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projectile.cpp
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/*
This file is part of Warzone 2100.
Copyright (C) 1999-2004 Eidos Interactive
Copyright (C) 2005-2012 Warzone 2100 Project
Warzone 2100 is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
Warzone 2100 is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with Warzone 2100; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
/***************************************************************************/
/*
* Projectile functions
*
*/
/***************************************************************************/
#include <string.h>
#include "lib/framework/frame.h"
#include "lib/framework/trig.h"
#include "lib/gamelib/gtime.h"
#include "objects.h"
#include "move.h"
#include "action.h"
#include "combat.h"
#include "effects.h"
#include "map.h"
#include "lib/sound/audio_id.h"
#include "lib/sound/audio.h"
#include "anim_id.h"
#include "projectile.h"
#include "visibility.h"
#include "lib/script/script.h"
#include "scripttabs.h"
#include "scriptcb.h"
#include "group.h"
#include "cmddroid.h"
#include "feature.h"
#include "lib/ivis_opengl/piestate.h"
#include "loop.h"
// FIXME Direct iVis implementation include!
#include "lib/ivis_opengl/piematrix.h"
#include "scores.h"
#include "display3d.h"
#include "display.h"
#include "multiplay.h"
#include "multistat.h"
#include "mapgrid.h"
#include "random.h"
#include <algorithm>
#include <functional>
#define VTOL_HITBOX_MODIFICATOR 100
#define HOMINGINDIRECT_HEIGHT_MIN 200
#define HOMINGINDIRECT_HEIGHT_MAX 450
struct INTERVAL
{
int begin, end; // Time 1 = 0, time 2 = 1024. Or begin >= end if empty.
};
// Watermelon:they are from droid.c
/* The range for neighbouring objects */
#define PROJ_NEIGHBOUR_RANGE (TILE_UNITS*4)
// used to create a specific ID for projectile objects to facilitate tracking them.
static const UDWORD ProjectileTrackerID = 0xdead0000;
/* The list of projectiles in play */
static std::vector<PROJECTILE *> psProjectileList;
/* The next projectile to give out in the proj_First / proj_Next methods */
static ProjectileIterator psProjectileNext;
/***************************************************************************/
// the last unit that did damage - used by script functions
BASE_OBJECT *g_pProjLastAttacker;
/***************************************************************************/
struct ObjectShape
{
ObjectShape() {}
ObjectShape(int radius) : isRectangular(false), size(radius, radius) {}
ObjectShape(int width, int breadth) : isRectangular(true), size(width, breadth) {}
ObjectShape(Vector2i widthBreadth) : isRectangular(true), size(widthBreadth) {}
int radius() const { return size.x; }
bool isRectangular; ///< True if rectangular, false if circular.
Vector2i size; ///< x == y if circular.
};
static ObjectShape establishTargetShape(BASE_OBJECT *psTarget);
static void proj_ImpactFunc( PROJECTILE *psObj );
static void proj_PostImpactFunc( PROJECTILE *psObj );
static void proj_checkBurnDamage(PROJECTILE *psProj);
static int32_t objectDamage(BASE_OBJECT *psObj, unsigned damage, WEAPON_CLASS weaponClass, WEAPON_SUBCLASS weaponSubClass, unsigned impactTime, bool isDamagePerSecond);
static inline void setProjectileDestination(PROJECTILE *psProj, BASE_OBJECT *psObj)
{
aiObjectAddExpectedDamage(psProj->psDest, -psProj->expectedDamageCaused); // The old target shouldn't be expecting any more damage from this projectile.
psProj->psDest = psObj;
aiObjectAddExpectedDamage(psProj->psDest, psProj->expectedDamageCaused); // Let the new target know to say its prayers.
}
/***************************************************************************/
bool gfxVisible(PROJECTILE *psObj)
{
// Already know it is visible
if (psObj->bVisible)
{
return true;
}
// You fired it
if (psObj->player == selectedPlayer)
{
return true;
}
// Someone elses structure firing at something you can't see
if (psObj->psSource != NULL
&& !psObj->psSource->died
&& psObj->psSource->type == OBJ_STRUCTURE
&& psObj->psSource->player != selectedPlayer
&& (psObj->psDest == NULL
|| psObj->psDest->died
|| !psObj->psDest->visible[selectedPlayer]))
{
return false;
}
// Something you cannot see firing at a structure that isn't yours
if (psObj->psDest != NULL
&& !psObj->psDest->died
&& psObj->psDest->type == OBJ_STRUCTURE
&& psObj->psDest->player != selectedPlayer
&& (psObj->psSource == NULL
|| !psObj->psSource->visible[selectedPlayer]))
{
return false;
}
// You can see the source
if (psObj->psSource != NULL
&& !psObj->psSource->died
&& psObj->psSource->visible[selectedPlayer])
{
return true;
}
// You can see the destination
if (psObj->psDest != NULL
&& !psObj->psDest->died
&& psObj->psDest->visible[selectedPlayer])
{
return true;
}
return false;
}
/***************************************************************************/
bool
proj_InitSystem( void )
{
psProjectileList.clear();
psProjectileNext = psProjectileList.end();
return true;
}
/***************************************************************************/
// Clean out all projectiles from the system, and properly decrement
// all reference counts.
