private void OnPlayerBodyCollision(BodyCollisionInfo info)
{
if (info.Penetration.Y < 0)
{
Fall();
}
}
private void OnBodyCollision(BodyCollisionInfo info)
{
var player = info.CollidingBody.UserData as Player;
if (player != null)
{
player.Damage(new DamageInfo(this, 1, Direction2DHelper.GetDirection(-info.Penetration)));
}
}
private void bodyCollide(Body bA, Body bB, List<BodyCollisionInfo> infoList)
{
int bApmCount = bA.PointMassCount;
int bBpmCount = bB.PointMassCount;
AABB boxB = bB.getAABB();
// check all PointMasses on bodyA for collision against bodyB. if there is a collision, return detailed info.
BodyCollisionInfo infoAway = new BodyCollisionInfo();
BodyCollisionInfo infoSame = new BodyCollisionInfo();
for (int i = 0; i < bApmCount; i++)
{
Vector2 pt = bA.getPointMass(i).Position;
// early out - if this point is outside the bounding box for bodyB, skip it!
if (!boxB.contains(ref pt))
continue;
// early out - if this point is not inside bodyB, skip it!
if (!bB.contains(ref pt))
continue;
int prevPt = (i>0) ? i-1 : bApmCount-1;
int nextPt = (i < bApmCount - 1) ? i + 1 : 0;
Vector2 prev = bA.getPointMass(prevPt).Position;
Vector2 next = bA.getPointMass(nextPt).Position;
// now get the normal for this point. (NOT A UNIT VECTOR)
Vector2 fromPrev = new Vector2();
fromPrev.X = pt.X - prev.X;
fromPrev.Y = pt.Y - prev.Y;
Vector2 toNext = new Vector2();
toNext.X = next.X - pt.X;
toNext.Y = next.Y - pt.Y;
Vector2 ptNorm = new Vector2();
ptNorm.X = fromPrev.X + toNext.X;
ptNorm.Y = fromPrev.Y + toNext.Y;
VectorTools.makePerpendicular(ref ptNorm);
// this point is inside the other body. now check if the edges on either side intersect with and edges on bodyB.
float closestAway = 100000.0f;
float closestSame = 100000.0f;
infoAway.Clear();
infoAway.bodyA = bA;
infoAway.bodyApm = i;
infoAway.bodyB = bB;
infoSame.Clear();
infoSame.bodyA = bA;
infoSame.bodyApm = i;
infoSame.bodyB = bB;
bool found = false;
int b1 = 0;
int b2 = 1;
for (int j = 0; j < bBpmCount; j++)
{
Vector2 hitPt;
Vector2 norm;
float edgeD;
b1 = j;
if (j < bBpmCount - 1)
b2 = j + 1;
else
b2 = 0;
Vector2 pt1 = bB.getPointMass(b1).Position;
Vector2 pt2 = bB.getPointMass(b2).Position;
// quick test of distance to each point on the edge, if both are greater than current mins, we can skip!
float distToA = ((pt1.X - pt.X) * (pt1.X - pt.X)) + ((pt1.Y - pt.Y) * (pt1.Y - pt.Y));
float distToB = ((pt2.X - pt.X) * (pt2.X - pt.X)) + ((pt2.Y - pt.Y) * (pt2.Y - pt.Y));
if ((distToA > closestAway) && (distToA > closestSame) && (distToB > closestAway) && (distToB > closestSame))
continue;
// test against this edge.
float dist = bB.getClosestPointOnEdgeSquared(pt, j, out hitPt, out norm, out edgeD);
// only perform the check if the normal for this edge is facing AWAY from the point normal.
float dot;
//Vector2.Dot(ref ptNorm, ref edgeNorm, out dot);
Vector2.Dot(ref ptNorm, ref norm, out dot);
if (dot <= 0f)
{
if (dist < closestAway)
{
closestAway = dist;
infoAway.bodyBpmA = b1;
infoAway.bodyBpmB = b2;
infoAway.edgeD = edgeD;
infoAway.hitPt = hitPt;
infoAway.normal = norm;
infoAway.penetration = dist;
found = true;
}
}
else
{
if (dist < closestSame)
{
closestSame = dist;
infoSame.bodyBpmA = b1;
infoSame.bodyBpmB = b2;
infoSame.edgeD = edgeD;
infoSame.hitPt = hitPt;
infoSame.normal = norm;
infoSame.penetration = dist;
}
}
}
// we've checked all edges on BodyB. add the collision info to the stack.
if ((found) && (closestAway > mPenetrationThreshold) && (closestSame < closestAway))
{
infoSame.penetration = (float)Math.Sqrt(infoSame.penetration);
infoList.Add(infoSame);
}
else
{
infoAway.penetration = (float)Math.Sqrt(infoAway.penetration);
infoList.Add(infoAway);
}
}
}
private void _handleCollisions()
{
// handle all collisions!
for (int i = 0; i < mCollisionList.Count; i++)
{
BodyCollisionInfo info = mCollisionList[i];
PointMass A = info.bodyA.getPointMass(info.bodyApm);
PointMass B1 = info.bodyB.getPointMass(info.bodyBpmA);
PointMass B2 = info.bodyB.getPointMass(info.bodyBpmB);
// velocity changes as a result of collision.
