How to make an agent/turtle not see through multiple walls? (Netlogo)

Question

I am new to posting in stackoverflow.

Before I had a problem with agents/turtles seeing through the walls I make, but I have found the solution here:

The problem now is when there is another wall within the vision-cone, the valid line of sight (green patches) are incorrect. I'm currently still tinkering on how to fix this.

Here is my current code that I have been working on,

breed [walls wall]
walls-own [first-end second-end]

to setup
  ca
  reset-ticks
  set-default-shape walls "line"
  crt 1 [setxy 4 0]
  ask turtles [facexy 0 0]

  ;color all cones in radius blue by default
  let dist 10
  let angle 80
  ask turtles [ask patches in-cone dist angle [set pcolor blue]]

  ;; place a wall down.... the line of sight is blocked (keyword: line)
  create-walls 1 [setxy 0 0]


  ;;This is an interpretation of a wall. Two points that define the edges.
  ask wall 1 [set size 10]


  ;;my wall is vertical. you can do trig above and below to adjust for not vert lines.
  ask wall 1 [set heading 45]
  ask wall 1 [set color hsb 216 50 100]

  ;; I made it so that it could consider not vertical lines
  ask wall 1 [ set first-end (list (round (sin heading * (size / 2))) (round (cos heading * (size / 2))))]
  ask wall 1 [ set second-end (list (round((-1 * (size / 2) * sin heading))) (round ((-1 * (size / 2) * cos heading))))]

  ;;Test wall. UN-COMMENT THE SET BELOW TO SEE THE PROBLEM
;  create-walls 1 [setxy 4 4]
;  ask wall 2 [set size 10]
;  ask wall 2 [set heading 90]
;  ask wall 2 [ set first-end (list (round (sin heading * (size / 2))) (round (cos heading * (size / 2))))]
;  ask wall 2 [ set second-end (list (round((-1 * (size / 2) * sin heading))) (round ((-1 * (size / 2) * cos heading))))]
;  ask wall 2 [set color hsb 216 50 100]

  ask turtle 0 [ask in-sight dist angle [set pcolor green]]
end

;;a turtle can see a patch if the line from the patch to the trutle isnt intersected by a wall.
to-report in-sight [dist angle]
  let turtle-x xcor
  let turtle-y ycor

  report patches in-cone dist angle with
  [
    not any? walls with [intersects [pxcor] of myself [pycor] of myself turtle-x turtle-y ;; line 1
      (first first-end)(last first-end)(first second-end)(last second-end)] ;; line 2
  ]
end

to-report counter-clockwise [x1 y1 x2 y2 x3 y3]
  ;; returns true if triplet creates counter clockwise angle (uses slopes)
  ;; (C.y-A.y) * (B.x-A.x) > (B.y-A.y*(C.x-A.x)
  report (y3 - y1)*(x2 - x1)>(y2 - y1)*(x3 - x1)
end

to-report intersects [x1 y1 x2 y2 x3 y3 x4 y4]
  ;; line 1: x1 y1 x2 y2
  ;; line 2: x3 y3 x4 y4
  ;;DANGER: Doesnt work for colinear segments
  report (counter-clockwise x1 y1 x3 y3 x4 y4) != (counter-clockwise x2 y2 x3 y3 x4 y4)
  and (counter-clockwise x1 y1 x2 y2 x3 y3) != (counter-clockwise x1 y1 x2 y2 x4 y4)
end

This is what it looks like if you would uncomment the set of code for the test wall.

Problem

Any suggestions or tips would be very helpful! Thank you in advance.

How to make an agent/turtle not see through multiple walls? (Netlogo)

0 Answers0