void
proj_FreeAllProjectiles( void )
{
psProjectileList.clear();
psProjectileNext = psProjectileList.end();
}
/***************************************************************************/
bool
proj_Shutdown( void )
{
proj_FreeAllProjectiles();
return true;
}
/***************************************************************************/
// Reset the first/next methods, and give out the first projectile in the list.
PROJECTILE *
proj_GetFirst( void )
{
psProjectileNext = psProjectileList.begin();
return psProjectileNext != psProjectileList.end()? *psProjectileNext : NULL;
}
/***************************************************************************/
// Get the next projectile
PROJECTILE *
proj_GetNext( void )
{
++psProjectileNext;
return psProjectileNext != psProjectileList.end()? *psProjectileNext : NULL;
}
/***************************************************************************/
/*
* Relates the quality of the attacker to the quality of the victim.
* The value returned satisfies the following inequality: 0.5 <= ret/65536 <= 2.0
*/
static uint32_t qualityFactor(DROID *psAttacker, DROID *psVictim)
{
uint32_t powerRatio = (uint64_t)65536 * calcDroidPower(psVictim) / calcDroidPower(psAttacker);
uint32_t pointsRatio = (uint64_t)65536 * calcDroidPoints(psVictim) / calcDroidPoints(psAttacker);
CLIP(powerRatio, 65536/2, 65536*2);
CLIP(pointsRatio, 65536/2, 65536*2);
return (powerRatio + pointsRatio) / 2;
}
// update the kills after a target is damaged/destroyed
static void proj_UpdateKills(PROJECTILE *psObj, int32_t experienceInc)
{
DROID *psDroid;
BASE_OBJECT *psSensor;
CHECK_PROJECTILE(psObj);
if (psObj->psSource == NULL || (psObj->psDest && psObj->psDest->type == OBJ_FEATURE)
|| (psObj->psDest && psObj->psSource->player == psObj->psDest->player)) // no exp for friendly fire
{
return;
}
// If experienceInc is negative then the target was killed
if (bMultiPlayer && experienceInc < 0)
{
updateMultiStatsKills(psObj->psDest, psObj->psSource->player);
}
// Since we are no longer interested if it was killed or not, abs it
experienceInc = abs(experienceInc);
if (psObj->psSource->type == OBJ_DROID) /* update droid kills */
{
psDroid = (DROID *) psObj->psSource;
// If it is 'droid-on-droid' then modify the experience by the Quality factor
// Only do this in MP so to not un-balance the campaign
if (psObj->psDest != NULL
&& psObj->psDest->type == OBJ_DROID
&& bMultiPlayer)
{
// Modify the experience gained by the 'quality factor' of the units
experienceInc = (uint64_t)experienceInc * qualityFactor(psDroid, (DROID *)psObj->psDest) / 65536;
}
ASSERT_OR_RETURN(, 0 <= experienceInc && experienceInc < (int)(2.1*65536), "Experience increase out of range");
psDroid->experience += experienceInc;
cmdDroidUpdateKills(psDroid, experienceInc);
psSensor = orderStateObj(psDroid, DORDER_FIRESUPPORT);
if (psSensor
&& psSensor->type == OBJ_DROID)
{
((DROID *)psSensor)->experience += experienceInc;
}
}
else if (psObj->psSource->type == OBJ_STRUCTURE)
{
ASSERT_OR_RETURN(, 0 <= experienceInc && experienceInc < (int)(2.1*65536), "Experience increase out of range");
// See if there was a command droid designating this target
psDroid = cmdDroidGetDesignator(psObj->psSource->player);
if (psDroid != NULL
&& psDroid->action == DACTION_ATTACK
&& psDroid->psActionTarget[0] == psObj->psDest)
{
psDroid->experience += experienceInc;
}
}
}
/***************************************************************************/
void _syncDebugProjectile(const char *function, PROJECTILE const *psProj, char ch)
{
int list[] =
{
ch,
psProj->player,
psProj->pos.x, psProj->pos.y, psProj->pos.z,
psProj->rot.direction, psProj->rot.pitch, psProj->rot.roll,
psProj->state,
(int)psProj->expectedDamageCaused,
(int)psProj->psDamaged.size(),
};
_syncDebugIntList(function, "%c projectile = p%d;pos(%d,%d,%d),rot(%d,%d,%d),state%d,expectedDamageCaused%d,numberDamaged%u", list, ARRAY_SIZE(list));
}
static int32_t randomVariation(int32_t val)
{
// Up to ±5% random variation.
