better rotations

[moebius2.git] / mgraph.c

diff --git a/mgraph.c b/mgraph.c
index 222bd094a92be74d70a52a6b0b05606a2a0b337c..cf57624262ae1c00224f6566cc112a81e6f50fb6 100644 (file)
--- a/mgraph.c
+++ b/mgraph.c
@@ -4,27 +4,10 @@
 
 #include "mgraph.h"
 
-static const unsigned dx[V6]= {   0,  +1,  -1,  +1,  -1,   0  },
-                      dy[V6]= { +Y1, +Y1,   0,   0, -Y1, -Y1  };
-
+static const unsigned dx[V6]= {  +1,  +1,   0,  -1,  -1,   0  },
+                      dy[V6]= {   0, -Y1, -Y1,   0, +Y1, +Y1  };
 
 int edge_end2(unsigned v1, int e) {
-  /* The topology is equivalent to that of a square lattice with only
-   * half of the diagonals.  Ie, the result of shearing the triangular
-   * lattice to make the lines of constant x vertical.  This gives
-   * these six directions:
-   *
-   *                0  1
-   *                | /
-   *                |/
-   *             2--*--3
-   *              /|
-   *             / |
-   *            4  5
-   *
-   * This also handily makes vertical the numbering discontinuity,
-   * where the join happens.
-   */
   unsigned x, y;
 
   y= (v1 & YMASK) + dy[e];