ASCII Square Construction

An optimized code and GUI application for generating dynamic ASCII art square patterns with performance monitoring and several rendering modes.

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Overview

This project combines a high-performance ASCII square generation algorithm with a Tkinter-based graphical interface. It builds an n_×_n square by computing the minimum distance of each cell to the nearest border, mapping that distance to a character, and rendering the result in a fully interactive window.

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Workflow

1. Input Validation

   • Ensure the square size is a positive integer (1–1000).
   • Ensure the starting character is a single alphabetic letter.
   • GUI fields enforce maximum lengths (size: 4 digits; character: 1 letter) and display error messages on invalid input.

2. Pattern Construction

   • Precompute a list of row/column offsets: each entry is the minimum distance to any edge.
   • Build a character lookup table by shifting from the starting character through the alphabet (wrapping A–Z, then a–z).
   • For each row, use the smaller of row-offset and column-offset to index into the lookup table and assemble the row string.
   • Combine all rows into the final square pattern.

3. Performance Monitoring & Caching

   • A decorator measures execution time on “cold” runs and reports whether a result came from cache.
   • An LRU cache stores recent square patterns (up to 128 sizes) to serve repeated requests instantly.

4. GUI Rendering

   • Launch a Tkinter window with input fields, palette selector, mode radios, Generate button, and a scrollable canvas.
   • On generation: clear any ongoing animations, validate inputs, compute or retrieve the square pattern, display execution time, and draw the square incrementally.
   • Incremental drawing via short delays keeps the UI responsive even for large patterns.
   • Copy-on-double-click for individual cells or labels, plus a “Copy ASCII square” button to copy the entire pattern to the clipboard.

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GUI Features

• Input Controls

  • Square size entry
  • Starting character entry
  • Color palette dropdown
  • Rendering mode radio buttons

• Rendering Modes

  • One-color: uniform color for all characters
  • Alternating: cycle through palette by layer
  • Snake: animate a “snake” of colors following a spiral path

• Color Palettes

  • None (default black), Red, Green, Blue, Orange, Purple, Cyan

• Interactive Canvas

  • Vertical and horizontal scrollbars
  • Click-and-drag panning
  • Double-click copy for any text element
  • Hover message confirming clipboard copy

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Performance Enhancements

• Offset Precomputation
  Eliminates per-cell distance calculations by computing each index’s distance once.

• Memoization
  Caches both the square construction and the spiral-order generator for instant retrieval on repeated inputs.

• Decorator-Based Timing
  Automatically logs elapsed time for profiling and displays it in the GUI as milliseconds, seconds, or “Cached.”

• Incremental Drawing
  Splits rendering into per-row tasks scheduled with short delays, preventing the UI from freezing during large draws.

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Limitations of Tkinter

• Single-Threaded Event Loop
  Heavy rendering can block user interactions because drawing and event handling share the same thread.

• No Native Animation Support
  Lacks hardware acceleration or double-buffered canvases, so animations may stutter.

• Canvas Overhead
  Thousands of text items slow redraw, scrolling, and event processing.

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License

Released under the MIT License. See the accompanying LICENSE file for full terms.