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author | Bjørn Lindeijer <bjorn@lindeijer.nl> | 2005-02-13 12:30:39 +0000 |
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committer | Bjørn Lindeijer <bjorn@lindeijer.nl> | 2005-02-13 12:30:39 +0000 |
commit | 37dd4043fe30c77bc0f64f0946c7070e38b5095f (patch) | |
tree | 619dd97901e4166c7207de8bd09374719e3ff5ba /src | |
parent | aec5250a740302fbf7b64eb1250d5ad15eaee57e (diff) | |
download | mana-37dd4043fe30c77bc0f64f0946c7070e38b5095f.tar.gz mana-37dd4043fe30c77bc0f64f0946c7070e38b5095f.tar.bz2 mana-37dd4043fe30c77bc0f64f0946c7070e38b5095f.tar.xz mana-37dd4043fe30c77bc0f64f0946c7070e38b5095f.zip |
Removed old A* implementation.
Diffstat (limited to 'src')
-rw-r--r-- | src/astar.cpp | 460 | ||||
-rw-r--r-- | src/astar.h | 10 |
2 files changed, 0 insertions, 470 deletions
diff --git a/src/astar.cpp b/src/astar.cpp deleted file mode 100644 index dcf4f59e..00000000 --- a/src/astar.cpp +++ /dev/null @@ -1,460 +0,0 @@ -#include "astar.h" - -#define MAP_WIDTH 200 -#define MAP_HEIGHT 200 - -#define WALKABLE 0 -#define NOT_WALKABLE 1 - -#define NOT_STARTED 0 -#define FOUND 1 -#define NOT_FOUND 2 - -// path-related constants -const int numberPeople = 1; -int onClosedList = 10; -const int notfinished = 0; - -// Declare needed arrays -//char tiledMap.getPathWalk [MAP_WIDTH][MAP_HEIGHT]; - -/** 1 dimensional array holding ID# of open list items */ -int openList[MAP_WIDTH * MAP_HEIGHT + 2]; - -/** - * 2 dimensional array used to record whether a cell is on the open list or - * on the closed list - */ -int whichList[MAP_WIDTH + 1][MAP_HEIGHT + 1]; - -/** 1d array stores the x location of an item on the open list */ -int openX[MAP_WIDTH * MAP_HEIGHT + 2]; - -/** 1d array stores the y location of an item on the open list */ -int openY[MAP_WIDTH * MAP_HEIGHT + 2]; - -/** 2d array to store parent of each cell (x) */ -int parentX[MAP_WIDTH + 1][MAP_HEIGHT + 1]; - -/** 2d array to store parent of each cell (y) */ -int parentY[MAP_WIDTH + 1][MAP_HEIGHT + 1]; - -/** 1d array to store F cost of a cell on the open list */ -int F_cost[MAP_WIDTH * MAP_HEIGHT + 2]; - -/** 2d array to store G_cost cost for each cell */ -int G_cost[MAP_WIDTH + 1][MAP_HEIGHT + 1]; - -/** 1d array to store H cost of a cell on the open list */ -int H_cost[MAP_WIDTH * MAP_HEIGHT + 2]; - -int pathLength; /**< length of the FOUND path for critter */ -int pathLocation; /**< current position along the chosen path for critter */ -int* path_bank = NULL; - -// Path reading variables -int pathStatus; -int xPath; -int yPath; - -/** Initialize pathfinder */ -void pathfinder_init() { - path_bank = (int*)malloc(4); -} - -/** Exit pathfinder */ -void pathfinder_exit() { - free(path_bank); -} - -/** Find path */ -PATH_NODE *find_path(int pathfinderID, int s_x, int s_y, int e_x, int e_y) -{ - int onOpenList = 0, parentXval = 0, parentYval = 0; - int a = 0, b = 0, m = 0, u = 0, v = 0, temp = 0, corner = 0; - int numberOfOpenListItems = 0, addedGCost = 0, tempG = 0, path = 0, x = 0; - int y = 0, tempx, pathX, pathY, cellPosition, newOpenListItemID = 0; - - // If starting location and target are in the same location... - if (s_x == e_x && s_y == e_y && pathLocation > 0) return NULL; - else if (s_x == e_x && s_y == e_y && pathLocation == 0) return NULL; - - // If dest tile is not walkable, return that it's a NOT_FOUND path. - if (!tiledMap.getWalk(e_x, e_y)) { - xPath = s_x; - yPath = s_y; - return NULL; - } - - // Reset some variables that need to be cleared - for (x = 0; x < MAP_WIDTH; x++) { - for (y = 0; y < MAP_HEIGHT; y++) { - whichList[x][y] = 