Drawing basic shapes

In Chapter 1, Getting Started with Processing 2, you learned how to draw lines and points in the Writing my first Processing sketch recipe. In this recipe, we'll take a look at how you can draw the most basic geometric shapes: rectangles, ellipses, triangles, and quads.

How to do it...

The following is the code for drawing the most basic shapes. The first thing you need to do is to write the setup() function and set the window size to 640 by 480 pixels:

void setup()
{
  size( 640, 480 );
  smooth();
}

The next piece of code is a function that will draw a grid with squares of 10 by 10 pixels. This function will be called in the draw() function:

void drawGrid()
{
  stroke( 225 );
  for ( int i = 0; i < 64; i++ ) {
    line( i*10, 0, i*10, height );
  }

  for ( int i = 0; i < 48; i++ ) {
    line( 0, i*10, width, i*10 );
  }
}

The last thing you need to do is write the draw() function. We'll start by setting the background to white, then draw the grid, and finally draw...