From 47cf24d254f2606adda08a32c710c1ae5dcf7166 Mon Sep 17 00:00:00 2001
From: Allanis <allanis@saracraft.net>
Date: Sun, 16 Jun 2013 16:24:39 +0100
Subject: [PATCH] [Fix] A* bugs where because of a typo. Changed to Djikstra
now though.
---
src/space.c | 42 ++++++++++++++++++++++++++----------------
1 file changed, 26 insertions(+), 16 deletions(-)
diff --git a/src/space.c b/src/space.c
index f1ace4c..ba1114e 100644
--- a/src/space.c
+++ b/src/space.c
@@ -165,7 +165,7 @@ static double A_h(StarSystem* n, StarSystem* g);
static double A_g(SysNode* n);
static SysNode* A_add(SysNode* first, SysNode* cur);
static SysNode* A_rm(SysNode* first, StarSystem* cur);
-static int A_in(SysNode* first, StarSystem* cur);
+static SysNode* A_in(SysNode* first, StarSystem* cur);
static SysNode* A_lowest(SysNode* first);
static void A_freeList(SysNode* first);
@@ -188,8 +188,11 @@ static SysNode* A_newNode(StarSystem* sys, SysNode* parent) {
}
static double A_h(StarSystem* n, StarSystem* g) {
+ (void)n;
+ (void)g;
// Euclidean distance.
- return sqrt(pow2(n->pos.x - g->pos.x) + pow2(n->pos.y - g->pos.y))/100.;
+ //return sqrt(pow2(n->pos.x - g->pos.x) + pow2(n->pos.y - g->pos.y))/100.;
+ return 0.;
}
// Get the g from a node.
@@ -217,8 +220,8 @@ static SysNode* A_rm(SysNode* first, StarSystem* cur) {
SysNode* n, *p;
if(first->sys == cur) {
- first->next = NULL;
n = first->next;
+ first->next = NULL;
return n;
}
@@ -236,18 +239,18 @@ static SysNode* A_rm(SysNode* first, StarSystem* cur) {
}
// Check if node is in linked list.
-static int A_in(SysNode* first, StarSystem* cur) {
+static SysNode* A_in(SysNode* first, StarSystem* cur) {
SysNode* n;
if(first == NULL)
- return 0;
+ return NULL;
n = first;
do {
if(n->sys == cur)
- return 1;
+ return n;
} while((n=n->next) != NULL);
- return 0;
+ return NULL;
}
// Return the lowest ranking node from a linked list of nodes.
@@ -288,10 +291,11 @@ static void A_freeList(SysNode* first) {
StarSystem** system_getJumpPath(int* njumps, char* sysstart, char* sysend) {
int i, cost;
- StarSystem* ssys, *esys, **res;
+ StarSystem* sys, *ssys, *esys, **res;
SysNode* cur, *neighbour;
SysNode* open, *closed;
+ SysNode* ocost, *ccost;
A_gc = NULL;
@@ -308,21 +312,27 @@ StarSystem** system_getJumpPath(int* njumps, char* sysstart, char* sysend) {
// Get best from open and toss to closed.
open = A_rm(open, cur->sys);
closed = A_add(closed, cur);
+ cost = A_g(cur) + 1;
for(i = 0; i < cur->sys->njumps; i++) {
- neighbour = A_newNode(&systems_stack[cur->sys->jumps[i]], cur);
- cost = A_g(cur) + 1;
+ sys = &systems_stack[cur->sys->jumps[i]];
+ neighbour = A_newNode(sys, NULL);
- if(A_in(open, neighbour->sys))
- open = A_rm(open, neighbour->sys); // New path is better.
+ ocost = A_in(open, sys);
+ if((ocost != NULL) && (cost < ocost->g)) {
+ open = A_rm(open, sys); // New path is better.
+ }
- if(A_in(closed, neighbour->sys))
- closed = A_rm(closed, neighbour->sys); // Shouldn't happen.
+ ccost = A_in(closed, sys);
+ if(ccost != NULL) {
+ closed = A_rm(closed, sys); // Shouldn't happen.
+ }
- if(!A_in(open, neighbour->sys) && !A_in(closed, neighbour->sys)) {
+ if((ocost == NULL) && (ccost == NULL)) {
neighbour->g = cost;
+ neighbour->r = A_g(neighbour) + A_h(cur->sys, sys);
+ neighbour->parent = cur;
open = A_add(open, neighbour);
- neighbour->r = (double)A_g(neighbour) + A_h(neighbour->sys, esys);
}
}
}