0; - } - } - - // Changing the values of onOpenList and onClosed list is faster than - // redimming whichList() array - onClosedList = 2; - onOpenList = 1; - pathLength = NOT_STARTED; - pathLocation = NOT_STARTED; - - // Reset starting square's G_cost value to 0 - G_cost[s_x][s_y] = 0; - - // Add the starting location to the open list of tiles to be checked. - numberOfOpenListItems = 1; - - // Assign it as the top (and currently only) item in the open list, which - // is maintained as a binary heap (explained below) - openList[1] = 1; - openX[1] = s_x ; openY[1] = s_y; - - // Do the following until a path is FOUND or deemed NOT_FOUND. - do { - // If the open list is not empty, take the first cell off of the list. - // This is the lowest F cost cell on the open list. - if (numberOfOpenListItems != 0) - { - // Pop the first item off the open list. - - // Record cell coordinates of the item - parentXval = openX[openList[1]]; - parentYval = openY[openList[1]]; - - // Add the item to the closed list - whichList[parentXval][parentYval] = onClosedList; - - // Open List = Binary Heap: Delete this item from the open list, - // which - // Reduce number of open list items by 1 - numberOfOpenListItems = numberOfOpenListItems - 1; - - // Delete the top item in binary heap and reorder the heap, with - // the lowest F cost item rising to the top. - // Move the last item in the heap up to slot #1 - openList[1] = openList[numberOfOpenListItems + 1]; - v = 1; - - // Repeat the following until the new item in slot #1 sinks to its - // proper spot in the heap. - do { - u = v; - // If both children exist - if (2 * u + 1 <= numberOfOpenListItems) { - // Check if the F cost of the parent is greater than each - // child. - // Select the lowest of the two children. - if (F_cost[openList[u]] >= F_cost[openList[2 * u]]) - v = 2 * u; - if (F_cost[openList[v]] >= F_cost[openList[2 * u + 1]]) - v = 2 * u + 1; - } else { - // If only child #1 exists - if (2 * u <= numberOfOpenListItems) { - // Check if the F cost of the parent is greater than - // child #1 - if (F_cost[openList[u]] >= F_cost[openList[2 * u]]) - v = 2 * u; - } - } - - if (u != v) { - // If parent's F is > one of its children, swap them - temp = openList[u]; - openList[u] = openList[v]; - openList[v] = temp; - } - else { - // Otherwise, exit loop - break; - } - } while (u != v); // Reorder the binary heap - - - // Check the adjacent squares. (Its "children" -- these path - // children are similar, conceptually, to the binary heap children - // mentioned above, but don't confuse them. They are different. - // Path children are portrayed in Demo 1 with grey pointers - // pointing toward their parents.) Add these adjacent child squares - // to the open list for later consideration if appropriate (see - // various if statements below). - - for (b = parentYval - 1; b <= parentYval + 1; b++) { - for (a = parentXval - 1; a <= parentXval + 1; a++) { - // Skip if off the map (do this first to avoid array - // out-of-bounds errors) - if (!(a != -1 && b != -1 && - a != MAP_WIDTH && b != MAP_HEIGHT)) - { - continue; - } - - // Skip if already on the closed list (items on the - // closed list have already been considered and can now - // be ignored). Skip also if the tile is obstructed. - if (whichList[a][b] == onClosedList || - !tiledMap.getWalk(a, b)) - { - continue; - } - - // Don't cut across corners - corner = WALKABLE; - - if (a == parentXval - 1) { - if (b == parentYval - 1) { - if (!tiledMap.getWalk(parentXval - 1, parentYval) || !tiledMap.getWalk(parentXval, parentYval - 1)) // cera