Shape Drawer

Overview

The Shape Drawer project is a graphical application that allows users to draw, manipulate, and interact with various shapes on a canvas. This project is built using C# and leverages the SplashKitSDK library for graphical rendering and event handling. The application supports drawing rectangles, circles, and lines, with features such as shape selection, color changes, and background customization.

How to Use

1. Drawing Shapes

• Left-click on the canvas to draw a shape at the cursor’s position.
• Press R for rectangles, C for circles, and L for lines.

2. Selecting and Editing Shapes

• Right-click on a shape to select it.
• Press Escape to change the shape's colour.
• Press Backspace or Delete to remove the selected shape.

3. Customising the Background

• Press the Space key to apply a random background colour.

Features

1. Shape Drawing

• Supports drawing rectangles, circles, and lines.
• Shapes are placed on the canvas based on user input.

2. Shape Selection

• Users can select individual shapes for modification.
• Selected shapes are visually highlighted.

3. Shape Manipulation

• Shapes can change colour.
• Selected shapes can be deleted from the canvas.

4. Background Customisation

• The canvas background can be modified.

5. Keyboard Shortcuts

• Various shortcuts enable quick interaction and modifications.

6. Dynamic Rendering

• The canvas updates dynamically to reflect changes.

Technical Details

1. Object-Oriented Programming (OOP) Concepts

This project is a great example of proper use of OOP principles:

• Encapsulation:
  • Each shape class (MyRectangle, MyCircle, MyLine) encapsulates its own properties (e.g., dimensions, position, color) and behavior (e.g., drawing, hit detection).
• Inheritance:
  • All shape classes inherit from the abstract base class Shape, which defines common properties and methods.
• Polymorphism:
  • The Shape class defines abstract methods (Draw, DrawOutline, IsAt) that are overridden by the derived classes to provide shape-specific implementations.
• Abstraction:
  • The Shape class abstracts the common functionality of all shapes, allowing the program to treat all shapes uniformly while delegating specific behavior to the derived classes.

2. Project Structure

• Abstract Base Class (Shape):
  • Defines common properties (X, Y, Color, Selected) and methods (Draw, DrawOutline, IsAt) for all shapes.
• Derived Classes:
  • MyRectangle: Implements rectangle-specific drawing and hit detection.
  • MyCircle: Implements circle-specific drawing and hit detection.
  • MyLine: Implements line-specific drawing and hit detection.
• Program Entry Point:
  • The Program class contains the Main method, which handles user input, event processing, and rendering.

3. Tools and Libraries

• C#: The programming language used for the project.
• SplashKitSDK:
  • A lightweight graphics library for rendering shapes, handling user input, and managing the application window.
  • Provides methods like FillRectangle, FillCircle, DrawLine, and PointInRectangle for graphical operations.
• .NET 6.0: The runtime environment for executing the application. The integrated development environment (IDE) used for designing, coding, and debugging this project.

4. Event Handling

• Mouse Events:
  • Left-click: Draws a new shape at the mouse position.
  • Right-click: Selects a shape at the mouse position.
• Keyboard Events:
  • Key presses are used to switch shape types, change colors, delete shapes, and modify the background.

5. Rendering Pipeline

• The Drawing class manages a collection of shapes and handles their rendering.
• The Draw method iterates through all shapes and calls their respective Draw methods.
• The SelectedShapeAt method identifies and selects a shape based on the mouse position.

Demo

Below is a demonstration of the Shape Drawer in action:

License

This project is licensed under the Apache License.