Chaikin's Corner-Cutting Subdivision (Rust)

---

Problem: Generating smooth curves from sparse control points is complex without using heavy math frameworks or relying on high-level GPU-bound graphics stacks.

Solution: An interactive Rust application implementing Chaikin's subdivision algorithm in a custom software renderer (Bresenham's and midpoint circle lines) drawing directly onto a 1D pixel buffer.

---

Key Features

• Interactive Canvas: Add control points using mouse left-clicks.
• Real-Time Drag and Drop: Drag existing control points to reshape the curve in real time.
• Animated Subdivision: View a 7-step progressive animation of Chaikin's corner-cutting algorithm.
• Strict Boundary Conditions: Pins endpoints to ensure open curve limits remain anchored.
• Custom Software Renderer: Uses Bresenham's line algorithm and midpoint circle drawing directly on a 1D pixel buffer.
• Robust Corner Cases: Handles 0, 1, and 2 control points gracefully, displaying status alerts and fallback rendering modes.

---

Architecture Flow

Mouse Input → AppState (points/drag/animation) → Chaikin Algorithm → Software Renderer (Bresenham) → Pixel Buffer → Window Display

---

Directory Structure

• Cargo.toml: Project manifest & external dependencies
• README.md: Project overview and quickstart guide
• TODO.md: Requirements checklist and audit log
• docs/: Detailed documentation & specifications
  • audit.md: Functional audit test checklist
  • guide.md: Comprehensive logic, flow, Rust features, and Q&A
  • requirements.md: Core requirements and specifications
• src/: Application source code
  • lib.rs: Library entrypoint exposing modules
  • main.rs: OS event loop, input polling, and main renderer
  • app.rs: AppState, animation ticks, and drag-and-drop state machine
  • chaikin.rs: Mathematical implementation of corner-cutting algorithm
  • renderer.rs: Bresenham lines, circle filling, and text rendering primitives
• tests/: Automated testing suites
  • chaikin_tests.rs: Core algorithmic math and point length edge case tests
  • integration-tests.rs: Full state transition and functional audit verification tests

---

Getting Started

Prerequisites

You must have Rust and Cargo installed. To install them, follow the instructions at rustup.rs.

Build and Run

To run the interactive application:

cargo run --release

Run Tests

To run the full suite of unit and integration tests:

cargo test

---

Interactive Controls

• Left Click: Place a new control point on the canvas (when not animating).
• Left Click + Drag: Drag an existing control point in real time.
• Enter / Right Click: Start / Restart the 7-step subdivision animation.
• C / R: Clear the screen, reset the state, and start over.
• Escape: Exit the application.

---

Codebase Architecture & Deep Dive

For an in-depth explanation of the application's logic, flow, software rendering math, and the specific Rust language features utilized, please see:

• Comprehensive Logic, Flow & Rust Architecture Guide

This guide includes:

• Structural analysis of app.rs, chaikin.rs, and renderer.rs.
• Rust concept explanation (trait derivations, pattern matching, memory safety, slices, lifetimes).
• Full answers to the audit checklist in docs/audit.md.
• Advanced Q&A testing understanding of Rust memory safety and performance design.

---

Related

• CV & Portfolio
• lem-in-e — Go algorithmic routing solver