slash - corner = NOT_WALKABLE; - } else if (b == parentYval + 1) { - if (!tiledMap.getWalk(parentXval, parentYval + 1) || !tiledMap.getWalk(parentXval - 1, parentYval)) - corner = NOT_WALKABLE; - } - } - else if (a == parentXval + 1) { - if (b == parentYval - 1) { - if (!tiledMap.getWalk(parentXval, parentYval - 1) || !tiledMap.getWalk(parentXval + 1, parentYval)) - corner = NOT_WALKABLE; - } else if (b == parentYval + 1) { - if (!tiledMap.getWalk(parentXval + 1, parentYval) || !tiledMap.getWalk(parentXval, parentYval + 1)) - corner = NOT_WALKABLE; - } - } - - // We can't skip corners, skip to the next square instead. - if (corner != WALKABLE) { - continue; - } - - // If not already on the open list, add it to the open - // list. - if (whichList[a][b] != onOpenList) { - // Create a new open list item in the binary heap. - // Each new item has a unique ID # - newOpenListItemID += 1; - m = numberOfOpenListItems + 1; - - // Place the new open list item (actually, its ID#) - // at the bottom of the heap - openList[m] = newOpenListItemID; - // Record the x and y coordinates of the new item - openX[newOpenListItemID] = a; - openY[newOpenListItemID] = b; - - // Figure out its G_cost cost - if (abs(a - parentXval) == 1 && - abs(b - parentYval) == 1) - { - // Cost of going to diagonal squares. - addedGCost = 14; - } - else { - // Cost of going to non-diagonal squares. - addedGCost = 10; - } - - G_cost[a][b] = G_cost[parentXval][parentYval] + - addedGCost; - - // Figure out its H and F costs and parent. - H_cost[openList[m]] = - 10 * (abs(a - e_x) + abs(b - e_y)); - F_cost[openList[m]] = - G_cost[a][b] + H_cost[openList[m]]; - parentX[a][b] = parentXval; - parentY[a][b] = parentYval; - - // Move the new open list item to the proper place in - // the binary heap. Starting at the bottom, - // successively compare to parent items, swapping as - // needed until the item finds its place in the heap or - // bubbles all the way to the top (if it has the lowest - // F cost). - - // While item hasn't bubbled to the top (m = 1) - while (m != 1) - { - // Check if child's F cost is < parent's F - // cost. If so, swap them. - - if (F_cost[openList[m]] <= F_cost[openList[m / 2]]) - { - temp = openList[m / 2]; - openList[m / 2] = openList[m]; - openList[m] = temp; - m = m / 2; - } - else { - break; - } - } - - // Add one to the number of items in the heap. - numberOfOpenListItems += 1; - // Change whichList to show that the new item is on - // the open list. - whichList[a][b] = onOpenList; - } else { - // If whichList(a,b) = onOpenList - - // If adjacent cell is already on the open list, check - // to see if this path to that cell from the starting - // location is a better one. If so, change the parent - // of the cell and its G_cost and F costs. Figure out - // the G_cost cost of this possible new path - - if (abs(a - parentXval) == 1 && - abs(b - parentYval) == 1) - { - // Cost of going to diagonal tiles - addedGCost = 14; - } - else { - // Cost of going to non-diagonal tiles - addedGCost = 10; - } - - tempG = G_cost[parentXval][parentYval] - + addedGCost; - - // If this path is shorter (G_cost cost is lower) - // then change the parent cell, G_cost cost and F - // cost. - if (tempG < G_cost[a][b]) - { - // If G_cost cost is less, - // change the square's parent - parentX[a][b] = parentXval; - parentY[a][b] = parentYval; - // Change the G_cost cost - G_cost[a][b] = tempG; - - // Because changing the G_cost cost also changes - // the F cost, if the item is on the open list we - // need to change the item's recorded F cost and - // its position on