public void LoosenRope(Rope rope)
{
if (rope.PhysicsSegments.Count * Rope.SegmentLength >= Rope.MaxLength)
{
// Maximum length reached, rope cannot be made any longer
return;
}
var lastSegment = rope.PhysicsSegments.Last();
var ropeSegmentVector = Vector2.Normalize(rope.AttachedEntity.Position - lastSegment.Position) * Rope.SegmentLength;
PhysicsWorld.RemoveJoint(rope.PhysicsEntityJoint);
//var newSegment = BodyFactory.CreateCircle(PhysicsWorld, Rope.SegmentWidth, Rope.SegmentDensity);// BodyFactory.CreateRectangle(PhysicsWorld, 0.05f, Rope.SegmentLength, 0.5f);
var newSegment = BodyFactory.CreateRectangle(PhysicsWorld, Rope.Diameter, Rope.SegmentLength, Rope.SegmentDensity);
newSegment.BodyType = BodyType.Dynamic;
newSegment.AngularDamping = 0.1f;
newSegment.LinearDamping = 0.1f;
newSegment.Friction = 0.5f;
newSegment.Restitution = 0.2f;
newSegment.CollisionCategories = Category.Cat3;
newSegment.Position = lastSegment.Position + ropeSegmentVector;
rope.PhysicsSegments.Add(newSegment);
var segmentJoint = JointFactory.CreateRevoluteJoint(PhysicsWorld, lastSegment, newSegment, new Vector2(0, Rope.SegmentLength / 2), new Vector2(0, -Rope.SegmentLength / 2));
segmentJoint.CollideConnected = false;
rope.PhysicsSegmentJoints.Add(segmentJoint);
var ballJoint = JointFactory.CreateRevoluteJoint(PhysicsWorld, rope.PhysicsSegments.Last(), rope.AttachedEntity.PhysicsBody, Vector2.Zero, Vector2.Zero);
ballJoint.CollideConnected = false;
rope.PhysicsEntityJoint = ballJoint;
}
public void ShortenRope(Rope rope)
{
if (rope.PhysicsSegments.Count <= 2)
{
// Rope cannot be any shorter as 2 segments is minimum
return;
}
// Only allow shortening rope if all joints are restful
for (int i = 0; i < rope.PhysicsSegmentJoints.Count; ++i)
{
var joint = rope.PhysicsSegmentJoints[i];
if (Vector2.Distance(joint.WorldAnchorA, joint.WorldAnchorB) > 0.3f * Rope.SegmentLength)
return;
}
PhysicsWorld.RemoveJoint(rope.PhysicsEntityJoint);
PhysicsWorld.RemoveJoint(rope.PhysicsSegmentJoints.Last());
rope.PhysicsSegmentJoints.Remove(rope.PhysicsSegmentJoints.Last());
RemoveBody(rope.PhysicsSegments.Last());
rope.PhysicsSegments.Remove(rope.PhysicsSegments.Last());
var ballJoint = JointFactory.CreateRevoluteJoint(PhysicsWorld, rope.PhysicsSegments.Last(), rope.AttachedEntity.PhysicsBody, Vector2.Zero, Vector2.Zero);
ballJoint.CollideConnected = false;
rope.PhysicsEntityJoint = ballJoint;
}
public void RemoveRope(Rope rope)
{
foreach (var joint in rope.PhysicsSegmentJoints)
{
PhysicsWorld.RemoveJoint(joint);
}
rope.PhysicsSegmentJoints.Clear();
foreach (var body in rope.PhysicsSegments)
{
RopesByPhysicsBody.Remove(body);
RemoveBody(body);
}
rope.PhysicsSegments.Clear();
if (rope.AttachedEntity is Ball)
{
(rope.AttachedEntity as Ball).PhysicsBody.Mass = 10f;
(rope.AttachedEntity as Ball).PhysicsBody.FixedRotation = true;
}
}
public void AddRope(Rope rope)
{
float ropeLength = (rope.AttachedEntity.Position - rope.AttachedPosition).Length();
int segmentCount = (int)Round(1 + (ropeLength / Rope.SegmentLength));
if (segmentCount < 2)
segmentCount = 2;
var ropeSegmentDir = Vector2.Normalize(rope.AttachedEntity.Position - rope.AttachedPosition);
// TODO: fix the RotationFromDirection function!
