Merge pull request #767 from Gryzor/add_32_diamonds_kotlin

Add Kotlin port of 32_Diamonds

32_Diamond/kotlin/README.md

@@ -1,3 +1,12 @@
 Original source downloaded [from Vintage Basic](http://www.vintage-basic.net/games.html)
 
-Conversion to [Kotlin](https://kotlinlang.org/)
+Conversion to [Kotlin](https://kotlinlang.org/), structure inspired from [the Java port](https://github.com/coding-horror/basic-computer-games/blob/main/32_Diamond/java/Diamond.java).
+
+### How to Run
+1. Install [kotlin command line](https://kotlinlang.org/docs/command-line.html) compiler from JetBrains.
+2. Compile with `kotlinc diamond.kt -include-runtime -d diamond.jar`
+3. Run with `java -jar diamond.jar`
+
+### Changes from Original
+This version validates that user input is correct.
+

32_Diamond/kotlin/diamond.kt

@@ -0,0 +1,154 @@
+
+/**
+ * Game of Diamond
+ * <p>
+ * Based on the BASIC game of Diamond
+ * https://github.com/coding-horror/basic-computer-games/blob/main/32%20Diamond/diamond.bas
+ * <p>
+ *
+ * Changes From Original: Input is validated.
+ *
+ * Converted from BASIC to Kotlin by Martin Marconcini (@Gryzor)
+ * Inspired in the Java code written by Darren Cardenas.
+ */
+
+
+fun main() {
+	Diamond().startGame()
+}
+
+class Diamond {
+	init {
+		printIntro()
+	}
+
+	fun startGame() {
+		var body: Int
+		var end: Int
+		var start: Int = 1
+		var row: Int = 1
+		var numPerRow: Int
+		var increment: Int = 2
+		var lineContent: String
+		var prefixIndex: Int
+		
+		printPrompt()
+
+		// Read the user input
+		val input = readLine()
+
+		// Validate input
+		val userInput: Int = try {
+			input?.toInt() ?: -1
+		} catch (e: NumberFormatException) {
+			-1
+		}
+		if (!isValid(userInput)) {
+			printInvalidInput()
+			return
+		}
+
+		// Calculate how many diamonds can horizontally fit in the given space
+		numPerRow = calculateDiamondsPerRow(userInput)
+		end = userInput
+
+		// Loop throw rows of Diamonds
+		while (row <= numPerRow) {
+			body = start
+			while (canLoop(increment, body, end)) {
+				lineContent = ""
+				
+				// Add white spaces to the "left" of the leftmost diamond.
+				while (lineContent.length < ((userInput - body) / 2)) {
+					lineContent += " "
+				}
+
+				// Begin loop through each column of diamonds
+				for (col in 1..numPerRow) {
+					prefixIndex = 1
+
+					// Begin loop that fills each diamond with characters (not whitespace)
+					for (fill in 1..body) {
+						// Right side of diamond, if the index is greater than the prefix, put a Symbol.
+						if (prefixIndex > PREFIX.length) {
+							lineContent += SYMBOL
+						}
+						// Left side of diamond, pick a Prefix character (-1 since it starts at 0)
+						else {
+							lineContent += PREFIX[prefixIndex - 1]
+							prefixIndex++
+						}
+					}// End loop that fills each diamond with characters
+
+					// Is Column finished?
+					if (col == numPerRow) {
+						break
+					}
+					// Column is not finished...
+					else {
+						// Add whitespace on the "right" side of the current diamond, and fill the "left" side of the
+						// next; doesn't fill the space to the right of the rightmost diamond.
+						while (lineContent.length < (userInput * col + (userInput - body) / 2)) {
+							lineContent += " "
+						}
+
+					}
+
+				}// End loop through each column of diamonds
+
+				// Print the current Line
+				println(lineContent)
+
+				// Increment the body that moves
+				body += increment
+			} //end While Loop throw rows of Diamonds
+
+			// Increment the current Row of diamonds.
+			row++
+
+			if (start != 1) {
+				start = 1
+				end = userInput
+				increment = 2
+			} else {
+				// We're rendering the "bottom half" of the total rendering.
+				// Alter the parameters, and decrease the row number so the logic can loop again.
+				start = userInput - 2
+				end = 1
+				increment = -2
+				row--
+			}
+		} // End loop through each row of diamonds
+	}
+
+	private fun canLoop(increment: Int, body: Int, end: Int): Boolean = if (increment < 0) body >= end else body <= end
+
+	private fun calculateDiamondsPerRow(totalDiamonds: Int): Int = LINE_WIDTH / totalDiamonds
+
+	private fun isValid(input: Int): Boolean = (input in 5..21) && (input % 2 != 0)
+
+	private fun printInvalidInput() = println("Invalid input")
+
+	private fun printPrompt() {
+		println(
+			"""
+			FOR A PRETTY DIAMOND PATTERN
+			TYPE IN AN ODD NUMBER BETWEEN 5 AND 21? 
+		""".trimIndent()
+		)
+		println()
+	}
+
+	private fun printIntro() {
+		println(" ".repeat(32) + "DIAMOND")
+		println(" ".repeat(14) + "CREATIVE COMPUTING MORRISTOWN, NEW JERSEY")
+		println()
+		println()
+	}
+
+	companion object {
+		const val LINE_WIDTH = 60
+		const val PREFIX = "CC"
+		const val SYMBOL = "!"
+	}
+}