// -----------------------------------------------------------------------------------------------------------
// add rotational velocity & acceleration
void do_physics_sim_rot(object *obj)
{
vms_angvec tangles;
vms_matrix rotmat,new_orient;
//fix rotdrag_scale;
physics_info *pi;
Assert(FrameTime > 0); //Get MATT if hit this!
pi = &obj->mtype.phys_info;
if (!(pi->rotvel.x || pi->rotvel.y || pi->rotvel.z || pi->rotthrust.x || pi->rotthrust.y || pi->rotthrust.z))
return;
if (obj->mtype.phys_info.drag) {
int count;
vms_vector accel;
fix drag,r,k;
count = FrameTime / FT;
r = FrameTime % FT;
k = fixdiv(r,FT);
drag = (obj->mtype.phys_info.drag*5)/2;
if (obj->mtype.phys_info.flags & PF_USES_THRUST) {
vm_vec_copy_scale(&accel,&obj->mtype.phys_info.rotthrust,fixdiv(f1_0,obj->mtype.phys_info.mass));
while (count--) {
vm_vec_add2(&obj->mtype.phys_info.rotvel,&accel);
vm_vec_scale(&obj->mtype.phys_info.rotvel,f1_0-drag);
}
//do linear scale on remaining bit of time
vm_vec_scale_add2(&obj->mtype.phys_info.rotvel,&accel,k);
vm_vec_scale(&obj->mtype.phys_info.rotvel,f1_0-fixmul(k,drag));
}
else {
fix total_drag=f1_0;
while (count--)
total_drag = fixmul(total_drag,f1_0-drag);
//do linear scale on remaining bit of time
total_drag = fixmul(total_drag,f1_0-fixmul(k,drag));
vm_vec_scale(&obj->mtype.phys_info.rotvel,total_drag);
}
}
//now rotate object
//unrotate object for bank caused by turn
if (obj->mtype.phys_info.turnroll) {
vms_matrix new_pm;
tangles.p = tangles.h = 0;
tangles.b = -obj->mtype.phys_info.turnroll;
vm_angles_2_matrix(&rotmat,&tangles);
vm_matrix_x_matrix(&new_pm,&obj->orient,&rotmat);
obj->orient = new_pm;
}
tangles.p = fixmul(obj->mtype.phys_info.rotvel.x,FrameTime);
tangles.h = fixmul(obj->mtype.phys_info.rotvel.y,FrameTime);
tangles.b = fixmul(obj->mtype.phys_info.rotvel.z,FrameTime);
vm_angles_2_matrix(&rotmat,&tangles);
vm_matrix_x_matrix(&new_orient,&obj->orient,&rotmat);
obj->orient = new_orient;
if (obj->mtype.phys_info.flags & PF_TURNROLL)
set_object_turnroll(obj);
//re-rotate object for bank caused by turn
if (obj->mtype.phys_info.turnroll) {
vms_matrix new_pm;
tangles.p = tangles.h = 0;
tangles.b = obj->mtype.phys_info.turnroll;
vm_angles_2_matrix(&rotmat,&tangles);
vm_matrix_x_matrix(&new_pm,&obj->orient,&rotmat);
obj->orient = new_pm;
}
check_and_fix_matrix(&obj->orient);
}
// -----------------------------------------------------------------------------------------------------------
// add rotational velocity & acceleration
void do_physics_sim_rot(object *obj)
{
vms_angvec tangles;
vms_matrix rotmat,new_orient;
//fix rotdrag_scale;
physics_info *pi;
Assert(FrameTime > 0); //Get MATT if hit this!
pi = &obj->mtype.phys_info;
if (!(pi->rotvel.x || pi->rotvel.y || pi->rotvel.z || pi->rotthrust.x || pi->rotthrust.y || pi->rotthrust.z))
return;
if (obj->mtype.phys_info.drag) {
int count;
vms_vector accel;
fix drag,r,k;
count = FrameTime / FT;
r = FrameTime % FT;
k = fixdiv(r,FT);
drag = (obj->mtype.phys_info.drag*5)/2;
const char ORIGINAL = 0;
const char LINEAR_INTERPOLATION = 1;
const char GEOMETRIC_DRAG = 2;
const char STRATEGY = ORIGINAL;
if (obj->mtype.phys_info.flags & PF_USES_THRUST) {
vm_vec_copy_scale(&accel,&obj->mtype.phys_info.rotthrust,fixdiv(f1_0,obj->mtype.phys_info.mass));
}
if(STRATEGY == ORIGINAL) {
while (count--) {
if (obj->mtype.phys_info.flags & PF_USES_THRUST) {
vm_vec_add2(&obj->mtype.phys_info.rotvel,&accel);
}
vm_vec_scale(&obj->mtype.phys_info.rotvel,f1_0-drag);
}
//do linear scale on remaining bit of time
if (obj->mtype.phys_info.flags & PF_USES_THRUST) {
vm_vec_scale_add2(&obj->mtype.phys_info.rotvel,&accel,k);
}
vm_vec_scale(&obj->mtype.phys_info.rotvel,f1_0-fixmul(k,drag));
} else if (STRATEGY == LINEAR_INTERPOLATION) {
vms_vector target_rotvel;
