functions.lua

function draw_graph (conky_value, table_length, radius, circle_width, table)
        cairo_set_source_rgba(cr,rgb_to_r_g_b(color, alpha))

        calculate_table(table_length, table)
        for i = 1, table_length do
                draw_line_in_circle(radius - (circle_width / 2), (circle_width / 100) * table[i], 4, (360 / table_length) * (i - 1), -1)
        end
end


function calculate_table(table_length, table, conky_value)
        for i = 1, table_length do
                if table[i] == nil then
                        table[i] = 0
                end
        end
        for i = table_length, 2, -1 do
                table[i] = table[i - 1]
        end
        value = tonumber(conky_parse('${downspeedf eth0}')/100)
        if value ~= nil then
                table[1] = value
        else
                table[1] = 0
        end
end

function draw_line_in_circle(offset, length, width, degree, r, g, b)
        cairo_set_line_width(cr, width)
        point = (math.pi / -180) * degree
        start_x = 0 + (offset * math.sin(point))
        start_y = 0 - (offset * math.cos(point))
        end_x = 0 + ((offset + length) * math.sin(point))
        end_y = 0 - ((offset + length) * math.cos(point))
        cairo_move_to(cr, start_x + center_x, start_y + center_y)
        cairo_line_to(cr, end_x + center_x, end_y + center_y)
        cairo_set_source_rgb (cr, r, g, b);
        cairo_stroke(cr)
end