// check whether a ship is in range of a stargate -----------------------------
//
PRIVATE
int ShipInStargateRange( Stargate *stargate, ShipObject *ship, geomv_t range )
{
ASSERT( stargate != NULL );
ASSERT( ship != NULL );
//NOTE:
// the ship is treated as a sphere for activation
// range detection.
Vector3 gatenormal;
FetchZVector( stargate->ObjPosition, &gatenormal );
Vertex3 gatepos;
FetchTVector( stargate->ObjPosition, &gatepos );
Vertex3 shippos;
FetchTVector( ship->ObjPosition, &shippos );
geomv_t shipdot = -DOT_PRODUCT( &gatenormal, &shippos );
geomv_t gatedot = -DOT_PRODUCT( &gatenormal, &gatepos );
geomv_t distance = shipdot - gatedot;
// bounding sphere touching in negative halfspace is still ok
distance += ship->BoundingSphere;
// not in range if ship in wrong halfspace
if ( GEOMV_NEGATIVE( distance ) ) {
return FALSE;
}
// in range if ship bounding sphere intersects gate range hemisphere
range += ship->BoundingSphere * 2;
return ( distance < range );
}
// check whether a ship is in jump range of a stargate ------------------------
//
PRIVATE
int ShipInStargateJumpRange( Stargate *stargate, ShipObject *ship, geomv_t range )
{
ASSERT( stargate != NULL );
ASSERT( ship != NULL );
//NOTE:
// the ship is treated as a point for jump
// range detection.
Vector3 gatenormal;
FetchZVector( stargate->ObjPosition, &gatenormal );
Vertex3 gatepos;
FetchTVector( stargate->ObjPosition, &gatepos );
Vertex3 shippos;
FetchTVector( ship->ObjPosition, &shippos );
geomv_t shipdot = -DOT_PRODUCT( &gatenormal, &shippos );
geomv_t gatedot = -DOT_PRODUCT( &gatenormal, &gatepos );
geomv_t distance = shipdot - gatedot;
// not in range if ship in wrong halfspace
if ( GEOMV_NEGATIVE( distance ) ) {
return FALSE;
}
// check whether inside of boundingsphere around stargate
Vector3 stargate_ship;
VECSUB( &stargate_ship, &shippos, &gatepos );
geomv_t stargate_ship_len = VctLenX( &stargate_ship );
if ( stargate_ship_len > stargate->BoundingSphere ) {
return FALSE;
}
// inside the activation distance/range ?
if ( distance < range ) {
Vector3 shipnormal;
FetchZVector( ship->ObjPosition, &shipnormal );
// ship must be flying approximately head-on into the gate
//FIXME: cone_angle like for teleporter
geomv_t dirdot = DOT_PRODUCT( &gatenormal, &shipnormal );
return ( dirdot > FLOAT_TO_GEOMV( 0.7f ) );
}
return FALSE;
}
// collision detection helper function ----------------------------------------
//
int G_CollDet::_CheckShipProjectileDisjoint()
{
// extend sphere for point sampling
geomv_t hugesphere = bd_sphere * CONSERVATIVE_POINTSAMPLE_EXPANSION;
// vector to center
Vector3 vectest;
vectest.X = obj_pos.X - test_pos.X;
vectest.Y = obj_pos.Y - test_pos.Y;
vectest.Z = obj_pos.Z - test_pos.Z;
// check enlarged vicinity for early-out
if ( vectest.X >= hugesphere )
return TRUE;
if ( vectest.Y >= hugesphere )
return TRUE;
if ( vectest.Z >= hugesphere )
return TRUE;
hugesphere = -hugesphere;
if ( vectest.X <= hugesphere )
return TRUE;
if ( vectest.Y <= hugesphere )
return TRUE;
if ( vectest.Z <= hugesphere )
return TRUE;
// test shield (bounding sphere)
if ( test_shield ) {
// squared distance to current position
geomv_t vectestl2 = DOT_PRODUCT( &vectest, &vectest );
// trivial intersect
if ( vectestl2 < bd_sphere2 )
return FALSE;
// squared distance to previous position
Vector3 vecprev;
vecprev.X = obj_pos.X - prev_pos.X;
vecprev.Y = obj_pos.Y - prev_pos.Y;
vecprev.Z = obj_pos.Z - prev_pos.Z;
geomv_t vecprevl2 = DOT_PRODUCT( &vecprev, &vecprev );
// trivial intersect
if ( vecprevl2 < bd_sphere2 )
return FALSE;
// calc nearest point on line to center
Vector3 vecline;
vecline.X = test_pos.X - prev_pos.X;
vecline.Y = test_pos.Y - prev_pos.Y;
vecline.Z = test_pos.Z - prev_pos.Z;
geomv_t scaledt = DOT_PRODUCT( &vecline, &vecprev );
// ray pointing away from sphere?
if ( GEOMV_NEGATIVE( scaledt ) )
return TRUE;
// ray not yet at the sphere?
geomv_t veclinel2 = DOT_PRODUCT( &vecline, &vecline );
if ( scaledt >= veclinel2 )
return TRUE;
ASSERT( veclinel2 > GEOMV_VANISHING );
// calc squared distance of nearest point
geomv_t dot2 = GEOMV_MUL( scaledt, scaledt );
geomv_t tlen2 = GEOMV_DIV( dot2, veclinel2 );
//NOTE:
// the actual point of impact could now be
// easily calculated without a sqrt().
