static void
playerUpdateVelocity(cpBody *body, cpVect gravity, cpFloat damping, cpFloat dt)
{
int jumpState = (ChipmunkDemoKeyboard.y > 0.0f);
// Grab the grounding normal from last frame
cpVect groundNormal = cpvzero;
cpBodyEachArbiter(playerBody, (cpBodyArbiterIteratorFunc)SelectPlayerGroundNormal, &groundNormal);
grounded = (groundNormal.y > 0.0);
if(groundNormal.y < 0.0f) remainingBoost = 0.0f;
// Do a normal-ish update
cpBool boost = (jumpState && remainingBoost > 0.0f);
cpVect g = (boost ? cpvzero : gravity);
cpBodyUpdateVelocity(body, g, damping, dt);
// Target horizontal speed for air/ground control
cpFloat 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 = cpv(-target_vx, 0.0);
playerShape->surfaceV = surface_v;
playerShape->u = (grounded ? PLAYER_GROUND_ACCEL/GRAVITY : 0.0);
// Apply air control if not grounded
if(!grounded){
// Smoothly accelerate the velocity
playerBody->v.x = cpflerpconst(playerBody->v.x, target_vx, PLAYER_AIR_ACCEL*dt);
}
body->v.y = cpfclamp(body->v.y, -FALL_VELOCITY, INFINITY);
}
// set gravity (of previously chosen objects) to point towards black holes
void orbit(cpBody * body, cpVect gravity, cpFloat damping, cpFloat dt)
{
extern struct objnode objroot[];
struct objnode *objx;
struct cpBody *hole;
cpVect bpos, hpos, unitv, gvect;
cpFloat hmass, g, distsq;
objx = objroot;
while ((objx = objx->next) != NULL) {
if (objx->bhole == true && objx->b != body) {
hole = objx->b;
bpos = cpBodyGetPos(body);
hpos = cpBodyGetPos(hole);
distsq = cpvdistsq(hpos, bpos);
distsq = (distsq == 0) ? 1e-50 : distsq; // don't divide by zero
hmass = cpBodyGetMass(hole);
g = hmass * BGRAV * (1 / distsq);
g = (distsq < RDSQ) ? g * -REPFS : g; // shoot close balls away
unitv = cpvmult(cpvsub(hpos, bpos), (1 / sqrt(distsq)));
gvect = cpvmult(unitv, g);
cpBodyUpdateVelocity(body, gvect, damping, dt);
}
}
}
static void
playerUpdateVelocity(cpBody *body, cpVect gravity, cpFloat damping, cpFloat dt)
{
cpBodyUpdateVelocity(body, gravity, damping, dt);
body->v.y = cpfmax(body->v.y, -700);
body->v.x = cpfclamp(body->v.x, -400, 400);
}
static void
planetGravityVelocityFunc(cpBody *body, cpVect gravity, cpFloat damping, cpFloat dt)
{
// Gravitational acceleration is proportional to the inverse square of
// distance, and directed toward the origin. The central planet is assumed
// to be massive enough that it affects the satellites but not vice versa.
cpVect p = cpBodyGetPosition(body);
cpFloat sqdist = cpvlengthsq(p);
cpVect g = cpvmult(p, -gravityStrength / (sqdist * cpfsqrt(sqdist)));
cpBodyUpdateVelocity(body, g, damping, dt);
}
static void internalBodyUpdateVelocity(cpBody *body, cpVect gravity, cpFloat damping, cpFloat dt)
{
cpBodyUpdateVelocity(body, cpvzero, damping, dt);
// Skip kinematic bodies.
if(cpBodyGetType(body) == CP_BODY_TYPE_KINEMATIC) return;
cpAssertSoft(body->m > 0.0f && body->i > 0.0f, "Body's mass and moment must be positive to simulate. (Mass: %f Moment: f)", body->m, body->i);
cocos2d::PhysicsBody *physicsBody = static_cast<cocos2d::PhysicsBody*>(body->userData);
if(physicsBody->isGravityEnabled())
body->v = cpvclamp(cpvadd(cpvmult(body->v, damping), cpvmult(cpvadd(gravity, cpvmult(body->f, body->m_inv)), dt)), physicsBody->getVelocityLimit());
else
body->v = cpvclamp(cpvadd(cpvmult(body->v, damping), cpvmult(cpvmult(body->f, body->m_inv), dt)), physicsBody->getVelocityLimit());
cpFloat w_limit = physicsBody->getAngularVelocityLimit();
body->w = cpfclamp(body->w*damping + body->t*body->i_inv*dt, -w_limit, w_limit);
// Reset forces.
body->f = cpvzero;
//to check body sanity
cpBodySetTorque(body, 0.0f);
}
void cBody::UpdateVelocity( cVect gravity, cpFloat damping, cpFloat dt ) {
cpBodyUpdateVelocity( mBody, tocpv( gravity ), damping, dt );
}
void bmx_cpbody_updatevelocity(cpBody * body, cpVect * gravity, cpFloat damping, cpFloat dt) {
cpBodyUpdateVelocity(body, *gravity, damping, dt);
}
static inline void cpBodyUpdateVelocityWithoutGravity(cpBody *body, cpVect gravity, cpFloat damping, cpFloat dt)
{
cpBodyUpdateVelocity(body, cpvzero, damping, dt);
}
// From cpBody.h
void wrBodyUpdateVelocity(cpBody *b, cpVect *g, cpFloat d, cpFloat dt) {
cpBodyUpdateVelocity(b, *g, d, dt);
}
static VALUE
rb_cpBodyUpdateVelocity(VALUE self, VALUE g, VALUE dmp, VALUE dt) {
cpBodyUpdateVelocity(BODY(self), *VGET(g), NUM2DBL(dmp), NUM2DBL(dt));
return self;
}
void Body::updateVelocity(const cp::Vect& gravity,cpFloat damping,cpFloat dt)
{
cpBodyUpdateVelocity(body,gravity,damping,dt);
}
