shithub: asif

Download patch

ref: f7b9f1912c0f10033006bb55deb3d48768b9f3a6
parent: 4fe8db493bb0fe8d4f6e280d685e94f6134b17f6
author: qwx <qwx@sciops.net>
date: Wed Mar 23 19:20:33 EDT 2022 

add bfs


--- /dev/null
+++ b/path/bfs.c
@@ -1,0 +1,151 @@
+#include <u.h>
+#include <libc.h>
+#include <thread.h>
+#include <draw.h>
+#include <mouse.h>
+#include <keyboard.h>
+#include "../asif.h"
+#include "dat.h"
+#include "fns.h"
+
+Node *start, *goal;
+
+static Node**	(*successorfn)(Node*);
+
+static void
+backtrack(void)
+{
+	Node *n;
+
+	assert(goal != start);
+	for(n=goal; n!=start; n=n->from)
+		n->from->to = n;
+}
+
+static Node **
+successors8(Node *n)
+{
+	static Node *suc[8+1];
+	static dtab[2*(nelem(suc)-1)]={
+		-1,-1, 0,-1, 1,-1,
+		-1,0, 1,0,
+		-1,1, 0,1, 1,1,
+	};
+	int i;
+	Node *s, **np;
+	Point p;
+	Rectangle r;
+
+	memset(suc, 0, sizeof suc);
+	p = n2p(n);
+	r = Rect(0, 0, mapwidth, mapheight);
+	for(i=0, np=suc; i<nelem(dtab); i+=2){
+		if(!ptinrect(addpt(p, Pt(dtab[i], dtab[i+1])), r))
+			continue;
+		s = n + dtab[i+1] * mapwidth + dtab[i];
+		assert(s >= map && s < map + mapwidth * mapheight);
+		if(isblocked(s))
+			continue;
+		s->Δg = dtab[i] != 0 && dtab[i+1] != 0 ? SQRT2 : 1;
+		*np++ = s;
+	}
+	return suc;
+}
+
+static Node **
+successors4(Node *n)
+{
+	static Node *suc[4+1];
+	static dtab[2*(nelem(suc)-1)]={
+		0,-1, -1,0, 1,0, 0,1,
+	};
+	int i;
+	Node *s, **np;
+	Point p;
+	Rectangle r;
+
+	memset(suc, 0, sizeof suc);
+	p = n2p(n);
+	r = Rect(0, 0, mapwidth, mapheight);
+	for(i=0, np=suc; i<nelem(dtab); i+=2){
+		if(!ptinrect(addpt(p, Pt(dtab[i], dtab[i+1])), r))
+			continue;
+		s = n + dtab[i+1] * mapwidth + dtab[i];
+		assert(s >= map && s < map + mapwidth * mapheight);
+		if(isblocked(s))
+			continue;
+		s->Δg = 1;
+		*np++ = s;
+	}
+	return suc;
+}
+
+static Node *
+bfs(Node *a, Node *b)
+{
+	Vector v;
+	Node *x, *s, **sl;
+
+	assert(a != nil && b != nil);
+	assert(a != b);
+	x = a;
+	newvec(&v, manhdist(a, b), sizeof a);
+	pushvec(&v, a);
+	while(v.n > 0){
+		x = popvec(&v);
+		if(x == b)
+			break;
+		x->closed = 1;
+		if((sl = successorfn(x)) == nil)
+			sysfatal("bfs: %r");
+		for(s=*sl++; s!=nil; s=*sl++){
+			if(s->closed || s->open)
+				continue;
+			s->from = x;
+			pushvec(&v, s);
+			s->open = 1;
+		}
+	}
+	freevec(&v);
+	return x;
+}
+
+static int
+findpath(void)
+{
+	if(start == nil || goal == nil)
+		return -1;
+	resetmap();
+	if(bfs(start, goal) != goal)
+		return -1;
+	backtrack();
+	return 0;
+}
+
+int
+mouseinput(Node *n, Mouse m)
+{
+	switch(m.buttons & 7){
+	case 1: if(start != n) goal = n; return findpath();
+	case 2: if(goal != n) start = n; return findpath();
+	case 4: n->blocked ^= 1; break;
+	}
+	return 0;
+}
+
+int
+keyinput(Rune)
+{
+	return 0;
+}
+
+void
+threadmain(int argc, char **argv)
+{
+	init(argc, argv);
+	if(fourdir)
+		successorfn = successors4;
+	else
+		successorfn = successors8;
+	evloop();
+}
--- a/path/dijkstra.c
+++ b/path/dijkstra.c
@@ -99,7 +99,7 @@
 			break;
 		x->closed = 1;
 		if((sl = successorfn(x)) == nil)
-			sysfatal("a∗: %r");
+			sysfatal("dijkstra: %r");
 		for(s=*sl++; s!=nil; s=*sl++){
 			if(s->closed)
 				continue;
--- a/path/mkfile
+++ b/path/mkfile
@@ -1,8 +1,9 @@
 </$objtype/mkfile
 BIN=$home/bin/$objtype/path
 TARG=\
-	dijkstra\
 	a∗\
+	bfs\
+	dijkstra\
 
 HFILES=../asif.h dat.h fns.h
 OFILES=\
@@ -16,6 +17,7 @@
 
 $O.dijkstra: $OFILES dijkstra.$O ../pheap.$O
 $O.a∗: $OFILES a∗.$O ../pheap.$O
+$O.bfs: $OFILES bfs.$O ../vec.$O
 
 dicks:V:
 	mkdir -p $BIN