The Improviz language is still changing somewhat but should be fairly stable at this point. This reference should keep up with it.
The most basic part of writing code with Improviz is calling functions that either draw shapes to the screen, or change those shapes in some way, with each of these functions being on their own separate line.
The reference document lists all of the available, functions what they do, and what values they can be given.
To call a function, you need to have its name, followed by a pair of parentheses
(). Within these you place any values that will change the way the function behaves, separated by commas.
A blue rectangle rotating on a red background.
background(255, 0, 0) fill(0, 0, 255) rotate() rectangle(2, 1)
Loops allow you to repeatedly call some lines of code. The piece of code that’s repeated is called a block and it must be indented with a tab.
stroke(0, 0, 0) fill(255, 0, 0) 100 times rotate() cube(8, 8, 8)
with variable can be used as well.
stroke(0, 0, 0) fill(255, 0, 0) n = 100 n times with i rotate() move(i) cube(8, 8, 8)
Any text that comes after two slashes
// is considered a comment and won’t be run
cube() //this is a comment //sphere() this line won't run
time is the major global variable and is used for all animation, whether as default variables for commands or used by the user. It is the only value that actually changes between frames.
rotate(1, 2, 3) cube() // this cube won't move rotate(time) sphere() // this sphere will move
If you want to calculate a value and then use it in multiple places, you can assign it to a variable.
a = 3 + 4 cube(a)
Variables can have their value re-assigned.
a = 3 + 4 cube(a) a = 2 sphere(a)
Conditional assignment is also available, and will set a variable only if it currently doesn’t have a value. This is mostly useful when defining functions and setting defaults for the arguments that are passed in.
a = 3 a := 4 cube(a) // cube will be of size 3
Control flow can be done using
else. The number 0 is considered False, with anything else being considered True.
10 times with x if (x % 3 < 1) fill(255, 0, 0) elif (x % 3 < 2) fill(0, 255, 0) else fill(0, 255, 0) rotate() rectangle(8)
Functions are defined using the
func keyword, followed by a name, argument list and then either an indented block or an arrow and single line expression
func val(a) => a + 1 func draw(r, g, b) rotate() fill(r, g, b) cube(val(1)) draw(255, 0, 0)
Functions can have default values for their arguments that will be used if a value isn’t passed in.
func defEx(rot:2, size:3) rotate(rot) cube(size) defEx()
When a function is called in can be passed an optional block. If the function has a BlockArg argument then this block is available to be used within the function body.
func myf(x, y, &blk) if (isNull(blk)) sphere() else move(x, y, 0) blk() myf(1, 1) rotate() cube()
These blocks can also have arguments defined so that values can be passed from the wrapping function to the block.
func gridit(x, y, &blk) x times with xVal y times with yVal move(xVal, yVal, 0) &blk(xVal, yVal) gridit(3, 3) |x: 0, y: 0| rotate() if ((x + y) % 2 < 1) fill(255, 0, 0) else fill(0, 255, 0) cube()
The BlockArg must start with an ampersand (&) symbol.
Functions can be passed as values.
func draw(f) rotate() fill(r, g, b) f(3) draw(cube)
Improviz supports basic lists, though currently they have a fixes size once declared.
sizes = [1,2,3,2+2] s = sizes[(time * 4) % length(sizes)] rotate(time) cube(s)
They can be created using square brackets and accessed also using the square brackets. The
length function is available to return the length of a list as a number.
Function Spread Arguments
The spread operator can be used to send multiple values in a list to a function as arguments.
lblue = [100, 100, 255] // These two calls to fill will do the same thing fill(...lblue) fill(100, 100, 255)
Saving and Loading GFX state
The built in functions pushScope and popScope can be used to save and load snapshots of the style and transformation state on a stack.
pushScope() rotate() cube() popScope() move(1,0,0) sphere()
This state will include the stroke and fill styling, as well as the matrix manipulations.
This feature is used in conjuction with the function blocks to allow simplified scoping of some commands.
fill(255, 0, 0) cube() rotate() move() fill(0, 255, 0) sphere()
A symbol is really just a name and is primarily used for giving the name of textures to the texture function. They can be assigned to variables if desired.
texture(:crystal) cube() move() t = :another texture(t) ball()