week 2

Introduction

• Importance of studying variables in programming

• Application of Processing; visual representation of code execution

Overview of Variables

• Variable Basics

  • Variables are identifiers used to store data values.

  • Examples discussed are width and height.

  • Inbuilt variables help manage certain data types within the Processing environment.

Memory Representation of Variables

• Each variable stores a value in a designated box (memory location) labeled by the variable name:

  • Example: size(400, 300);

    • width stores 400.

    • height stores 300.

• Variable names must be unique to avoid conflicts.

Types of Variables

• Inbuilt Variables:

  • mouseX, mouseY: track cursor locations.

  • Importance of naming conventions (case sensitivity).

• User-defined Variables:

  • User can define variables with specific data types:

    • int: for integers (whole numbers).

    • float: for decimal numbers.

    • char: for single characters.

    • boolean: true/false values.

Coding Setup

• Basic Structure:

  • void setup(): initializes settings once when the program starts.

  • void draw(): continuously executes code; runs in a loop.

Drawing with Cursor Interaction

• Drawing a line from the top left corner to cursor position using mouseX and mouseY.

• Implementation of resetting the background using background(255) to clear previous drawings.

• Execution speed: draw() runs 60 times per second,

Common Errors

• Potential errors arise from variable names and their casing (e.g., MouseY vs mouseY).

• Importance of checking the spelling of inbuilt variables when errors occur.

Incrementing Values

• Using variables to change visual representations:

  • Example: Making a circle or object move by incrementing the Y-coordinate (yPosition++).

• Need for update in variable assignment each frame in draw() to create movement.

• Global Variables allow access across multiple functions; declared outside the setup and draw.

Animation Concept

• Create animations with objects moving across the screen and changing properties over time (increasing size, position).

• Importance of clever use of loops and conditional statements for dynamic movement.

Challenge: Create a Random Circle App

• Task to create a program generating random circles upon mouse click:

  • Use random(width) and random(height) to place circles at random coordinates.

• Adjusting circle sizes upon each click to increase diameter to visualize growth over time.

• Encouragement to keep learning through practice and further projects involving conditions and variable interactions.

Conclusion

• Recap importance of variables, conditions, and loops in programming.

• Reminder about practice to solidify programming concepts discussed in the session.