static void
gas_preprocess (ELEMENT *ElementPtr)
{
STARSHIP *StarShipPtr;
SDWORD dx, dy;
// Baul's gas now flies forward. Slow down the gas smoothly.
GetCurrentVelocityComponentsSdword (&ElementPtr->velocity, &dx, &dy);
if (dx != 0 || dy != 0)
{
dx = (SDWORD)(dx * 9 / 10);
dy = (SDWORD)(dy * 9 / 10);
SetVelocityComponents (&ElementPtr->velocity, dx, dy);
}
GetElementStarShip (ElementPtr, &StarShipPtr);
// Move to next image frame. (Abusing thrust_wait to slow down the anim.)
if (ElementPtr->thrust_wait > 0)
--ElementPtr->thrust_wait;
else
{
// Abusing thrust_wait to slow down the anim. (Should help performance a bit.)
ElementPtr->thrust_wait = 1;
// This makes the gas animate even if the ships are not moving and the screen is stationary.
ElementPtr->state_flags |= CHANGING;
if (GetFrameIndex (ElementPtr->current.image.frame) >= LAST_DISSOLVE_INDEX
&& GetFrameIndex (ElementPtr->current.image.frame) < LAST_DISSOLVE_INDEX + NUM_EMERGE_FRAMES)
ElementPtr->next.image.frame = IncFrameIndex (ElementPtr->current.image.frame);
else if (GetFrameIndex (ElementPtr->current.image.frame) < LAST_GAS_INDEX - 1)
ElementPtr->next.image.frame = IncFrameIndex (ElementPtr->current.image.frame);
else
ElementPtr->next.image.frame = SetAbsFrameIndex (ElementPtr->current.image.frame, 0);
}
// If enemy ship dies, remove the gas (this prevents game crashing upon enemy ship dying with gas on it).
if ((!(ElementPtr->state_flags & IGNORE_VELOCITY) && ElementPtr->hTarget == 0)
|| StarShipPtr->RaceDescPtr->ship_info.crew_level == 0)
{
ElementPtr->life_span = 0;
ElementPtr->state_flags |= DISAPPEARING;
}
// When the gas has collided with enemy ship, it sticks to the ship until expires.
// (When the gas is sticking to enemy ship, the gas's IGNORE_VELOCITY flag is disabled.)
else if (!(ElementPtr->state_flags & IGNORE_VELOCITY) && !(ElementPtr->state_flags & DISAPPEARING))
{
ELEMENT *eptr;
SIZE offs_x, offs_y;
SBYTE leftOrRight, upOrDown;
COUNT angle, angleCorrect;
static BYTE alignment[NUM_SIDES]={0,0};
// eptr points to enemy ship now.
LockElement (ElementPtr->hTarget, &eptr);
// Make gas's location the same as the enemy ship's.
ElementPtr->next.location = eptr->next.location;
// Randomize the gas's location so every gas cloud doesn't stick to the same place on the enemy ship.
GetElementStarShip (eptr, &StarShipPtr);
angle = (ElementPtr->weapon_element_index) % 16;
alignment[ElementPtr->playerNr] = ElementPtr->weapon_element_index % 4;
if (alignment[ElementPtr->playerNr] == 0)
{
leftOrRight = -1;
upOrDown = 1;
angleCorrect = 0;
}
else if (alignment[ElementPtr->playerNr] == 1)
{
leftOrRight = 1;
upOrDown = -1;
angleCorrect = 0;
}
else if (alignment[ElementPtr->playerNr] == 2)
{
leftOrRight = -1;
upOrDown = 1;
angleCorrect = HALF_CIRCLE / 2;
}
else
{
leftOrRight = 1;
upOrDown = -1;
angleCorrect = HALF_CIRCLE / 2;
}
offs_x = SINE (angle - angleCorrect, (ElementPtr->weapon_element_index % 16) * (5 << RESOLUTION_FACTOR));
offs_y = COSINE (angle - angleCorrect, (ElementPtr->weapon_element_index % 16) * (5 << RESOLUTION_FACTOR));
ElementPtr->next.location.x = ElementPtr->next.location.x + leftOrRight * offs_x;
ElementPtr->next.location.y = ElementPtr->next.location.y + upOrDown * offs_y;
if (ElementPtr->turn_wait)
{
HELEMENT hEffect;
hEffect = AllocElement ();
if (hEffect)
{
// eptr points to the new gas element now.
LockElement (hEffect, &eptr);
eptr->playerNr = ElementPtr->playerNr;
eptr->state_flags = FINITE_LIFE | GASSY_SUBSTANCE | CHANGING;
eptr->life_span = 1;
eptr->thrust_wait = 1;
eptr->weapon_element_index = ElementPtr->weapon_element_index;
eptr->current = eptr->next = ElementPtr->next;
eptr->preprocess_func = gas_preprocess;
eptr->collision_func = gas_collision;
// No need to have death_func here: It carries on from the declaration in gas_collision.
