From 26266ab14c2c24632aeedc7b1b129b1bee0f32db Mon Sep 17 00:00:00 2001
From: Omar Rizwan <omar@omar.website>
Date: Sun, 9 Jul 2023 18:27:08 -0400
Subject: Fix region and vec2 rotate

---
 virtual-programs/regions.folk | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

(limited to 'virtual-programs')

diff --git a/virtual-programs/regions.folk b/virtual-programs/regions.folk
index b1cf45a0..0e261b34 100644
--- a/virtual-programs/regions.folk
+++ b/virtual-programs/regions.folk
@@ -15,8 +15,8 @@ namespace eval ::vec2 {
     }
     proc rotate {a theta} {
         lassign $a x y
-        list [expr {$x*cos($theta) - $y*sin($theta)}] \
-             [expr {$x*sin($theta) + $y*cos($theta)}]
+        list [expr {$x*cos($theta) + $y*sin($theta)}] \
+             [expr {-$x*sin($theta) + $y*cos($theta)}]
     }
     proc distance {a b} {
         lassign $a ax ay
@@ -130,12 +130,14 @@ namespace eval ::region {
     proc rotate {r angle} {
         set theta [angle $r]
         set c [centroid $r]
-        mapVertices v $r {
+        set r' [mapVertices v $r {
             set v [vec2 sub $v $c]
             set v [vec2 rotate $v $angle]
             set v [vec2 add $v $c]
             set v
-        }
+        }]
+        lset r' 2 [+ $theta $angle]
+        set r'
     }
 
     # Scales about the center of the region, along the x and y axes of
-- 
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