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Merge pull request #4688 from zaxcav/pathFindLoopDetection 

Add pathfinding loop detection based on peep->pathfind_history
This commit is contained in:
Michael Steenbeek 2016-11-06 17:34:31 +01:00 committed by GitHub
parent 98981b691d 86ae14c65d
commit d9c19479d1
1 changed files with 35 additions and 15 deletions
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50
src/peep/peep.c
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@ -8974,7 +8974,7 @@ static bool path_is_thin_junction(rct_map_element *path, sint16 x, sint16 y, uin
*
* rct2: 0x0069A997
*/
static void peep_pathfind_heuristic_search(sint16 x, sint16 y, uint8 z, rct_map_element *currentMapElement, uint8 counter, uint16 *endScore, int test_edge, uint8 *endJunctions, rct_xyz8 junctionList[16], uint8 directionList[16], rct_xyz8 *endXYZ, uint8 *endSteps) {
static void peep_pathfind_heuristic_search(sint16 x, sint16 y, uint8 z, rct_peep *peep, rct_map_element *currentMapElement, uint8 counter, uint16 *endScore, int test_edge, uint8 *endJunctions, rct_xyz8 junctionList[16], uint8 directionList[16], rct_xyz8 *endXYZ, uint8 *endSteps) {
uint8 searchResult = PATH_SEARCH_FAILED;
x += TileDirectionDelta[test_edge].x;
@ -9280,21 +9280,41 @@ static void peep_pathfind_heuristic_search(sint16 x, sint16 y, uint8 z, rct_map_
* junction on this map element. Only 'thin' junctions
* are counted towards the junction search limit. */
/* Check the pathfind_history to see if this junction has been
* previously passed through in the current search path.
* i.e. this is a loop in the current search path.
* If so, the current search path ends here.
* Continue to the next map element without updating the parameters (best result so far). */
/* First check if going through the junction would be
* a loop. If so, the current search path ends here.
* Path finding loop detection can take advantage of both the
* peep->pathfind_history - loops through remembered junctions
* the peep has already passed through getting to its
* current position while on the way to its current goal;
* _peepPathFindHistory - loops in the current search path. */
bool pathLoop = false;
for (int junctionNum = _peepPathFindNumJunctions + 1; junctionNum <= _peepPathFindMaxJunctions; junctionNum++) {
if ((_peepPathFindHistory[junctionNum].location.x == (uint8)(x >> 5)) &&
(_peepPathFindHistory[junctionNum].location.y == (uint8)(y >> 5)) &&
(_peepPathFindHistory[junctionNum].location.z == (uint8)z)) {
pathLoop = true;
break;
/* Check the peep->pathfind_history to see if this junction has
* already been visited by the peep while heading for this goal. */
for (int i = 0; i < 4; ++i) {
if (peep->pathfind_history[i].x == x >> 5 &&
peep->pathfind_history[i].y == y >> 5 &&
peep->pathfind_history[i].z == z) {
pathLoop = true;
break;
}
}
if (!pathLoop) {
/* Check the _peepPathFindHistory to see if this junction has been
* previously passed through in the current search path.
* i.e. this is a loop in the current search path. */
for (int junctionNum = _peepPathFindNumJunctions + 1; junctionNum <= _peepPathFindMaxJunctions; junctionNum++) {
if ((_peepPathFindHistory[junctionNum].location.x == (uint8)(x >> 5)) &&
(_peepPathFindHistory[junctionNum].location.y == (uint8)(y >> 5)) &&
(_peepPathFindHistory[junctionNum].location.z == (uint8)z)) {
pathLoop = true;
break;
}
}
}
if (pathLoop) {
/* Loop detected. The current search path ends here.
* Continue to the next map element without updating the parameters (best result so far). */
#if defined(DEBUG_LEVEL_2) && DEBUG_LEVEL_2
if (gPathFindDebug) {
log_info("[%03d] Search path ends at %d,%d,%d; Loop", counter, x >> 5, y >> 5, z);
@ -9376,7 +9396,7 @@ static void peep_pathfind_heuristic_search(sint16 x, sint16 y, uint8 z, rct_map_
_peepPathFindHistory[_peepPathFindNumJunctions + 1].direction = test_edge;
}
peep_pathfind_heuristic_search(x, y, height, mapElement, counter, endScore, test_edge, endJunctions, junctionList, directionList, endXYZ, endSteps);
peep_pathfind_heuristic_search(x, y, height, peep, mapElement, counter, endScore, test_edge, endJunctions, junctionList, directionList, endXYZ, endSteps);
_peepPathFindNumJunctions = savedNumJunctions;
#if defined(DEBUG_LEVEL_2) && DEBUG_LEVEL_2
@ -9480,7 +9500,7 @@ int peep_pathfind_choose_direction(sint16 x, sint16 y, uint8 z, rct_peep *peep)
edges = peep->pathfind_history[i].direction & 0xF;
#if defined(DEBUG_LEVEL_1) && DEBUG_LEVEL_1
if (gPathFindDebug) {
log_verbose("Getting untried edges from pf_history for %d,%d,%d: %d", x >> 5, y >> 5, z, edges);
log_verbose("Getting untried edges from pf_history for %d,%d,%d: %s,%s,%s,%s", x >> 5, y >> 5, z, (edges & 1) ? "0" : "-", (edges & 2) ? "1" : "-", (edges & 4) ? "2" : "-", (edges & 8) ? "3" : "-");
}
#endif // defined(DEBUG_LEVEL_1) && DEBUG_LEVEL_1
break;
@ -9566,7 +9586,7 @@ int peep_pathfind_choose_direction(sint16 x, sint16 y, uint8 z, rct_peep *peep)
rct_xyz8 endJunctionList[16] = { 0 };
uint8 endDirectionList[16] = { 0 };
peep_pathfind_heuristic_search(x, y, height, dest_map_element, 0, &score, test_edge, &endJunctions, endJunctionList, endDirectionList, &endXYZ, &endSteps);
peep_pathfind_heuristic_search(x, y, height, peep, dest_map_element, 0, &score, test_edge, &endJunctions, endJunctionList, endDirectionList, &endXYZ, &endSteps);
#if defined(DEBUG_LEVEL_1) && DEBUG_LEVEL_1
if (gPathFindDebug) {
log_verbose("Pathfind test edge: %d score: %d steps: %d end: %d,%d,%d junctions: %d", test_edge, score, endSteps, endXYZ.x, endXYZ.y, endXYZ.z, endJunctions);