lighttroupe/luz

#
# Path is a helper class for building 2D paths in the format [x1, y1, x2, y2, ...], useful for passing to an OpenGL Tessellator
#
class Path < Array
    def self.generate
        p = Path.new
        yield p
        return p
    end

    def start_at(x,y)
        clear
        line_to(x,y)
        self
    end

    def line_to(x,y)
        self << x
        self << y
        self
    end

    def first
        self[0, 2]
    end

    def last
        self[-2, 2]
    end

    #def [](i)
        #super[i*2, 2]
    #end

    #def each
        #0.upto(size - 2, 2) { |i| yield [self[i], self[i+1]] }
    #end

    #def size
        #super / 2
    #end

    def append_with_callback(num_points)
        0.upto(num_points-1) { |i| line_to(*yield(i)) }
        self
    end

    def arc_to(center_x, center_y, radius_x, radius_y, radians_start, radians_stop, detail)
        radians_step = (radians_stop - radians_start) / detail.to_f
        radians = radians_start
        for i in 0..detail
            self << center_x + (radius_x * Math.cos(radians))
            self << center_y + (radius_y * Math.sin(radians))
            radians += radians_step
        end
        self
    end
end