the open list to make sure that - // we maintain a properly ordered open list. - - // Look for the item in the heap - for (int x = 1; x <= numberOfOpenListItems; x++) - { - if (openX[openList[x]] == a && - openY[openList[x]] == b) - { - // Item FOUND, change the F cost - F_cost[openList[x]] = G_cost[a][b] + - H_cost[openList[x]]; - - // See if changing the F score bubbles the - // item up from it's current location in - // the heap - m = x; - - // While item hasn't bubbled to the top - // (m = 1) - while (m != 1) - { - // Check if child is < parent. If so, - // swap them. - if (F_cost[openList[m]] < - F_cost[openList[m / 2]]) { - temp = openList[m / 2]; - openList[m / 2] = openList[m]; - openList[m] = temp; - m = m / 2; - } - else { - break; - } - } - // Exit for x = loop - break; - } // If openX(openList(x)) = a - } // F x = 1 To nrOfOpenListItems - } // If tempG < G_cost(a, b) - } // else If whichList(a, b) = onOpenList - } // for (a = parentXval - 1; a <= parentXval + 1; a++) - } // for (b = parentYval - 1; b <= parentYval + 1; b++) - } else { // if (numberOfOpenListItems != 0) - // If open list is empty then there is no path. - path = NOT_FOUND; - break; - } - - // If target is added to open list then path has been FOUND. - if (whichList[e_x][e_y] == onOpenList) { - path = FOUND; - break; - } - - } - // Do until path is FOUND or deemed NOT_FOUND - while (path != FOUND && path != NOT_FOUND); - - // Save the path if it exists. - if (path == FOUND) - { - // Working backwards from the target to the starting location by - // checking each cell's parent, figure out the length of the path. - pathX = e_x; pathY = e_y; - do { - // Look up the parent of the current cell. - tempx = parentX[pathX][pathY]; - pathY = parentY[pathX][pathY]; - pathX = tempx; - - // Figure out the path length - pathLength = pathLength + 1; - } - while (pathX != s_x || pathY != s_y); - - // Resize the data bank to the right size in bytes - path_bank = (int*)realloc(path_bank, pathLength * 8); - - // Now copy the path information over to the databank. Since we are - // working backwards from the target to the start location, we copy the - // information to the data bank in reverse order. The result is a - // properly ordered set of path data, from the first step to the last. - - pathX = e_x ; pathY = e_y; - // Start at the end - cellPosition = pathLength * 2; - do { - // Work backwards 2 integers - cellPosition = cellPosition - 2; - path_bank[cellPosition] = pathX; - path_bank[cellPosition + 1] = pathY; - // Look up the parent of the current cell. - tempx = parentX[pathX][pathY]; - pathY = parentY[pathX][pathY]; - pathX = tempx; - // If we have reached the starting square, exit the loop. - } - while (pathX != s_x || pathY != s_y); - - PATH_NODE *ret = NULL, *temp = NULL; - pathLocation = 1; - ret = new PATH_NODE(s_x, s_y); - temp = ret; - while (pathLocation < pathLength) { - temp->next = new PATH_NODE( - path_bank[pathLocation * 2 - 2], - path_bank[pathLocation * 2 - 1]); - if (temp->next == NULL) throw "Unable to create path node"; - temp = temp->next; - pathLocation++; - } - if (temp != NULL) { - temp->next = new PATH_NODE(e_x, e_y); - } - else { - throw "Null reference"; - } - - return ret; - } - - // Path not found - return NULL; -} diff --git a/src/astar.h b/src/astar.h deleted file mode 100644 index fbe45aae..00000000 --- a/src/astar.h +++ /dev/null @@ -1,10 +0,0 @@ -#ifndef _ASTAR_H -#define _ASTAR_H - -#include "map.h" -#include "being.h" - -PATH_NODE *find_path(int pathfinderID, int startingX, int startingY, - int targetX, int targetY); - -#endif |