Bootcamp

Day 1

Library - a bunch of code that someone else already wrote
openFrameworks - a library that helps you draw graphics and other creative code related tasks
C - invented in the 70s, one of the first programming languages
C++ - built off of C, an improvement on C that adds new concepts. A "type a" language.
Variable
- Allow you to save information in the computer's memory
- Must have a type
Parameter
- Functions can have parameters. Another word is "argument".
What can computers do?
- Math
- Remember stuff
- Control flow — Choose your own adventure stuff

How do I create a new openFrameworks project?
What are the different source files for?
- main.cpp
- ofApp.cpp
- ofApp.h
Coordinate systems start at the top left. (0, 0) is at the top left, and down is positive in Y.
How do I change the width and height?
- Open main.cpp, look for width/height
I get this error: "Expected ';' after expression"
- Almost every line in C++ ends with a semi-colon. This is an important piece of coding syntax. This is a way a computer knows the division between lines.
do i need to use spaces in between symbols? example: ofDrawLine(x+10,5,x+20,20); This is syntactically valid, but it is not the convention.
Does it matter what order I put lines of code?
- Absolutely, the order of lines is very important.
  - Background example
  - Variable example
How do I create a new function?
- add the "function header" to the .h file
- add a "function definition" to the .cpp file
What happens if i define a variable called x inside a function with a parameter called x?
very important use ofApp::

draw function
Coordinate system
ofDrawLine(x1, y1, x2, y2)
- x's come before y
ofBackground(r, g, b)
- each value ranges from 0-255
Painter's algorithm
- The order of the lines matters
Comments are a letter to yourself // This is a comment
- command + slash
ofDrawCircle(x, y, radius)
- radius, not diameter
ofDrawRectangle(x, y, width, height)
- width and height are (relative)
variables:
- binary can be used to represent numbers, letters, other types of data
- int x = 10;
  - A number that has no fractional component
- float x = 50;
  - A decimal number. 1.1, 3.14, -103345.2543
- char c = 'x';
  - a single letter
- bool b = true;
- types are fundamental to programming languages
mouseX / mouseY
custom functions
- double click on .h file
- add a new function under "public:"
  
  void drawLetterR()
parameters
- in .h file:
  - void drawLetterR(float x);
- in .cpp file: void drawLetterR(float x) { }
Always reduce redundancy

Exercise 1: Draw line from top left to bottom right
Exercise 2: Draw your name
- Coordinate systems?
- how do i change line width
- how do i use ofDrawCurve
- S's are hard ofPolyline curve;
  curve.arc(centre, radiusX, radiusY, startAngle, endAngle, arcResolution);
  curve.draw();
- you can use mathematical expressions in parameters
Exercise 3: Take the first letter of your name, and draw it twice on the screen
- make the computer do the math
  
  if this is our old line
  
  ofDrawLine(30, 30, 20, 500);
  
  then we can draw this new line
  
  ofDrawLine(200 + 30, 30, 200 + 20, 500)
  - we keep repeating the same number again and again
  - we can use a variable to store this number
  - we can move this code to a function
  - we can parameterize this function
Homework assignment:
- Rewrite drawLetter function so that it accepts 4 parameters:
  
  void drawLetter(int x, int y, int width, int height) { // ... }

Turn off autocomplete at the start
Color as 0-255 was called out by student, but needs to be reemphasized more clearly.
What happens if ofBackground comes after ofLine?
Overemphasis on XCode short cuts
"Little bit of addition" — not easy!
Don't show multi-cursor features
Lines of code are run top-down
don't introduce binary so early. i think that "you need to tell c++ what type of variable you want to store" is enough.
A program is a recipe.
More focus on syntax. Ex: variable declaration (doesn't need to be called x)
mental model of the execution thread
scope
"people who have coded before in the past"
"has anyone used processing"
if statement - "has anyone heard of this before"
use debugger?
easing is a hard example to introduce a function with. it's using state, parameters AND return values all at once.
introduce arrays before object?
bag isn't good analogy for array. list is better.
"has anyone heard of array before?"
drawing vector example is not motivated well. it's the same as before.
when giving homework, dont say "maybe we can bah blah". homework should be well defined, written down, and confidently stated
wish we had a "picture vocabulary" for memory (variables are boxes, arrays are stacks of boxes)
more questions for students. "turn to the person next to you and tell them what you think" or "try doing this task with the person next to you"
don't need to store array of bugs for perlin noise
emphasize boolean earlier