// In fact, if gas_death is put here as death_func, it just messes up the graphics.
SetPrimType (&(GLOBAL (DisplayArray))[eptr->PrimIndex], STAMP_PRIM);
GetElementStarShip (ElementPtr, &StarShipPtr);
SetElementStarShip (eptr, StarShipPtr);
eptr->hTarget = ElementPtr->hTarget;
UnlockElement (hEffect);
PutElement (hEffect);
}
}
UnlockElement (ElementPtr->hTarget);
}
}
static void
thraddash_intelligence (ELEMENT *ShipPtr, EVALUATE_DESC *ObjectsOfConcern,
COUNT ConcernCounter)
{
STARSHIP *StarShipPtr;
EVALUATE_DESC *lpEvalDesc;
lpEvalDesc = &ObjectsOfConcern[ENEMY_SHIP_INDEX];
if (lpEvalDesc->ObjectPtr)
{
SDWORD dx, dy;
GetCurrentVelocityComponentsSdword (
&lpEvalDesc->ObjectPtr->velocity, &dx, &dy
);
if (lpEvalDesc->which_turn > 8
|| (long)dx * dx + (long)dy * dy <=
(long)STATIONARY_SPEED * STATIONARY_SPEED)
lpEvalDesc->MoveState = PURSUE;
else
lpEvalDesc->MoveState = ENTICE;
}
ship_intelligence (ShipPtr, ObjectsOfConcern, ConcernCounter);
GetElementStarShip (ShipPtr, &StarShipPtr);
if (StarShipPtr->special_counter == 0)
{
StarShipPtr->ship_input_state &= ~SPECIAL;
if (ObjectsOfConcern[ENEMY_WEAPON_INDEX].ObjectPtr
&& ObjectsOfConcern[ENEMY_WEAPON_INDEX].MoveState == ENTICE)
{
if ((StarShipPtr->ship_input_state & THRUST)
|| (ShipPtr->turn_wait == 0
&& !(StarShipPtr->ship_input_state & (LEFT | RIGHT)))
|| NORMALIZE_FACING (ANGLE_TO_FACING (
GetVelocityTravelAngle (
&ObjectsOfConcern[ENEMY_WEAPON_INDEX].ObjectPtr->velocity
) + HALF_CIRCLE + OCTANT)
- StarShipPtr->ShipFacing) > ANGLE_TO_FACING (QUADRANT))
StarShipPtr->ship_input_state |= SPECIAL;
}
else if (lpEvalDesc->ObjectPtr)
{
if (lpEvalDesc->MoveState == PURSUE)
{
if (StarShipPtr->RaceDescPtr->ship_info.energy_level >= WEAPON_ENERGY_COST
+ SPECIAL_ENERGY_COST
&& ShipPtr->turn_wait == 0
&& !(StarShipPtr->ship_input_state & (LEFT | RIGHT))
&& (!(StarShipPtr->cur_status_flags & SPECIAL)
|| !(StarShipPtr->cur_status_flags
& (SHIP_AT_MAX_SPEED | SHIP_BEYOND_MAX_SPEED))))
StarShipPtr->ship_input_state |= SPECIAL;
}
else if (lpEvalDesc->MoveState == ENTICE)
{
COUNT direction_angle;
SDWORD delta_x, delta_y;
delta_x = lpEvalDesc->ObjectPtr->next.location.x
- ShipPtr->next.location.x;
delta_y = lpEvalDesc->ObjectPtr->next.location.y
- ShipPtr->next.location.y;
direction_angle = ARCTAN (delta_x, delta_y);
if ((lpEvalDesc->which_turn > 24
&& !(StarShipPtr->ship_input_state & (LEFT | RIGHT)))
|| (lpEvalDesc->which_turn <= 16
&& NORMALIZE_ANGLE (direction_angle
- (FACING_TO_ANGLE (StarShipPtr->ShipFacing) + HALF_CIRCLE)
+ QUADRANT) <= HALF_CIRCLE
&& (lpEvalDesc->which_turn < 12
|| NORMALIZE_ANGLE (direction_angle
- (GetVelocityTravelAngle (
&lpEvalDesc->ObjectPtr->velocity
) + HALF_CIRCLE)
+ (OCTANT + 2)) <= ((OCTANT + 2) << 1))))
StarShipPtr->ship_input_state |= SPECIAL;
}
}
if ((StarShipPtr->ship_input_state & SPECIAL)
&& StarShipPtr->RaceDescPtr->ship_info.energy_level >=
SPECIAL_ENERGY_COST)
StarShipPtr->ship_input_state &= ~THRUST;
}
}
