Refactor: Use 'in' modifier for B2Circle parameters

ikpil · ikpil · commit ff782bf7c18c · 2026-02-28T13:08:48.000+09:00
- Changed `B2Circle` struct parameters from `ref` to the `in` modifier in collision functions (`b2CollideCircles`, `b2CollidePolygonAndCircle`, etc.) and `b2Shape_SetCircle`.
- This is a C# performance optimization that passes the struct by read-only reference, avoiding unnecessary copies.
- Updated all call sites in the core library and samples to match the new, more efficient method signatures.
diff --git a/src/Box2D.NET.Samples/Samples/Collisions/Manifold.cs b/src/Box2D.NET.Samples/Samples/Collisions/Manifold.cs
@@ -244,7 +244,7 @@ public override void Step()
             B2Transform transform1 = new B2Transform(offset, b2Rot_identity);
             B2Transform transform2 = new B2Transform(b2Add(m_transform.p, offset), m_transform.q);
 
-            B2Manifold m = b2CollideCircles(ref circle1, transform1, ref circle2, transform2);
+            B2Manifold m = b2CollideCircles(circle1, transform1, circle2, transform2);
 
             DrawSolidCircle(m_draw, new B2Transform(circle1.center, transform1.q), circle1.radius, color1);
             DrawSolidCircle(m_draw, new B2Transform(circle2.center, transform2.q), circle2.radius, color2);
@@ -262,7 +262,7 @@ public override void Step()
             B2Transform transform1 = new B2Transform(offset, b2Rot_identity);
             B2Transform transform2 = new B2Transform(b2Add(m_transform.p, offset), m_transform.q);
 
-            B2Manifold m = b2CollideCapsuleAndCircle(capsule, transform1, ref circle, transform2);
+            B2Manifold m = b2CollideCapsuleAndCircle(capsule, transform1, circle, transform2);
 
             B2Vec2 v1 = b2TransformPoint(transform1, capsule.center1);
             B2Vec2 v2 = b2TransformPoint(transform1, capsule.center2);
@@ -283,7 +283,7 @@ public override void Step()
             B2Transform transform1 = new B2Transform(offset, b2Rot_identity);
             B2Transform transform2 = new B2Transform(b2Add(m_transform.p, offset), m_transform.q);
 
-            B2Manifold m = b2CollideSegmentAndCircle(segment, transform1, ref circle, transform2);
+            B2Manifold m = b2CollideSegmentAndCircle(segment, transform1, circle, transform2);
 
             B2Vec2 p1 = b2TransformPoint(transform1, segment.point1);
             B2Vec2 p2 = b2TransformPoint(transform1, segment.point2);
@@ -305,7 +305,7 @@ public override void Step()
             B2Transform transform1 = new B2Transform(offset, b2Rot_identity);
             B2Transform transform2 = new B2Transform(b2Add(m_transform.p, offset), m_transform.q);
 
-            B2Manifold m = b2CollidePolygonAndCircle(ref box, transform1, ref circle, transform2);
+            B2Manifold m = b2CollidePolygonAndCircle(ref box, transform1, circle, transform2);
 
             DrawSolidPolygon(m_draw, transform1, box.vertices.AsSpan(), box.count, m_round, color1);
             DrawSolidCircle(m_draw, new B2Transform(circle.center, transform2.q), circle.radius, color2);
@@ -569,7 +569,7 @@ public override void Step()
             B2Transform transform1 = new B2Transform(offset, b2Rot_identity);
             B2Transform transform2 = new B2Transform(b2Add(m_transform.p, offset), m_transform.q);
 
-            B2Manifold m = b2CollideChainSegmentAndCircle(segment, transform1, ref circle, transform2);
+            B2Manifold m = b2CollideChainSegmentAndCircle(segment, transform1, circle, transform2);
 
