From 62635ec285c5ba65a10847b7a7f24f92c048ee61 Mon Sep 17 00:00:00 2001
From: Kp <kp@valhallalegends.com>
Date: Tue, 24 May 2022 02:32:58 +0000
Subject: [PATCH] Use enum class for vm_magnitude_squared

---
 common/include/fwd-vecmat.h |  2 +-
 common/include/vecmat.h     | 23 ++++++++++++++---------
 common/maths/vecmat.cpp     |  3 +--
 similar/main/fvi.cpp        |  4 ++--
 similar/main/laser.cpp      | 20 ++++++++++++--------
 5 files changed, 30 insertions(+), 22 deletions(-)

diff --git a/common/include/fwd-vecmat.h b/common/include/fwd-vecmat.h
index 533e17128..ced9da492 100644
--- a/common/include/fwd-vecmat.h
+++ b/common/include/fwd-vecmat.h
@@ -17,7 +17,7 @@ class vm_distance_squared;
 class vm_distance;
 class vm_magnitude;
 class vm_distance_squared;
-class vm_magnitude_squared;
+enum class vm_magnitude_squared : uint64_t;
 struct vms_angvec;
 struct vms_matrix;
 struct vms_quaternion;
diff --git a/common/include/vecmat.h b/common/include/vecmat.h
index 35d077678..f74f70b1c 100644
--- a/common/include/vecmat.h
+++ b/common/include/vecmat.h
@@ -132,6 +132,10 @@ public:
 		d2(f2)
 	{
 	}
+	constexpr vm_distance_squared(vm_magnitude_squared m) :
+		d2{static_cast<int64_t>(static_cast<uint64_t>(m))}
+	{
+	}
 	constexpr bool operator<(const vm_distance_squared &rhs) const
 	{
 		return d2 < rhs.d2;
@@ -171,20 +175,21 @@ public:
 	}
 };
 
-class vm_magnitude_squared : public vm_distance_squared
-{
-public:
-	constexpr explicit vm_magnitude_squared(const uint64_t &f2) :
-		vm_distance_squared(static_cast<fix64>(f2))
-	{
-	}
-};
-
 constexpr vm_distance_squared vm_distance::operator*(const vm_distance &rhs) const
 {
 	return vm_distance_squared{static_cast<fix64>(static_cast<fix>(*this)) * static_cast<fix64>(static_cast<fix>(rhs))};
 }
 
+constexpr bool operator<(const vm_magnitude_squared a, const fix &b)
+{
+	return static_cast<uint64_t>(a) < b;
+}
+
+constexpr bool operator<(const vm_magnitude_squared a, const vm_distance_squared b)
+{
+	return static_cast<uint64_t>(a) < static_cast<uint64_t>(b.operator fix64());
+}
+
 #define DEFINE_SERIAL_VMS_VECTOR_TO_MESSAGE()	\
 	DEFINE_SERIAL_UDT_TO_MESSAGE(vms_vector, v, (v.x, v.y, v.z));	\
 	ASSERT_SERIAL_UDT_MESSAGE_SIZE(vms_vector, 12)
diff --git a/common/maths/vecmat.cpp b/common/maths/vecmat.cpp
index dffa34144..159ee0355 100644
--- a/common/maths/vecmat.cpp
+++ b/common/maths/vecmat.cpp
@@ -160,7 +160,6 @@ fix vm_vec_dot(const vms_vector &v0,const vms_vector &v1)
 	return vm_vec_dot3(v0.x, v0.y, v0.z, v1);
 }
 
-//returns magnitude of a vector
 vm_magnitude_squared vm_vec_mag2(const vms_vector &v)
 {
 	const int64_t x = v.x;
@@ -172,7 +171,7 @@ vm_magnitude_squared vm_vec_mag2(const vms_vector &v)
 vm_magnitude vm_vec_mag(const vms_vector &v)
 {
 	quadint q;
-	q.q = vm_vec_mag2(v).d2;
+	q.q = static_cast<uint64_t>(vm_vec_mag2(v));
 	return vm_magnitude{quad_sqrt(q)};
 }
 
diff --git a/similar/main/fvi.cpp b/similar/main/fvi.cpp
index 38c90cf8c..f76437599 100644
--- a/similar/main/fvi.cpp
+++ b/similar/main/fvi.cpp
@@ -417,10 +417,10 @@ static vm_distance_squared check_vector_to_sphere_1(vms_vector &intp,const vms_v
 	if (mag_d == 0) {
 		const auto int_dist = vm_vec_mag2(w);
 		intp = p0;
-		if (int_dist.d2 < sphere_rad)
+		if (int_dist < sphere_rad)
 			return int_dist;
 		const fix64 sphere_rad64 = sphere_rad;
-		if (int_dist < vm_distance_squared{sphere_rad64 * sphere_rad64})
+		if (int_dist < vm_magnitude_squared{static_cast<uint64_t>(sphere_rad64 * sphere_rad64)})
 			return int_dist;
 		return vm_distance_squared::minimum_value();
 	}
diff --git a/similar/main/laser.cpp b/similar/main/laser.cpp
index c09f83dc4..533919b02 100644
--- a/similar/main/laser.cpp
+++ b/similar/main/laser.cpp
@@ -1105,16 +1105,20 @@ imobjptridx_t find_homing_object_complete(const vms_vector &curpos, const vmobjp
 	}
 
 	const fix64 HOMING_MAX_TRACKABLE_DIST = F1_0*250;
-	vm_distance_squared max_trackable_dist{HOMING_MAX_TRACKABLE_DIST * HOMING_MAX_TRACKABLE_DIST};
-	fix min_trackable_dot = HOMING_MIN_TRACKABLE_DOT;
-
+	const auto max_trackable_dist =
 #if defined(DXX_BUILD_DESCENT_II)
-	if (tracker_id == weapon_id_type::OMEGA_ID)
-	{
-		max_trackable_dist = OMEGA_MAX_TRACKABLE_DIST * OMEGA_MAX_TRACKABLE_DIST;
-		min_trackable_dot = OMEGA_MIN_TRACKABLE_DOT;
-	}
+		(tracker_id == weapon_id_type::OMEGA_ID)
+		? vm_distance_squared{(OMEGA_MAX_TRACKABLE_DIST * OMEGA_MAX_TRACKABLE_DIST)}
+		:
 #endif
+		vm_distance_squared{HOMING_MAX_TRACKABLE_DIST * HOMING_MAX_TRACKABLE_DIST};
+	const auto min_trackable_dot =
+#if defined(DXX_BUILD_DESCENT_II)
+		(tracker_id == weapon_id_type::OMEGA_ID)
+		? OMEGA_MIN_TRACKABLE_DOT
+		:
+#endif
+		HOMING_MIN_TRACKABLE_DOT;
 
 	imobjptridx_t	best_objnum = object_none;
 	range_for (const auto &&curobjp, vmobjptridx)