return (int64_t)val*(95000 + gameRand(10001))/100000;
}
int32_t projCalcIndirectVelocities(const int32_t dx, const int32_t dz, int32_t v, int32_t *vx, int32_t *vz, int min_angle)
{
// Find values of vx and vz, which solve the equations:
// dz = -1/2 g t² + vz t
// dx = vx t
// v² = vx² + vz²
// Increases v, if needed for there to be a solution. Decreases v, if needed for vz > 0.
// Randomly changes v by up to 2.5%, so the shots don't all follow the same path.
const int32_t g = ACC_GRAVITY; // In units/s².
int32_t a = randomVariation(v*v) - dz*g; // In units²/s².
uint64_t b = g*g*((uint64_t)dx*dx + (uint64_t)dz*dz); // In units⁴/s⁴. Casting to uint64_t does sign extend the int32_t.
int64_t c = (uint64_t)a*a - b; // In units⁴/s⁴.
if (c < 0)
{
// Must increase velocity, target too high. Find the smallest possible a (which corresponds to the smallest possible velocity).
a = i64Sqrt(b) + 1; // Still in units²/s². Adding +1, since i64Sqrt rounds down.
c = (uint64_t)a*a - b; // Still in units⁴/s⁴. Should be 0, plus possible rounding errors.
}
int32_t t = MAX(1, iSqrt(2*(a - i64Sqrt(c)))*(GAME_TICKS_PER_SEC/g)); // In ticks. Note that a - √c ≥ 0, since c ≤ a². Try changing the - to +, and watch the mini-rockets.
*vx = dx*GAME_TICKS_PER_SEC/t; // In units/sec.
*vz = dz*GAME_TICKS_PER_SEC/t + g*t/(2*GAME_TICKS_PER_SEC); // In units/sec.
STATIC_ASSERT(GAME_TICKS_PER_SEC/ACC_GRAVITY*ACC_GRAVITY == GAME_TICKS_PER_SEC); // On line that calculates t, must cast iSqrt to uint64_t, and remove brackets around TICKS_PER_SEC/g, if changing ACC_GRAVITY.
if (*vz < 0)
{
// Don't want to shoot downwards, reduce velocity and let gravity take over.
t = MAX(1, i64Sqrt(-2*dz*(uint64_t)GAME_TICKS_PER_SEC*GAME_TICKS_PER_SEC/g)); // Still in ticks.
*vx = dx*GAME_TICKS_PER_SEC/t; // Still in units/sec.
*vz = 0; // Still in units/sec. (Wouldn't really matter if it was pigeons/inch, since it's 0 anyway.)
}
/* CorvusCorax: Check against min_angle */
if (iAtan2(*vz, *vx) < min_angle)
{
/* set pitch to pass terrain */
// tan(min_angle)=mytan/65536
int64_t mytan = ((int64_t)iSin(min_angle)*65536)/iCos(min_angle);
t = MAX(1, i64Sqrt(2*((int64_t)dx*mytan - dz*65536)*(int64_t)GAME_TICKS_PER_SEC*GAME_TICKS_PER_SEC/(int64_t)(g*65536))); // Still in ticks.
