private void Form1_Load(object sender, EventArgs e)
{
sogc = new SimpleOpenGlControl();
sogc.Dock = DockStyle.Fill;
sogc.Paint += new PaintEventHandler(sogc_Paint);
sogc.Resize += new EventHandler(sogc_Resize);
Controls.Add(sogc);
sogc.InitializeContexts();
InitOpenGL(sogc.Size, 1, PointF.Empty);
// Define the gravity vector.
b2Vec2 gravity = new b2Vec2(0.0f, -10.0f);
// Do we want to let bodies sleep?
bool doSleep = true;
// Construct a world object, which will hold and simulate the rigid bodies.
world = new b2World(gravity, doSleep);
// world.SetWarmStarting(true);
{
b2BodyDef bd = new b2BodyDef();
b2Body ground = world.CreateBody(bd);
b2PolygonShape shape = new b2PolygonShape();
shape.SetAsEdge(new b2Vec2(-40.0f, 0.0f), new b2Vec2(40.0f, 0.0f));
ground.CreateFixture(shape, 0.0f);
}
{
float a = 0.5f;
b2CircleShape shape = new b2CircleShape();
shape.m_radius = a;
b2Vec2 x = new b2Vec2(-7.0f, 0.95f);
b2Vec2 y;
b2Vec2 deltaX = new b2Vec2(0, 1.25f);
b2Vec2 deltaY = new b2Vec2(0, 1.25f);
y= deltaY;
for (int j = 0; j < 8; ++j)
{
b2BodyDef bd = new b2BodyDef();
bd.type = b2BodyType.b2_dynamicBody;
bd.position = y;
b2Body body = world.CreateBody(bd);
body.CreateFixture(shape, 5.0f);
y += deltaY;
}
}
GDIDebugThing.instance.SetFlags(EDebugFlags.e_shapeBit);
world.SetDebugDraw(GDIDebugThing.instance);
System.Timers.Timer timer = new System.Timers.Timer();
timer.Interval = 85;
timer.SynchronizingObject = this;
timer.Elapsed += new System.Timers.ElapsedEventHandler(timer_Elapsed);
timer.Start();
}
public Car(
b2World b2world,
double width,
double length,
double[] position,
double angle,
double power,
double max_steer_angle,
double max_speed,
Wheel[] wheels
)
{
this.wheels = wheels;
// /*
// pars is an object with possible attributes:
// width - width of the car in meters
// length - length of the car in meters
// position - starting position of the car, array [x, y] in meters
// angle - starting angle of the car, degrees
// max_steer_angle - maximum angle the wheels turn when steering, degrees
// max_speed - maximum speed of the car, km/h
// power - engine force, in newtons, that is applied to EACH powered wheel
// wheels - wheel definitions: [{x, y, rotatable, powered}}, ...] where
// x is wheel position in meters relative to car body center
// y is wheel position in meters relative to car body center
// revolving - boolean, does this turn rotate when steering?
// powered - is force applied to this wheel when accelerating/braking?
// */
// this.max_steer_angle=pars.max_steer_angle;
// this.max_speed=pars.max_speed;
// this.power=pars.power;
var wheel_angle = 0.0;//keep track of current wheel angle relative to car.
// //when steering left/right, angle will be decreased/increased gradually over 200ms to prevent jerkyness.
//initialize body
var def = new b2BodyDef();
def.type = b2Body.b2_dynamicBody;
def.position = new b2Vec2(position[0], position[1]);
def.angle = angle.DegreesToRadians();
def.linearDamping = 0.55; //gradually reduces velocity, makes the car reduce speed slowly if neither accelerator nor brake is pressed
def.bullet = true; //dedicates more time to collision detection - car travelling at high speeds at low framerates otherwise might teleport through obstacles.
def.angularDamping = 0.3;
this.body = b2world.CreateBody(def);
//initialize shape
var fixdef = new b2FixtureDef();
fixdef.density = 1.0;
fixdef.friction = 0.3; //friction when rubbing agaisnt other shapes
fixdef.restitution = 0.4; //amount of force feedback when hitting something. >0 makes the car bounce off, it's fun!
