11 + a32 * b21 + a33 * b31 + a34 * b41;
            te[6] = a31 * b12 + a32 * b22 + a33 * b32 + a34 * b42;
            te[10] = a31 * b13 + a32 * b23 + a33 * b33 + a34 * b43;
            te[14] = a31 * b14 + a32 * b24 + a33 * b34 + a34 * b44;

            te[3] = a41 * b11 + a42 * b21 + a43 * b31 + a44 * b41;
            te[7] = a41 * b12 + a42 * b22 + a43 * b32 + a44 * b42;
            te[11] = a41 * b13 + a42 * b23 + a43 * b33 + a44 * b43;
            te[15] = a41 * b14 + a42 * b24 + a43 * b34 + a44 * b44;

            return this;

        },
        // 解决角度为90的整数倍导致Math.cos得到极小的数，其实是0。导致不渲染
        _rounded: function(value,i){
            i= Math.pow(10, i || 15);
            // default
            return Math.round(value*i)/i;
        },
        appendTransform: function (x, y, z, scaleX, scaleY, scaleZ, rotateX, rotateY, rotateZ,skewX,skewY, originX, originY, originZ) {

            var rx = rotateX * Matrix3D.DEG_TO_RAD;
            var cosx =this._rounded( Math.cos(rx));
            var sinx = this._rounded(Math.sin(rx));
            var ry = rotateY * Matrix3D.DEG_TO_RAD;
            var cosy =this._rounded( Math.cos(ry));
            var siny = this._rounded(Math.sin(ry));
            var rz = rotateZ * Matrix3D.DEG_TO_RAD;
            var cosz =this._rounded( Math.cos(rz * -1));
            var sinz =this._rounded( Math.sin(rz * -1));

            this.multiplyMatrices(this, [
                1, 0, 0, x,
                0, cosx, sinx, y,
                0, -sinx, cosx, z,
                0, 0, 0, 1
            ]);

            this.multiplyMatrices(this, [
                cosy, 0, siny, 0,
                0, 1, 0, 0,
                -siny, 0, cosy, 0,
                0, 0, 0, 1
            ]);

            this.multiplyMatrices(this,[
                cosz * scaleX, sinz * scaleY, 0, 0,
                -sinz * scaleX, cosz * scaleY, 0, 0,
                0, 0, 1 * scaleZ, 0,
                0, 0, 0, 1
            ]);

            if(skewX||skewY){
                this.multiplyMatrices(this,[
                    this._rounded(Math.cos(skewX* Matrix3D.DEG_TO_RAD)), this._rounded( Math.sin(skewX* Matrix3D.DEG_TO_RAD)), 0, 0,
                    -1*this._rounded(Math.sin(skewY* Matrix3D.DEG_TO_RAD)), this._rounded( Math.cos(skewY* Matrix3D.DEG_TO_RAD)), 0, 0,
                    0, 0, 1, 0,
                    0, 0, 0, 1
                ]);
            }

            if (originX || originY || originZ) {
                this.elements[12] -= originX * this.elements[0] + originY * this.elements[4] + originZ * this.elements[8];
                this.elements[13] -= originX * this.elements[1] + originY * this.elements[5] + originZ * this.elements[9];
                this.elements[14] -= originX * this.elements[2] + originY * this.elements[6] + originZ * this.elements[10];
            }
            return this;
        }
    };

    function observe(target, props, callback) {
        for (var i = 0, len = props.length; i < len; i++) {
            var prop = props[i];
            watch(target, prop, callback);
        }
    }

    function watch(target, prop, callback) {
        Object.defineProperty(target, prop, {
            get: function () {
                return this["__" + prop];
            },
            set: function (value) {
                if (value !== this["__" + prop]) {
                    this["__" + prop] = value;
                    callback();
                }

            }
        });
    }

    window.Transform = function (element) {

        observe(
            element,
            ["translateX", "translateY", "translateZ", "scaleX", "scaleY", "scaleZ" , "rotateX", "rotateY", "rotateZ","skewX","skewY", "originX", "originY", "originZ"],
            function () {
                var mtx = element.matrix3D.identity().appendTransform( element.translateX, element.translateY, element.translateZ, element.scaleX, element.scaleY, element.scaleZ, element.rotateX, element.rotateY, element.rotateZ,element.skewX,element.skewY, element.originX, element.originY, element.originZ);
                element.style.transform = element.style.msTransform = element.style.OTransform = element.style.MozTransform = element.style.webkitTransform = "perspective("+element.perspective+"px) matrix3d(" + Array.prototype.slice.call(mtx.elements).join(",") + ")";
            });

        observe(
            element,
            [ "perspective"],
            function () {
                element.style.transform = element.style.msTransform = element.style.OTransform = element.style.MozTransform = element.style.webkitTransform = "perspective("+element.perspective+"px) matrix3d(" + Array.prototype.slice.call(element.matrix3D.elements).join(",") + ")";
            });

        element.matrix3D = new Matrix3D();
        element.perspective = 500;
        element.scaleX = element.scaleY = element.scaleZ = 1;
        //由于image自带了x\y\z，所有加上translate前缀
        element.translateX = element.translateY = element.translateZ = element.rotateX = element.rotateY = element.rotateZ =element.skewX=element.skewY= element.originX = element.originY = element.originZ = 0;
    }
})();