vm_vec_copy_scale(&target_rotvel, &obj->mtype.phys_info.rotvel, F1_0);
// Target 21.3 FPS -- three iterations
for(int i = 0; i < 3; i++) {
if (obj->mtype.phys_info.flags & PF_USES_THRUST) {
vm_vec_add2(&target_rotvel, &accel);
}
vm_vec_scale(&target_rotvel,f1_0-drag);
}
fix target_frametime = F1_0 / 64 * 3;
fix interpolation_fraction = fixdiv(FrameTime, target_frametime);
vm_vec_sub2(&target_rotvel, &obj->mtype.phys_info.rotvel);
vm_vec_scale(&target_rotvel, interpolation_fraction);
vm_vec_add2(&obj->mtype.phys_info.rotvel, &target_rotvel);
} else if(STRATEGY == GEOMETRIC_DRAG) {
while (count--) {
if (obj->mtype.phys_info.flags & PF_USES_THRUST) {
vm_vec_add2(&obj->mtype.phys_info.rotvel,&accel);
}
vm_vec_scale(&obj->mtype.phys_info.rotvel,f1_0-drag);
}
//do linear scale on remaining bit of time
if (obj->mtype.phys_info.flags & PF_USES_THRUST) {
vm_vec_scale_add2(&obj->mtype.phys_info.rotvel,&accel,k);
}
double target_frametime = 3.0/64.0;
const double fix_offset = 65536.0;
double interpolation_fraction = ((double)(r) / fix_offset) / target_frametime ;
double ddrag = (double)(drag) / fix_offset;
double kdrag = pow((1.0 - ddrag), interpolation_fraction*3);
fix fractional_drag = (fix)(kdrag * fix_offset);
vm_vec_scale(&obj->mtype.phys_info.rotvel,fractional_drag);
//vm_vec_scale(&obj->mtype.phys_info.rotvel,f1_0-fixmul(k,drag));
}
/*
fix k_drag = f1_0-fixmul(k,drag);
if(FrameTime < F1_0/30) {
// Pegged to 30 FPS for now
double fix_offset = (double) F1_0;
double target_framerate = 20.0;
double ddrag = ((double) drag)/fix_offset;
//double target_drag = (1.0-ddrag)*(1.0-ddrag)*(1.0-ddrag*2.0/15.0); // Drag value multiplied by at 30 hz
double target_drag = (1.0-ddrag)*(1.0-ddrag)*(1.0-ddrag)*(1.0-ddrag*2.0/15.0); // Drag value at 20 hz
double frame_pow = 20.0 * ((double)(FrameTime)/fix_offset);
double frame_drag = pow(target_drag, frame_pow);
k_drag = (fix) (frame_drag*fix_offset);
}
if (obj->mtype.phys_info.flags & PF_USES_THRUST) {
vm_vec_copy_scale(&accel,&obj->mtype.phys_info.rotthrust,fixdiv(f1_0,obj->mtype.phys_info.mass));
// CED -- fix this for frame independence!
while (count--) {
vm_vec_add2(&obj->mtype.phys_info.rotvel,&accel);
vm_vec_scale(&obj->mtype.phys_info.rotvel,f1_0-drag);
}
//do linear scale on remaining bit of time
vm_vec_scale_add2(&obj->mtype.phys_info.rotvel,&accel,k);
//vm_vec_scale(&obj->mtype.phys_info.rotvel,f1_0-fixmul(k,drag));
vm_vec_scale(&obj->mtype.phys_info.rotvel,k_drag);
}
else
{
fix total_drag=f1_0;
while (count--)
total_drag = fixmul(total_drag,f1_0-drag);
//do linear scale on remaining bit of time
//total_drag = fixmul(total_drag,f1_0-fixmul(k,drag));
total_drag = fixmul(total_drag,k_drag);
vm_vec_scale(&obj->mtype.phys_info.rotvel,total_drag);
}
*/
}
//now rotate object
//unrotate object for bank caused by turn
if (obj->mtype.phys_info.turnroll) {
vms_matrix new_pm;
tangles.p = tangles.h = 0;
tangles.b = -obj->mtype.phys_info.turnroll;
vm_angles_2_matrix(&rotmat,&tangles);
vm_matrix_x_matrix(&new_pm,&obj->orient,&rotmat);
obj->orient = new_pm;
}
tangles.p = fixmul(obj->mtype.phys_info.rotvel.x,FrameTime);
tangles.h = fixmul(obj->mtype.phys_info.rotvel.y,FrameTime);
tangles.b = fixmul(obj->mtype.phys_info.rotvel.z,FrameTime);
vm_angles_2_matrix(&rotmat,&tangles);
vm_matrix_x_matrix(&new_orient,&obj->orient,&rotmat);
obj->orient = new_orient;
if (obj->mtype.phys_info.flags & PF_TURNROLL)
set_object_turnroll(obj);
//re-rotate object for bank caused by turn
if (obj->mtype.phys_info.turnroll) {
vms_matrix new_pm;
tangles.p = tangles.h = 0;
tangles.b = obj->mtype.phys_info.turnroll;
vm_angles_2_matrix(&rotmat,&tangles);
vm_matrix_x_matrix(&new_pm,&obj->orient,&rotmat);
obj->orient = new_pm;
}
check_and_fix_matrix(&obj->orient);
}