             B2Vec2 g1 = b2TransformPoint(transform1, segment.ghost1);
             B2Vec2 g2 = b2TransformPoint(transform1, segment.ghost2);
diff --git a/src/Box2D.NET.Samples/Samples/Collisions/SmoothManifold.cs b/src/Box2D.NET.Samples/Samples/Collisions/SmoothManifold.cs
@@ -286,7 +286,7 @@ public override void Draw()
             for (int i = 0; i < m_count; ++i)
             {
                 ref readonly B2ChainSegment segment = ref m_segments[i];
-                B2Manifold m = b2CollideChainSegmentAndCircle(segment, transform1, ref circle, transform2);
+                B2Manifold m = b2CollideChainSegmentAndCircle(segment, transform1, circle, transform2);
                 DrawManifold(m);
             }
         }
diff --git a/src/Box2D.NET.Samples/Samples/Shapes/ModifyGeometry.cs b/src/Box2D.NET.Samples/Samples/Shapes/ModifyGeometry.cs
@@ -81,7 +81,7 @@ void UpdateShape()
         {
             case B2ShapeType.b2_circleShape:
                 m_us.circle = new B2Circle(new B2Vec2(0.0f, 0.0f), 0.5f * m_scale);
-                b2Shape_SetCircle(m_shapeId, ref m_us.circle);
+                b2Shape_SetCircle(m_shapeId, m_us.circle);
                 break;
 
             case B2ShapeType.b2_capsuleShape:
diff --git a/src/Box2D.NET/B2Contacts.cs b/src/Box2D.NET/B2Contacts.cs
@@ -45,13 +45,13 @@ public static class B2Contacts
         internal static B2Manifold b2CircleManifold(B2Shape shapeA, in B2Transform xfA, B2Shape shapeB, in B2Transform xfB, ref B2SimplexCache cache)
         {
             B2_UNUSED(cache);
-            return b2CollideCircles(ref shapeA.us.circle, xfA, ref shapeB.us.circle, xfB);
+            return b2CollideCircles(shapeA.us.circle, xfA, shapeB.us.circle, xfB);
         }
 
         internal static B2Manifold b2CapsuleAndCircleManifold(B2Shape shapeA, in B2Transform xfA, B2Shape shapeB, in B2Transform xfB, ref B2SimplexCache cache)
         {
             B2_UNUSED(cache);
-            return b2CollideCapsuleAndCircle(shapeA.us.capsule, xfA, ref shapeB.us.circle, xfB);
+            return b2CollideCapsuleAndCircle(shapeA.us.capsule, xfA, shapeB.us.circle, xfB);
         }
 
         internal static B2Manifold b2CapsuleManifold(B2Shape shapeA, in B2Transform xfA, B2Shape shapeB, in B2Transform xfB, ref B2SimplexCache cache)
@@ -63,7 +63,7 @@ internal static B2Manifold b2CapsuleManifold(B2Shape shapeA, in B2Transform xfA,
         internal static B2Manifold b2PolygonAndCircleManifold(B2Shape shapeA, in B2Transform xfA, B2Shape shapeB, in B2Transform xfB, ref B2SimplexCache cache)
         {
             B2_UNUSED(cache);
-            return b2CollidePolygonAndCircle(ref shapeA.us.polygon, xfA, ref shapeB.us.circle, xfB);
+            return b2CollidePolygonAndCircle(ref shapeA.us.polygon, xfA, shapeB.us.circle, xfB);
         }
 
         internal static B2Manifold b2PolygonAndCapsuleManifold(B2Shape shapeA, in B2Transform xfA, B2Shape shapeB, in B2Transform xfB, ref B2SimplexCache cache)
@@ -81,7 +81,7 @@ internal static B2Manifold b2PolygonManifold(B2Shape shapeA, in B2Transform xfA,
         internal static B2Manifold b2SegmentAndCircleManifold(B2Shape shapeA, in B2Transform xfA, B2Shape shapeB, in B2Transform xfB, ref B2SimplexCache cache)
         {
             B2_UNUSED(cache);
-            return b2CollideSegmentAndCircle(shapeA.us.segment, xfA, ref shapeB.us.circle, xfB);
+            return b2CollideSegmentAndCircle(shapeA.us.segment, xfA, shapeB.us.circle, xfB);
         }
 
