Function linearFn

src/components/drawing/index.js:580–582

(x, x0, x1, y0, y1)

    // linear interpolation
    var linearFn = function (x, x0, x1, y0, y1) {
        return y0 + ((y1 - y0) * (x - x0)) / (x1 - x0);
    };

    var path, linewidth, radius;
    var patternTag;