elements: A DSL for optimizing and calculating Genshin Impact damage rotations

Genshin Impact is an open world RPG released in 2020. In Genshin, you control a team of up to four characters, and engage in various levels of combat. The goal is typically to clear content as fast as possible, which requires efficient team rotations with high levels of sustained damage. This package implements a damage calculator as a hosted DSL. With elements, you can easily define the basics of a team lineup, including weapons, elemental skills, and characters. From there, you can setup damage rotations against enemies of varying toughness, and calculate potential damage output. Additionally, elements compares old rotations to newer ones, allowing you to easily keep track of what combination has provided the highest sustained damage.

Here is a simple example that defines a character with a set of weapons/skills and a lineup. Then, a calculation is run using the lineup to display the output of the rotation.

#lang racket

(require "main.rkt")

(genshin-calc

 (define-attack-sequence attack-chain
   ([(base-dmg atk% 10) 0.5 physical]
    [(base-dmg atk% 25) 0.2 physical]
    [(base-dmg atk% 125) 0.8 physical]
    [(base-dmg atk% 250) 1.5 physical]
    #:charged [(base-dmg hp% 5) 3.5 pyro]
    #:plunging [(base-dmg hp% 10) 3.5 physical]))

 (define-weapon wolfs-gravestone
   450 
   (mod critr 24.1)
   (triggered-buff
    [dmgup
     #:effect (buff atk% 20.0) 
     #:trigger normal-attack
     #:limit 1
     #:party-wide #f
     #:duration 10.0])

   (unconditional-buff
    [crit-up
     #:effect (buff critd 20) 
     #:party-wide #f])
   )

 (define-skill super-charge
   #:cooldown 60.0
   #:attr (base-dmg hp% 500)
   #:duration 2.0
   #:type hydro
   (applied-buff
    [skill-atkup
     #:effect (buff atk% 200)
     #:limit 1
     #:party-wide #t
     #:duration 20])
   (applied-buff
    [skill-atkup
     #:effect (buff def% 300)
     #:limit 3
     #:party-wide #f
     #:duration 30])
   )

 (define-skill holy-blast
   #:cooldown 90.0 
   #:attr (base-dmg atk% 500)
   #:duration 1.0 
   #:type hydro 
   )

 (define-artifact flaming-feather
   "fiery flames of a bygone era" 
   (mod atk 325) 
   (mod atk 27) 
   (mod em 42)
   )

 (define-artifact universal-timepiece
   "relics from the edge of space" 
   (mod critd 60) 
   (mod em 300)
   )

 (define-character zhongli
   #:hp 15000 
   #:def 200  
   #:atk 1200   
   #:em 100    
   #:critr 75     
   #:critd 150    
   #:attacks attack-chain
   #:weapon wolfs-gravestone
   #:skill super-charge 
   #:burst holy-blast
   #:artifacts flaming-feather
   universal-timepiece
   )

 (define-enemy dummy
   #:def 1000
   #:res (#:pyro 50
          #:hydro 10
          #:electro 10
          #:cryo 10
          #:geo 10
          #:anemo 10
          #:dendro 10
          #:physical -20)
   #:reduction 5
   )

 (define-team-lineup all-alone (zhongli))

 (calculate-rotation-damage all-alone dummy (E Q C N N N N ND))
 )

An example of the printed output would be:

Thanks for using ELEMENTS!

[]=======================================================================================[]
  Simulation run with input string: (E Q C N N N N ND)
  Total damage: 386765.04 Total time: 9.6 seconds DPS: 40288.02


  The best run with this layout was a sequence of: (E Q C N N N N ND)
  Total damage: 386765.04 Total time 9.6 seconds DPS: 40288.02
[]=======================================================================================[]

As seen above, elements allows for descriptive definitions of weapons, artifacts, characters, and more. This allows users to easily define new characters with varying stats, or modify current characters by applying new weapons, artifacts, or even useable skills. Keywords also make the definitions easier to read, allowing their meanings to be reasonably readable without the need to check documentation notes. Additionally, elements ensures that users only reference the data they mean to use. This means that if a character is given an artifact or attack-string for their equipped weapon, a readable error will be displayed before being run. With this, elements reduces the potential for unhelpful runtime errors by making sure the correct definitions are in the right places. This also extends to helpful compile time errors for duplicate names, giving clear errors when two definitions share the same name.

Installing and running

Clone this Git repository and, in the directory, run:

raco pkg install

Then import as

(require elements)

Once installed, you can access the documentation via:

raco docs elements

Finally, you can run the tests with:

raco test -p elements

Developer documentation:

Want to work on Elements? See the developer documentation here.