void BodyPair2DSW::solve(float p_step) {
if (!collided)
return;
for (int i = 0; i < contact_count; ++i) {
Contact& c = contacts[i];
cc++;
if (!c.active)
continue;
// Relative velocity at contact
Vector2 crA( -A->get_angular_velocity() * c.rA.y, A->get_angular_velocity() * c.rA.x );
Vector2 crB( -B->get_angular_velocity() * c.rB.y, B->get_angular_velocity() * c.rB.x );
Vector2 dv = B->get_linear_velocity() + crB - A->get_linear_velocity() - crA;
Vector2 crbA( -A->get_biased_angular_velocity() * c.rA.y, A->get_biased_angular_velocity() * c.rA.x );
Vector2 crbB( -B->get_biased_angular_velocity() * c.rB.y, B->get_biased_angular_velocity() * c.rB.x );
Vector2 dbv = B->get_biased_linear_velocity() + crbB - A->get_biased_linear_velocity() - crbA;
real_t vn = dv.dot(c.normal);
real_t vbn = dbv.dot(c.normal);
Vector2 tangent = c.normal.tangent();
real_t vt = dv.dot(tangent);
real_t jbn = (c.bias - vbn)*c.mass_normal;
real_t jbnOld = c.acc_bias_impulse;
c.acc_bias_impulse = MAX(jbnOld + jbn, 0.0f);
Vector2 jb = c.normal * (c.acc_bias_impulse - jbnOld);
A->apply_bias_impulse(c.rA,-jb);
B->apply_bias_impulse(c.rB, jb);
real_t jn = -(c.bounce + vn)*c.mass_normal;
real_t jnOld = c.acc_normal_impulse;
c.acc_normal_impulse = MAX(jnOld + jn, 0.0f);
real_t friction = A->get_friction() * B->get_friction();
real_t jtMax = friction*c.acc_normal_impulse;
real_t jt = -vt*c.mass_tangent;
real_t jtOld = c.acc_tangent_impulse;
c.acc_tangent_impulse = CLAMP(jtOld + jt, -jtMax, jtMax);
Vector2 j =c.normal * (c.acc_normal_impulse - jnOld) + tangent * ( c.acc_tangent_impulse - jtOld );
A->apply_impulse(c.rA,-j);
B->apply_impulse(c.rB, j);
}
}
bool BodyPair2DSW::setup(real_t p_step) {
//cannot collide
if (!A->test_collision_mask(B) || A->has_exception(B->get_self()) || B->has_exception(A->get_self()) || (A->get_mode() <= Physics2DServer::BODY_MODE_KINEMATIC && B->get_mode() <= Physics2DServer::BODY_MODE_KINEMATIC && A->get_max_contacts_reported() == 0 && B->get_max_contacts_reported() == 0)) {
collided = false;
return false;
}
if (A->is_shape_set_as_disabled(shape_A) || B->is_shape_set_as_disabled(shape_B)) {
collided = false;
return false;
}
//use local A coordinates to avoid numerical issues on collision detection
offset_B = B->get_transform().get_origin() - A->get_transform().get_origin();
_validate_contacts();
Vector2 offset_A = A->get_transform().get_origin();
Transform2D xform_Au = A->get_transform().untranslated();
Transform2D xform_A = xform_Au * A->get_shape_transform(shape_A);
Transform2D xform_Bu = B->get_transform();
xform_Bu.elements[2] -= A->get_transform().get_origin();
Transform2D xform_B = xform_Bu * B->get_shape_transform(shape_B);
Shape2DSW *shape_A_ptr = A->get_shape(shape_A);
Shape2DSW *shape_B_ptr = B->get_shape(shape_B);
Vector2 motion_A, motion_B;
if (A->get_continuous_collision_detection_mode() == Physics2DServer::CCD_MODE_CAST_SHAPE) {
motion_A = A->get_motion();
}
if (B->get_continuous_collision_detection_mode() == Physics2DServer::CCD_MODE_CAST_SHAPE) {
motion_B = B->get_motion();
}
//faster to set than to check..
