• If no animation is required, you can skip the void draw() and put everything into void setup().
• Initialising the size of the canvas is sometimes not necessary - it will be initialised to (100, 100) by default.
• If you need to use height and width in your code, it is usually shorter to use their numeric values instead. For example, with a canvas of size (100, 100), using 99 to replace height and width can save you 7 bytes.

If you only run code in the setup method then you don't need write the method outline. For example you can write:

rect(10,10,90,90); 

instead of

void setup { rect(10,10,90,90); } 

And as long as you don't use any other methods then everything will be put in the setup method before running

White #FFFFFF

^{Related: Colour Notation}

Instead of using this for white:

color(255) //10 bytes 

you can do this:

color(-1) //9 bytes 

and save 1 byte.

Colours (R, G, B) notation

Hexadecimal colours

Processing is very flexible in colour format.

fill(255,255,0); //16 bytes 

can be written using hexadecimal notation as

fill(#ffff00); //14 bytes (2 bytes saved) 

Grayscale

Here is a special usage for colours if all the Red, Green and the Blue values are the same (white):

fill(255,255,255); //18 bytes fill(#ffffff); //14 bytes fill(255); //10 bytes 

All the three parameters can be shortened into one parameter containing the grayscale value: from 0 black to 255 white.

This can be extended for alpha as well:

fill(175,175,175,50); //translucent gray fill(175,50); //8 bytes shorter 

Both mean the same colour, but the latter way is shorter by 8 bytes.

Alpha

Although obvious, it should be stated that the alpha parameter in specifying colours is optional since colours are defaulted to an alpha value of 255 (100% opaque).

Summary: Color formats

Use the shortest colour format to express your colour (remember to leave out unnecessary bits -depending on the context of the program- for example: alpha or grayscale)

R: Red G: green B: blue A: alpha g: grayscale

RRR,GGG,BBB #RRGGBB ggg RRR,GGG,BBB,AAA ggg,AAA 

Abbreviate constants

If you're ever using one of the all-caps keywords in Processing (such as DIFFERENCE or TRIANGLE_FAN), see if the number they correspond to is shorter.

For example, DIFFERENCE is just an int that's equal to 32. Instead of using DIFFERENCE here, I could write 32, saving 8 characters.

Shorter alternative to void keyPressed(){}

void draw(){}void keyPressed(){foo;} //36 bytes void draw(){if(key>0)foo;} //26 bytes 

The void draw(){} is needed by default in order for key to be updated. If the user hasn't pressed a key since the start of the program, key is given a value of 0. By checking if it is more than 0 (ie the user has pressed a key), we have golfier code and save 10 bytes.

Setting and committing pixels using set()

It's more efficient to set pixels via pixels[]:

pixels[0] = color(255) updatePixels(); 

However, that requires updatePixels() and also using an index which depending on the scenario will require converting an x,y position to a pixel index. To keep things short, even though it's less CPU efficient (as each call updates the whole buffer), set() allows a pixel to set and committed to buffer straight away in one call.

set(0,0,color(255));