Data commit

Task/Matrix-digital-rain/Nim/matrix-digital-rain.nim

@@ -0,0 +1,67 @@
+import os, random, sequtils
+import ncurses
+
+const RowDelay = 40   # In milliseconds.
+
+proc exit() {.noconv.} =
+  endwin()
+  quit QuitSuccess
+
+proc run() =
+
+  const
+    Chars = "0123456789"    # Characters to randomly appear in the rain sequence.
+
+  let stdscr = initscr()
+  noEcho()
+  cursSet(0)
+  startColor()
+  initPair(1, COLOR_GREEN, COLOR_BLACK)
+  attron(COLOR_PAIR(1).cint)
+
+  var width, height: cint
+  stdscr.getmaxyx(height, width)
+  let maxX = width - 1
+  let maxY = height - 1
+
+  # Create arrays of columns based on screen width.
+
+  # Array containing the current row of each column.
+  # Set top row as current row for all columns.
+  var columnsRow = repeat(cint -1, width)
+
+  # Array containing the active status of each column.
+  # A column draws characters on a row when active.
+  var columnsActive = newSeq[bool](width)
+
+
+  setControlCHook(exit)
+  while true:
+
+    for i in 0..maxX:
+      if columnsRow[i] == -1:
+        # If a column is at the top row, pick a random starting row and active status.
+        columnsRow[i] = cint(rand(maxY))
+        columnsActive[i] = bool(rand(1))
+
+    # Loop through columns and draw characters on rows.
+    for i in 0..maxX:
+      if columnsActive[i]:
+        # Draw a random character at this column's current row.
+        let charIndex = rand(Chars.high)
+        mvprintw(columnsRow[i], i, "%c", Chars[charIndex])
+      else:
+        # Draw an empty character if the column is inactive.
+        mvprintw(columnsRow[i], i, " ")
+
+      inc columnsRow[i]
+      # When a column reaches the bottom row, reset to top.
+      if columnsRow[i] > maxY: columnsRow[i] = -1
+
+      # Randomly alternate the column's active status.
+      if rand(999) == 0: columnsActive[i] = not columnsActive[i]
+
+    sleep(RowDelay)
+    refresh()
+
+run()