//bool prev_collided=collided;
collided = CollisionSolver2DSW::solve(shape_A_ptr, xform_A, motion_A, shape_B_ptr, xform_B, motion_B, _add_contact, this, &sep_axis);
if (!collided) {
//test ccd (currently just a raycast)
if (A->get_continuous_collision_detection_mode() == Physics2DServer::CCD_MODE_CAST_RAY && A->get_mode() > Physics2DServer::BODY_MODE_KINEMATIC) {
if (_test_ccd(p_step, A, shape_A, xform_A, B, shape_B, xform_B))
collided = true;
}
if (B->get_continuous_collision_detection_mode() == Physics2DServer::CCD_MODE_CAST_RAY && B->get_mode() > Physics2DServer::BODY_MODE_KINEMATIC) {
if (_test_ccd(p_step, B, shape_B, xform_B, A, shape_A, xform_A, true))
collided = true;
}
if (!collided) {
oneway_disabled = false;
return false;
}
}
if (oneway_disabled)
return false;
//if (!prev_collided) {
{
if (A->is_shape_set_as_one_way_collision(shape_A)) {
Vector2 direction = xform_A.get_axis(1).normalized();
bool valid = false;
if (B->get_linear_velocity().dot(direction) >= 0) {
for (int i = 0; i < contact_count; i++) {
Contact &c = contacts[i];
if (!c.reused)
continue;
if (c.normal.dot(direction) < 0)
continue;
valid = true;
break;
}
}
if (!valid) {
collided = false;
oneway_disabled = true;
return false;
}
}
if (B->is_shape_set_as_one_way_collision(shape_B)) {
Vector2 direction = xform_B.get_axis(1).normalized();
bool valid = false;
if (A->get_linear_velocity().dot(direction) >= 0) {
for (int i = 0; i < contact_count; i++) {
Contact &c = contacts[i];
if (!c.reused)
continue;
if (c.normal.dot(direction) < 0)
continue;
valid = true;
break;
}
}
if (!valid) {
collided = false;
oneway_disabled = true;
return false;
}
}
}
real_t max_penetration = space->get_contact_max_allowed_penetration();
real_t bias = 0.3;
if (shape_A_ptr->get_custom_bias() || shape_B_ptr->get_custom_bias()) {
if (shape_A_ptr->get_custom_bias() == 0)
bias = shape_B_ptr->get_custom_bias();
else if (shape_B_ptr->get_custom_bias() == 0)
bias = shape_A_ptr->get_custom_bias();
else
bias = (shape_B_ptr->get_custom_bias() + shape_A_ptr->get_custom_bias()) * 0.5;
}
cc = 0;
real_t inv_dt = 1.0 / p_step;
bool do_process = false;
for (int i = 0; i < contact_count; i++) {
Contact &c = contacts[i];
Vector2 global_A = xform_Au.xform(c.local_A);
Vector2 global_B = xform_Bu.xform(c.local_B);
real_t depth = c.normal.dot(global_A - global_B);
if (depth <= 0 || !c.reused) {
c.active = false;
continue;
}
c.active = true;
#ifdef DEBUG_ENABLED
if (space->is_debugging_contacts()) {
space->add_debug_contact(global_A + offset_A);
space->add_debug_contact(global_B + offset_A);
}
#endif
int gather_A = A->can_report_contacts();
int gather_B = B->can_report_contacts();
c.rA = global_A;
c.rB = global_B - offset_B;
if (gather_A | gather_B) {
//Vector2 crB( -B->get_angular_velocity() * c.rB.y, B->get_angular_velocity() * c.rB.x );
global_A += offset_A;
global_B += offset_A;
if (gather_A) {
Vector2 crB(-B->get_angular_velocity() * c.rB.y, B->get_angular_velocity() * c.rB.x);
A->add_contact(global_A, -c.normal, depth, shape_A, global_B, shape_B, B->get_instance_id(), B->get_self(), crB + B->get_linear_velocity());
}
if (gather_B) {
Vector2 crA(-A->get_angular_velocity() * c.rA.y, A->get_angular_velocity() * c.rA.x);
B->add_contact(global_B, c.normal, depth, shape_B, global_A, shape_A, A->get_instance_id(), A->get_self(), crA + A->get_linear_velocity());
}
}
if ((A->get_mode() <= Physics2DServer::BODY_MODE_KINEMATIC && B->get_mode() <= Physics2DServer::BODY_MODE_KINEMATIC)) {
c.active = false;
collided = false;
continue;
}
// Precompute normal mass, tangent mass, and bias.
real_t rnA = c.rA.dot(c.normal);
real_t rnB = c.rB.dot(c.normal);
real_t kNormal = A->get_inv_mass() + B->get_inv_mass();
kNormal += A->get_inv_inertia() * (c.rA.dot(c.rA) - rnA * rnA) + B->get_inv_inertia() * (c.rB.dot(c.rB) - rnB * rnB);
c.mass_normal = 1.0f / kNormal;
Vector2 tangent = c.normal.tangent();
real_t rtA = c.rA.dot(tangent);
real_t rtB = c.rB.dot(tangent);
real_t kTangent = A->get_inv_mass() + B->get_inv_mass();
kTangent += A->get_inv_inertia() * (c.rA.dot(c.rA) - rtA * rtA) + B->get_inv_inertia() * (c.rB.dot(c.rB) - rtB * rtB);
c.mass_tangent = 1.0f / kTangent;
c.bias = -bias * inv_dt * MIN(0.0f, -depth + max_penetration);
c.depth = depth;
//c.acc_bias_impulse=0;
#ifdef ACCUMULATE_IMPULSES
{
// Apply normal + friction impulse
Vector2 P = c.acc_normal_impulse * c.normal + c.acc_tangent_impulse * tangent;
A->apply_impulse(c.rA, -P);
B->apply_impulse(c.rB, P);
}
#endif
c.bounce = MAX(A->get_bounce(), B->get_bounce());
if (c.bounce) {
Vector2 crA(-A->get_angular_velocity() * c.rA.y, A->get_angular_velocity() * c.rA.x);
Vector2 crB(-B->get_angular_velocity() * c.rB.y, B->get_angular_velocity() * c.rB.x);
Vector2 dv = B->get_linear_velocity() + crB - A->get_linear_velocity() - crA;
c.bounce = c.bounce * dv.dot(c.normal);
}
do_process = true;
}
return do_process;
}