Physics2D/RigidBody2D: Add ClosestPointQuery method

ChangeLog.md

@@ -114,6 +114,7 @@ Nazara Engine:
 - Fixed a lot of classes not having their move constructor/assignation operator marked noexcept
 - ⚠️ SocketPoller::Wait now returns the number of socket marked as ready, and takes an additional optional parameter allowing to query the last error.
 - SocketPoller will now silently ignore "interrupt errors"
+- Added RigidBody2D::ClosestPointQuery
 
 Nazara Development Kit:
 - Added ImageWidget (#139)
@@ -164,6 +165,7 @@ Nazara Development Kit:
 - Fixed EntityOwner move assignment which was losing entity ownership
 - Add GraphicsComponent:ForEachRenderable method
 - Fixed GraphicsComponent reflective material count which was not initialized
+- Added PhysicsComponent2D::ClosestPointQuery
 
 # 0.4:
 

SDK/include/NDK/Components/PhysicsComponent2D.hpp

@@ -30,6 +30,8 @@ namespace Ndk
 			void AddImpulse(const Nz::Vector2f& impulse, const Nz::Vector2f& point, Nz::CoordSys coordSys = Nz::CoordSys_Global);
 			void AddTorque(float torque);
 
+			bool ClosestPointQuery(const Nz::Vector2f& position, Nz::Vector2f* closestPoint, float* closestDistance) const;
+
 			Nz::Rectf GetAABB() const;
 			float GetAngularVelocity() const;
 			Nz::Vector2f GetCenterOfGravity(Nz::CoordSys coordSys = Nz::CoordSys_Local) const;

SDK/include/NDK/Components/PhysicsComponent2D.inl

@@ -2,6 +2,7 @@
 // This file is part of the "Nazara Development Kit"
 // For conditions of distribution and use, see copyright notice in Prerequisites.hpp
 
+#include <NDK/Components/PhysicsComponent2D.hpp>
 #include <Nazara/Core/Error.hpp>
 
 namespace Ndk
@@ -97,6 +98,23 @@ namespace Ndk
 		m_object->AddTorque(torque);
 	}
 
+	/*!
+	* \brief Finds the closest point on the entity relative to a position
+	* \return True if such a point exists (will return false if no collider exists)
+	*
+	* \param position The starting point which will be used for the query
+	* \param closestPoint The closest point on entity surface
+	* \param closestDistance The distance between the closest point and the starting point, may be negative if starting point is inside the entity
+	*
+	* \remark Produces a NazaraAssert if the physics object is invalid
+	*/
+	inline bool PhysicsComponent2D::ClosestPointQuery(const Nz::Vector2f& position, Nz::Vector2f* closestPoint, float* closestDistance) const
+	{
+		NazaraAssert(m_object, "Invalid physics object");
+
+		return m_object->ClosestPointQuery(position, closestPoint, closestDistance);
+	}
+
 	/*!
 	* \brief Gets the AABB of the physics object
 	* \return AABB of the object

include/Nazara/Physics2D/RigidBody2D.hpp

@@ -36,6 +36,8 @@ namespace Nz
 			void AddImpulse(const Vector2f& impulse, const Vector2f& point, CoordSys coordSys = CoordSys_Global);
 			void AddTorque(float torque);
 
+			bool ClosestPointQuery(const Nz::Vector2f& position, Nz::Vector2f* closestPoint = nullptr, float* closestDistance = nullptr) const;
+
 			void EnableSimulation(bool simulation);
 
 			Rectf GetAABB() const;

src/Nazara/Physics2D/RigidBody2D.cpp

@@ -7,6 +7,7 @@
 #include <chipmunk/chipmunk.h>
 #include <chipmunk/chipmunk_private.h>
 #include <algorithm>
+#include <cmath>
 #include <Nazara/Physics3D/Debug.hpp>
 
 namespace Nz
@@ -127,6 +128,37 @@ namespace Nz
 		cpBodySetTorque(m_handle, cpBodyGetTorque(m_handle) + ToRadians(torque));
 	}
 
+	bool RigidBody2D::ClosestPointQuery(const Nz::Vector2f& position, Nz::Vector2f* closestPoint, float* closestDistance) const
+	{
+		cpVect pos = cpv(cpFloat(position.x), cpFloat(position.y));
+
+		float minDistance = std::numeric_limits<float>::infinity();
+		Nz::Vector2f closest;
+		for (cpShape* shape : m_shapes)
+		{
+			cpPointQueryInfo result;
+			cpShapePointQuery(shape, pos, &result);
+
+			float resultDistance = float(result.distance);
+			if (resultDistance < minDistance)
+			{
+				closest.Set(float(result.point.x), float(result.point.y));
+				minDistance = resultDistance;
+			}
+		}
+
+		if (std::isinf(minDistance))
+			return false;
+
+		if (closestPoint)
+			*closestPoint = closest;
+
+		if (minDistance)
+			*closestDistance = minDistance;
+
+		return true;
+	}
+
 	void RigidBody2D::EnableSimulation(bool simulation)
 	{
 		if (m_isRegistered != simulation)