void ApplyFrictionForce(CustomRigidbody objectA, CustomRigidbody objectB, Vector2 normal, float impValue, Vector2 impulse)
{
//assign new friction values
float aInverseMass = 1 / objectA.m_Mass;
float bInverseMass = 1 / objectB.m_Mass;
// Get the recalculated relative velocity after the previous impulse has been applied
Vector2 rv = objectB.m_Velocity - objectA.m_Velocity;
// Retrieve the tangent vector, the vector that determines the direction of friction force to apply
Vector2 tangent = rv - Vector2.Dot(rv, normal) * normal;
tangent.Normalize();
// calculate the friction impulse value
float jT = -Vector2.Dot(rv, tangent) / (aInverseMass + bInverseMass);
// Coulombs law: force of friction <= force along the normal * mu
float mu = (objectA.m_MaterialType.m_StaticFriction + objectB.m_MaterialType.m_StaticFriction) / 2;
Vector2 frictionImpulse;
// clamp the magnitude of the friction and create the friction impulse vector
if (Mathf.Abs(jT) < impValue * mu)
{
frictionImpulse = jT * tangent;
}
else
{
float dynamicFriction = (objectA.m_MaterialType.m_DynamicFriction + objectB.m_MaterialType.m_DynamicFriction) / 2;
impulse.Scale(tangent);
Vector2 j = new Vector2(-impulse.x, -impulse.y);
frictionImpulse = j * dynamicFriction;
}
objectA.m_Velocity -= (aInverseMass) * frictionImpulse;
objectB.m_Velocity += (bInverseMass) * frictionImpulse;
}
// all physics calculations are done within here
// this is called from within MainManager
public void PhysicsUpdate()
{
accum += deltaTime;
//Calculate physics on the current frame
while (accum > deltaTime)
{
colliderTest1 = null;
colliderTest2 = null;
currentCollisionPair = new List <CollisionPair>();
depthX = 0f;
depthY = 0f;
xDistance = 0f;
yDistance = 0f;
xDirection = 0f;
yDirection = 0f;
// if no path simulate normally
//calculate rigidbodies
for (int i = 0; i < rigidBodiesInScene.Count; i++)
{
// entity calc
if (rigidBodiesInScene[i].tag == "Entity")
{
bool charging = false;
recentHit = false;
// check if player attacked
// player charge attack
if (Input.GetMouseButtonDown(0))
{
chargeDmg = 0;
chargeRate = 1000f;
charging = true;
if (charging == true)
{
chargeDmg += chargeRate * Time.deltaTime;
}
}
if (Input.GetMouseButtonUp(0))
{
charging = false;
chargeDmg = Mathf.Clamp(chargeDmg, 0f, 100f);
//create a player attack area and check if the enemy is inside it
GameObject t = Instantiate(Resources.Load("EntityAttack")) as GameObject;
GameObject graphic = Instantiate(Resources.Load("AttackGraphic")) as GameObject;
EntityAttack et = t.GetComponent <EntityAttack>();
et.InitAttack();
CustomRigidbody player = GameObject.FindGameObjectWithTag("Player").GetComponent <CustomRigidbody>();
Vector2 direction = et.GetDirection(player).normalized;
t.transform.position = (Vector2)player.transform.position + direction;
graphic.transform.position = (Vector2)player.transform.position + direction;
graphic.transform.SetParent(player.transform);
Transform[] q = graphic.GetComponentsInChildren <Transform>();
foreach (Transform tr in q)
{
if (tr.tag == "pointer")
{
graphic.transform.rotation = tr.rotation;
}
}
if (et.IsColliding(rigidBodiesInScene[i]))
{
// if hit, set enemy velocity to the direction of where the player pointed
rigidBodiesInScene[i].m_IsIgnoringGravity = false;
rigidBodiesInScene[i].m_Velocity = direction * chargeDmg;
rigidBodiesInScene[i].m_IsEnemyDead = true;
Destroy(et.gameObject);
DestroyObject(graphic.gameObject, 0.5f);
}
else
{