var fixdef_shape = new b2PolygonShape();
fixdef.shape = fixdef_shape;
fixdef_shape.SetAsBox(width / 2, length / 2);
body.CreateFixture(fixdef);
//initialize wheels
foreach (var item in wheels)
{
item.Initialize(this);
}
//return array of wheels that turn when steering
IEnumerable <Wheel> getRevolvingWheels = from w in wheels where w.revolving select w;
// //return array of powered wheels
IEnumerable <Wheel> getPoweredWheels = from w in wheels where w.powered select w;
#region setSpeed
Action <double> setSpeed = (speed) =>
{
/*
* speed - speed in kilometers per hour
*/
var velocity0 = this.body.GetLinearVelocity();
//Console.WriteLine("car setSpeed velocity0 " + new { velocity0.x, velocity0.y });
var velocity2 = vectors.unit(new[] { velocity0.x, velocity0.y });
//Console.WriteLine("car setSpeed velocity2 " + new { x = velocity2[0], y = velocity2[1] });
var velocity = new b2Vec2(
velocity2[0] * ((speed * 1000.0) / 3600.0),
velocity2[1] * ((speed * 1000.0) / 3600.0)
);
//Console.WriteLine("car setSpeed SetLinearVelocity " + new { velocity.x, velocity.y });
this.body.SetLinearVelocity(velocity);
};
#endregion
#region getSpeedKMH
this.getSpeedKMH = delegate
{
var velocity = this.body.GetLinearVelocity();
var len = vectors.len(new double[] { velocity.x, velocity.y });
return((len / 1000.0) * 3600.0);
};
#endregion
#region getLocalVelocity
Func <double[]> getLocalVelocity = delegate
{
/*
* returns car's velocity vector relative to the car
*/
var retv = this.body.GetLocalVector(this.body.GetLinearVelocityFromLocalPoint(new b2Vec2(0, 0)));
return(new double[] { retv.x, retv.y });
};
#endregion
#region update
this.update = (msDuration) =>
{
#region 1. KILL SIDEWAYS VELOCITY
//kill sideways velocity for all wheels
for (var i = 0; i < wheels.Length; i++)
{
wheels[i].killSidewaysVelocity();
}
#endregion
#region 2. SET WHEEL ANGLE
//calculate the change in wheel's angle for this update, assuming the wheel will reach is maximum angle from zero in 200 ms
var incr = (max_steer_angle / 200.0) * msDuration;
if (steer_right == STEER_RIGHT)
{
wheel_angle = Math.Min(Math.Max(wheel_angle, 0) + incr, max_steer_angle); //increment angle without going over max steer
}
else if (steer_left == STEER_LEFT)
{
wheel_angle = Math.Max(Math.Min(wheel_angle, 0) - incr, -max_steer_angle); //decrement angle without going over max steer
}
else
{
wheel_angle = 0;
}
//update revolving wheels
getRevolvingWheels.WithEach(
w => w.setAngle(wheel_angle)
);
#endregion
#region 3. APPLY FORCE TO WHEELS
var base_vect = new double[2]; //vector pointing in the direction force will be applied to a wheel ; relative to the wheel.
//if accelerator is pressed down and speed limit has not been reached, go forwards
var lessthanlimit = (getSpeedKMH() < max_speed);
var flag1 = (accelerate == ACC_ACCELERATE) && lessthanlimit;
if (flag1)
{
base_vect = new double[] { 0, -1 };
}
else if (accelerate == ACC_BRAKE)
{
//braking, but still moving forwards - increased force
if (getLocalVelocity()[1] < 0)
{
base_vect = new double[] { 0, 1.3 };
}
//going in reverse - less force
else
{
base_vect = new double[] { 0, 0.7 };
}
}
else
{
base_vect[0] = 0;
base_vect[1] = 0;
}
//multiply by engine power, which gives us a force vector relative to the wheel
var fvect = new double[] {
power *base_vect[0],
power *base_vect[1]
};
//apply force to each wheel
getPoweredWheels.WithEachIndex(
(w, i) =>
{
var wp = w.body.GetWorldCenter();
var wf = w.body.GetWorldVector(new b2Vec2(fvect[0], fvect[1]));
//Console.WriteLine("getPoweredWheels ApplyForce #" + i);
w.body.ApplyForce(wf, wp);
}
);
//if going very slow, stop - to prevent endless sliding
var veryslow = (getSpeedKMH() < 4);
var flag2 = veryslow && (accelerate == ACC_NONE);
if (flag2)
{
//Console.WriteLine("setSpeed 0");
setSpeed(0);
}
#endregion
};
#endregion
}
public Wheel()
{
this.Initialize = car =>
{
/*
* wheel object
*
* pars:
*
* car - car this wheel belongs to
* x - horizontal position in meters relative to car's center
* y - vertical position in meters relative to car's center
* width - width in meters
* length - length in meters
* revolving - does this wheel revolve when steering?
* powered - is this wheel powered?
