void moveVertically(ref FixVec2 deltaMovement)
{
var isGoingUp = deltaMovement.y > 0;
var rayDistance = FixMath.Abs(deltaMovement.y) + _skinWidth;
var rayDirection = isGoingUp ? FixVec2.up : -FixVec2.up;
var initialRayOrigin = isGoingUp ? _raycastOrigins.topLeft : _raycastOrigins.bottomLeft;
// apply our horizontal deltaMovement here so that we do our raycast from the actual position we would be in if we had moved
initialRayOrigin.x += deltaMovement.x;
// if we are moving up, we should ignore the layers in oneWayPlatformMask
var mask = platformMask;
if ((isGoingUp && !collisionState.wasGroundedLastFrame) || ignoreOneWayPlatformsThisFrame)
{
mask &= ~oneWayPlatformMask;
}
for (var i = 0; i < totalVerticalRays; i++)
{
FixVec2 ray = new FixVec2(initialRayOrigin.x + i * _horizontalDistanceBetweenRays, initialRayOrigin.y);
DrawRay((Vector3)ray, (Vector3)(rayDirection * rayDistance), Color.red);
_raycastHit = TFPhysics.Raycast(ray, rayDirection, rayDistance, mask);
if (_raycastHit)
{
// set our new deltaMovement and recalculate the rayDistance taking it into account
deltaMovement.y = _raycastHit.point.y - ray.y;
rayDistance = FixMath.Abs(deltaMovement.y);
// remember to remove the skinWidth from our deltaMovement
if (isGoingUp)
{
deltaMovement.y -= _skinWidth;
collisionState.above = true;
}
else
{
deltaMovement.y += _skinWidth;
collisionState.below = true;
}
_raycastHitsThisFrame.Add(_raycastHit);
// this is a hack to deal with the top of slopes. if we walk up a slope and reach the apex we can get in a situation
// where our ray gets a hit that is less then skinWidth causing us to be ungrounded the next frame due to residual velocity.
if (!isGoingUp && deltaMovement.y > Fix.zero)
{
_isGoingUpSlope = true;
}
// we add a small fudge factor for the float operations here. if our rayDistance is smaller
// than the width + fudge bail out because we have a direct impact
if (rayDistance < _skinWidth + kSkinWidthFloatFudgeFactor)
{
break;
}
}
}
}
private void Update()
{
if (Input.GetMouseButtonDown(0))
{
var v3 = Input.mousePosition;
v3.z = 0;
v3 = Camera.main.ScreenToWorldPoint(v3);
FixVec2 pointB = new FixVec2((Fix)v3.x, (Fix)v3.y);
TFRaycastHit2D h = TFPhysics.Raycast((FixVec2)tfTransform.Position, (FixVec2)(pointB - tfTransform.Position).Normalized(), 5, platformMask);
}
}
/// <summary>
/// checks the center point under the BoxCollider2D for a slope. If it finds one then the deltaMovement is adjusted so that
/// the player stays grounded and the slopeSpeedModifier is taken into account to speed up movement.
/// </summary>
/// <param name="deltaMovement">Delta movement.</param>
private void handleVerticalSlope(ref FixVec2 deltaMovement)
{
// slope check from the center of our collider
Fix centerOfCollider = (_raycastOrigins.bottomLeft.x + _raycastOrigins.bottomRight.x) * (Fix.one / 2);
FixVec2 rayDirection = -FixVec2.up;
// the ray distance is based on our slopeLimit
Fix slopeCheckRayDistance = _slopeLimitTangent * (_raycastOrigins.bottomRight.x - centerOfCollider);
FixVec2 slopeRay = new FixVec2(centerOfCollider, _raycastOrigins.bottomLeft.y);
_raycastHit = TFPhysics.Raycast(slopeRay, rayDirection, slopeCheckRayDistance, platformMask);
if (_raycastHit)
{
// bail out if we have no slope
var angle = FixVec2.Angle(_raycastHit.normal, FixVec2.up);
if (angle == 0)
{
return;
}
// we are moving down the slope if our normal and movement direction are in the same x direction
var isMovingDownSlope = FixMath.Sign(_raycastHit.normal.x) == FixMath.Sign(deltaMovement.x);
if (isMovingDownSlope)
{
// going down we want to speed up in most cases so the slopeSpeedMultiplier curve should be > 1 for negative angles
Fix slopeModifier = (Fix)slopeSpeedMultiplier.Evaluate((float)-angle);
// we add the extra downward movement here to ensure we "stick" to the surface below
deltaMovement.y += _raycastHit.point.y - slopeRay.y - skinWidth;
deltaMovement = new FixVec2(deltaMovement.x, deltaMovement.y)
+ new FixVec2(deltaMovement.x * slopeModifier * (1 - (angle / 90)), (deltaMovement.x * slopeModifier * (angle / 90)));
collisionState.movingDownSlope = true;
collisionState.slopeAngle = angle;
}
}
}
/// <summary>
/// handles adjusting deltaMovement if we are going up a slope.
