Advanced Features

This page explains the advanced editing features included in DyNode.

Expressions

Warning

This is a very early experimental feature and may change frequently in upcoming versions. It is recommended to back up your project before using it.

Press 0 to input an expression.

A valid expression is a meaningful statement composed of a series of operators, numbers, and variables, for example: a=10+b*c, 100>90, etc.

Expressions support the basic arithmetic operators +,-,*,/,%, bitwise operators <<,>>,|,&, logical operators &&,||,!, relational operators >,<,>=,<=,==,!=, and the assignment operator =.

You can write expressions in a C-like syntax. Some valid expression examples are as follows:

a=(10+20)*30     // a becomes 900
b=a              // b becomes 900
b=a=20           // b is assigned (a=20), right-associative
c=10*20/20       // c becomes (10*20)/20, left-associative

You can use expressions to batch modify the properties of all notes or selected notes.

The currently supported note property variables are listed in the table below:

Property	Function	Unit	Note Type Restriction
time	The time the note occurs	ms
pos	The position of the note
wid	The width of the note
len	The duration of the note	ms	HOLD
htime	The head time of the note (for Hold)	ms	HOLD
etime	The tail time of the note (for Hold)	ms	HOLD

The expression is computed independently on each note. The computation process is as follows:

The expression’s variables are initialized based on the note’s properties.
The expression is evaluated, and the variables may change during computation.
The final values of the variables are used to update the note’s properties.

In DyNode, multiple expressions are separated by ; and are executed sequentially. All variables are stored as double‐precision floating-point numbers.

Note that some variables are restricted to certain note types; that is, they only affect specific types of notes. All computations will ignore SUB type notes (the tail notes of HOLD notes). See Modifying HOLD Properties for details.

Below are some valid examples of expressions, each on a separate line:

wid = wid * 2                   // Double the width of the note
pos = 2.5                       // Set the note position to 2.5
 time = time + 10               // Increase the note time by 10ms (adding delay)

pos = 2 * 2.5 - pos              // Mirror the note across the center at position 2.5
 time = time / 1.5; len = len / 1.5   // Speed up the chart by a factor of 1.5 (divide note times and HOLD durations by 1.5)
a = 20; time = a                // Define variable a and assign it to time

Modifying HOLD Properties

All expression evaluations ignore SUB type notes. Instead, for HOLD type notes there are special property variables available:

Property	Function	Unit
len	The duration of the note	ms
htime	The head time of the note	ms
etime	The tail time of the note	ms

This means that modifying the time property of a HOLD note will not affect its duration; changing time effectively moves the entire HOLD note rather than adjusting its head and tail separately.

If you want to modify the head and tail separately, you need to change the htime and etime properties instead of time.

You may notice that these three properties can conflict; that is, if you modify htime and etime, then len would theoretically change. However, during expression evaluation, variables are not bound to each other – a change in one does not automatically update another.

In practice, we do not recommend including two HOLD-related variables in the same expression. The conflict resolution is as follows:

If both time and htime are modified, the modification to htime takes precedence.
If both len and etime are modified, the modification to len takes precedence.

Here are some valid examples of modifying HOLD properties:

htime = htime + 10; etime = etime - 10       // Increase the head time by 10ms and decrease the tail time by 10ms for all HOLD notes
len = len / 2                                // Halve the duration of all HOLD notes
htime = 100                                  // Set the head time of all HOLD notes to 100ms
htime = 100; len = 100                        // Equivalent to setting time and duration to 100ms