/// <summary>
/// This function is called every fixed framerate frame, if the MonoBehaviour is enabled.
/// </summary>
void FixedUpdate()
{
// For convenience
bodyBox = new Rect(
bodyCd.bounds.min.x,
bodyCd.bounds.min.y,
bodyCd.bounds.size.x,
bodyCd.bounds.size.y
);
// Set default values
finalAccel = accel;
// --- Gravity ---
// If enemy is not grounded, apply gravity
if (!grounded)
{
velocity = new Vector2(velocity.x, Mathf.Max(velocity.y - gravity, -maxFall));
}
// Check if enemy is falling
if (velocity.y < 0)
{
if (state.Missing(MovementState.Falling))
{
state = state.Include(MovementState.Falling);
if (OnFall != null)
{
OnFall(this, System.EventArgs.Empty);
}
}
}
// Determine first and last rays
Vector2 minDownRay = new Vector2(bodyBox.xMin, bodyBox.center.y);
Vector2 maxDownRay = new Vector2(bodyBox.xMax, bodyBox.center.y);
// Calculate ray distance (if not grounded, set to current fall speed)
float rayDownDistance = bodyBox.height / 2 + ((grounded) ? 0 : Mathf.Abs(velocity.y * Time.deltaTime));
// Check below for ground
RaycastHit2D[] hitDownInfo = new RaycastHit2D[vRays];
bool hit = false;
float closestDownHit = float.MaxValue;
int closestDownHitIndex = 0;
for (int i = 0; i < vRays; i++)
{
// Create and cast ray
float lerpDistance = (float)i / (float)(vRays - 1);
Vector2 rayOrigin = Vector2.Lerp(minDownRay, maxDownRay, lerpDistance);
Ray2D ray = new Ray2D(rayOrigin, Vector2.down);
hitDownInfo[i] = Physics2D.Raycast(rayOrigin, Vector2.down, rayDownDistance, RayLayers.downRay);
// Check raycast results and keep track of closest ground hit
if (hitDownInfo[i].fraction > 0)
{
hit = true;
if (hitDownInfo[i].fraction < closestDownHit)
{
closestDownHit = hitDownInfo[i].fraction;
closestDownHitIndex = i;
closestDownHitInfo = hitDownInfo[i];
}
}
}
// If enemy hits ground, snap to the closest ground
if (hit)
{
// Check if enemy is landing this frame
if (state.Has(MovementState.Falling) && state.Missing(MovementState.Landing))
{
if (OnLand != null)
{
OnLand(this, System.EventArgs.Empty);
}
state = state.Include(MovementState.Landing);
state = state.Remove(MovementState.Jumping);
}
grounded = true;
state = state.Remove(MovementState.Falling);
velocity = new Vector2(velocity.x, 0);
}
else
{
grounded = false;
}
// --- Behavior ---
// Idle behavior
if (behaviorState.Has(BehaviorState.Idle))
{
behaviorTime += Time.deltaTime;
// Set new behavior
if (behaviorTime > idleBehaviorTime)
{
float newHAxis = Random.Range(-1, 1);
// Flip sprite if changing direction of movement
if (newHAxis != 0 && newHAxis != ((rend.flipX) ? -1 : 1))
{
rend.flipX = !rend.flipX;
}
hAxis = newHAxis;
behaviorTime = 0f;
idleBehaviorTime = GetNewIdleBehaviorTime();
//Debug.Log("Rolled: " + hAxis + " for " + idleBehaviorTime);
}
}
// --- Lateral Collisions & Movement ---
ApplyGroundEffects();
// Move horizontally
float newVelocityX = velocity.x;
if (hAxis != 0)
{
newVelocityX += finalAccel * hAxis;
newVelocityX = Mathf.Clamp(newVelocityX, -maxSpeed, maxSpeed);
}
// Decelerate if moving without input
else if (velocity.x != 0)
{
int decelDir = (velocity.x > 0) ? -1 : 1;
// Ensure enemy doesn't decelerate past zero
newVelocityX += (velocity.x > 0) ?
((newVelocityX + finalAccel * decelDir) < 0) ?
-newVelocityX : finalAccel * decelDir
: ((newVelocityX + finalAccel * decelDir) > 0) ?
-newVelocityX : finalAccel * decelDir;
}
// Account for slope
if (Mathf.Abs(closestDownHitInfo.normal.x) > 0.1f)
{
float friction = 0.7f;
newVelocityX = Mathf.Clamp((newVelocityX - (closestDownHitInfo.normal.x * friction)), -maxSpeed, maxSpeed);
Vector2 newPosition = transform.position;
newPosition.y += -closestDownHitInfo.normal.x * Mathf.Abs(newVelocityX) * Time.deltaTime * ((newVelocityX - closestDownHitInfo.normal.x > 0) ? 1 : -1);
transform.position = newPosition;
state = state.Remove(MovementState.Landing);
}
velocity = new Vector2(newVelocityX, velocity.y);
// Lateral collisions
bool lateralCollision = false;
// Determine first and last rays
Vector2 minLatRay = new Vector2(bodyBox.center.x, bodyBox.yMin);
Vector2 maxLatRay = new Vector2(bodyBox.center.x, bodyBox.yMax);
// Calculate ray distance and determine direction of movement
float rayDistance = bodyBox.width / 2 + Mathf.Abs(newVelocityX * Time.deltaTime);
Vector2 rayDirection = (newVelocityX > 0) ? Vector2.right : Vector2.left;
RaycastHit2D[] latHitInfo = new RaycastHit2D[hRays];
float closestLatHit = float.MaxValue;
int closestLatHitIndex = 0;
float lastFraction = 0;
int numHits = 0; // for debugging
for (int i = 0; i < hRays; i++)
{
// Create and cast ray
float lerpDistance = (float)i / (float)(hRays - 1);
Vector2 rayOrigin = Vector2.Lerp(minLatRay, maxLatRay, lerpDistance);
latHitInfo[i] = Physics2D.Raycast(rayOrigin, rayDirection, rayDistance, RayLayers.sideRay);
Debug.DrawRay(rayOrigin, rayDirection * rayDistance, Color.cyan, Time.deltaTime);
// Check raycast results
if (latHitInfo[i].fraction > 0)
{
lateralCollision = true;
numHits++; // for debugging
if (latHitInfo[i].fraction < closestLatHit)
{
closestLatHit = latHitInfo[i].fraction;
closestLatHitIndex = i;
}
// If more than one ray hits, check the slope of what player is colliding with
if (lastFraction > 0)
{
float slopeAngle = Vector2.Angle(latHitInfo[i].point - latHitInfo[i - 1].point, Vector2.right);
// If we hit a wall, snap to it
if (Mathf.Abs(slopeAngle - 90) < angleLeeway)
{
transform.Translate(rayDirection * (latHitInfo[i].distance - bodyBox.width / 2));
if (OnLateralCollision != null)
{
OnLateralCollision(this, System.EventArgs.Empty);
}
velocity = new Vector2(0, velocity.y);
break;
}
}
lastFraction = latHitInfo[i].fraction;
}
}
// TODO: Ceiling collisions?
// TODO: Check if accel/decel is making enemy sink into slopes
}