How to Generate Mazes in Scratch

Introduction

• Presented by Griffpatch
• Focus on generating your own mazes
• Mazes consist of corridors and dead ends

Setting Up

Step 1: Prepare Stage

• Delete existing sprite
• Switch to backdrop editor
• Set background color to pure black (walls of the maze)

Step 2: Create Bounds Sprite

• Name: Bounds
• Draw a non-filled rectangle with a pen width of 40, positioned inside the canvas border
• Set x and y position to 0

Step 3: Create Maze Sprite

• Name: Maze
• Create costumes:
  • Tile: Draw an 8x8 pixel square (2x2 grid squares), pastel yellow with transparent pen color
  • Corridor: Duplicate Tile, stretch it to 5 grid squares long
  • Add a thin red border and arrow to the corridor costume for visibility

Coding the Maze

Step 4: Pen Extension

• Add Pen extension
• Use "Erase All" block to clear previous drawings

Step 5: Maze Size

• Create a variable: Tile Size (set to 40)
• Adjust sprite size to correspond to tile size
  • Calculate size for 12 pixels

Step 6: Start Drawing

• Position sprite at start of maze
• Randomly determine initial direction (90, 0, 90, or 180 degrees)

Step 7: Drawing the Maze

• Create custom block: Draw Maze
• Use pen stamp block with corridor costume
• Move forward by tile size
• Implement turns to create bends

Handling Maze Boundaries

Step 8: Avoiding Boundaries

• Use an IF condition to check if touching the bounds
• Extend with an OR to check for collision with corridor color

Step 9: Dead Ends

• Add a Detector costume to prevent overlapping
• Use a repeat loop for trying different directions when hitting walls

Recursive Maze Drawing

Step 10: Custom Block for Direction

• Create a custom block: Try Directions From with input for start direction
• Use a method to backtrack when dead ends are encountered

Step 11: Completing the Maze

• Ensure maze fills the entire screen
• Switch corridor costume to an X at the end of the maze completion

Customizing the Maze

Step 12: Resizing and Tweaking

• Experiment with tile sizes for more complexity
• Adjust turning probability to influence maze shape

Step 13: Adding Start Point

• Track distances to find the longest corridor
• Create variables for furthest x, y, and distance
• Record distance as maze is drawn

Player Control

Step 14: Setting Up Player Sprite

• Create a new sprite named Player
• Control player using keyboard input
• Implement collision detection with maze walls

Step 15: Move Functionality

• Create custom move block to handle movement smoothly
• Use small increments for detailed control

Step 16: Resetting Maze

• Broadcast a reset event to regenerate the maze

Conclusion

• Encourage customization and experimentation with maze designs
• Suggest adding features like timers to enhance gameplay
• Final thoughts on creativity within Scratch

Call to Action

• Invite viewers to like and subscribe for more tutorials
• End with "Scratch on!"