public void PlayerUpdateVelocity(cpVect gravity, float damping, float dt)
{
bool jumpState = key.y > 0.0f;
cpVect groundNormal = cpVect.Zero;
mPlayerBody.EachArbiter((arbiter, o) => BodyArbiterIteratorFunc(arbiter, ref groundNormal), null);
grounded = (groundNormal.y > ground);
if (groundNormal.y < ground)
{
remainingBoost = ground;
}
bool boost = (jumpState && remainingBoost > ground);
cpVect g = (boost ? cpVect.Zero : gravity);
mPlayerBody.UpdateVelocity(g, damping, dt);
float target_vx = PLAYER_VELOCITY * key.x;
cpVect surface_v = new cpVect(-target_vx, 0.0f);
mPlayerShape.surfaceV = surface_v;
mPlayerShape.u = (grounded ? PLAYER_GROUND_ACCEL / GRAVITY : ground);
if (!grounded)
{
mPlayerBody.v.x = cp.cpflerpconst(mPlayerBody.v.x, target_vx, PLAYER_AIR_ACCEL * dt);
}
mPlayerBody.v.y = cp.cpfclamp(mPlayerBody.v.y, -FALL_VELOCITY, cp.Infinity);
}
public override void Update(float dt)
{
base.Update(dt);
space.Step(dt);
SetSubTitle("Place objects on the scale to weigh them. The ball marks the shapes it's sitting on.\n");
// Sum the total impulse applied to the scale from all collision pairs in the contact graph.
// If your compiler supports blocks, your life is a little easier.
// You can use the "Block" versions of the functions without needing the callbacks above.
cpVect impulseSum = cpVect.Zero;
scaleStaticBody.EachArbiter(
(a, o) => ScaleIterator(scaleStaticBody, a, ref impulseSum)
, null);
// Force is the impulse divided by the timestep.
float force = cpVect.cpvlength(impulseSum) / dt;
// Weight can be found similarly from the gravity vector.
cpVect g = space.GetGravity(); // cpSpaceGetGravity();
float weight = cpVect.cpvdot(g, impulseSum) / (cpVect.cpvlengthsq(g) * dt);
SetSubTitle(string.Format("Total force: {0}, Total weight: {1}. ", force, weight));
// Highlight and count the number of shapes the ball is touching.
int count = 0;
ballBody.EachArbiter((a, o) => BallIterator(ballBody, a, ref count), null);
SetSubTitle(string.Format("The ball is touching {0} shapes.", count));
CrushingContext crush = new CrushingContext(0.0f, cpVect.Zero);
ballBody.EachArbiter((a, o) => EstimateCrushing(ballBody, a, ref crush), null);
float crushForce = (crush.magnitudeSum - cpVect.cpvlength(crush.vectorSum)) * dt;
if (crushForce > 10.0f)
{
SetSubTitle(string.Format("The ball is being crushed. (f: {0})", crushForce));
}
else
{
SetSubTitle(string.Format("The ball is not being crushed. (f: {0})", crushForce));
}
draw.Clear();
}
public void playerUpdateVelocity(cpBody body, cpVect gravity, float damping, float dt)
{
bool jumpState = (CCMouse.Instance.dblclick);
// Grab the grounding normal from last frame
cpVect groundNormal = cpVect.Zero;
playerBody.EachArbiter(
(arbiter, o) => SelectPlayerGroundNormal(arbiter, ref groundNormal)
, null);
grounded = (groundNormal.y > 0.0f);
if (groundNormal.y < 0.0f)
{
remainingBoost = 0f;
}
// Do a normal-ish update
bool boost = (jumpState && remainingBoost > 0.0f);
cpVect g = (boost ? cpVect.Zero : gravity);
body.UpdateVelocity(g, damping, dt);
// Target horizontal speed for air/ground control
float target_vx = PLAYER_VELOCITY * ChipmunkDemoKeyboard.x;
// Update the surface velocity and friction
// Note that the "feet" move in the opposite direction of the player.
cpVect surface_v = new cpVect(-target_vx, 0.0f);
playerShape.surfaceV = surface_v;
playerShape.u = (grounded ? PLAYER_GROUND_ACCEL / GRAVITY : 0f);
// Apply air control if not grounded
if (!grounded)
{
// Smoothly accelerate the velocity
playerBody.v.x = cp.cpflerpconst(playerBody.v.x, target_vx, PLAYER_AIR_ACCEL * dt);
}
body.v.y = cp.cpfclamp(body.v.y, -FALL_VELOCITY, cp.Infinity);
}
