1 files changed, 30 insertions, 8 deletions

diff --git a/libphysics/body.c b/libphysics/body.c
index d8a17e5..9495305 100644
--- a/libphysics/body.c
+++ b/libphysics/body.c
@@ -1,6 +1,7 @@
 #include <vecmath.h>
 #include <physics.h>
 #include <stdlib.h>
+#include <assert.h>
 
 #include "dat.h"
 
@@ -19,44 +20,44 @@ phxnew(BodyType type)
 	if((b = allocbody()) == -1)
 		return b;
 
-	phxbodypool[b].type = type;
+	__getbodydata(b)->type = type;
 	return b;
 }
 
 void
 phxdel(BodyID id)
 {
-	phxbodypool[id].active = 0;
+	__getbodydata(id)->active = 0;
 }
 
 void
 phxsetpos(BodyID b, float x, float y)
 {
-	vec2_dup(phxbodypool[b].pos, (vec2){ x, y });
+	vec2_dup(__getbodydata(b)->pos, (vec2){ x, y });
 }
 
 void
 phxsetsize(BodyID b, float w, float h)
 {
-	vec2_dup(phxbodypool[b].size, (vec2){ w, h });
+	vec2_dup(__getbodydata(b)->size, (vec2){ w, h });
 }
 
 void
 phxgetpos(BodyID b, float p[2])
 {
-	vec2_dup(p, phxbodypool[b].pos);
+	vec2_dup(p, __getbodydata(b)->pos);
 }
 
 void
 phxgetsize(BodyID b, float p[2])
 {
-	vec2_dup(p, phxbodypool[b].size);
+	vec2_dup(p, __getbodydata(b)->size);
 }
 
 void
 phxapplyaccel(BodyID b, float a[2])
 {
-	vec2_add(phxbodypool[b].accel, phxbodypool[b].accel, a);
+	vec2_add(__getbodydata(b)->accel, __getbodydata(b)->accel, a);
 }
 
 BodyID
@@ -75,5 +76,26 @@ allocbody(void)
 	}
 
 	phxbodypool[i].active = 1;
-	return i;
+	phxbodypool[i].generation++;
+
+	return __getbodyid(phxbodypool + i);
+}
+
+Body *
+__getbodydata(BodyID id)
+{
+	unsigned int i = id >> 16;
+	unsigned int g = id & 0xFFFF;
+
+	assert(i < POOL_SIZE);
+	assert((phxbodypool[i].generation & 0xFFFF) == g);
+
+	return phxbodypool + i;
+}
+
+BodyID
+__getbodyid(Body *b)
+{
+	unsigned int i = b - phxbodypool;
+	return (i << 16) | (phxbodypool[i].generation & 0xFFFF);
 }