Difference between revisions of "Expression"

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m (Reorganize wanted links in expressions)
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=== Values ===
=== Values ===


* The value of a [[variable]]
* A constant number. This is the same as not using an expression.
*A constant number. This is the same as not using an expression.
*The value of a [[variable]]
*The value of a [[Behavior]] property
*The value of a [[Behavior]] property


=== Choices===
=== Choices===


* [[Weighted choose expression|Weighted choose]]
* Weighted choose
*[[Choose expression|Choose]]
*Choose
*[[Maximum expression|Maximum]]
*Maximum
*[[Minimum expression|Minimum]]
*Minimum


===Randomness===
===Randomness===
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*[[A random number with a Gaussian distribution expression|A random number with a Gaussian distribution]]
*[[A random number with a Gaussian distribution expression|A random number with a Gaussian distribution]]
*[[Perlin noise in 2 dimensions expression|Perlin noise in 2 dimensions]]
*[[Perlin noise in 2 dimensions expression|Perlin noise in 2 dimensions]]
*[[A random number in a range expression|A random number in a range]]
*A random number in a range


===Spacial relationships===  
===Spacial relationships===  


*[[The speed of an actor expression|The speed of an actor]]
*The speed of an actor
*[[The angle of motion of an actor expression|The angle of motion of an actor]]
*The angle of motion of an actor
*[[The angle from one actor to another (degrees) expression|The angle from one actor to another (degrees)]]
*The angle from one actor to another (degrees)
*[[The distance between two actors expression|The distance between two actors]]
*The distance between two actors
=== Arithmetic ===
=== Arithmetic ===


*[[The number of repeats finished expression|The number of repeats finished]]
*The number of [[Repeat|Repeats]] finished
*[[Logarithm expression|Logarithm]]
*Logarithm
*[[Power expression|Power]]
*Power
* [[Modulo expression|Modulo]]
* Modulo
*[[Divide expression|Divide]]
*Divide
* [[Multiply expression|Multiply]]
* Multiply
* [[Subtract expression|Subtract]]
* Subtract
* [[Add expression|Add]]
* Add


===Clock===
===[[Clock]]===


*[[Time elapsed since the card started expression|Time elapsed since the card started]]
*Time elapsed since the card started
* [[The clock tempo expression|The clock tempo]]
* The clock tempo
*[[Time since the last beat expression|Time since the last beat]]
*Time since the last beat
* [[The current bar expression|The current bar]]
* The current bar
*[[The current beat in the current bar expression|The current beat in the current bar]]
*The current beat in the current bar
*[[Beats elapsed since the card started expression|Beats elapsed since the card started]]
*Beats elapsed since the card started


=== Music ===
=== [[Music]] ===


* The note played (only appears under the "track plays note" trigger)
* The note played (only appears under the "track plays note" trigger)
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=== Functions===
=== Functions===


*[[The number of actors with a tag expression|The number of actors with a tag]]
*The number of actors with a [[Tag]]
*[[Degrees to radians expression|Degrees to radians]]
*Degrees to radians
*[[Sine expression|Sine]]
*Sine
*[[Clamp a value between two bounds expression|Clamp a value between two bounds]]
*Clamp a value between two bounds
*[[Mix two values expression|Mix two values]]
*Mix two values
*[[Round expression|Round]]
*Round
* [[Round down expression|Round down]]
* Round down
*[[Absolute value expression|Absolute value]]
*Absolute value

Revision as of 21:27, 11 May 2022

An Expression is a representation of a value that is resolved while the deck is playing. Some common uses for expressions include: Reading the value of variables, performing simple math, or creating randomness. Expressions can also be nested and combined to support more complex things, such as calculating health for characters, crafting procedural games and animations, and even making generative artwork.

Expressions always resolve to a numeric value.

Some expressions take arguments. For example, when reading the value of a Variable, you need to specify which variable to read. When adding two numbers, you need to specify which two numbers (or expressions) to add. Other expressions don't take any arguments, such as the Time elapsed since the card started.

Using Expressions

Expressions are an important component of Rules in Castle. Typically, when editing a rule, any numeric value can be an expression. To edit an expression, look for the round beaker icon to the left of a number input. Press it to open a sheet to edit that expression.

List of Expression Types

Some expressions are contextual to the enclosing Response. For example, the "Number of repeats finished" expression only appears if already inside a Repeat response.

Values

  • A constant number. This is the same as not using an expression.
  • The value of a variable
  • The value of a Behavior property

Choices

  • Weighted choose
  • Choose
  • Maximum
  • Minimum

Randomness

Spacial relationships

  • The speed of an actor
  • The angle of motion of an actor
  • The angle from one actor to another (degrees)
  • The distance between two actors

Arithmetic

  • The number of Repeats finished
  • Logarithm
  • Power
  • Modulo
  • Divide
  • Multiply
  • Subtract
  • Add

Clock

  • Time elapsed since the card started
  • The clock tempo
  • Time since the last beat
  • The current bar
  • The current beat in the current bar
  • Beats elapsed since the card started

Music

  • The note played (only appears under the "track plays note" trigger)

Functions

  • The number of actors with a Tag
  • Degrees to radians
  • Sine
  • Clamp a value between two bounds
  • Mix two values
  • Round
  • Round down
  • Absolute value