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(svn r10111) -Codechange: Add new vehicle hash table for collision detection and finding vehicles on a tile. The hash area scanned is far smaller than the old hash table, which is now used for viewport updates only. This should give a significant performance improvement for games with many vehicles. (Based on work by 'B. N. SmatZ!' and 'madman2003')

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peter1138
2007-06-12 11:22:32 +00:00
parent 105c7455ae
commit 78d797a6b7
4 changed files with 119 additions and 32 deletions
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122
src/vehicle.cpp
View File

@@ -394,44 +394,117 @@ bool AllocateVehicles(Vehicle **vl, int num)
return true;
}
/* Size of the hash, 6 = 64 x 64, 7 = 128 x 128. Larger sizes will (in theory) reduce hash
* lookup times at the expense of memory usage. */
const int HASH_BITS = 7;
const int HASH_SIZE = 1 << HASH_BITS;
const int HASH_MASK = HASH_SIZE - 1;
const int TOTAL_HASH_SIZE = 1 << (HASH_BITS * 2);
const int TOTAL_HASH_MASK = TOTAL_HASH_SIZE - 1;
static Vehicle *_vehicle_position_hash[0x1000];
/* Resolution of the hash, 0 = 1*1 tile, 1 = 2*2 tiles, 2 = 4*4 tiles, etc.
* Profiling results show that 0 is fastest. */
const int HASH_RES = 0;
void *VehicleFromPos(TileIndex tile, void *data, VehicleFromPosProc *proc)
static Vehicle *_new_vehicle_position_hash[TOTAL_HASH_SIZE];
static void *VehicleFromHash(int xl, int yl, int xu, int yu, void *data, VehicleFromPosProc *proc)
{
Point pt = RemapCoords(TileX(tile) * TILE_SIZE, TileY(tile) * TILE_SIZE, 0);
/* The hash area to scan */
const int xl = GB(pt.x - 174, 7, 6);
const int xu = GB(pt.x + 104, 7, 6);
const int yl = GB(pt.y - 294, 6, 6) << 6;
const int yu = GB(pt.y + 56, 6, 6) << 6;
int x;
int y;
for (y = yl;; y = (y + (1 << 6)) & (0x3F << 6)) {
for (x = xl;; x = (x + 1) & 0x3F) {
Vehicle *v = _vehicle_position_hash[(x + y) & 0xFFFF];
while (v != NULL) {
void* a = proc(v, data);
for (int y = yl; ; y = (y + (1 << HASH_BITS)) & (HASH_MASK << HASH_BITS)) {
for (int x = xl; ; x = (x + 1) & HASH_MASK) {
Vehicle *v = _new_vehicle_position_hash[(x + y) & TOTAL_HASH_MASK];
for (; v != NULL; v = v->next_new_hash) {
void *a = proc(v, data);
if (a != NULL) return a;
v = v->next_hash;
}
if (x == xu) break;
}
if (y == yu) break;
}
return NULL;
}
void *VehicleFromPosXY(int x, int y, void *data, VehicleFromPosProc *proc)
{
const int COLL_DIST = 6;
/* Hash area to scan is from xl,yl to xu,yu */
int xl = GB((x - COLL_DIST) / TILE_SIZE, HASH_RES, HASH_BITS);
int xu = GB((x + COLL_DIST) / TILE_SIZE, HASH_RES, HASH_BITS);
int yl = GB((y - COLL_DIST) / TILE_SIZE, HASH_RES, HASH_BITS) << HASH_BITS;
int yu = GB((y + COLL_DIST) / TILE_SIZE, HASH_RES, HASH_BITS) << HASH_BITS;
return VehicleFromHash(xl, yl, xu, yu, data, proc);
}
void *VehicleFromPos(TileIndex tile, void *data, VehicleFromPosProc *proc)
{
int x = GB(TileX(tile), HASH_RES, HASH_BITS);
int y = GB(TileY(tile), HASH_RES, HASH_BITS) << HASH_BITS;
Vehicle *v = _new_vehicle_position_hash[(x + y) & TOTAL_HASH_MASK];
for (; v != NULL; v = v->next_new_hash) {
if (v->tile != tile) continue;
void *a = proc(v, data);
if (a != NULL) return a;
}
return NULL;
}
static void UpdateNewVehiclePosHash(Vehicle *v)
{
Vehicle **old_hash = v->old_new_hash;
Vehicle **new_hash;
if (v->tile == INVALID_TILE || v->tile == 0) {
new_hash = NULL;
} else {
int x = GB(TileX(v->tile), HASH_RES, HASH_BITS);
int y = GB(TileY(v->tile), HASH_RES, HASH_BITS) << HASH_BITS;
new_hash = &_new_vehicle_position_hash[(x + y) & TOTAL_HASH_MASK];
}
if (old_hash == new_hash) return;
/* Remove from the old position in the hash table */
if (old_hash != NULL) {
Vehicle *last = NULL;
Vehicle *u = *old_hash;
while (u != v) {
last = u;
u = u->next_new_hash;
assert(u != NULL);
}
if (last == NULL) {
*old_hash = v->next_new_hash;
} else {
last->next_new_hash = v->next_new_hash;
}
}
/* Insert vehicle at beginning of the new position in the hash table */
if (new_hash != NULL) {
v->next_new_hash = *new_hash;
*new_hash = v;
assert(v != v->next_new_hash);
}
/* Remember current hash position */
v->old_new_hash = new_hash;
}
static Vehicle *_vehicle_position_hash[0x1000];
static void UpdateVehiclePosHash(Vehicle* v, int x, int y)
{
UpdateNewVehiclePosHash(v);
Vehicle **old_hash, **new_hash;
int old_x = v->left_coord;
int old_y = v->top_coord;
@@ -468,6 +541,7 @@ static void UpdateVehiclePosHash(Vehicle* v, int x, int y)
void ResetVehiclePosHash()
{
memset(_vehicle_position_hash, 0, sizeof(_vehicle_position_hash));
memset(_new_vehicle_position_hash, 0, sizeof(_new_vehicle_position_hash));
}
void InitializeVehicles()
@@ -611,8 +685,10 @@ void DestroyVehicle(Vehicle *v)
InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
}
v->tile = INVALID_TILE;
UpdateVehiclePosHash(v, INVALID_COORD, 0);
v->next_hash = NULL;
v->next_new_hash = NULL;
if (IsPlayerBuildableVehicleType(v)) DeleteVehicleOrders(v);
/* Now remove any artic part. This will trigger an other