fix: Turtle.Towards relative angle ( Fixes #123 )

Author: StartAutomating

Turtle.tests.ps1

@@ -18,4 +18,33 @@ describe Turtle {
         $png = New-Turtle | Move-Turtle SierpinskiTriangle 15 5 | Select-Object -ExpandProperty PNG
         $png[1..3] -as 'char[]' -as 'string[]' -join '' | Should -Be PNG
     }
+
+
+    context 'Turtle Directions' {
+        it 'Can tell you the way towards a point' {
+            $turtle = turtle
+            $turtle.Towards(0,1) | should -be 90
+            $turtle.Towards(1,1) | Should -be 45
+            $turtle.Towards(1,0) | should -be 0
+            $turtle.Towards(-1,1) | Should -be 135
+            $turtle.Towards(-1,0) | Should -be 180
+            $turtle.Towards(0,-1) | Should -be -90
+        }
+
+        it 'Will return a relative heading' {
+            $turtle = turtle
+            $turtle = $turtle.Rotate($turtle.Towards(1,1))
+            $turtle = $turtle.Forward($turtle.Distance(1,1))
+            $turtle.Heading | Should -be 45
+            $turtle.Position.X | Should -be 1
+            $turtle.Position.Y | Should -be 1
+            $turtle = $turtle.Rotate($turtle.Towards(2,2))
+            $turtle = $turtle.Forward($turtle.Distance(2,2))
+            $turtle.Heading | Should -be 45
+            $turtle.Position.X | Should -be 2
+            $turtle.Position.Y | Should -be 2
+        }
+    }
+
+    
 }

Types/Turtle/Distance.ps1

@@ -12,7 +12,8 @@ param(
 )
 
 # Determine the delta from the turtle's current position to the specified point
-$deltaX = $this.Position.X - $X
-$deltaY = $this.Position.Y - $Y
+$deltaX = $X - $this.Position.X
+$deltaY = $Y - $this.Position.Y
+
 # Calculate the distance using the Pythagorean theorem
-return [Math]::Sqrt($deltaX * $deltaX + $deltaY * $deltaY)
+return [Math]::Sqrt($deltaX*$deltaX + $deltaY*$deltaY)

Types/Turtle/Towards.ps1

@@ -2,7 +2,7 @@
 .SYNOPSIS
     Determines the angle towards a point
 .DESCRIPTION
-    Determines the angle from the turtle's current position towards a point.
+    Determines the angle from the turtle's current heading towards a point.
 #>
 param(
 # The X-coordinate
@@ -12,9 +12,9 @@ param(
 )
 
 # Determine the delta from the turtle's current position to the specified point
-$deltaX = $this.Position.X - $X
-$deltaY = $this.Position.Y - $Y
+$deltaX = $X - $this.Position.X 
+$deltaY = $Y - $this.Position.Y
 # Calculate the angle in radians and convert to degrees
 $angle = [Math]::Atan2($deltaY, $deltaX) * 180 / [Math]::PI
-# Return the angle rotate by 90 to account for the turtle's coordinate system
-return $angle + 90
+# Return the angle minus the current heading (modulo 360)
+return $angle - ($this.Heading % 360)