*vx = dx*GAME_TICKS_PER_SEC/t;
// mytan=65536*vz/vx
*vz = (mytan*(*vx))/65536;
}
return t;
}
bool proj_SendProjectile(WEAPON *psWeap, SIMPLE_OBJECT *psAttacker, int player, Vector3i target, BASE_OBJECT *psTarget, bool bVisible, int weapon_slot)
{
return proj_SendProjectileAngled(psWeap, psAttacker, player, target, psTarget, bVisible, weapon_slot, 0, gameTime - 1);
}
bool proj_SendProjectileAngled(WEAPON *psWeap, SIMPLE_OBJECT *psAttacker, int player, Vector3i target, BASE_OBJECT *psTarget, bool bVisible, int weapon_slot, int min_angle, unsigned fireTime)
{
WEAPON_STATS *psStats = &asWeaponStats[psWeap->nStat];
ASSERT_OR_RETURN( false, psWeap->nStat < numWeaponStats, "Invalid range referenced for numWeaponStats, %d > %d", psWeap->nStat, numWeaponStats);
ASSERT_OR_RETURN( false, psStats != NULL, "Invalid weapon stats" );
ASSERT_OR_RETURN( false, psTarget == NULL || !psTarget->died, "Aiming at dead target!" );
PROJECTILE *psProj = new PROJECTILE(ProjectileTrackerID | (realTime >> 4), player);
/* get muzzle offset */
if (psAttacker == NULL)
{
// if there isn't an attacker just start at the target position
// NB this is for the script function to fire the las sats
psProj->src = target;
}
else if (psAttacker->type == OBJ_DROID && weapon_slot >= 0)
{
calcDroidMuzzleLocation((DROID *)psAttacker, &psProj->src, weapon_slot);
/*update attack runs for VTOL droid's each time a shot is fired*/
updateVtolAttackRun((DROID *)psAttacker, weapon_slot);
}
else if (psAttacker->type == OBJ_STRUCTURE && weapon_slot >= 0)
{
calcStructureMuzzleLocation((STRUCTURE *)psAttacker, &psProj->src, weapon_slot);
}
else // incase anything wants a projectile
{
psProj->src = psAttacker->pos;
}
/* Initialise the structure */
psProj->psWStats = psStats;
psProj->pos = psProj->src;
psProj->dst = target;
psProj->bVisible = false;
psProj->died = 0;
// Must set ->psDest and ->expectedDamageCaused before first call to setProjectileDestination().
psProj->psDest = NULL;
psProj->expectedDamageCaused = objGuessFutureDamage(psStats, player, psTarget);
setProjectileDestination(psProj, psTarget); // Updates expected damage of psProj->psDest, using psProj->expectedDamageCaused.
/*
When we have been created by penetration (spawned from another projectile),
we shall live no longer than the original projectile may have lived
*/
if (psAttacker && psAttacker->type == OBJ_PROJECTILE)
{
PROJECTILE * psOldProjectile = (PROJECTILE*)psAttacker;
psProj->born = psOldProjectile->born;
psProj->src = psOldProjectile->src;
psProj->prevSpacetime.time = psOldProjectile->time; // Have partially ticked already.
psProj->time = gameTime;
psProj->prevSpacetime.time -= psProj->prevSpacetime.time == psProj->time; // Times should not be equal, for interpolation.
setProjectileSource(psProj, psOldProjectile->psSource);
psProj->psDamaged = psOldProjectile->psDamaged;
// TODO Should finish the tick, when penetrating.
}
else
{
psProj->born = fireTime; // Born at the start of the tick.
psProj->prevSpacetime.time = fireTime;
psProj->time = psProj->prevSpacetime.time;
setProjectileSource(psProj, psAttacker);
}
if (psTarget)
{
int maxHeight = establishTargetHeight(psTarget);
int minHeight = std::min(std::max(maxHeight + 2 * LINE_OF_FIRE_MINIMUM - areaOfFire(psAttacker, psTarget, weapon_slot, true), 0), maxHeight);
scoreUpdateVar(WD_SHOTS_ON_TARGET);
psProj->dst.z = psTarget->pos.z + minHeight + gameRand(std::max(maxHeight - minHeight, 1));
/* store visible part (LOCK ON this part for homing :) */
psProj->partVisible = maxHeight - minHeight;
}
else
{
psProj->dst.z = target.z + LINE_OF_FIRE_MINIMUM;
scoreUpdateVar(WD_SHOTS_OFF_TARGET);
}
Vector3i deltaPos = psProj->dst - psProj->src;
/* roll never set */
psProj->rot.roll = 0;
psProj->rot.direction = iAtan2(removeZ(deltaPos));
// Get target distance, horizontal distance only.
uint32_t dist = iHypot(removeZ(deltaPos));
if (proj_Direct(psStats))
{
psProj->rot.pitch = iAtan2(deltaPos.z, dist);
}
else
{
/* indirect */
projCalcIndirectVelocities(dist, deltaPos.z, psStats->flightSpeed, &psProj->vXY, &psProj->vZ, min_angle);
psProj->rot.pitch = iAtan2(psProj->vZ, psProj->vXY);
}
psProj->state = PROJ_INFLIGHT;
// If droid or structure, set muzzle pitch.
if (psAttacker != NULL && weapon_slot >= 0)
{
if (psAttacker->type == OBJ_DROID)
{
((DROID *)psAttacker)->asWeaps[weapon_slot].rot.pitch = psProj->rot.pitch;
}
else if (psAttacker->type == OBJ_STRUCTURE)
{
((STRUCTURE *)psAttacker)->asWeaps[weapon_slot].rot.pitch = psProj->rot.pitch;
}
}
/* put the projectile object in the global list */
psProjectileList.push_back(psProj);
/* play firing audio */
// only play if either object is visible, i know it's a bit of a hack, but it avoids the problem
// of having to calculate real visibility values for each projectile.
