public void UpdateBitmask(Body body) { BoundingSquare box = body.aabb; int minX = (int)Math.Floor((box.min.X - aabb.min.X) / cell.X); int maxX = (int)Math.Floor((box.max.X - aabb.min.X) / cell.X); if (minX < 0) { minX = 0; } else if (minX > 32) { minX = 32; } if (maxX < 0) { maxX = 0; } else if (maxX > 32) { maxX = 32; } int minY = (int)Math.Floor((box.min.Y - aabb.min.Y) / cell.Y); int maxY = (int)Math.Floor((box.max.Y - aabb.min.Y) / cell.Y); if (minY < 0) { minY = 0; } else if (minY > 32) { minY = 32; } if (maxY < 0) { maxY = 0; } else if (maxY > 32) { maxY = 32; } body.bitmaskx.clear(); for (int i = minX; i <= maxX; i++) { body.bitmaskx.setOn(i); } body.bitmasky.clear(); for (int i = minY; i <= maxY; i++) { body.bitmasky.setOn(i); } }
public bool Intersects(ref BoundingSquare aabb) { // Exit with no intersecton if separated along an axis if (this.max.X < aabb.min.X || this.min.X > aabb.max.X) { return(false); } if (this.max.Y < aabb.min.Y || this.min.Y > aabb.max.Y) { return(false); } // Overlapping on all axis means AABBs are intersecting return(true); }
public void SetWorldLimits(Vector2 min, Vector2 max) { aabb = new BoundingSquare(ref min, ref max); size = max - min; cell = size / 32; }
public static List <CollisionInfo> Intersects(Body body_a, Body body_b) { List <CollisionInfo> data = new List <CollisionInfo>(); int bApmCount = body_a.count; int bBpmCount = body_b.count; BoundingSquare boxB = body_b.aabb; // check all PointMasses on bodyA for collision against bodyB. if there is a collision, return detailed info. CollisionInfo infoAway = new CollisionInfo(); CollisionInfo infoSame = new CollisionInfo(); for (int i = 0; i < bApmCount; i++) { Vector2 pt = body_a.pointmass_list[i].position; // early out - if this point is outside the bounding box for bodyB, skip it! if (!boxB.Contains(pt.X, pt.Y)) { continue; } // early out - if this point is not inside bodyB, skip it! if (!body_b.Contains(ref pt)) { continue; } int prevPt = (i > 0) ? i - 1 : bApmCount - 1; int nextPt = (i < bApmCount - 1) ? i + 1 : 0; Vector2 prev = body_a.pointmass_list[prevPt].position; Vector2 next = body_a.pointmass_list[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; VectorHelper.Perpendicular(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.body_a = body_a; infoAway.pointmass_a = body_a.pointmass_list[i]; infoAway.body_b = body_b; infoSame.Clear(); infoSame.body_a = body_a; infoSame.pointmass_a = body_a.pointmass_list[i]; infoSame.body_b = body_b; 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 = body_b.pointmass_list[b1].position; Vector2 pt2 = body_b.pointmass_list[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 = body_b.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 norm, out dot); if (dot <= 0f) { if (dist < closestAway) { closestAway = dist; infoAway.pointmass_b = body_b.pointmass_list[b1]; infoAway.pointmass_c = body_b.pointmass_list[b2]; infoAway.edge_distance = edgeD; infoAway.point = hitPt; infoAway.normal = norm; infoAway.penetration = dist; found = true; } } else { if (dist < closestSame) { closestSame = dist; infoSame.pointmass_b = body_b.pointmass_list[b1]; infoSame.pointmass_c = body_b.pointmass_list[b2]; infoSame.edge_distance = edgeD; infoSame.point = hitPt; infoSame.normal = norm; infoSame.penetration = dist; } } } // we've checked all edges on BodyB. if ((found) && (closestAway > 0.3f) && (closestSame < closestAway)) { infoSame.penetration = (float)Math.Sqrt(infoSame.penetration); data.Add(infoSame); } else { infoAway.penetration = (float)Math.Sqrt(infoAway.penetration); data.Add(infoAway); } } return(data); }
public bool Intersects(ref BoundingSquare aabb) { // Exit with no intersecton if separated along an axis if (this.max.X < aabb.min.X || this.min.X > aabb.max.X) return false; if (this.max.Y < aabb.min.Y || this.min.Y > aabb.max.Y) return false; // Overlapping on all axis means AABBs are intersecting return true; }