/// </summary>
/// <returns><c>true</c>, if horizontal slope was handled, <c>false</c> otherwise.</returns>
/// <param name="deltaMovement">Delta movement.</param>
/// <param name="angle">Angle.</param>
bool handleHorizontalSlope(ref FixVec2 deltaMovement, Fix angle)
{
// disregard 90 degree angles (walls)
if (FixMath.Round(angle) == 90)
{
return(false);
}
if (angle < slopeLimit)
{
// we only need to adjust the deltaMovement if we are not jumping
// TODO: this uses a magic number which isn't ideal! The alternative is to have the user pass in if there is a jump this frame
if (deltaMovement.y < jumpingThreshold)
{
// apply the slopeModifier to slow our movement up the slope
Fix slopeModifier = (Fix)slopeSpeedMultiplier.Evaluate((float)angle);
deltaMovement.x *= slopeModifier;
// we dont set collisions on the sides for this since a slope is not technically a side collision.
// smooth y movement when we climb. we make the y movement equivalent to the actual y location that corresponds
// to our new x location using our good friend Pythagoras
deltaMovement.y = FixMath.Abs(FixMath.Tan(angle * FixMath.Deg2Rad) * deltaMovement.x);
var isGoingRight = deltaMovement.x > 0;
// safety check. we fire a ray in the direction of movement just in case the diagonal we calculated above ends up
// going through a wall. if the ray hits, we back off the horizontal movement to stay in bounds.
var ray = isGoingRight ? _raycastOrigins.bottomRight : _raycastOrigins.bottomLeft;
TFRaycastHit2D raycastHit;
if (collisionState.wasGroundedLastFrame)
{
raycastHit = TFPhysics.Raycast((FixVec2)ray, (FixVec2)deltaMovement.Normalized(), deltaMovement.GetMagnitude(), platformMask);
}
else
{
raycastHit = TFPhysics.Raycast((FixVec2)ray, (FixVec2)deltaMovement.Normalized(), deltaMovement.GetMagnitude(), platformMask & ~oneWayPlatformMask);
}
if (raycastHit)
{
// we crossed an edge when using Pythagoras calculation, so we set the actual delta movement to the ray hit location
deltaMovement = raycastHit.point - ray;
if (isGoingRight)
{
deltaMovement.x -= _skinWidth;
}
else
{
deltaMovement.x += _skinWidth;
}
}
_isGoingUpSlope = true;
collisionState.below = true;
collisionState.slopeAngle = -angle;
}
}
else // too steep. get out of here
{
deltaMovement.x = Fix.zero;
}
return(true);
}
/// <summary>
/// we have to use a bit of trickery in this one. The rays must be cast from a small distance inside of our
/// collider (skinWidth) to avoid zero distance rays which will get the wrong normal. Because of this small offset
/// we have to increase the ray distance skinWidth then remember to remove skinWidth from deltaMovement before
/// actually moving the player
/// </summary>
void moveHorizontally(ref FixVec2 deltaMovement)
{
var isGoingRight = deltaMovement.x > 0;
var rayDistance = FixMath.Abs(deltaMovement.x) + _skinWidth;
var rayDirection = isGoingRight ? FixVec2.right : -FixVec2.right;
var initialRayOrigin = isGoingRight ? _raycastOrigins.bottomRight : _raycastOrigins.bottomLeft;
for (var i = 0; i < totalHorizontalRays; i++)
{
var ray = new FixVec2(initialRayOrigin.x, initialRayOrigin.y + i * _verticalDistanceBetweenRays);
// if we are grounded we will include oneWayPlatforms only on the first ray (the bottom one). this will allow us to
// walk up sloped oneWayPlatforms.
if (i == 0 && collisionState.wasGroundedLastFrame)
{
_raycastHit = TFPhysics.Raycast(ray, rayDirection, rayDistance, platformMask);
}
else
{
_raycastHit = TFPhysics.Raycast(ray, rayDirection, rayDistance, platformMask & ~oneWayPlatformMask);
}
if (_raycastHit)
{
// the bottom ray can hit a slope but no other ray can so we have special handling for these cases
if (i == 0 && handleHorizontalSlope(ref deltaMovement, FixVec2.Angle(_raycastHit.normal, FixVec2.up)))
{
_raycastHitsThisFrame.Add(_raycastHit);
// if we weren't grounded last frame, that means we're landing on a slope horizontally.
// this ensures that we stay flush to that slope
if (!collisionState.wasGroundedLastFrame)
{
Fix flushDistance = FixMath.Sign(deltaMovement.x) * (_raycastHit.distance - skinWidth);
tfTransform.Position += new FixVec2(flushDistance, 0);
}
break;
}
// set our new deltaMovement and recalculate the rayDistance taking it into account
deltaMovement.x = _raycastHit.point.x - ray.x;
rayDistance = FixMath.Abs(deltaMovement.x);
// remember to remove the skinWidth from our deltaMovement
if (isGoingRight)
{
deltaMovement.x -= _skinWidth;
collisionState.right = true;
}
else
{
deltaMovement.x += _skinWidth;
collisionState.left = true;
}
_raycastHitsThisFrame.Add(_raycastHit);
// we add a small fudge factor for the float operations here. if our rayDistance is smaller
// than the width + fudge bail out because we have a direct impact
if (rayDistance < _skinWidth + kSkinWidthFloatFudgeFactor)
{
break;
}
}
}
}