Vector2 bVel = new Vector2();
bVel.x = (B1.Velocity.x + B2.Velocity.x) * 0.5f;
bVel.y = (B1.Velocity.y + B2.Velocity.y) * 0.5f;
Vector2 relVel = new Vector2();
relVel.x = A.Velocity.x - bVel.x;
relVel.y = A.Velocity.y - bVel.y;
float relDot;
// Vector2.Dot(ref relVel, ref info.normal, out relDot);
relDot = Vector2.Dot(relVel, info.normal);
// collision filter!
if (!mMaterialPairs[info.bodyA.Material, info.bodyB.Material].CollisionFilter(info.bodyA, info.bodyApm, info.bodyB, info.bodyBpmA, info.bodyBpmB, info.hitPt, relDot))
{
continue;
}
if (info.penetration > mPenetrationThreshold)
{
//Console.WriteLine("penetration above Penetration Threshold!! penetration={0} threshold={1} difference={2}",
// info.penetration, mPenetrationThreshold, info.penetration-mPenetrationThreshold);
mPenetrationCount++;
continue;
}
float b1inf = 1.0f - info.edgeD;
float b2inf = info.edgeD;
float b2MassSum = ((float.IsPositiveInfinity(B1.Mass)) || (float.IsPositiveInfinity(B2.Mass))) ? float.PositiveInfinity : (B1.Mass + B2.Mass);
float massSum = A.Mass + b2MassSum;
float Amove;
float Bmove;
if (float.IsPositiveInfinity(A.Mass))
{
Amove = 0f;
Bmove = (info.penetration) + 0.001f;
}
else if (float.IsPositiveInfinity(b2MassSum))
{
Amove = (info.penetration) + 0.001f;
Bmove = 0f;
}
else
{
Amove = (info.penetration * (b2MassSum / massSum));
Bmove = (info.penetration * (A.Mass / massSum));
}
float B1move = Bmove * b1inf;
float B2move = Bmove * b2inf;
float AinvMass = (float.IsPositiveInfinity(A.Mass)) ? 0f : 1f / A.Mass;
float BinvMass = (float.IsPositiveInfinity(b2MassSum)) ? 0f : 1f / b2MassSum;
float jDenom = AinvMass + BinvMass;
Vector2 numV = new Vector2();
float elas = 1f + mMaterialPairs[info.bodyA.Material, info.bodyB.Material].Elasticity;
numV.x = relVel.x * elas;
numV.y = relVel.y * elas;
float jNumerator;
// Vector2.Dot(ref numV, ref info.normal, out jNumerator);
jNumerator = Vector2.Dot(numV, info.normal);
jNumerator = -jNumerator;
float j = jNumerator / jDenom;
if (!float.IsPositiveInfinity(A.Mass))
{
A.Position.x += info.normal.x * Amove;
A.Position.y += info.normal.y * Amove;
}
if (!float.IsPositiveInfinity(B1.Mass))
{
B1.Position.x -= info.normal.x * B1move;
B1.Position.y -= info.normal.y * B1move;
}
if (!float.IsPositiveInfinity(B2.Mass))
{
B2.Position.x -= info.normal.x * B2move;
B2.Position.y -= info.normal.y * B2move;
}
Vector2 tangent = new Vector2();
VectorTools.getPerpendicular(ref info.normal, ref tangent);
float friction = mMaterialPairs[info.bodyA.Material, info.bodyB.Material].Friction;
float fNumerator;
// Vector2.Dot(ref relVel, ref tangent, out fNumerator);
fNumerator = Vector2.Dot(relVel, tangent);
fNumerator *= friction;
float f = fNumerator / jDenom;
// adjust velocity if relative velocity is moving toward each other.
if (relDot <= 0.0001f)
{
if (!float.IsPositiveInfinity(A.Mass))
{
A.Velocity.x += (info.normal.x * (j / A.Mass)) - (tangent.x * (f / A.Mass));
A.Velocity.y += (info.normal.y * (j / A.Mass)) - (tangent.y * (f / A.Mass));
}
if (!float.IsPositiveInfinity(b2MassSum))
{
B1.Velocity.x -= (info.normal.x * (j / b2MassSum) * b1inf) - (tangent.x * (f / b2MassSum) * b1inf);
B1.Velocity.y -= (info.normal.y * (j / b2MassSum) * b1inf) - (tangent.y * (f / b2MassSum) * b1inf);
}
if (!float.IsPositiveInfinity(b2MassSum))
{
B2.Velocity.x -= (info.normal.x * (j / b2MassSum) * b2inf) - (tangent.x * (f / b2MassSum) * b2inf);
B2.Velocity.y -= (info.normal.y * (j / b2MassSum) * b2inf) - (tangent.y * (f / b2MassSum) * b2inf);
}
}
}
mCollisionList.Clear();
}
private void bodyCollide(Body bA, Body bB, List <BodyCollisionInfo> infoList)
{
int bApmCount = bA.PointMassCount;
int bBpmCount = bB.PointMassCount;
AABB boxB = bB.getAABB();
// check all PointMasses on bodyA for collision against bodyB. if there is a collision, return detailed info.
