Use vector types in match_cell_ab(), and correct left handed cells

1 files changed, 25 insertions, 38 deletions

diff --git a/src/cell.c b/src/cell.c
index b1579251..ff9ff3d9 100644
--- a/src/cell.c
+++ b/src/cell.c
@@ -844,9 +844,7 @@ UnitCell *match_cell(UnitCell *cell, UnitCell *template, int verbose,
 }
 
 
-/* FIXME: Unify with proper match_cell(), or work out if it's even possible.
- * FIXME: Negative vectors are allowable, but keep a right-handed unit cell.
- * FIXME: Make sure unit cell is right handed.  */
+/* FIXME: Unify with proper match_cell(), or work out if it's even possible. */
 UnitCell *match_cell_ab(UnitCell *cell, UnitCell *template)
 {
 	double ax, ay, az;
@@ -855,16 +853,13 @@ UnitCell *match_cell_ab(UnitCell *cell, UnitCell *template)
 	int i;
 	double lengths[3];
 	int used[3];
-	double real_ax, real_ay, real_az;
-	double real_bx, real_by, real_bz;
-	double real_cx, real_cy, real_cz;
-	double params[3][3];
+	struct rvec real_a, real_b, real_c;
+	struct rvec params[3];
 	double alen, blen, clen;
 	float ltl = 5.0;     /* percent */
 	int have_real_a;
 	int have_real_b;
 	int have_real_c;
-	UnitCell *new_cell;
 
 	/* Get the lengths to match */
 	if ( cell_get_cartesian(template, &ax, &ay, &az,
@@ -889,53 +884,43 @@ UnitCell *match_cell_ab(UnitCell *cell, UnitCell *template)
 	lengths[0] = modulus(ax, ay, az);
 	lengths[1] = modulus(bx, by, bz);
 	lengths[2] = modulus(cx, cy, cz);
-	used[0] = 0;
-	used[1] = 0;
-	used[2] = 0;
-	params[0][0] = ax;  params[0][1] = ay;  params[0][2] = az;
-	params[1][0] = bx;  params[1][1] = by;  params[1][2] = bz;
-	params[2][0] = cx;  params[2][1] = cy;  params[2][2] = cz;
+	used[0] = 0;  used[1] = 0;  used[2] = 0;
+	params[0].u = ax;  params[0].v = ay;  params[0].w = az;
+	params[1].u = bx;  params[1].v = by;  params[1].w = bz;
+	params[2].u = cx;  params[2].v = cy;  params[2].w = cz;
 
-	real_ax = 0.0;  real_ay = 0.0;  real_az = 0.0;
-	real_bx = 0.0;  real_by = 0.0;  real_bz = 0.0;
-	real_cx = 0.0;  real_cy = 0.0;  real_cz = 0.0;
+	real_a.u = 0.0;  real_a.v = 0.0;  real_a.w = 0.0;
+	real_b.u = 0.0;  real_b.v = 0.0;  real_b.w = 0.0;
+	real_c.u = 0.0;  real_c.v = 0.0;  real_c.w = 0.0;
 
 	/* Check each vector against a and b */
 	have_real_a = 0;
 	have_real_b = 0;
 	for ( i=0; i<3; i++ ) {
-		if ( within_tolerance(lengths[i], alen, ltl) && !used[i]
-		     && !have_real_a )
+		if ( within_tolerance(lengths[i], alen, ltl)
+		     && !used[i] && !have_real_a )
 		{
 			used[i] = 1;
-			real_ax = params[i][0];
-			real_ay = params[i][1];
-			real_az = params[i][2];
+			memcpy(&real_a, &params[i], sizeof(struct rvec));
 			have_real_a = 1;
 		}
-		if ( within_tolerance(lengths[i], blen, ltl) && !used[i]
-		     && !have_real_b )
+		if ( within_tolerance(lengths[i], blen, ltl)
+		     && !used[i] && !have_real_b )
 		{
 			used[i] = 1;
-			real_bx = params[i][0];
-			real_by = params[i][1];
-			real_bz = params[i][2];
+			memcpy(&real_b, &params[i], sizeof(struct rvec));
 			have_real_b = 1;
 		}
 	}
 
 	/* Have we matched both a and b? */
-	if ( !(have_real_a && have_real_b) ) {
-		return NULL;
-	}
+	if ( !(have_real_a && have_real_b) ) return NULL;
 
 	/* "c" is "the other one" */
 	have_real_c = 0;
 	for ( i=0; i<3; i++ ) {
 		if ( !used[i] ) {
-			real_cx = params[i][0];
-			real_cy = params[i][1];
-			real_cz = params[i][2];
+			memcpy(&real_c, &params[i], sizeof(struct rvec));
 			have_real_c = 1;
 		}
 	}
@@ -946,12 +931,14 @@ UnitCell *match_cell_ab(UnitCell *cell, UnitCell *template)
 		return NULL;
 	}
 
-	new_cell = cell_new();
-	cell_set_cartesian(new_cell, real_ax, real_ay, real_az,
-	                             real_bx, real_by, real_bz,
-	                             real_cx, real_cy, real_cz);
+	/* Flip c if not right-handed */
+	if ( !right_handed(real_a, real_b, real_c) ) {
+		real_c.u = -real_c.u;
+		real_c.v = -real_c.v;
+		real_c.w = -real_c.w;
+	}
 
-	return new_cell;
+	return cell_new_from_direct_axes(real_a, real_b, real_c);
 }