// collision if nearest point inside
return ( ( vecprevl2 - tlen2 ) >= bd_sphere2 );
} else {
ASSERT( FALSE );
/*
// shield is down: test actual object
#ifdef CHECK_BOX_BEFORE_BSP_COLLISION
// clip lineseg into box
geomv_t isect;
geomv_t seglen;
geomv_t vtx0t = GEOMV_0;
geomv_t vtx1t = GEOMV_1;
int collside = -1;
static geomv_t vanish = FLOAT_TO_GEOMV( 0.00001 );
// cull/clip against +Z
geomv_t curax = obj_pos.Z + bd_sphere;
geomv_t dist0 = prev_pos.Z - curax;
geomv_t dist1 = test_pos.Z - curax;
dword outcode = ( ( DW32( dist0 ) & 0x80000000 ) >> 1 ) |
( DW32( dist1 ) & 0x80000000 );
// both outside?
if ( outcode == 0x00000000 )
return TRUE;
// at least one outside?
if ( outcode != 0xc0000000 ) {
if ( outcode == 0x40000000 ) {
// v0 inside, v1 outside
ABS_GEOMV( dist0 );
seglen = dist0 + dist1;
if ( seglen <= vanish )
return TRUE;
vtx1t = GEOMV_DIV( dist0, seglen );
} else {
// v0 outside, v1 inside
ABS_GEOMV( dist1 );
seglen = dist0 + dist1;
if ( seglen <= vanish )
return TRUE;
vtx0t = GEOMV_DIV( dist0, seglen );
collside = 0;
}
}
#define AXIAL_CLIP_T(s) { \
\
outcode = ( ( DW32( dist0 ) & 0x80000000 ) >> 1 ) | \
( DW32( dist1 ) & 0x80000000 ); \
if ( outcode == 0x00000000 ) \
return TRUE; \
if ( outcode != 0xc0000000 ) { \
if ( outcode == 0x40000000 ) { \
ABS_GEOMV( dist0 ); \
seglen = dist0 + dist1; \
if ( seglen <= vanish ) \
return TRUE; \
isect = GEOMV_DIV( dist0, seglen ); \
if ( isect <= vtx0t ) \
return TRUE; \
if ( isect < vtx1t ) \
vtx1t = isect; \
} else { \
ABS_GEOMV( dist1 ); \
seglen = dist0 + dist1; \
if ( seglen <= vanish ) \
return TRUE; \
isect = GEOMV_DIV( dist0, seglen ); \
if ( isect >= vtx1t ) \
return TRUE; \
if ( isect > vtx0t ) { \
vtx0t = isect; \
collside = (s); \
} \
} \
} \
}
// cull/clip against -Z
curax = obj_pos.Z - bd_sphere;
dist0 = curax - prev_pos.Z;
dist1 = curax - test_pos.Z;
AXIAL_CLIP_T( 1 );
// cull/clip against +X
curax = obj_pos.X + bd_sphere;
dist0 = prev_pos.X - curax;
dist1 = test_pos.X - curax;
AXIAL_CLIP_T( 2 );
// cull/clip against -X
curax = obj_pos.X - bd_sphere;
dist0 = curax - prev_pos.X;
dist1 = curax - test_pos.X;
AXIAL_CLIP_T( 3 );
// cull/clip against +Y
curax = obj_pos.Y + bd_sphere;
dist0 = prev_pos.Y - curax;
dist1 = test_pos.Y - curax;
AXIAL_CLIP_T( 4 );
// cull/clip against -Y
curax = obj_pos.Y - bd_sphere;
dist0 = curax - prev_pos.Y;
dist1 = curax - test_pos.Y;
AXIAL_CLIP_T( 5 );
//NOTE:
// collside now contains the code of the collider side
// (-1 means the lineseg starts in the bounding box)
//TODO:
// use already clipped segment in BSP test?
#endif // CHECK_BOX_BEFORE_BSP_COLLISION
// test actual object (polygon accurate)
// transform line vertices into object-space
CalcOrthoInverse( cur_ship->ObjPosition, DestXmatrx );
Vertex3 v0;
MtxVctMUL( DestXmatrx, &prev_pos, &v0 );
Vertex3 v1;
MtxVctMUL( DestXmatrx, &test_pos, &v1 );
// assume collision if no bsp tree
CullBSPNode *node = cur_ship->AuxBSPTree;
if ( node == NULL )
return FALSE;
dword nodeid = 0;
geomv_t impact_t;
int collided = BSP_FindColliderLine( node, &v0, &v1, &nodeid, &impact_t );
// no collision?
if ( !collided )
return TRUE;
// react only if not started in solid leaf
if ( nodeid > 0 ) {
// fetch collider
node = &cur_ship->AuxBSPTree[ nodeid ];
// calc collision position (object-space)
v1.X -= v0.X;
v1.Y -= v0.Y;
v1.Z -= v0.Z;
v1.X = v0.X + GEOMV_MUL( v1.X, impact_t );
v1.Y = v0.Y + GEOMV_MUL( v1.Y, impact_t );
v1.Z = v0.Z + GEOMV_MUL( v1.Z, impact_t );
// create hull impact particles
SFX_HullImpact( cur_ship, &v1, &node->plane );
}
// disable shield
test_shield = FALSE;
*/
}
return FALSE;
}
