Step by Step solution about How to resolve the algorithm Cistercian numerals step by step in the Julia programming language

The provided Julia code creates a graphical user interface (GUI) with a canvas and displays a moon cipher, which is a representation of numbers as digits and lines. Here's a detailed explanation of the code:

1. Package Import:

   using Gtk, Cairo

   This code imports the Gtk and Cairo packages, which are used for creating GUI elements and drawing on a canvas, respectively.

2. Canvas and Window Creation:

   const can = GtkCanvas(800, 100)
   const win = GtkWindow(can, "Canvas")

   A canvas (can) with a width of 800 pixels and height of 100 pixels is created using GtkCanvas. This canvas is then placed inside a window (win) with the title "Canvas" using GtkWindow.

3. Numerals:

   const numbers = [0, 1, 20, 300, 4000, 5555, 6789, 8123]

   An array numbers is defined, containing various numbers that will be displayed in the moon cipher representation.

4. Custom Drawing Function:

   function drawcnum(ctx, xypairs)
      move_to(ctx, xypairs[1][1], xypairs[1][2])
      for p in xypairs[2:end]
          line_to(ctx, p[1], p[2])
      end
      stroke(ctx)
   end

   This function, drawcnum, takes a Cairo context (ctx) and an array of pairs xypairs as arguments. It moves the context's cursor to the first pair of coordinates in xypairs. Then, it connects all the subsequent pairs of coordinates with lines using line_to and finally draws the path using stroke. This function is used to draw individual numerals.

5. Drawing Function:

   @guarded draw(can) do widget
      ctx = getgc(can)
      hlen, wlen, len = height(can), width(can), length(numbers)
      halfwspan, thirdcolspan, voffset = wlen ÷ (len * 2), wlen ÷ (len * 3), hlen ÷ 8
      set_source_rgb(ctx, 0, 0, 2550)
      # ... (code continued below)
   end

   The draw function is defined with the @guarded macro, which is used to handle exceptions within the function.

   Inside the function:

   • ctx is set to the Cairo context of the canvas (can).
   • hlen, wlen, and len are calculated to get the height, width, and length of the numbers array, respectively.
   • halfwspan, thirdcolspan, and voffset are calculated to determine the spacing and offsets for drawing.
   • set_source_rgb(ctx, 0, 0, 2550) sets the color for drawing to dark blue.

6. Moon Cipher Drawing:

   • The code iterates through the numbers array:
     • For each number, it calculates the vertical position of the digit (x position) by dividing the canvas width by the number of elements times two.
     • It calculates the x and y offsets for drawing the digit based on its value (1, 10, 100, or 1000), using a ternary conditional expression.
     • Then, it draws the lines for the digit using the drawcnum function based on the number's value.
     • Finally, it draws the text representation of the number below the digit.

7. Moon Cipher Display:

   function mooncipher()
      draw(can)
      # ... (code continued below)
   end

   The mooncipher function calls the draw function to draw the moon cipher on the canvas.

   • It also creates a Condition object (cond) and defines a function endit that notifies the condition when the window is destroyed.
   • The endit function is connected to the :destroy signal of the window (win).
   • The canvas is shown using show(can), and the condition is waited on using wait(cond). This means the program will wait until the window is closed before proceeding.

8. Main Execution:

   mooncipher()

   The mooncipher function is called to display the moon cipher representation of the given numbers on the canvas. When the user closes the window, the program exits.

In summary, this code creates a GUI window with a canvas and draws a moon cipher representation of the numbers in the numbers array. The moon cipher is a visual representation of numbers using digits and lines, and the program displays it using Cairo drawing commands. The program waits for the user to close the window before exiting.

using Gtk, Cairo

const can = GtkCanvas(800, 100)
const win = GtkWindow(can, "Canvas")
const numbers = [0, 1, 20, 300, 4000, 5555, 6789, 8123]

function drawcnum(ctx, xypairs)
    move_to(ctx, xypairs[1][1], xypairs[1][2])
    for p in xypairs[2:end]
        line_to(ctx, p[1], p[2])
    end
    stroke(ctx)
end

@guarded draw(can) do widget
    ctx = getgc(can)
    hlen, wlen, len = height(can), width(can), length(numbers)
    halfwspan, thirdcolspan, voffset = wlen ÷ (len * 2), wlen ÷ (len * 3), hlen ÷ 8
    set_source_rgb(ctx, 0, 0, 2550)
    for (i, n) in enumerate(numbers)
        # paint vertical as width 2 rectangle
        x = halfwspan * (2 * i - 1)
        rectangle(ctx, x, voffset, 2, hlen - 2 * voffset)
        stroke(ctx)
        # determine quadrant and draw numeral lines there
        dig = [(10^(i - 1), m) for (i, m) in enumerate(digits(n))]
        for (d, m) in dig
            y, dx, dy = (d == 1) ? (voffset, thirdcolspan, thirdcolspan) :
                (d == 10) ? (voffset, -thirdcolspan, thirdcolspan) :
                (d == 100) ? (hlen - voffset, thirdcolspan, -thirdcolspan) :
                (hlen - voffset, -thirdcolspan, -thirdcolspan)
            m == 1 && drawcnum(ctx, [[x, y], [x + dx, y]])
            m == 2 && drawcnum(ctx, [[x, y + dy], [x + dx, y + dy]])
            m == 3 && drawcnum(ctx, [[x, y], [x + dx, y + dy]])
            m == 4 && drawcnum(ctx, [[x, y + dy], [x + dx, y]])
            m == 5 && drawcnum(ctx, [[x, y + dy], [x + dx, y], [x, y]])
            m == 6 && drawcnum(ctx, [[x + dx, y], [x + dx, y + dy]])
            m == 7 && drawcnum(ctx, [[x, y], [x + dx, y], [x + dx, y + dy]])
            m == 8 && drawcnum(ctx, [[x, y + dy], [x + dx, y + dy], [x + dx, y]])
            m == 9 && drawcnum(ctx, [[x, y], [x + dx, y], [x + dx, y + dy], [x, y + dy]])
        end
        move_to(ctx, x - halfwspan ÷ 6, hlen - 4)
        Cairo.show_text(ctx, string(n))
        stroke(ctx)
    end
end

function mooncipher()
    draw(can)
    cond = Condition()
    endit(w) = notify(cond)
    signal_connect(endit, win, :destroy)
    show(can)
    wait(cond)
end

mooncipher()