DestroyObject(graphic.gameObject);
Destroy(et.gameObject, 0.5f);
}
}
// if entity has been attacked, dont path find
AStarPathfind a = new AStarPathfind();
if (rigidBodiesInScene[i].m_IsEnemyDead != true)
{
// calculate entity positions for pathfinding
playerPos = new Vector2(0, 0);
enemyPos = new Vector2(0, 0);
for (int l = 0; l < entityBoundingBoxes.Count; l++)
{
if (entityBoundingBoxes[l].tag == "Player")
{
playerPos = entityBoundingBoxes[l].transform.position;
}
}
// generate path to player
playerNode = grid.NodeFromWorldPoint(playerPos);
enemyNode = grid.NodeFromWorldPoint(rigidBodiesInScene[i].transform.position);
path = a.AStarSearch(grid, enemyNode, playerNode);
dPath = path;
//path = null;
}
else
{
Destroy(a);
path = null;
}
// if path exists move through it
if (path != null)
{
for (int j = 0; j < path.Count; j++)
{
rigidBodiesInScene[i].m_EnemyHasPath = false;
Vector2 direction = (path[j] - (Vector2)rigidBodiesInScene[i].transform.position);
direction.Normalize();
rigidBodiesInScene[i].m_EnemyMoveDirection = direction;
rigidBodiesInScene[i].m_EnemyHasPath = true;
rigidBodiesInScene[i].EnemyPhysicsLoop();
}
}
// if entity has been attacked, re enable gravity
else if (path == null || rigidBodiesInScene[i].m_IsEnemyDead == true)
{
rigidBodiesInScene[i].m_EnemyHasPath = false;
rigidBodiesInScene[i].m_IsIgnoringGravity = false;
rigidBodiesInScene[i].EnemyPhysicsLoop();
}
}
// calc player and other rigidbodies
if (rigidBodiesInScene[i].tag == "Player")
{
rigidBodiesInScene[i].PlayerPhysicsLoop();
}
else if (rigidBodiesInScene[i].tag != "Player" || rigidBodiesInScene[i].tag != "Entity")
{
rigidBodiesInScene[i].PlayerPhysicsLoop();
}
}
//calculate collisions
for (int j = 0; j < entityBoundingBoxes.Count; j++)
{
// this is the current entity we are checking colliders against
// we dont need to check collisions between platforms.
colliderTest1 = entityBoundingBoxes[j];
//collision between entity and ground
for (int k = 0; k < floorBoundingBoxes.Count; k++)
{
colliderTest2 = floorBoundingBoxes[k];
if (TestAABBOverlap(colliderTest1, colliderTest2))
{
if (colliderTest1.GetComponent <CustomRigidbody>().m_IsEnemyDead == true)
{
entityBoundingBoxes.Remove(colliderTest1);
rigidBodiesInScene.Remove(colliderTest1.GetComponent <CustomRigidbody>());
Destroy(colliderTest1.gameObject);
isEnemyActive = false;
}
colliderTest1.GetComponent <CustomRigidbody>().m_IsGrounded = true;
//Debug.Log(string.Format("Ground Collision between: {0} and {1}", colliderTest1, colliderTest2));
PopulateCollisionData(colliderTest1, colliderTest2);
}
}
//collision between entity and entity
for (int l = 0; l < entityBoundingBoxes.Count; l++)
{
colliderTest2 = entityBoundingBoxes[l];
//Don't collide with itself
if (colliderTest1 == colliderTest2)
{
continue;
}
if (TestAABBOverlap(colliderTest1, colliderTest2))
{
//Debug.Log(string.Format("Entity Collision between: {0} and {1}", colliderTest1, colliderTest2));
PopulateCollisionData(colliderTest1, colliderTest2);
float[] moveVals = { 12, -12 };
int chooseAxis = 0;
// enemy 'attacks'
// choose a random direction to set the players velocity in
if (colliderTest1.tag == "Player")
{
CustomRigidbody rb = colliderTest1.GetComponent <CustomRigidbody>();
rb.m_PlayerHasBeenHit = true;
float v = Random.Range(0, moveVals.Length);
chooseAxis = Random.Range(0, 1);
if (chooseAxis == 0)
{
rb.m_Velocity = new Vector2(moveVals[Random.Range(0, moveVals.Length)], 0);
}
if (chooseAxis == 1)
{
