3d turtle graphics

Create a 3d representation of a house and bar chart, similar to that of Simple turtle graphics, but

• Use a cube and an equilateral square pyramid for the house, and
• use columns with a square cross section for the bar chart.

J

Assumes jqt and a "recent" (2022) version of J. <lang J>NB. pre-requisites: NB. ;install each cut 'gl2 gles github:zerowords/tgsjo' load'zerowords/tgsjo' stop clearscreen createTurtle 0 0 0

EYE_tgsjo_=: 0 0 _90 rotR 180+94 10 0

column=: {{

   4 repeats {{'height width'=. y
       2 repeats {{'height width'=. y
           forward width
           pitch 90
           forward height
           pitch 90
     }} y
     forward width
     right 90
   }} y

}}

cube=: Template:Column y,y

codihedral=: 180p_1*_3 o.%%:2 pyramid=: {{

   4 repeats {{
       roll codihedral
       pitch triangle y
       roll-codihedral
       forward y
       left 90
   }} y

}}

NB. in 3d, we want to know which turning mechanism to use, when drawing a plane figure triangle=: {{

   3 repeats (u {{
       forward y
       u 120
   }}) y

}}

house=: {{

   cube y
   roll 180
   pyramid y

}}

barchart=: {{'lst size'=. y

   if.#lst do.
       scale=. size%>./lst
       width=. size%#lst
       for_j. lst do.
           column (j * scale),width
           forward width
       end.
       back size
   end.

}}

penColor Red house 150 pen 0 back 30 right 180 pen 1 penColor Blue barchart 0.5 0.3333 2 1.3 0.5; 200 pen 0 left 180 forward 30 roll 180</lang>