         internal static B2Manifold b2SegmentAndCapsuleManifold(B2Shape shapeA, in B2Transform xfA, B2Shape shapeB, in B2Transform xfB, ref B2SimplexCache cache)
@@ -99,7 +99,7 @@ internal static B2Manifold b2SegmentAndPolygonManifold(B2Shape shapeA, in B2Tran
         internal static B2Manifold b2ChainSegmentAndCircleManifold(B2Shape shapeA, in B2Transform xfA, B2Shape shapeB, in B2Transform xfB, ref B2SimplexCache cache)
         {
             B2_UNUSED(cache);
-            return b2CollideChainSegmentAndCircle(shapeA.us.chainSegment, xfA, ref shapeB.us.circle, xfB);
+            return b2CollideChainSegmentAndCircle(shapeA.us.chainSegment, xfA, shapeB.us.circle, xfB);
         }
 
         internal static B2Manifold b2ChainSegmentAndCapsuleManifold(B2Shape shapeA, in B2Transform xfA, B2Shape shapeB, in B2Transform xfB, ref B2SimplexCache cache)
diff --git a/src/Box2D.NET/B2Manifolds.cs b/src/Box2D.NET/B2Manifolds.cs
@@ -42,7 +42,7 @@ public static B2Polygon b2MakeCapsule(B2Vec2 p1, B2Vec2 p2, float radius)
         // localAnchorB = qBc * (point - pB)
         // anchorB = point - pB = qA * localAnchorA + pA - pB
         //         = anchorA + (pA - pB)
-        public static B2Manifold b2CollideCircles(ref B2Circle circleA, in B2Transform xfA, ref B2Circle circleB, in B2Transform xfB)
+        public static B2Manifold b2CollideCircles(in B2Circle circleA, in B2Transform xfA, in B2Circle circleB, in B2Transform xfB)
         {
             B2Manifold manifold = new B2Manifold();
 
@@ -80,7 +80,7 @@ public static B2Manifold b2CollideCircles(ref B2Circle circleA, in B2Transform x
 
         /// Compute the contact manifold between a capsule and circle
         /// Compute the collision manifold between a capsule and circle
-        public static B2Manifold b2CollideCapsuleAndCircle(in B2Capsule capsuleA, in B2Transform xfA, ref B2Circle circleB, in B2Transform xfB)
+        public static B2Manifold b2CollideCapsuleAndCircle(in B2Capsule capsuleA, in B2Transform xfA, in B2Circle circleB, in B2Transform xfB)
         {
             B2Manifold manifold = new B2Manifold();
 
@@ -145,7 +145,7 @@ public static B2Manifold b2CollideCapsuleAndCircle(in B2Capsule capsuleA, in B2T
         }
 
         /// Compute the contact manifold between a polygon and a circle
-        public static B2Manifold b2CollidePolygonAndCircle(ref B2Polygon polygonA, in B2Transform xfA, ref B2Circle circleB, in B2Transform xfB)
+        public static B2Manifold b2CollidePolygonAndCircle(ref B2Polygon polygonA, in B2Transform xfA, in B2Circle circleB, in B2Transform xfB)
         {
             B2Manifold manifold = new B2Manifold();
             float speculativeDistance = B2_SPECULATIVE_DISTANCE;
@@ -1088,10 +1088,10 @@ public static B2Manifold b2CollidePolygons(ref B2Polygon polygonA, in B2Transfor
         }
 
         /// Compute the contact manifold between an segment and a circle
-        public static B2Manifold b2CollideSegmentAndCircle(in B2Segment segmentA, in B2Transform xfA, ref B2Circle circleB, in B2Transform xfB)
+        public static B2Manifold b2CollideSegmentAndCircle(in B2Segment segmentA, in B2Transform xfA, in B2Circle circleB, in B2Transform xfB)
         {
             B2Capsule capsuleA = new B2Capsule(segmentA.point1, segmentA.point2, 0.0f);
-            return b2CollideCapsuleAndCircle(capsuleA, xfA, ref circleB, xfB);
+            return b2CollideCapsuleAndCircle(capsuleA, xfA, circleB, xfB);
         }
 
         /// Compute the contact manifold between an segment and a polygon
@@ -1102,7 +1102,7 @@ public static B2Manifold b2CollideSegmentAndPolygon(in B2Segment segmentA, in B2
         }
 