rb.m_Velocity = new Vector2(0, moveVals[Random.Range(0, moveVals.Length)]);
}
}
if (colliderTest2.tag == "Player")
{
CustomRigidbody rb = colliderTest2.GetComponent <CustomRigidbody>();
rb.m_PlayerHasBeenHit = true;
int v = Random.Range(0, moveVals.Length);
chooseAxis = Random.Range(0, 1);
if (chooseAxis == 0)
{
rb.m_Velocity = new Vector2(moveVals[Random.Range(0, moveVals.Length)], 0);
}
if (chooseAxis == 1)
{
rb.m_Velocity = new Vector2(0, moveVals[Random.Range(0, moveVals.Length)]);
}
}
}
}
// Finally check whether an entity has hit the boundaries of the screen
// and needs to be removed from scene
for (int i = 0; i < boundaryBoundingBoxes.Count; i++)
{
colliderTest2 = boundaryBoundingBoxes[i];
if (TestAABBOverlap(colliderTest1, colliderTest2))
{
if (colliderTest1.tag == "Player")
{
entityBoundingBoxes.Remove(colliderTest1);
rigidBodiesInScene.Remove(colliderTest1.GetComponent <CustomRigidbody>());
Destroy(colliderTest1.gameObject);
isPlayerActive = false;
}
if (colliderTest1.tag == "Entity")
{
entityBoundingBoxes.Remove(colliderTest1);
rigidBodiesInScene.Remove(colliderTest1.GetComponent <CustomRigidbody>());
Destroy(colliderTest1.gameObject);
isEnemyActive = false;
}
}
}
}
accum -= deltaTime;
}
}
void ResolveCollisionPair(List <CollisionPair> pairs)
{
CustomRigidbody objectA = pairs[0].m_ObjectA.GetComponent <CustomRigidbody>();
CustomRigidbody objectB = pairs[0].m_ObjectB.GetComponent <CustomRigidbody>();
// get relative velocity of each object this is used to find out how far to move each object
Vector2 objAVelocity = objectA.m_Velocity;
Vector2 objBVelocity = objectB.m_Velocity;
Vector2 relativeVelocity = objBVelocity - objAVelocity;
// normalise the contact normal to make sure it only points in the right direction
Vector2 normalMagnitude = pairs[0].m_CollisionNormal;
normalMagnitude.Normalize();
// get the velocity along the normal
float velocityAlongNormal = Vector2.Dot(relativeVelocity, normalMagnitude);
// calculate the restitution (elasticity) which is between 0 and 1
// should change to a property of each rigidbody
float coefficientOfRestitution = Mathf.Min(0.01f, 0.02f);
// calculate the inverse mass to impulse (force) the objects away
// do this to save from having to calculate it like 5 more times
float aInverseMass;
float bInverseMass;
if (objectA.m_Mass == 0)
{
aInverseMass = 0;
}
else
{
aInverseMass = 1 / objectA.m_Mass;
}
if (objectB.m_Mass == 0)
{
bInverseMass = 0;
}
else
{
bInverseMass = 1 / objectB.m_Mass;
}
// calculate the impulse
float impulse = -(1 + coefficientOfRestitution) * velocityAlongNormal / (aInverseMass + bInverseMass);
// create and assign the new velocities
Vector2 imp = impulse * normalMagnitude;
objectA.m_Velocity -= aInverseMass * imp;
objectB.m_Velocity += bInverseMass * imp;
// stop sinking objects by offsetting the positions to above a certain threshold
// depending on the penetration depth
float percent = 0.2f; // the amount we want to move each colliding object
float slop = 0.01f; // the amount we let the 2 objects sink into eachother to stop jittering
float xAmount = 0f;
float yAmount = 0f;
// get the side that is being most penetrated
xAmount = pairs[0].m_PenetrationDepth.x;
yAmount = pairs[0].m_PenetrationDepth.y;
Vector2 correction = Mathf.Max(-yAmount - slop, 0.0f) / (aInverseMass + bInverseMass) * percent * pairs[0].m_CollisionNormal;
objectA.m_Velocity -= aInverseMass * correction;
objectB.m_Velocity += bInverseMass * correction;
}