/**********************************************************************************************
*
* Physac
* Original -https://github.com/raysan5/raylib/blob/master/src/physac.h
*
**********************************************************************************************/
using System;
using System.Runtime.InteropServices;
namespace Raylib
{
#region Raylib-cs Enums
public enum PhysicsShapeType
{
PHYSICS_CIRCLE,
PHYSICS_POLYGON
}
#endregion
#region Raylib-cs Types
// Mat2 type (used for polygon shape rotation matrix)
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi)]
public struct Mat2
{
public float m00;
public float m01;
public float m10;
public float m11;
}
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi)]
public struct PolygonData
{
public uint vertexCount; // Current used vertex and normals count
[MarshalAs(UnmanagedType.ByValArray, ArraySubType = UnmanagedType.Struct, SizeConst = Raylib.PHYSAC_MAX_VERTICES)]
public Vector2[] positions; // Polygon vertex positions vectors
[MarshalAs(UnmanagedType.ByValArray, ArraySubType = UnmanagedType.Struct, SizeConst = Raylib.PHYSAC_MAX_VERTICES)]
public Vector2[] normals; // Polygon vertex normals vectors
}
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi)]
public struct PhysicsShape
{
public PhysicsShapeType type; // Physics shape type (circle or polygon)
public IntPtr body; // Shape physics body reference
public float radius; // Circle shape radius (used for circle shapes)
public Mat2 transform; // Vertices transform matrix 2x2
public PolygonData vertexData; // Polygon shape vertices position and normals data (just used for polygon shapes)
}
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi)]
public struct PhysicsBodyData
{
public uint id; // Reference unique identifier
public bool enabled; // Enabled dynamics state (collisions are calculated anyway)
public Vector2 position; // Physics body shape pivot
public Vector2 velocity; // Current linear velocity applied to position
public Vector2 force; // Current linear force (reset to 0 every step)
public float angularVelocity; // Current angular velocity applied to orient
public float torque; // Current angular force (reset to 0 every step)
public float orient; // Rotation in radians
public float inertia; // Moment of inertia
public float inverseInertia; // Inverse value of inertia
public float mass; // Physics body mass
public float inverseMass; // Inverse value of mass
public float staticFriction; // Friction when the body has not movement (0 to 1)
public float dynamicFriction; // Friction when the body has movement (0 to 1)
public float restitution; // Restitution coefficient of the body (0 to 1)
public bool useGravity; // Apply gravity force to dynamics
public bool isGrounded; // Physics grounded on other body state
public bool freezeOrient; // Physics rotation constraint
public PhysicsShape shape; // Physics body shape information (type, radius, vertices, normals)
}
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi)]
public struct PhysicsManifoldData
{
public uint id; // Reference unique identifier
public PhysicsBodyData bodyA; // Manifold first physics body reference
public PhysicsBodyData bodyB; // Manifold second physics body reference
public float penetration; // Depth of penetration from collision
public Vector2 normal; // Normal direction vector from 'a' to 'b'
[MarshalAs(UnmanagedType.ByValArray, ArraySubType = UnmanagedType.Struct, SizeConst = 2)]
public Vector2[] contacts; // Points of contact during collision
public uint contactsCount; // Current collision number of contacts
public float restitution; // Mixed restitution during collision
public float dynamicFriction; // Mixed dynamic friction during collision
public float staticFriction; // Mixed static friction during collision
}
#endregion
public static partial class Raylib
{
#region Raylib-cs Variables
// Used by DllImport to load the native library.