if ( bVisible || gfxVisible(psProj) )
{
// note that the projectile is visible
psProj->bVisible = true;
if ( psStats->iAudioFireID != NO_SOUND )
{
if ( psProj->psSource )
{
/* firing sound emitted from source */
audio_PlayObjDynamicTrack(psProj->psSource, psStats->iAudioFireID, NULL);
/* GJ HACK: move howitzer sound with shell */
if ( psStats->weaponSubClass == WSC_HOWITZERS )
{
audio_PlayObjDynamicTrack(psProj, ID_SOUND_HOWITZ_FLIGHT, NULL);
}
}
//don't play the sound for a LasSat in multiPlayer
else if (!(bMultiPlayer && psStats->weaponSubClass == WSC_LAS_SAT))
{
audio_PlayObjStaticTrack(psProj, psStats->iAudioFireID);
}
}
}
if (psAttacker != NULL && !proj_Direct(psStats))
{
//check for Counter Battery Sensor in range of target
counterBatteryFire(castBaseObject(psAttacker), psTarget);
}
syncDebugProjectile(psProj, '*');
CHECK_PROJECTILE(psProj);
return true;
}
/***************************************************************************/
static INTERVAL intervalIntersection(INTERVAL i1, INTERVAL i2)
{
INTERVAL ret = {MAX(i1.begin, i2.begin), MIN(i1.end, i2.end)};
return ret;
}
static bool intervalEmpty(INTERVAL i)
{
return i.begin >= i.end;
}
static INTERVAL collisionZ(int32_t z1, int32_t z2, int32_t height)
{
INTERVAL ret = {-1, -1};
if (z1 > z2)
{
z1 *= -1;
z2 *= -1;
}
if (z1 > height || z2 < -height)
return ret; // No collision between time 1 and time 2.
if (z1 == z2)
{
if (z1 >= -height && z1 <= height)
{
ret.begin = 0;
ret.end = 1024;
}
return ret;
}
ret.begin = 1024*(-height - z1)/(z2 - z1);
ret.end = 1024*( height - z1)/(z2 - z1);
return ret;
}
static INTERVAL collisionXY(int32_t x1, int32_t y1, int32_t x2, int32_t y2, int32_t radius)
{
// Solve (1 - t)v1 + t v2 = r.
int32_t dx = x2 - x1, dy = y2 - y1;
int64_t a = (int64_t)dx*dx + (int64_t)dy*dy; // a = (v2 - v1)²
int64_t b = (int64_t)x1*dx + (int64_t)y1*dy; // b = v1(v2 - v1)
int64_t c = (int64_t)x1*x1 + (int64_t)y1*y1 - (int64_t)radius*radius; // c = v1² - r²
// Equation to solve is now a t^2 + 2 b t + c = 0.
int64_t d = b*b - a*c; // d = b² - a c
// Solution is (-b ± √d)/a.
INTERVAL empty = {-1, -1};
INTERVAL full = {0, 1024};
INTERVAL ret;
if (d < 0)
{
return empty; // Missed.
}
if (a == 0)
{
return c < 0 ? full : empty; // Not moving. See if inside the target.
}
int32_t sd = i64Sqrt(d);
ret.begin = MAX( 0, 1024*(-b - sd)/a);
ret.end = MIN(1024, 1024*(-b + sd)/a);
return ret;
}
static int32_t collisionXYZ(Vector3i v1, Vector3i v2, ObjectShape shape, int32_t height)
{
INTERVAL i = collisionZ(v1.z, v2.z, height);
if (!intervalEmpty(i)) // Don't bother checking x and y unless z passes.
{
if (shape.isRectangular)
{
i = intervalIntersection(i, collisionZ(v1.x, v2.x, shape.size.x));
if (!intervalEmpty(i)) // Don't bother checking y unless x and z pass.
{
i = intervalIntersection(i, collisionZ(v1.y, v2.y, shape.size.y));
}
}
else // Else is circular.
{
i = intervalIntersection(i, collisionXY(v1.x, v1.y, v2.x, v2.y, shape.radius()));
}
if (!intervalEmpty(i))
{
return MAX(0, i.begin);
}
}
return -1;
}
static void proj_InFlightFunc(PROJECTILE *psProj)
{
/* we want a delay between Las-Sats firing and actually hitting in multiPlayer
magic number but that's how long the audio countdown message lasts! */
const unsigned int LAS_SAT_DELAY = 4;
// Projectile is missile:
bool bMissile = false;
BASE_OBJECT *closestCollisionObject = NULL;
Spacetime closestCollisionSpacetime;
memset(&closestCollisionSpacetime, 0, sizeof(Spacetime)); // Squelch uninitialised warning.