         /// Compute the contact manifold between a chain segment and a circle
-        public static B2Manifold b2CollideChainSegmentAndCircle(in B2ChainSegment segmentA, in B2Transform xfA, ref B2Circle circleB, in B2Transform xfB)
+        public static B2Manifold b2CollideChainSegmentAndCircle(in B2ChainSegment segmentA, in B2Transform xfA, in B2Circle circleB, in B2Transform xfB)
         {
             B2Manifold manifold = new B2Manifold();
 
diff --git a/src/Box2D.NET/B2Shapes.cs b/src/Box2D.NET/B2Shapes.cs
@@ -1460,7 +1460,7 @@ public static B2Polygon b2Shape_GetPolygon(in B2ShapeId shapeId)
             return shape.us.polygon;
         }
 
-        public static void b2Shape_SetCircle(in B2ShapeId shapeId, ref B2Circle circle)
+        public static void b2Shape_SetCircle(in B2ShapeId shapeId, in B2Circle circle)
         {
             B2World world = b2GetWorldLocked(shapeId.world0);
             if (world == null)

Original file line number	Diff line number	Diff line change
`@@ -286,7 +286,7 @@ public override void Draw()`
`286`	`286`	`for (int i = 0; i < m_count; ++i)`
`287`	`287`	`{`
`288`	`288`	`ref readonly B2ChainSegment segment = ref m_segments[i];`
`289`		`- B2Manifold m = b2CollideChainSegmentAndCircle(segment, transform1, ref circle, transform2);`
	`289`	`+ B2Manifold m = b2CollideChainSegmentAndCircle(segment, transform1, circle, transform2);`
`290`	`290`	`DrawManifold(m);`
`291`	`291`	`}`
`292`	`292`	`}`
Original file line number	Diff line number	Diff line change
`@@ -81,7 +81,7 @@ void UpdateShape()`
`81`	`81`	`{`
`82`	`82`	`case B2ShapeType.b2_circleShape:`
`83`	`83`	`m_us.circle = new B2Circle(new B2Vec2(0.0f, 0.0f), 0.5f * m_scale);`
`84`		`- b2Shape_SetCircle(m_shapeId, ref m_us.circle);`
	`84`	`+ b2Shape_SetCircle(m_shapeId, m_us.circle);`
`85`	`85`	`break;`
`86`	`86`
`87`	`87`	`case B2ShapeType.b2_capsuleShape:`
Original file line number	Diff line number	Diff line change
`@@ -45,13 +45,13 @@ public static class B2Contacts`
`45`	`45`	`internal static B2Manifold b2CircleManifold(B2Shape shapeA, in B2Transform xfA, B2Shape shapeB, in B2Transform xfB, ref B2SimplexCache cache)`
`46`	`46`	`{`
`47`	`47`	`B2_UNUSED(cache);`
`48`		`- return b2CollideCircles(ref shapeA.us.circle, xfA, ref shapeB.us.circle, xfB);`
	`48`	`+ return b2CollideCircles(shapeA.us.circle, xfA, shapeB.us.circle, xfB);`
`49`	`49`	`}`
`50`	`50`
`51`	`51`	`internal static B2Manifold b2CapsuleAndCircleManifold(B2Shape shapeA, in B2Transform xfA, B2Shape shapeB, in B2Transform xfB, ref B2SimplexCache cache)`
`52`	`52`	`{`
`53`	`53`	`B2_UNUSED(cache);`
`54`		`- return b2CollideCapsuleAndCircle(shapeA.us.capsule, xfA, ref shapeB.us.circle, xfB);`
	`54`	`+ return b2CollideCapsuleAndCircle(shapeA.us.capsule, xfA, shapeB.us.circle, xfB);`
`55`	`55`	`}`
`56`	`56`
`57`	`57`	`internal static B2Manifold b2CapsuleManifold(B2Shape shapeA, in B2Transform xfA, B2Shape shapeB, in B2Transform xfB, ref B2SimplexCache cache)`
`@@ -63,7 +63,7 @@ internal static B2Manifold b2CapsuleManifold(B2Shape shapeA, in B2Transform xfA,`
