vendor/transformation-matrix/shear.js
function shear(shx, shy) {
    return {
        a: 1, c: shx, e: 0,
        b: shy, d: 1, f: 0
    };
}
function shear(shx, shy) {
    return {
        a: 1, c: shx, e: 0,
        b: shy, d: 1, f: 0
    };
}
function shear ( shx , shy ) { return { a : 1 , c : shx , e : 0 , b : shy , d : 1 , f : 0 } ; }
Calculate a shear matrix
@param shx Shear on axis x
@param shy Shear on axis y
@returns {{a: number, b: number, c: number, e: number, d: number, f: number}} Affine matrix
Calculate a shear matrix