*/
var position = new double[] { x, y };
//this.car=pars.car;
//this.revolving=pars.revolving;
//this.powered=pars.powered;
//initialize body
var def = new b2BodyDef();
def.type = b2Body.b2_dynamicBody;
def.position = car.body.GetWorldPoint(new b2Vec2(position[0], position[1]));
def.angle = car.body.GetAngle();
this.body = b2world.CreateBody(def);
//initialize shape
var fixdef = new b2FixtureDef();
fixdef.density = 1;
fixdef.isSensor = true; //wheel does not participate in collision calculations: resulting complications are unnecessary
var fixdef_shape = new b2PolygonShape();
fixdef.shape = fixdef_shape;
fixdef_shape.SetAsBox(width / 2, length / 2);
body.CreateFixture(fixdef);
var jointdef = new b2RevoluteJointDef();
//create joint to connect wheel to body
if (revolving)
{
jointdef.Initialize(car.body, body, body.GetWorldCenter());
jointdef.enableMotor = false; //we'll be controlling the wheel's angle manually
}
else
{
jointdef.Initialize(car.body, body, body.GetWorldCenter()
//, new b2Vec2(1, 0)
);
jointdef.enableLimit = true;
//jointdef.lowerTranslation = 0;
//jointdef.upperTranslation = 0;
}
b2world.CreateJoint(jointdef);
#region setAngle
this.setAngle +=
(angle) =>
{
this.rotation = angle.DegreesToRadians();
/*
* angle - wheel angle relative to car, in degrees
*/
body.SetAngle(car.body.GetAngle() + angle.DegreesToRadians());
};
#endregion
#region getLocalVelocity
Func <double[]> getLocalVelocity = delegate
{
/*returns get velocity vector relative to car
*/
var res = car.body.GetLocalVector(car.body.GetLinearVelocityFromLocalPoint(new b2Vec2(position[0], position[1])));
return(new double[] { res.x, res.y });
};
#endregion
#region getDirectionVector
Func <double[]> getDirectionVector = delegate
{
/*
* returns a world unit vector pointing in the direction this wheel is moving
*/
if (getLocalVelocity()[1] > 0)
{
return(vectors.rotate(new double[] { 0, 1 }, body.GetAngle()));
}
else
{
return(vectors.rotate(new double[] { 0, -1 }, body.GetAngle()));
}
};
#endregion
#region getKillVelocityVector
Func <double[]> getKillVelocityVector = delegate
{
/*
* substracts sideways velocity from this wheel's velocity vector and returns the remaining front-facing velocity vector
*/
var velocity = body.GetLinearVelocity();
var sideways_axis = getDirectionVector();
var dotprod = vectors.dot(new[] { velocity.x, velocity.y }, sideways_axis);
return(new double[] { sideways_axis[0] * dotprod, sideways_axis[1] * dotprod });
};
#endregion
#region killSidewaysVelocity
this.killSidewaysVelocity = delegate
{
/*
* removes all sideways velocity from this wheels velocity
*/
var kv = getKillVelocityVector();
body.SetLinearVelocity(new b2Vec2(kv[0], kv[1]));
};
#endregion
};
}
private void initPhysics()
{
CCSize s = CCDirector.SharedDirector.WinSize;
var gravity = new b2Vec2(0.0f, -10.0f);
_world = new b2World(gravity);
float debugWidth = s.Width / PTM_RATIO * 2f;
float debugHeight = s.Height / PTM_RATIO * 2f;
CCDraw debugDraw = new CCDraw(new b2Vec2(debugWidth / 2f + 10, s.Height - debugHeight - 10), 2);
debugDraw.AppendFlags(b2DrawFlags.e_shapeBit);
_world.SetDebugDraw(debugDraw);
_world.SetAllowSleeping(true);
_world.SetContinuousPhysics(true);
//m_debugDraw = new GLESDebugDraw( PTM_RATIO );
//world->SetDebugDraw(m_debugDraw);
//uint32 flags = 0;
//flags += b2Draw::e_shapeBit;
// flags += b2Draw::e_jointBit;
// flags += b2Draw::e_aabbBit;
// flags += b2Draw::e_pairBit;
// flags += b2Draw::e_centerOfMassBit;
//m_debugDraw->SetFlags(flags);
// Call the body factory which allocates memory for the ground body
// from a pool and creates the ground box shape (also from a pool).
// The body is also added to the world.
b2BodyDef def = b2BodyDef.Create();
def.allowSleep = true;
def.position = b2Vec2.Zero;
def.type = b2BodyType.b2_staticBody;
b2Body groundBody = _world.CreateBody(def);
groundBody.SetActive(true);
// Define the ground box shape.
// bottom
b2EdgeShape groundBox = new b2EdgeShape();
groundBox.Set(b2Vec2.Zero, new b2Vec2(s.Width / PTM_RATIO, 0));
b2FixtureDef fd = b2FixtureDef.Create();
fd.shape = groundBox;
groundBody.CreateFixture(fd);
// top
groundBox = new b2EdgeShape();
groundBox.Set(new b2Vec2(0, s.Height / PTM_RATIO), new b2Vec2(s.Width / PTM_RATIO, s.Height / PTM_RATIO));
fd.shape = groundBox;
groundBody.CreateFixture(fd);
// left
groundBox = new b2EdgeShape();
groundBox.Set(new b2Vec2(0, s.Height / PTM_RATIO), b2Vec2.Zero);
fd.shape = groundBox;
groundBody.CreateFixture(fd);
// right
groundBox = new b2EdgeShape();
groundBox.Set(new b2Vec2(s.Width / PTM_RATIO, s.Height / PTM_RATIO), new b2Vec2(s.Width / PTM_RATIO, 0));
fd.shape = groundBox;
groundBody.CreateFixture(fd);
// _world.Dump();
}
