Intro to Processing

Question 1

What is the command to draw a rectangle?

Answer 1

rect(x of top left, y of top left, width, height);

Question 2

What is the command to draw a line?

Answer 2

line(x of start, y of start, x of stop, y of stop);

Question 3

What is the command to draw an ellipse?

Answer 3

ellipse(x of center, y of center, width, height);

Question 4

In order, what are the primary colours of light?

Answer 4

Red, Green, Blue

Question 5

What are the 3 different colours you can change in processing?

Answer 5

Background, Stroke, Fill

Question 6

In greyscale, what value represents black? White?

Answer 6

0, 255

Question 7

What is the fourth parameter of a colour command?

Answer 7

Transparency

Question 8

What value would you use to make something transparent? Opaque?

Answer 8

0, 255

Question 9

What is the command to change the thickness of a line?

Answer 9

strokeWeight(width in pixels);

Question 10

What are parameters?

Answer 10

The information needed for a function to do its job. (inside the method call)

Question 11

What is a compile time error?

Answer 11

A syntax error: the program won’t run until you fix it

Question 12

What is an execution time error?

Answer 12

The program will compile, but will stop running when it comes across the error

Question 13

What is a logic error?

Answer 13

The program will run, but not as you expect/want it to

Question 14

What happens in a static program?

Answer 14

Begins with the first line in the file, and runs each line at a time

Question 15

What happens in an active program?

Answer 15

The program starts, and keeps running. Global constants and variables are declared once at the top, the setup() function runs once, and the draw() function runs over and over until you stop it

Question 16

What is the default frame rate?

Answer 16

60 frames per second

Question 17

What is a block?

Answer 17

Grouped sets of commands. Any code inside a pair of { } forms a block.

Question 18

What are the predefined variables in processing for the position of the mouse at the start of the current frame?

Answer 18

mouseX and mouseY

Question 19

What are the predefined variables in processing for the position of the mouse at the end of the previous frame?

Answer 19

pmouseX and pmouseY

Question 20

What is the command to find the minimum of two numbers?

Answer 20

min(int, int); or min(float, float);

Question 21

What is the command to find the maximum of two numbers?

Answer 21

max(int, int); or max(float, float);

Question 22

What is the command to find the square root of a number?

Answer 22

sqrt(float);

Question 23

What is the command to find the square of a number?

Answer 23

sq(float);

Question 24

What is the command to find the absolute value of a number?

Answer 24

abs(float); or abs(int);

Question 25

What is the command to find a random value between two numbers?

Answer 25

random(float, float); or random(float);

Question 26

What set of numbers could be the result of
(int)random(1, 3);

Answer 26

{1, 2}

Question 27

What should you write to keep a value x within the bounds of the canvas?

Answer 27

min(width, max(0, x));

Question 28

What is the result of
x = 5;
println(x++);
println(++x);

Answer 28

5
7

Question 29

What is the formula for scaling problems?

Answer 29

destinationMin + (destinationMax - destinationMin)*(current-sourceMin)/(sourceMax - sourceMin);

Question 30

What is the command to get an angle in processing?

Answer 30

atan2(opp, adj);

Question 31

What should you write to get the distance between two points?

Answer 31

sqrt(sq(x1-x2) + sq(y1-y2));

Question 32

Write code to calculate the x and y values of a point moving clockwise in a circle

Answer 32

float x = CENTRE_X + RADIUScos(angle);
float y = CENTRE_Y + RADIUSsin(angle);