// private const string nativeLibName = "raylib.dll";
public const int PHYSAC_MAX_BODIES = 64;
public const int PHYSAC_MAX_MANIFOLDS = 4096;
public const int PHYSAC_MAX_VERTICES = 24;
public const int PHYSAC_CIRCLE_VERTICES = 24;
public const float PHYSAC_DESIRED_DELTATIME = 1.0f / 60.0f;
public const float PHYSAC_MAX_TIMESTEP = 0.02f;
public const int PHYSAC_COLLISION_ITERATIONS = 100;
public const float PHYSAC_PENETRATION_ALLOWANCE = 0.05f;
public const float PHYSAC_PENETRATION_CORRECTION = 0.4f;
public const float PHYSAC_PI = 3.14159265358979323846f;
public const float PHYSAC_DEG2RAD = (PHYSAC_PI / 180.0f);
#endregion
#region Raylib-cs Functions
// Initializes physics values, pointers and creates physics loop thread
[DllImport(nativeLibName,CallingConvention = CallingConvention.Cdecl)]
public static extern void InitPhysics();
// Returns true if physics thread is currently enabled
[DllImport(nativeLibName,CallingConvention = CallingConvention.Cdecl)]
public static extern bool IsPhysicsEnabled();
// Sets physics global gravity force
[DllImport(nativeLibName,CallingConvention = CallingConvention.Cdecl)]
public static extern void SetPhysicsGravity(float x, float y);
// Creates a new circle physics body with generic parameters
[DllImport(nativeLibName, EntryPoint = "CreatePhysicsBodyCircle")]
// [return: MarshalAs(UnmanagedType.LPStruct)]
private static extern IntPtr CreatePhysicsBodyCircleImport(Vector2 pos, float radius, float density);
public static PhysicsBodyData CreatePhysicsBodyCircle(Vector2 pos, float radius, float density)
{
var body = CreatePhysicsBodyCircleImport(pos, radius, density);
var data = (PhysicsBodyData)Marshal.PtrToStructure(body, typeof(PhysicsBodyData));
return data;
}
// Creates a new rectangle physics body with generic parameters
[DllImport(nativeLibName, EntryPoint = "CreatePhysicsBodyRectangle")]
private static extern IntPtr CreatePhysicsBodyRectangleImport(Vector2 pos, float width, float height, float density);
public static PhysicsBodyData CreatePhysicsBodyRectangle(Vector2 pos, float width, float height, float density)
{
var body = CreatePhysicsBodyRectangleImport(pos, width, height, density);
var data = (PhysicsBodyData)Marshal.PtrToStructure(body, typeof(PhysicsBodyData));
return data;
}
// Creates a new polygon physics body with generic parameters
[DllImport(nativeLibName, EntryPoint = "CreatePhysicsBodyPolygon")]
private static extern IntPtr CreatePhysicsBodyPolygonImport(Vector2 pos, float radius, int sides, float density);
public static PhysicsBodyData CreatePhysicsBodyPolygon(Vector2 pos, float radius, int sides, float density)
{
var body = CreatePhysicsBodyPolygonImport(pos, radius, sides, density);
var data = (PhysicsBodyData)Marshal.PtrToStructure(body, typeof(PhysicsBodyData));
return data;
}
// Adds a force to a physics body
[DllImport(nativeLibName,CallingConvention = CallingConvention.Cdecl)]
public static extern void PhysicsAddForce(PhysicsBodyData body, Vector2 force);
// Adds an angular force to a physics body
[DllImport(nativeLibName,CallingConvention = CallingConvention.Cdecl)]
public static extern void PhysicsAddTorque(PhysicsBodyData body, float amount);
// Shatters a polygon shape physics body to little physics bodies with explosion force
[DllImport(nativeLibName,CallingConvention = CallingConvention.Cdecl)]
public static extern void PhysicsShatter(PhysicsBodyData body, Vector2 position, float force);
// Returns the current amount of created physics bodies
[DllImport(nativeLibName,CallingConvention = CallingConvention.Cdecl)]
public static extern int GetPhysicsBodiesCount();
// Returns a physics body of the bodies pool at a specific index
[DllImport(nativeLibName, EntryPoint = "GetPhysicsBody")]
public static extern IntPtr GetPhysicsBodyImport(int index);
public static PhysicsBodyData GetPhysicsBody(int index)
{
var body = GetPhysicsBodyImport(index);
var data = (PhysicsBodyData)Marshal.PtrToStructure(body, typeof(PhysicsBodyData));
return data;
}
// Returns the physics body shape type (PHYSICS_CIRCLE or PHYSICS_POLYGON)
[DllImport(nativeLibName,CallingConvention = CallingConvention.Cdecl)]
public static extern int GetPhysicsShapeType(int index);
// Returns the amount of vertices of a physics body shape
[DllImport(nativeLibName,CallingConvention = CallingConvention.Cdecl)]
public static extern int GetPhysicsShapeVerticesCount(int index);
// Returns transformed position of a body shape (body position + vertex transformed position)
[DllImport(nativeLibName,CallingConvention = CallingConvention.Cdecl)]
public static extern Vector2 GetPhysicsShapeVertex(PhysicsBodyData body, int vertex);
// Sets physics body shape transform based on radians parameter
[DllImport(nativeLibName,CallingConvention = CallingConvention.Cdecl)]
public static extern void SetPhysicsBodyRotation(PhysicsBodyData body, float radians);
// Unitializes and destroy a physics body
[DllImport(nativeLibName,CallingConvention = CallingConvention.Cdecl)]
public static extern void DestroyPhysicsBody(PhysicsBodyData body);
// Destroys created physics bodies and manifolds and resets global values
[DllImport(nativeLibName,CallingConvention = CallingConvention.Cdecl)]
public static extern void ResetPhysics();
// Unitializes physics pointers and closes physics loop thread
[DllImport(nativeLibName,CallingConvention = CallingConvention.Cdecl)]
public static extern void ClosePhysics();
#endregion
}
}