CHECK_PROJECTILE(psProj);
int timeSoFar = gameTime - psProj->born;
psProj->time = gameTime;
int deltaProjectileTime = psProj->time - psProj->prevSpacetime.time;
WEAPON_STATS *psStats = psProj->psWStats;
ASSERT_OR_RETURN( , psStats != NULL, "Invalid weapon stats pointer");
/* we want a delay between Las-Sats firing and actually hitting in multiPlayer
magic number but that's how long the audio countdown message lasts! */
if (bMultiPlayer && psStats->weaponSubClass == WSC_LAS_SAT &&
(unsigned)timeSoFar < LAS_SAT_DELAY * GAME_TICKS_PER_SEC)
{
return;
}
/* Calculate extended lifespan where appropriate */
int distanceExtensionFactor; /* Extended lifespan */
switch (psStats->weaponSubClass)
{
case WSC_MGUN:
case WSC_COMMAND:
distanceExtensionFactor = 120;
break;
case WSC_CANNON:
case WSC_BOMB:
case WSC_ELECTRONIC:
case WSC_EMP:
case WSC_FLAME:
case WSC_ENERGY:
case WSC_GAUSS:
distanceExtensionFactor = 150;
break;
case WSC_AAGUN: // No extended distance
distanceExtensionFactor = 100;
break;
case WSC_ROCKET:
case WSC_MISSILE:
case WSC_SLOWROCKET:
case WSC_SLOWMISSILE:
bMissile = true; // Take the same extended targetDistance as artillery
case WSC_COUNTER:
case WSC_MORTARS:
case WSC_HOWITZERS:
case WSC_LAS_SAT:
distanceExtensionFactor = 150;
break;
default:
// WSC_NUM_WEAPON_SUBCLASSES
ASSERT(false, "Bad WSC_NUM_WEAPON_SUBCLASS.");
distanceExtensionFactor = 0;
break;
}
/* Calculate movement vector: */
int32_t currentDistance;
switch (psStats->movementModel)
{
case MM_DIRECT: // Go in a straight line.
case MM_ERRATICDIRECT: // Same as MM_DIRECT, used by bombs for unknown reason.
{
Vector3i delta = psProj->dst - psProj->src;
if (psStats->weaponSubClass == WSC_LAS_SAT)
{
// LASSAT doesn't have a z
delta.z = 0;
}
int targetDistance = std::max(iHypot(removeZ(delta)), 1);
currentDistance = timeSoFar * psStats->flightSpeed / GAME_TICKS_PER_SEC;
psProj->pos = psProj->src + delta * currentDistance/targetDistance;
break;
}
case MM_INDIRECT: // Ballistic trajectory.
{
Vector3i delta = psProj->dst - psProj->src;
delta.z = (psProj->vZ - (timeSoFar * ACC_GRAVITY / (GAME_TICKS_PER_SEC * 2))) * timeSoFar / GAME_TICKS_PER_SEC; // '2' because we reach our highest point in the mid of flight, when "vZ is 0".
int targetDistance = std::max(iHypot(removeZ(delta)), 1);
currentDistance = timeSoFar * psProj->vXY / GAME_TICKS_PER_SEC;
psProj->pos = psProj->src + delta * currentDistance/targetDistance;
psProj->pos.z = psProj->src.z + delta.z; // Use raw z value.
psProj->rot.pitch = iAtan2(psProj->vZ - (timeSoFar * ACC_GRAVITY / GAME_TICKS_PER_SEC), psProj->vXY);
break;
}
case MM_HOMINGDIRECT: // Fly towards target, even if target moves.
case MM_HOMINGINDIRECT: // Fly towards target, even if target moves. Avoid terrain.
{
if (psProj->psDest != NULL)
{
if (psStats->movementModel == MM_HOMINGDIRECT)
{
// If it's homing and has a target (not a miss)...
// Home at the centre of the part that was visible when firing.
psProj->dst = psProj->psDest->pos + Vector3i(0, 0, establishTargetHeight(psProj->psDest) - psProj->partVisible/2);
}
else
{
psProj->dst = psProj->psDest->pos + Vector3i(0, 0, establishTargetHeight(psProj->psDest)/2);
}
DROID *targetDroid = castDroid(psProj->psDest);
if (targetDroid != NULL)
{
// Do target prediction.