`63`	`63`	`internal static B2Manifold b2PolygonAndCircleManifold(B2Shape shapeA, in B2Transform xfA, B2Shape shapeB, in B2Transform xfB, ref B2SimplexCache cache)`
`64`	`64`	`{`
`65`	`65`	`B2_UNUSED(cache);`
`66`		`- return b2CollidePolygonAndCircle(ref shapeA.us.polygon, xfA, ref shapeB.us.circle, xfB);`
	`66`	`+ return b2CollidePolygonAndCircle(ref shapeA.us.polygon, xfA, shapeB.us.circle, xfB);`
`67`	`67`	`}`
`68`	`68`
`69`	`69`	`internal static B2Manifold b2PolygonAndCapsuleManifold(B2Shape shapeA, in B2Transform xfA, B2Shape shapeB, in B2Transform xfB, ref B2SimplexCache cache)`
`@@ -81,7 +81,7 @@ internal static B2Manifold b2PolygonManifold(B2Shape shapeA, in B2Transform xfA,`
`81`	`81`	`internal static B2Manifold b2SegmentAndCircleManifold(B2Shape shapeA, in B2Transform xfA, B2Shape shapeB, in B2Transform xfB, ref B2SimplexCache cache)`
`82`	`82`	`{`
`83`	`83`	`B2_UNUSED(cache);`
`84`		`- return b2CollideSegmentAndCircle(shapeA.us.segment, xfA, ref shapeB.us.circle, xfB);`
	`84`	`+ return b2CollideSegmentAndCircle(shapeA.us.segment, xfA, shapeB.us.circle, xfB);`
`85`	`85`	`}`
`86`	`86`
`87`	`87`	`internal static B2Manifold b2SegmentAndCapsuleManifold(B2Shape shapeA, in B2Transform xfA, B2Shape shapeB, in B2Transform xfB, ref B2SimplexCache cache)`
`@@ -99,7 +99,7 @@ internal static B2Manifold b2SegmentAndPolygonManifold(B2Shape shapeA, in B2Tran`
`99`	`99`	`internal static B2Manifold b2ChainSegmentAndCircleManifold(B2Shape shapeA, in B2Transform xfA, B2Shape shapeB, in B2Transform xfB, ref B2SimplexCache cache)`
`100`	`100`	`{`
`101`	`101`	`B2_UNUSED(cache);`
`102`		`- return b2CollideChainSegmentAndCircle(shapeA.us.chainSegment, xfA, ref shapeB.us.circle, xfB);`
	`102`	`+ return b2CollideChainSegmentAndCircle(shapeA.us.chainSegment, xfA, shapeB.us.circle, xfB);`
`103`	`103`	`}`
`104`	`104`
`105`	`105`	`internal static B2Manifold b2ChainSegmentAndCapsuleManifold(B2Shape shapeA, in B2Transform xfA, B2Shape shapeB, in B2Transform xfB, ref B2SimplexCache cache)`
Original file line number	Diff line number	Diff line change
`@@ -42,7 +42,7 @@ public static B2Polygon b2MakeCapsule(B2Vec2 p1, B2Vec2 p2, float radius)`
`42`	`42`	`// localAnchorB = qBc * (point - pB)`
`43`	`43`	`// anchorB = point - pB = qA * localAnchorA + pA - pB`
`44`	`44`	`// = anchorA + (pA - pB)`
`45`		`- public static B2Manifold b2CollideCircles(ref B2Circle circleA, in B2Transform xfA, ref B2Circle circleB, in B2Transform xfB)`
	`45`	`+ public static B2Manifold b2CollideCircles(in B2Circle circleA, in B2Transform xfA, in B2Circle circleB, in B2Transform xfB)`
`46`	`46`	`{`
`47`	`47`	`B2Manifold manifold = new B2Manifold();`
`48`	`48`
`@@ -80,7 +80,7 @@ public static B2Manifold b2CollideCircles(ref B2Circle circleA, in B2Transform x`
`80`	`80`
`81`	`81`	`/// Compute the contact manifold between a capsule and circle`
`82`	`82`	`/// Compute the collision manifold between a capsule and circle`
