Update coordinates_xy.js

src/programs/basics/coordinates_xy.js

@@ -5,11 +5,20 @@
 @desc   Use of coord.x and coord.y
 */
 
-const chars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ.:!?'
+const density = 'Ñ@#W$9876543210?!abc;:+=-,._ '
 
 export function main(coord, context, cursor, buffer) {
-	// To generate an output return a character
+	// To generate an output return a single character
 	// or an object with a “char” field, for example {char: 'x'}
-	const i = (coord.y + coord.x + context.frame) % chars.length
-	return chars[i]
+
+	// Shortcuts for frame and coord
+	const f = context.frame
+	const {x, y} = coord
+
+	// Invert direction for odd rows
+	if (coord.y % 2 == 0) {
+		return density[(y + x + f) % density.length]
+	} else {
+		return density[(y + context.cols - x + f) % density.length]
+	}
 }