Vector3i delta = psProj->dst - psProj->pos;
int flightTime = iHypot(removeZ(delta)) * GAME_TICKS_PER_SEC / psStats->flightSpeed;
psProj->dst += Vector3i(iSinCosR(targetDroid->sMove.moveDir, std::min<int>(targetDroid->sMove.speed, psStats->flightSpeed*3/4)*flightTime / GAME_TICKS_PER_SEC), 0);
}
psProj->dst.x = clip(psProj->dst.x, 0, world_coord(mapWidth) - 1);
psProj->dst.y = clip(psProj->dst.y, 0, world_coord(mapHeight) - 1);
if (psStats->movementModel == MM_HOMINGINDIRECT)
{
int horizontalTargetDistance = iHypot(removeZ(psProj->dst - psProj->pos));
int terrainHeight = std::max(map_Height(removeZ(psProj->pos)), map_Height(removeZ(psProj->pos) + iSinCosR(iAtan2(removeZ(psProj->dst - psProj->pos)), psStats->flightSpeed*2*deltaProjectileTime/GAME_TICKS_PER_SEC)));
int desiredMinHeight = terrainHeight + std::min(horizontalTargetDistance/4, HOMINGINDIRECT_HEIGHT_MIN);
int desiredMaxHeight = std::max(psProj->dst.z, terrainHeight + HOMINGINDIRECT_HEIGHT_MAX);
int heightError = psProj->pos.z - clip(psProj->pos.z, desiredMinHeight, desiredMaxHeight);
psProj->dst.z -= horizontalTargetDistance*heightError*2/HOMINGINDIRECT_HEIGHT_MIN;
}
}
Vector3i delta = psProj->dst - psProj->pos;
int targetDistance = std::max(iHypot(delta), 1);
if (psProj->psDest == NULL && targetDistance < 10000)
{
psProj->dst = psProj->pos + delta*10; // Target missing, so just keep going in a straight line.
}
currentDistance = timeSoFar * psStats->flightSpeed / GAME_TICKS_PER_SEC;
Vector3i step = quantiseFraction(delta * psStats->flightSpeed, GAME_TICKS_PER_SEC*targetDistance, psProj->time, psProj->prevSpacetime.time);
psProj->pos += step;
psProj->rot.direction = iAtan2(removeZ(delta));
psProj->rot.pitch = iAtan2(delta.z, targetDistance);
break;
}
default:
case MM_SWEEP: // Unused.
case NUM_MOVEMENT_MODEL: // Unused.
currentDistance = 1000000;
ASSERT(false, "Movement model not implemented.");
break;
}
closestCollisionSpacetime.time = 0xFFFFFFFF;
/* Check nearby objects for possible collisions */
gridStartIterate(psProj->pos.x, psProj->pos.y, PROJ_NEIGHBOUR_RANGE);
for (BASE_OBJECT *psTempObj = gridIterate(); psTempObj != NULL; psTempObj = gridIterate())
{
CHECK_OBJECT(psTempObj);
if (std::find(psProj->psDamaged.begin(), psProj->psDamaged.end(), psTempObj) != psProj->psDamaged.end())
{
// Dont damage one target twice
continue;
}
if (psTempObj->died)
{
// Do not damage dead objects further
continue;
}
if (psTempObj->type == OBJ_PROJECTILE &&
!(bMissile || ((PROJECTILE*)psTempObj)->psWStats->weaponSubClass == WSC_COUNTER))
{
// A projectile should not collide with another projectile unless it's a counter-missile weapon
continue;
}
if (psTempObj->type == OBJ_FEATURE &&
!((FEATURE*)psTempObj)->psStats->damageable)
{
// Ignore oil resources, artifacts and other pickups
continue;
}
if (aiCheckAlliances(psTempObj->player, psProj->player)
&& psTempObj != psProj->psDest)
{
// No friendly fire unless intentional
continue;
}
if (!(psStats->surfaceToAir & SHOOT_ON_GROUND) &&
(psTempObj->type == OBJ_STRUCTURE ||
psTempObj->type == OBJ_FEATURE ||
(psTempObj->type == OBJ_DROID && !isFlying((DROID *)psTempObj))
))
{
// AA weapons should not hit buildings and non-vtol droids
continue;
}
Vector3i psTempObjPrevPos = isDroid(psTempObj)? castDroid(psTempObj)->prevSpacetime.pos : psTempObj->pos;
const Vector3i diff = psProj->pos - psTempObj->pos;
const Vector3i prevDiff = psProj->prevSpacetime.pos - psTempObjPrevPos;
const unsigned int targetHeight = establishTargetHeight(psTempObj);
const ObjectShape targetShape = establishTargetShape(psTempObj);
const int32_t collision = collisionXYZ(prevDiff, diff, targetShape, targetHeight);
const uint32_t collisionTime = psProj->prevSpacetime.time + (psProj->time - psProj->prevSpacetime.time)*collision/1024;
if (collision >= 0 && collisionTime < closestCollisionSpacetime.time)
{
// We hit!
closestCollisionSpacetime = interpolateObjectSpacetime(psProj, collisionTime);
closestCollisionObject = psTempObj;
// Keep testing for more collisions, in case there was a closer target.
