"-Sdpi=300" does not work for mindmap diagrams

Question

Description

The -Sdpi=300 doesn’t work for mindmap diagrams

Reproducing steps

1. create an puml file, named oo.puml

   @startmindmap
   
   * the root
   ** one
   ** two
   
   @endmindmap
   

2. generate png file with the different -Sdpi=NNN params

   java -Djava.awt.headless=true -DPLANTUML_LIMIT_SIZE=102400 -Xmx8192m -jar "/path/to/plantuml.jar" -charset utf-8 -Sdpi=300  oo.puml
   

   java -Djava.awt.headless=true -DPLANTUML_LIMIT_SIZE=102400 -Xmx8192m -jar "/path/to/plantuml.jar" -charset utf-8 -Sdpi=96  oo.puml
   

3. The output files result in the same size

Tested plantuml version

plantuml-1.2019.4.jar

Notes

The same params work well for generating sequence diagrams.

Comments

Anyway, something like `scale 3` may relief the pain.