Pixel Composer Expression (PCX) is a scripting language used for controlling properties value. Instead of using keyframe animation, you can write a script to control the value of a property.

Using Expression

In the inspector panel. Click on the expression icon, or right click at the property and select "Use expression" to enable/disable expression.

Syntax

Statement

Statements are separated by line, and code block is done with bracklet {}

Returns value

The returns value of the PCX is the last result. So it can be as simple as a single expression: 1 + 1Which will returns the value 2.

Variables

Local variable

Local variable can be define directly:a = 5
a * 2will returns 10.

Global variable

Global variable are read only, and can be call simply by typing the variable name.

Value variable

value is a reserved variable for getting the value of the property itself. You can use it to get value from keyframe animation or from other node through connection.

Global Structs

There are several global structs that can be used to access other global values.

Variable	Description
Project.frame	The current frame index
Project.progress	Animation progress from 0 - 1
Project.frameTotal	Total frames in the animation
Project.fps	Current preview speed
Project.time	Current preview time (in seconds)
Project.name	Current project name
Device.timeSecond	Current (real time) second.
Device.timeMinute	Current (real time) minute
Device.timeHour	Current (real time) hour
Device.timeDay	Current (real time) day
Device.timeDayInWee	Current (real time) day in a week (0 - 6)
Device.timeMonth	Current (real time) month
Device.timeYear	Current (real time) year

Constants

Some words are also reserved for mathematical constants.

Variable	Value
pi	3.1415926535
e	2.7182818284

String

String can be defined with the double quote "". String support some arithmetic operation and array-like access.s = "Pixel"
s += " Composer"
s[0] will returns "P".

Array

Array can be created and access with square bracket []. Pixel Composer use zero-indexing for array.a = [ 0, 1, 2, 3, 4, 5 ]
a[2]will return 2.

Conditions

You can create conditional statement with if, elseif, and else: if(value > 10) {
  1
} elseif(value < 0) {
  -1
} else {
  0
}This will return -1, 0, 1 based on the junction value.

Functions Reference

sin(radian)

sin

cos(radian)

cos

tan(radian)

tan

dsin(degree)

dsin

dcos(degree)

dcos

dtan(degree)

dtan

arcsin(x)

arcsin

arccos(x)

arccos

arctan(x)

arctan

arctan2(y, x)

arctan2

darcsin(x)

darcsin

darccos(x)

darccos

darctan(x)

darctan

darctan2(y, x)

darctan2

abs(x)

abs

round(x)

round

ceil(x)

ceil

floor(x)

floor

fract(x)

fract

sign(x)

sign

min(x, y)

min

max(x, y)

max

clamp(x, min = 0, max = 1)

clamp

lerp(x, y, amount)

lerp

wiggle(time, frequency, octave = 1, seed = 0)

wiggle

random(min = 0, max = 1)

random

irandom(min = 0, max = 1)

irandom

range(length, start = 0, step = 1)

range

length(value)

length

string(value)

string

number(value)

number

chr(x)

chr

ord(char)

ord

draw(surface, x = 0, y = 0, xs = 1, ys = 1, rot = 0, color = white, alpha = 1)

draw

surface_get_dimension(surface)

surface_get_dimension

surface_get_width(surface)

surface_get_width

surface_get_height(surface)

surface_get_height

color_hex(char)

color_hex

color_rgb(red, green, blue)

color_rgb

color_hsv(red, green, blue)

color_hsv