Abstract away the operations involving a sentinel value for coordinates.

[super-star-trek.git] / src / sst.h

diff --git a/src/sst.h b/src/sst.h
index f96ea03bbd1499f0e8f1c388b365911bf2af0395..a9bf781e546a588bcd558fdde1a99ff2441fb253 100644 (file)
--- a/src/sst.h
+++ b/src/sst.h
@@ -45,14 +45,15 @@ typedef struct {int x; int y;} coord;
 #define square(i)              ((i)*(i))
 #define same(c1, c2)           ((c1.x == c2.x) && (c1.y == c2.y))
 #define distance(c1, c2)       sqrt(square(c1.x - c2.x) + square(c1.y - c2.y))
+#define invalidate(w)          w.x = w.y = 0
+#define is_valid(w)            (w.x == 0 || w.y == 0)
 
 typedef struct {
     coord w;
     enum {M=0, N=1, O=2} pclass;
     int inhabited;     /* if NZ, an index into a name array */
 #define UNINHABITED    -1
-    int crystals; /* has crystals */
-#define MINED  -1      /* used to have crystals, but they were mined out */
+    enum {mined=-1, present=0, absent=1} crystals; /* has crystals */
     enum {unknown, known, shuttle_down} known;
 } planet;