var ropeRotation = ropeSegmentDir.RotationFromDirection();
rope.PhysicsSegments.Clear();
for (int i = 0; i < segmentCount; i++)
{
var ropeSegmentLength = i > 0 ? Rope.SegmentLength : Rope.Diameter;
var ropeSegmentVector = ropeSegmentDir * ropeSegmentLength;
var segmentStart = rope.AttachedPosition + ropeSegmentVector * i;
var segmentCenter = rope.AttachedPosition + ropeSegmentVector * (i + 0.5f);
var boxWidth = Rope.Diameter;
var boxHeight = i > 0 ? Rope.SegmentLength : Rope.Diameter;
//var segment = BodyFactory.CreateCircle(PhysicsWorld, Rope.JointRadius, Rope.SegmentDensity);// BodyFactory.CreateRectangle(PhysicsWorld, 0.05f, Rope.SegmentLength, 0.5f);
var segment = BodyFactory.CreateRectangle(PhysicsWorld, boxWidth, boxHeight, Rope.SegmentDensity);
segment.BodyType = BodyType.Dynamic;
segment.Friction = 0.5f;
segment.Restitution = 0.2f;
segment.AngularDamping = 0.2f;//1.1f;
segment.LinearDamping = 0.2f;// 1.1f;
segment.CollisionCategories = Category.Cat3;
segment.SetTransform(segmentCenter, -ropeRotation - 0.5f * (float)Math.PI);
rope.PhysicsSegments.Add(segment);
if (i > 0)
{
var segmentJoint = JointFactory.CreateRevoluteJoint(PhysicsWorld, rope.PhysicsSegments[i - 1], segment, new Vector2(0, i == 1 ? Rope.Diameter / 2 : Rope.SegmentLength / 2), new Vector2(0, -Rope.SegmentLength / 2));
segmentJoint.CollideConnected = false;
rope.PhysicsSegmentJoints.Add(segmentJoint);
}
else
{
segment.BodyType = BodyType.Static;
}
}
//var ballAnchor = rope.AttachedEntity.Position + new Vector2(0, rope.AttachedEntity.Radius + 1f);
var ballJoint = JointFactory.CreateRevoluteJoint(PhysicsWorld, rope.PhysicsSegments.Last(), rope.AttachedEntity.PhysicsBody, new Vector2(0, Rope.SegmentLength / 2), Vector2.Zero);
ballJoint.CollideConnected = false;
rope.PhysicsEntityJoint = ballJoint;
rope.AttachedEntity.PhysicsBody.FixedRotation = false;
//rope.AttachedEntity.PhysicsBody.Mass = 2f;
}
public void DrawRope(Rope rope)
{
bool first = true;
foreach(var segment in rope.PhysicsSegments)
{
//DrawSphere(segment.Position, segment.Rotation, Rope.JointRadius, true);
DrawRectangle(segment.Position, Rope.Diameter, first ? Rope.Diameter : Rope.SegmentLength, segment.Rotation, true);
first = false;
}
}
public void DrawRope(Rope rope)
{
//var segmentPositions = (from s in rope.PhysicsSegments select s.Position).ToArray();
//var segmentPositions = (from s in rope.PhysicsSegments select s.GetWorldPoint(new Vector2(0, 0.5f))).ToArray();
var segmentPositionsList = (from s in rope.PhysicsSegmentJoints select s.WorldAnchorA).ToList();
segmentPositionsList.Insert(0, rope.AttachedPosition);
segmentPositionsList.Add(rope.AttachedEntity.Position);
var segmentPositions = segmentPositionsList.ToArray();
var triangleCount = (segmentPositions.Length - 1) * 2;
VertexPositionColorTexture[] vpc = new VertexPositionColorTexture[triangleCount * 3];
float u = 0;
for(int i = 0; i < segmentPositions.Length - 1; i++)
{
var p0 = segmentPositions[i + 1];
var p1 = segmentPositions[i];
var d = Vector2.Normalize(p1 - p0);
var n = new Vector2(d.Y, -d.X);
var u0 = u - d.Length() * 0.05f;
var u1 = u + (p1 - p0).Length() + d.Length() * 0.05f;
p0 -= d * 0.05f;
p1 += d * 0.05f;
var t00 = p0 + n * RopeWidth;
var t10 = p1 + n * RopeWidth;
var t01 = p0 - n * RopeWidth;
var t11 = p1 - n * RopeWidth;
vpc[i * 6 + 0].Color = Color.White;
vpc[i * 6 + 0].Position = new Vector3(t11, -1);
vpc[i * 6 + 0].TextureCoordinate = new Vector2(1, u1 / (2f * RopeWidth));
vpc[i * 6 + 1].Color = Color.White;
vpc[i * 6 + 1].Position = new Vector3(t10, -1);
vpc[i * 6 + 1].TextureCoordinate = new Vector2(0, u1 / (2f * RopeWidth));
vpc[i * 6 + 2].Color = Color.White;
vpc[i * 6 + 2].Position = new Vector3(t00, -1);
vpc[i * 6 + 2].TextureCoordinate = new Vector2(0, u0 / (2f * RopeWidth));
vpc[i * 6 + 3].Color = Color.White;
vpc[i * 6 + 3].Position = new Vector3(t01, -1);
vpc[i * 6 + 3].TextureCoordinate = new Vector2(1, u0 / (2f * RopeWidth));
vpc[i * 6 + 4].Color = Color.White;
vpc[i * 6 + 4].Position = new Vector3(t11, -1);
vpc[i * 6 + 4].TextureCoordinate = new Vector2(1, u1 / (2f * RopeWidth));
vpc[i * 6 + 5].Color = Color.White;
vpc[i * 6 + 5].Position = new Vector3(t00, -1);
vpc[i * 6 + 5].TextureCoordinate = new Vector2(0, u0 / (2f * RopeWidth));
u = u1;
}
RopeEffect.World = Matrix.Identity;
RopeEffect.View = Game.Camera.View;
RopeEffect.Projection = Game.Camera.Projection;
RopeEffect.CurrentTechnique.Passes[0].Apply();
GraphicsDevice.SamplerStates[0] = new SamplerState
{
AddressU = TextureAddressMode.Wrap,
AddressV = TextureAddressMode.Wrap
};
GraphicsDevice.DrawUserPrimitives<VertexPositionColorTexture>(PrimitiveType.TriangleList, vpc, 0, triangleCount);
}
