Data commit

Task/Matrix-digital-rain/Go/matrix-digital-rain.go

@@ -0,0 +1,106 @@
+package main
+
+import (
+    gc "github.com/rthornton128/goncurses"
+    "log"
+    "math/rand"
+    "time"
+)
+
+// Time between row updates in microseconds.
+// Controls the speed of the digital rain effect.
+const rowDelay = 40000
+
+func main() {
+    start := time.Now()
+    rand.Seed(time.Now().UnixNano())
+
+    // Characters to randomly appear in the rain sequence.
+    chars := []byte("0123456789")
+    totalChars := len(chars)
+
+    // Set up ncurses screen and colors.
+    stdscr, err := gc.Init()
+    if err != nil {
+        log.Fatal("init", err)
+    }
+    defer gc.End()
+
+    gc.Echo(false)
+    gc.Cursor(0)
+
+    if !gc.HasColors() {
+        log.Fatal("Program requires a colour capable terminal")
+    }
+
+    if err := gc.StartColor(); err != nil {
+        log.Fatal(err)
+    }
+
+    if err := gc.InitPair(1, gc.C_GREEN, gc.C_BLACK); err != nil {
+        log.Fatal("InitPair failed: ", err)
+    }
+    stdscr.ColorOn(1)
+    maxY, maxX := stdscr.MaxYX()
+
+    /* Create slices of columns based on screen width. */
+
+    // Slice containing the current row of each column.
+    columnsRow := make([]int, maxX)
+
+    // Slice containing the active status of each column.
+    // A column draws characters on a row when active.
+    columnsActive := make([]int, maxX)
+
+    // Set top row as current row for all columns.
+    for i := 0; i < maxX; i++ {
+        columnsRow[i] = -1
+        columnsActive[i] = 0
+    }
+
+    for {
+        for i := 0; i < maxX; i++ {
+            if columnsRow[i] == -1 {
+                // If a column is at the top row, pick a
+                // random starting row and active status.
+                columnsRow[i] = rand.Intn(maxY + 1)
+                columnsActive[i] = rand.Intn(2)
+            }
+        }
+
+        // Loop through columns and draw characters on rows.
+        for i := 0; i < maxX; i++ {
+            if columnsActive[i] == 1 {
+                // Draw a random character at this column's current row.
+                charIndex := rand.Intn(totalChars)
+                stdscr.MovePrintf(columnsRow[i], i, "%c", chars[charIndex])
+            } else {
+                // Draw an empty character if the column is inactive.
+                stdscr.MovePrintf(columnsRow[i], i, "%c", ' ')
+            }
+
+            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.Intn(1001) == 0 {
+                if columnsActive[i] == 0 {
+                    columnsActive[i] = 1
+                } else {
+                    columnsActive[i] = 0
+                }
+            }
+        }
+        time.Sleep(rowDelay * time.Microsecond)
+        stdscr.Refresh()
+        elapsed := time.Since(start)
+        // Stop after 1 minute.
+        if elapsed.Minutes() >= 1 {
+            break
+        }
+    }
+}