}
}
unsigned terrainIntersectTime = map_LineIntersect(psProj->prevSpacetime.pos, psProj->pos, psProj->time - psProj->prevSpacetime.time);
if (terrainIntersectTime != UINT32_MAX)
{
const uint32_t collisionTime = psProj->prevSpacetime.time + terrainIntersectTime;
if (collisionTime < closestCollisionSpacetime.time)
{
// We hit the terrain!
closestCollisionSpacetime = interpolateObjectSpacetime(psProj, collisionTime);
closestCollisionObject = NULL;
}
}
if (closestCollisionSpacetime.time != 0xFFFFFFFF)
{
// We hit!
setSpacetime(psProj, closestCollisionSpacetime);
psProj->time = std::max(psProj->time, gameTime - deltaGameTime + 1); // Make sure .died gets set in the interval [gameTime - deltaGameTime + 1; gameTime].
if(psProj->time == psProj->prevSpacetime.time)
{
--psProj->prevSpacetime.time;
}
setProjectileDestination(psProj, closestCollisionObject); // We hit something.
// Buildings and terrain cannot be penetrated and we need a penetrating weapon.
if (closestCollisionObject != NULL && closestCollisionObject->type == OBJ_DROID && psStats->penetrate)
{
WEAPON asWeap;
asWeap.nStat = psStats - asWeaponStats;
// Assume we damaged the chosen target
psProj->psDamaged.push_back(closestCollisionObject);
proj_SendProjectile(&asWeap, psProj, psProj->player, psProj->dst, NULL, true, -1);
}
psProj->state = PROJ_IMPACT;
return;
}
if (currentDistance*100u >= psStats->longRange*distanceExtensionFactor) // We've travelled our maximum range.
{
psProj->state = PROJ_IMPACT;
setProjectileDestination(psProj, NULL); /* miss registered if NULL target */
return;
}
/* Paint effects if visible */
if (gfxVisible(psProj))
{
uint32_t effectTime;
for (effectTime = ((psProj->prevSpacetime.time + 31) & ~31); effectTime < psProj->time; effectTime += 32)
{
Spacetime st = interpolateObjectSpacetime(psProj, effectTime);
Vector3i posFlip = swapYZ(st.pos);
switch (psStats->weaponSubClass)
{
case WSC_FLAME:
posFlip.z -= 8; // Why?
effectGiveAuxVar(PERCENT(currentDistance, psStats->longRange));
addEffect(&posFlip, EFFECT_EXPLOSION, EXPLOSION_TYPE_FLAMETHROWER, false, NULL, 0, effectTime);
break;
case WSC_COMMAND:
case WSC_ELECTRONIC:
case WSC_EMP:
posFlip.z -= 8; // Why?
effectGiveAuxVar(PERCENT(currentDistance, psStats->longRange)/2);
addEffect(&posFlip, EFFECT_EXPLOSION, EXPLOSION_TYPE_LASER, false, NULL, 0, effectTime);
break;
case WSC_ROCKET:
case WSC_MISSILE:
case WSC_SLOWROCKET:
case WSC_SLOWMISSILE:
posFlip.z += 8; // Why?
addEffect(&posFlip, EFFECT_SMOKE, SMOKE_TYPE_TRAIL, false, NULL, 0, effectTime);
break;
default:
// Add smoke trail to indirect weapons, even if firing directly.
if (!proj_Direct(psStats))
{
posFlip.z += 4; // Why?
addEffect(&posFlip, EFFECT_SMOKE, SMOKE_TYPE_TRAIL, false, NULL, 0, effectTime);
}
// Otherwise no effect.
break;
}
}
}
}
/***************************************************************************/
static void proj_ImpactFunc( PROJECTILE *psObj )
{
WEAPON_STATS *psStats;
SDWORD iAudioImpactID;
int32_t relativeDamage;
Vector3i position, scatter;
iIMDShape *imd;
BASE_OBJECT *temp;
CHECK_PROJECTILE(psObj);
psStats = psObj->psWStats;
ASSERT(psStats != NULL, "proj_ImpactFunc: Invalid weapon stats pointer");
// note the attacker if any
g_pProjLastAttacker = psObj->psSource;
/* play impact audio */
if (gfxVisible(psObj))
{
if (psStats->iAudioImpactID == NO_SOUND)
{
/* play richochet if MG */
if (psObj->psDest != NULL && psStats->weaponSubClass == WSC_MGUN
&& ONEINTHREE)
{