`83`		`- public static B2Manifold b2CollideCapsuleAndCircle(in B2Capsule capsuleA, in B2Transform xfA, ref B2Circle circleB, in B2Transform xfB)`
	`83`	`+ public static B2Manifold b2CollideCapsuleAndCircle(in B2Capsule capsuleA, in B2Transform xfA, in B2Circle circleB, in B2Transform xfB)`
`84`	`84`	`{`
`85`	`85`	`B2Manifold manifold = new B2Manifold();`
`86`	`86`
`@@ -145,7 +145,7 @@ public static B2Manifold b2CollideCapsuleAndCircle(in B2Capsule capsuleA, in B2T`
`145`	`145`	`}`
`146`	`146`
`147`	`147`	`/// Compute the contact manifold between a polygon and a circle`
`148`		`- public static B2Manifold b2CollidePolygonAndCircle(ref B2Polygon polygonA, in B2Transform xfA, ref B2Circle circleB, in B2Transform xfB)`
	`148`	`+ public static B2Manifold b2CollidePolygonAndCircle(ref B2Polygon polygonA, in B2Transform xfA, in B2Circle circleB, in B2Transform xfB)`
`149`	`149`	`{`
`150`	`150`	`B2Manifold manifold = new B2Manifold();`
`151`	`151`	`float speculativeDistance = B2_SPECULATIVE_DISTANCE;`
`@@ -1088,10 +1088,10 @@ public static B2Manifold b2CollidePolygons(ref B2Polygon polygonA, in B2Transfor`
`1088`	`1088`	`}`
`1089`	`1089`
`1090`	`1090`	`/// Compute the contact manifold between an segment and a circle`
`1091`		`- public static B2Manifold b2CollideSegmentAndCircle(in B2Segment segmentA, in B2Transform xfA, ref B2Circle circleB, in B2Transform xfB)`
	`1091`	`+ public static B2Manifold b2CollideSegmentAndCircle(in B2Segment segmentA, in B2Transform xfA, in B2Circle circleB, in B2Transform xfB)`
`1092`	`1092`	`{`
`1093`	`1093`	`B2Capsule capsuleA = new B2Capsule(segmentA.point1, segmentA.point2, 0.0f);`
`1094`		`- return b2CollideCapsuleAndCircle(capsuleA, xfA, ref circleB, xfB);`
	`1094`	`+ return b2CollideCapsuleAndCircle(capsuleA, xfA, circleB, xfB);`
`1095`	`1095`	`}`
`1096`	`1096`
`1097`	`1097`	`/// Compute the contact manifold between an segment and a polygon`
`@@ -1102,7 +1102,7 @@ public static B2Manifold b2CollideSegmentAndPolygon(in B2Segment segmentA, in B2`
`1102`	`1102`	`}`
`1103`	`1103`
`1104`	`1104`	`/// Compute the contact manifold between a chain segment and a circle`
`1105`		`- public static B2Manifold b2CollideChainSegmentAndCircle(in B2ChainSegment segmentA, in B2Transform xfA, ref B2Circle circleB, in B2Transform xfB)`
	`1105`	`+ public static B2Manifold b2CollideChainSegmentAndCircle(in B2ChainSegment segmentA, in B2Transform xfA, in B2Circle circleB, in B2Transform xfB)`
`1106`	`1106`	`{`
`1107`	`1107`	`B2Manifold manifold = new B2Manifold();`
`1108`	`1108`
Original file line number	Diff line number	Diff line change
`@@ -1460,7 +1460,7 @@ public static B2Polygon b2Shape_GetPolygon(in B2ShapeId shapeId)`
`1460`	`1460`	`return shape.us.polygon;`
`1461`	`1461`	`}`
`1462`	`1462`
`1463`		`- public static void b2Shape_SetCircle(in B2ShapeId shapeId, ref B2Circle circle)`
	`1463`	`+ public static void b2Shape_SetCircle(in B2ShapeId shapeId, in B2Circle circle)`
`1464`	`1464`	`{`
`1465`	`1465`	`B2World world = b2GetWorldLocked(shapeId.world0);`
`1466`	`1466`	`if (world == null)`