Any one-sheet cribsheet for beginners?

KSara

Hello all - it would be very useful if there were a very short summary of the most common idioms needed by beginners, which I could give out to high-school kids I am helping learn Processing.

Does anyone know of any such?

Search engines are a bit hopeless in finding anything due to the generality of the term "Processing" :).

quark

Rather than search on Processing try 'programming idioms' that will provide better results that are still valid for Processing.

quark

One of my favourites is garbage in - garbage out :)

PhiLho

In the Common Questions category, I grouped a series of articles trying to tackle some base idioms, and some recurrent errors we see in the forum.

Note: if you search from the main site (the search box of the main page), you will get a Google search focused on the Processing site, so you will get more relevant results (but it excludes good sites external to this one, alas).

Chrisir

there is a full length, full text reference here

http://www.clairdunn.com/reference/complete-ref-alpha.pdf

it's ~ 220 pages

KSara

Thank you Chrisir - but your 220 pages is a far cry from the one-page summary that I was hoping to find.

And quark - I didn't find a "garbage in - garbage out" page - I hope you were not calling my message garbage?

I really just wanted something that can clarify the simple "Chapter 1" material - the arguments to background, fill, booleans, loops, etc.

Chrisir

just write your own

One-sheet cribsheet for beginners

This basic sketch shows Animation

// this is a comment
int pos = 0; // pos is a variable with value 0 

void setup() {
    size (400,400); // comment: window size
    frameRate(44); // speed
} // end of function setup()

void draw() {
    background(204);
    pos++; // increase pos 
    line(pos, 20, pos, 80); // use pos 
    if (pos > width) { 
    pos = 0;  // reset 
    }
} // end of function draw()

Use of mousePressed()

// Click within the image to change 
// the value of the rectangle

int value = 0;

void draw() {
  fill(value);
  rect(25, 25, 50, 50);
}

void mousePressed() {
  // when a button is pressed down
  if (value == 0) {
    value = 255;
  } else {
    value = 0;
  }
}

Use of Mouse Position

void draw() {
  background(204);
  line(mouseX, 20, mouseX, 80);
}

A simple for-loop (iteration)

for (int i = 40; i < 80; i = i+5) {
    line(30, i, 80, i);
}

(use this inside the basic sketch above)

A simple if-clause

void draw() {
  background(111);// clear the background  
  stroke(255);    // Set the color to white
  int i = mouseY; // store the y position of the mouse  
  if (i < 35) {   // When 'i' is less than 35...
    stroke(0);    //...set the color to black
  }
  line(30, i, 80, i); // draw a line with y-value 'i'
}

If-clause with else

void draw() {
  background(111);// clear the background  
  int i = mouseY; // store the y position of the mouse  
  if (i < 35) {   // When 'i' is less than 35...
    stroke(0);    //...set the color to black
  } else {
    stroke(255);    // Set the color to white
  }
  line(30, i, 80, i); // draw a line with y-value 'i'
}

Further reading:

look at the first 6 tutorials

https://www.processing.org/tutorials

and the reference

https://www.processing.org/reference

quark

I was not calling your message garbage.

Chrisir

just write your own one-page sheet with my entries e.g.

Chrisir

background(202); is a gray value. 0 means black, 255 white.

background(255,0,0); delivers red. Three values mean red, green and blue. All three go from 0 to 255. You can compose all colors by using this (in the menu is a color selector).

fill and stroke work the same way. fill for the area, stroke for the outline.

Basic figures

point - x,y

line from x,y to x2,y2

rect from x,y with width and then height

ellipse from x,y and width and height

triangle with three times x,y

Basic variables

variables can have a name, a value and a type.

boolean vars are truth vars: can only be true or false

int vars can be negativ or positive integers

float can be floats

e.g. float a = 2.5;

KSara

Many thanks Chrisir - I will procede and try to build a one-page summary based on that.

Quark - I was just checking :).

quark

When I taught programming to beginners the main problem they experienced was how to find and correct their program based on the error messages.
I was forever interpreting error messages for them. For instance mis matched braces, missing semi colons. You might find it useful to have a crib sheet providing stratagems for different types of error.
You can get the students to help by noting errors, noting the code mistake and then noting the correction. This will help the students develop as problem solvers.

Chrisir

when you give the one-page reference online you can just make links into the reference