public Cloth()
{
FixtureDef boxFix = new FixtureDef(new CircleShape(ClothBodySize), 0.2f);
BodyDef boxBod = new BodyDef(BodyType.Dynamic, Vec2.Empty);
boxFix.Filter.GroupIndex = -1;
boxBod.Position = new Vec2(-ClothTotalWidth / 2, 30);
Body bar;
{
bar = m_world.CreateBody(new BodyDef(BodyType.Static, new Vec2(-ClothBodySpacingWidth / 2, 30)));
var fd = new FixtureDef(new PolygonShape((ClothTotalWidth / 2) + ClothBodySpacingWidth, 0.25f));
fd.Filter.GroupIndex = -1;
bar.CreateFixture(fd);
}
for (int y = 0; y < ClothSegmentsHeight; ++y)
{
for (int x = 0; x < ClothSegmentsWidth; ++x)
{
Body body = m_world.CreateBody(boxBod);
boxBod.Position += new Vec2(ClothBodySpacingWidth, 0);
body.CreateFixture(boxFix);
if (y == 0)
{
WeldJointDef wjd = new WeldJointDef();
wjd.Initialize(body, bar, body.WorldCenter);
m_world.CreateJoint(wjd);
}
cloth[x, y] = body;
}
boxBod.Position = new Vec2(-ClothTotalWidth / 2, boxBod.Position.Y - ClothBodySpacingWidth);
}
for (int y = 0; y < ClothSegmentsHeight; ++y)
{
for (int x = 0; x < ClothSegmentsWidth; ++x)
{
Body leftBody, rightBody;
DistanceJointDef djd = new DistanceJointDef();
djd.FrequencyHz = 15 + Rand.RandomFloat(0, 6);
djd.DampingRatio = 0.11f + Rand.RandomFloat(0.01f, 0.15f);
// connect to right
if (x != ClothSegmentsWidth - 1)
{
leftBody = cloth[x, y];
rightBody = cloth[x + 1, y];
djd.Initialize(leftBody, rightBody, leftBody.WorldCenter, rightBody.WorldCenter);
m_world.CreateJoint(djd);
}
// connect to up
if (y != 0)
{
leftBody = cloth[x, y];
rightBody = cloth[x, y - 1];
djd.Initialize(leftBody, rightBody, leftBody.WorldCenter, rightBody.WorldCenter);
m_world.CreateJoint(djd);
}
}
}
}
void CreateLeg(float s, Vec2 wheelAnchor)
{
Vec2 p1 = new Vec2(5.4f * s, -6.1f);
Vec2 p2 = new Vec2(7.2f * s, -1.2f);
Vec2 p3 = new Vec2(4.3f * s, -1.9f);
Vec2 p4 = new Vec2(3.1f * s, 0.8f);
Vec2 p5 = new Vec2(6.0f * s, 1.5f);
Vec2 p6 = new Vec2(2.5f * s, 3.7f);
FixtureDef fd1 = new FixtureDef(), fd2 = new FixtureDef();
fd1.Filter.GroupIndex = fd2.Filter.GroupIndex = -1;
fd1.Density = 1.0f;
fd2.Density = 1.0f;
PolygonShape poly1 = new PolygonShape(), poly2 = new PolygonShape();
if (s > 0.0f)
{
Vec2[] vertices = new Vec2[3];
vertices[0] = p1;
vertices[1] = p2;
vertices[2] = p3;
poly1.Vertices = vertices;
vertices[0] = Vec2.Empty;
vertices[1] = p5 - p4;
vertices[2] = p6 - p4;
poly2.Vertices = vertices;
}
else
{
Vec2[] vertices = new Vec2[3];
vertices[0] = p1;
vertices[1] = p3;
vertices[2] = p2;
poly1.Vertices = vertices;
vertices[0] = Vec2.Empty;
vertices[1] = p6 - p4;
vertices[2] = p5 - p4;
poly2.Vertices = vertices;
}
fd1.Shape = poly1;
fd2.Shape = poly2;
BodyDef bd1 = new BodyDef(), bd2 = new BodyDef();
bd1.BodyType = BodyType.Dynamic;
bd2.BodyType = BodyType.Dynamic;
bd1.Position = m_offset;
bd2.Position = p4 + m_offset;
bd1.AngularDamping = 10.0f;
bd2.AngularDamping = 10.0f;
Body body1 = m_world.CreateBody(bd1);
Body body2 = m_world.CreateBody(bd2);
body1.CreateFixture(fd1);
body2.CreateFixture(fd2);
DistanceJointDef djd = new DistanceJointDef();
// Using a soft distance constraint can reduce some jitter.
// It also makes the structure seem a bit more fluid by
// acting like a suspension system.
djd.DampingRatio = 0.5f;
djd.FrequencyHz = 10.0f;
djd.Initialize(body1, body2, p2 + m_offset, p5 + m_offset);
m_world.CreateJoint(djd);
djd.Initialize(body1, body2, p3 + m_offset, p4 + m_offset);
m_world.CreateJoint(djd);
djd.Initialize(body1, m_wheel, p3 + m_offset, wheelAnchor + m_offset);
m_world.CreateJoint(djd);
djd.Initialize(body2, m_wheel, p6 + m_offset, wheelAnchor + m_offset);
m_world.CreateJoint(djd);
RevoluteJointDef rjd = new RevoluteJointDef();
rjd.Initialize(body2, m_chassis, p4 + m_offset);
m_world.CreateJoint(rjd);
}