BodyCollisionInfo infoAway = new BodyCollisionInfo();
BodyCollisionInfo infoSame = new BodyCollisionInfo();
for (int i = 0; i < bApmCount; i++)
{
Vector2 pt = bA.getPointMass(i).Position;
// early out - if this point is outside the bounding box for bodyB, skip it!
if (!boxB.contains(ref pt))
{
continue;
}
// early out - if this point is not inside bodyB, skip it!
if (!bB.contains(ref pt))
{
continue;
}
int prevPt = (i > 0) ? i - 1 : bApmCount - 1;
int nextPt = (i < bApmCount - 1) ? i + 1 : 0;
Vector2 prev = bA.getPointMass(prevPt).Position;
Vector2 next = bA.getPointMass(nextPt).Position;
// now get the normal for this point. (NOT A UNIT VECTOR)
Vector2 fromPrev = new Vector2();
fromPrev.x = pt.x - prev.x;
fromPrev.y = pt.y - prev.y;
Vector2 toNext = new Vector2();
toNext.x = next.x - pt.x;
toNext.y = next.y - pt.y;
Vector2 ptNorm = new Vector2();
ptNorm.x = fromPrev.x + toNext.x;
ptNorm.y = fromPrev.y + toNext.y;
VectorTools.makePerpendicular(ref ptNorm);
// this point is inside the other body. now check if the edges on either side intersect with and edges on bodyB.
float closestAway = 100000.0f;
float closestSame = 100000.0f;
infoAway.Clear();
infoAway.bodyA = bA;
infoAway.bodyApm = i;
infoAway.bodyB = bB;
infoSame.Clear();
infoSame.bodyA = bA;
infoSame.bodyApm = i;
infoSame.bodyB = bB;
bool found = false;
int b1 = 0;
int b2 = 1;
for (int j = 0; j < bBpmCount; j++)
{
Vector2 hitPt;
Vector2 norm;
float edgeD;
b1 = j;
if (j < bBpmCount - 1)
{
b2 = j + 1;
}
else
{
b2 = 0;
}
Vector2 pt1 = bB.getPointMass(b1).Position;
Vector2 pt2 = bB.getPointMass(b2).Position;
// quick test of distance to each point on the edge, if both are greater than current mins, we can skip!
float distToA = ((pt1.x - pt.x) * (pt1.x - pt.x)) + ((pt1.y - pt.y) * (pt1.y - pt.y));
float distToB = ((pt2.x - pt.x) * (pt2.x - pt.x)) + ((pt2.y - pt.y) * (pt2.y - pt.y));
if ((distToA > closestAway) && (distToA > closestSame) && (distToB > closestAway) && (distToB > closestSame))
{
continue;
}
// test against this edge.
float dist = bB.getClosestPointOnEdgeSquared(pt, j, out hitPt, out norm, out edgeD);
// only perform the check if the normal for this edge is facing AWAY from the point normal.
float dot;
//Vector2.Dot(ref ptNorm, ref edgeNorm, out dot);
// Vector2.Dot(ref ptNorm, ref norm, out dot);
dot = Vector2.Dot(ptNorm, norm);
if (dot <= 0f)
{
if (dist < closestAway)
{
closestAway = dist;
infoAway.bodyBpmA = b1;
infoAway.bodyBpmB = b2;
infoAway.edgeD = edgeD;
infoAway.hitPt = hitPt;
infoAway.normal = norm;
infoAway.penetration = dist;
found = true;
}
}
else
{
if (dist < closestSame)
{
closestSame = dist;
infoSame.bodyBpmA = b1;
infoSame.bodyBpmB = b2;
infoSame.edgeD = edgeD;
infoSame.hitPt = hitPt;
infoSame.normal = norm;
infoSame.penetration = dist;
}
}
}
// we've checked all edges on BodyB. add the collision info to the stack.
if ((found) && (closestAway > mPenetrationThreshold) && (closestSame < closestAway))
{
infoSame.penetration = (float)Math.Sqrt(infoSame.penetration);
infoList.Add(infoSame);
}
else
{
infoAway.penetration = (float)Math.Sqrt(infoAway.penetration);
infoList.Add(infoAway);
}
}
}
