Method midpoint

examples/extern/gmath.bundle.js:600–602

(other)

        return new Vector4(-this.x, -this.y, -this.z, -this.w);
    }
    midpoint(other) {
        return other.sub(this).div(2).add(this);
    }
    eq(other) {
        return this.x === other.x && this.y === other.y && this.z === other.z && this.w === other.w;
    }