Make symmetry implementation more flexible

1 files changed, 61 insertions, 29 deletions

diff --git a/src/symmetry.c b/src/symmetry.c
index 913e887f..bedc146c 100644
--- a/src/symmetry.c
+++ b/src/symmetry.c
@@ -23,8 +23,9 @@
 
 /* Conditions for a reflection to be in the asymmetric unit cell */
 #define COND_1(h, k, l) (1)
-#define COND_6MMM(h, k, i, l) ( (h>=0) && (k>=0) && (l>=0) && ((h>k)||((h==0)&&(k==0))) )
-
+#define COND_6MMM(h, k, i, l) ( (h>=0) && (k>=0) && (l>=0) \
+                             && ((h>k)||((h==0)&&(k==0))) )
+/* TODO: Add more groups here */
 
 /* Macros for checking the above conditions and returning if satisfied */
 #define CHECK_COND_FOURIDX(h, k, i, l, cond)       \
@@ -46,6 +47,55 @@
 	abort();
 
 
+/* FIXME: Should take into account special indices
+ * e.g. l==0 has fewer equivalent reflections */
+static int num_equivs4(signed int h, signed int k, signed int i, signed int l,
+                       const char *sym)
+{
+	if ( strcmp(sym, "6/mmm") == 0 ) return 24;
+	/* TODO: Add more groups here */
+
+	return 1;
+}
+
+
+static void get_equiv4(signed int h, signed int k, signed int i, signed int l,
+                       signed int *he, signed int *ke, signed int *ie,
+                       signed int *le, const char *sym, int idx)
+{
+	if ( strcmp(sym, "6/mmm") == 0 ) {
+		switch ( idx ) {
+		case  0 : *he = h;  *ke = k;  *ie = i;  *le = l;  return;
+		case  1 : *he = h;  *ke = i;  *ie = k;  *le = l;  return;
+		case  2 : *he = k;  *ke = h;  *ie = i;  *le = l;  return;
+		case  3 : *he = k;  *ke = i;  *ie = h;  *le = l;  return;
+		case  4 : *he = i;  *ke = h;  *ie = k;  *le = l;  return;
+		case  5 : *he = i;  *ke = k;  *ie = h;  *le = l;  return;
+		case  6 : *he = h;  *ke = k;  *ie = i;  *le = -l;  return;
+		case  7 : *he = h;  *ke = i;  *ie = k;  *le = -l;  return;
+		case  8 : *he = k;  *ke = h;  *ie = i;  *le = -l;  return;
+		case  9 : *he = k;  *ke = i;  *ie = h;  *le = -l;  return;
+		case 10 : *he = i;  *ke = h;  *ie = k;  *le = -l;  return;
+		case 11 : *he = i;  *ke = k;  *ie = h;  *le = -l;  return;
+		case 12 : *he = -h;  *ke = -k;  *ie = -i;  *le = l;  return;
+		case 13 : *he = -h;  *ke = -i;  *ie = -k;  *le = l;  return;
+		case 14 : *he = -k;  *ke = -h;  *ie = -i;  *le = l;  return;
+		case 15 : *he = -k;  *ke = -i;  *ie = -h;  *le = l;  return;
+		case 16 : *he = -i;  *ke = -h;  *ie = -k;  *le = l;  return;
+		case 17 : *he = -i;  *ke = -k;  *ie = -h;  *le = l;  return;
+		case 18 : *he = -h;  *ke = -k;  *ie = -i;  *le = -l;  return;
+		case 19 : *he = -h;  *ke = -i;  *ie = -k;  *le = -l;  return;
+		case 20 : *he = -k;  *ke = -h;  *ie = -i;  *le = -l;  return;
+		case 21 : *he = -k;  *ke = -i;  *ie = -h;  *le = -l;  return;
+		case 22 : *he = -i;  *ke = -h;  *ie = -k;  *le = -l;  return;
+		case 23 : *he = -i;  *ke = -k;  *ie = -h;  *le = -l;  return;
+		}
+	}
+
+	*he = h;  *ke = k;  *ie = i;  *le = l;
+}
+
+
 void get_asymm(signed int h, signed int k, signed int l,
                signed int *hp, signed int *kp, signed int *lp,
                const char *sym)
@@ -58,39 +108,21 @@ void get_asymm(signed int h, signed int k, signed int l,
 	if ( strcmp(sym, "6/mmm") == 0 ) {
 
 		const signed int i = h+k;
+		int nequiv = num_equivs4(h, k, i, l, sym);
+		int p;
 
-		CHECK_COND_FOURIDX(h, k, i, l, 6MMM);
-		CHECK_COND_FOURIDX(h, i, k, l, 6MMM);
-		CHECK_COND_FOURIDX(k, h, i, l, 6MMM);
-		CHECK_COND_FOURIDX(k, i, h, l, 6MMM);
-		CHECK_COND_FOURIDX(i, h, k, l, 6MMM);
-		CHECK_COND_FOURIDX(i, k, h, l, 6MMM);
-
-		CHECK_COND_FOURIDX(h, k, i, -l, 6MMM);
-		CHECK_COND_FOURIDX(h, i, k, -l, 6MMM);
-		CHECK_COND_FOURIDX(k, h, i, -l, 6MMM);
-		CHECK_COND_FOURIDX(k, i, h, -l, 6MMM);
-		CHECK_COND_FOURIDX(i, h, k, -l, 6MMM);
-		CHECK_COND_FOURIDX(i, k, h, -l, 6MMM);
-
-		CHECK_COND_FOURIDX(-h, -k, -i, l, 6MMM);
-		CHECK_COND_FOURIDX(-h, -i, -k, l, 6MMM);
-		CHECK_COND_FOURIDX(-k, -h, -i, l, 6MMM);
-		CHECK_COND_FOURIDX(-k, -i, -h, l, 6MMM);
-		CHECK_COND_FOURIDX(-i, -h, -k, l, 6MMM);
-		CHECK_COND_FOURIDX(-i, -k, -h, l, 6MMM);
-
-		CHECK_COND_FOURIDX(-h, -k, -i, -l, 6MMM);
-		CHECK_COND_FOURIDX(-h, -i, -k, -l, 6MMM);
-		CHECK_COND_FOURIDX(-k, -h, -i, -l, 6MMM);
-		CHECK_COND_FOURIDX(-k, -i, -h, -l, 6MMM);
-		CHECK_COND_FOURIDX(-i, -h, -k, -l, 6MMM);
-		CHECK_COND_FOURIDX(-i, -k, -h, -l, 6MMM);
+		for ( p=0; p<nequiv; p++ ) {
+			signed int he, ke, ie, le;
+			get_equiv4(h, k, i, l, &he, &ke, &ie, &le, sym, p);
+			CHECK_COND_FOURIDX(he, ke, ie, le, 6MMM);
+		}
 
 		SYM_ABORT;  /* Should never reach here */
 
 	}
 
+	/* TODO: Add more groups here */
+
 	ERROR("Unknown point group '%s'\n", sym);
 	abort();
 }