From ba7a7b5500b86182ba05e51cb28084148b50ce53 Mon Sep 17 00:00:00 2001
From: Max Cahill <1bardesign@gmail.com>
Date: Thu, 8 Dec 2022 13:36:29 +1100
Subject: [PATCH] fixed intersection tests with zero radius shapes (treated as
 points generally)

---
 intersect.lua | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/intersect.lua b/intersect.lua
index 7c5cff8..9bf955b 100644
--- a/intersect.lua
+++ b/intersect.lua
@@ -29,12 +29,12 @@ local COLLIDE_EPS = 1e-6
 -- circles
 
 function intersect.circle_point_overlap(pos, rad, v)
-	return pos:distance_squared(v) < rad * rad
+	return pos:distance_squared(v) <= rad * rad
 end
 
 function intersect.circle_circle_overlap(a_pos, a_rad, b_pos, b_rad)
 	local rad = a_rad + b_rad
-	return a_pos:distance_squared(b_pos) < rad * rad
+	return a_pos:distance_squared(b_pos) <= rad * rad
 end
 
 function intersect.circle_circle_collide(a_pos, a_rad, b_pos, b_rad, into)
@@ -46,7 +46,7 @@ function intersect.circle_circle_collide(a_pos, a_rad, b_pos, b_rad, into)
 	local rad = a_rad + b_rad
 	local dist = delta:length_squared()
 	local res = false
-	if dist < rad * rad then
+	if dist <= rad * rad then
 		if dist == 0 then
 			--singular case; just resolve vertically
 			dist = 1
@@ -278,7 +278,7 @@ function intersect.aabb_point_overlap(pos, hs, v)
 		:pooled_copy()
 		:vector_sub_inplace(v)
 		:abs_inplace()
-	local overlap = delta.x < hs.x and delta.y < hs.y
+	local overlap = delta.x <= hs.x and delta.y <= hs.y
 	delta:release()
 	return overlap
 end
@@ -320,7 +320,7 @@ function intersect.aabb_aabb_overlap(a_pos, a_hs, b_pos, b_hs)
 	local total_size = a_hs
 		:pooled_copy()
 		:vector_add_inplace(b_hs)
-	local overlap = delta.x < total_size.x and delta.y < total_size.y
+	local overlap = delta.x <= total_size.x and delta.y <= total_size.y
 	vec2.release(delta, total_size)
 	return overlap
 end
@@ -375,7 +375,7 @@ function intersect.aabb_circle_overlap(a_pos, a_hs, b_pos, b_rad)
 	local clamped = intersect.aabb_point_clamp(a_pos, a_hs, b_pos, vec2:pooled())
 	local edge_distance_squared = clamped:distance_squared(b_pos)
 	clamped:release()
-	return edge_distance_squared < (b_rad * b_rad)
+	return edge_distance_squared <= (b_rad * b_rad)
 end
 
 -- return msv on collision, false otherwise