From 0e87344904723c04857c5a2a1dc8e4f5606755c1 Mon Sep 17 00:00:00 2001
From: Mart Lubbers <mart@martlubbers.net>
Date: Fri, 8 Apr 2016 12:05:16 +0200
Subject: [PATCH] initial state encoding done, I think

---
 modelchecker/main.c   |  4 +-
 modelchecker/object.c | 94 +++++++++++++++++++++++++++++++++++++++++--
 2 files changed, 93 insertions(+), 5 deletions(-)

diff --git a/modelchecker/main.c b/modelchecker/main.c
index 02cda40..e954c07 100644
--- a/modelchecker/main.c
+++ b/modelchecker/main.c
@@ -48,9 +48,9 @@ void solve(FILE *inputstream)
 	time_start_read = clock();
 	sokoban_screen *screen = parse_screen(inputstream);
 	if (screen == NULL) printf("Something went wrong...\n");
-	sokoban_print(screen);
-
+	//sokoban_print(screen);
 	time_end_read = clock();
+
 	time_start_encode = clock();
 
 	lace_init(0, 1000000);
diff --git a/modelchecker/object.c b/modelchecker/object.c
index 5829ed3..769163f 100644
--- a/modelchecker/object.c
+++ b/modelchecker/object.c
@@ -1,11 +1,99 @@
 #include <sylvan.h>
+#include <stdbool.h>
 
 #include "object.h"
 #include "sokoban.h"
 
-BDD solve_object(sokoban_screen *screen)
+#define MAX_BOX 50
+#define EPRINTF(fmt, as...) fprintf(stderr, fmt, ##as)
+
+int ilog2(int x)
+{
+	int l = 1;
+	while((x >>= 1) >= 1)
+		l++;
+	return l;
+}
+
+void get_screen_metrics(sokoban_screen *screen, 
+		int *boxes, 
+		int *mx, int *my,
+		int *agentx, int *agenty,
+		int *boxxes, int *boxyes)
+{
+	*boxes = 0;
+	*mx = 0;
+	*my = 0;
+	*agentx = 0;
+	*agenty = 0;
+	sokoban_screen *r;
+	for(r=screen; r != NULL; r = (sokoban_screen *)(r->hh.next)){
+		*mx = r->coord.x > *mx ? r->coord.x : *mx;
+		*my = r->coord.x > *mx ? r->coord.x : *mx;
+		switch(r->tile){
+		case TARGAGENT:
+		case AGENT:
+			*agentx = r->coord.x;
+			*agenty = r->coord.y;
+			break;
+		case TARGBOX:
+		case BOX:
+			boxxes[*boxes] = r->coord.x;
+			boxyes[*boxes] = r->coord.y;
+			*boxes += 1;
+			break;
+		default:;
+		}
+	}
+}
+
+BDD encode_int(BDD state, int x, int bx, int *variablenum)
+{
+	LACE_ME;
+	char *encoding = malloc(bx);
+	for(int i = 0; i<bx; i++){
+		if((x & (1<<i)) > 0){
+			state = sylvan_and(state, sylvan_ithvar(*variablenum));
+		} else {
+			state = sylvan_and(state, sylvan_nithvar(*variablenum));
+		}
+		*variablenum += 1;
+	}
+	free(encoding);
+	return state;
+}
+
+BDD encode_position(BDD state, int x, int y, int bx, int by, int *variablenum)
+{
+	state = encode_int(state, x, bx, variablenum);
+	return encode_int(state, y, by, variablenum);
+}
+
+/*
+ * We have variables numbered 1...
+ * Per coordinate we need k=bitsx+bitsy variables
+ *
+ * agent: 0     till k
+ * box_i: k+k*i till k+k*(i+1)
+ * We start with the agent
+ */
+BDD solve_object(sokoban_screen *scr)
 {
-	BDD state = sylvan_false;
+	int nboxes, mx, my, wx, wy, agentx, agenty;
+	int varnum = 0;
+	int boxx[MAX_BOX];
+	int boxy[MAX_BOX];
+	get_screen_metrics(scr, &nboxes, &mx, &my, &agentx, &agenty, boxx, boxy);
+
+	EPRINTF("Max x: %d, thus %d bits\n", mx, (wx = ilog2(mx)));
+	EPRINTF("Max y: %d, thus %d bits\n", my, (wy = ilog2(my)));
+	EPRINTF("%d boxes\n", nboxes);
+
+	BDD state = sylvan_true;
+	state = encode_position(state, agentx, agenty, wx, wy, &varnum);
+	for(int i = 0; i<nboxes; i++){
+		state = encode_position(state, boxx[i], boxy[i], wx, wy, &varnum);
+	}
+	
 	return state;
-	(void) screen; //To avoid not used error
 }
-- 
2.20.1