boundary: add public functions for querying boundary information

Should allow treating boundaries in a generic manner.

API bump

1 files changed, 59 insertions, 0 deletions

diff --git a/boundary.c b/boundary.c
index 86803fc..419a310 100644
--- a/boundary.c
+++ b/boundary.c
@@ -16,6 +16,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include <errno.h>
 #include <stddef.h>
 #include <stdlib.h>
 
@@ -73,3 +74,61 @@ void mg2di_bc_free(MG2DBoundary **pbnd)
     free(bnd);
     *pbnd = NULL;
 }
+
+static const struct {
+    unsigned int coord_idx;
+    unsigned int is_upper;
+} boundary_def[] = {
+    [MG2D_BOUNDARY_0L] = {
+        .coord_idx = 0,
+        .is_upper  = 0,
+    },
+    [MG2D_BOUNDARY_0U] = {
+        .coord_idx = 0,
+        .is_upper  = 1,
+    },
+    [MG2D_BOUNDARY_1L] = {
+        .coord_idx = 1,
+        .is_upper  = 0
+    },
+    [MG2D_BOUNDARY_1U] = {
+        .coord_idx = 1,
+        .is_upper  = 1,
+    },
+};
+
+int mg2d_bnd_coord_idx(enum MG2DBoundaryLoc loc)
+{
+    if (loc < 0 || loc >= ARRAY_ELEMS(boundary_def))
+        return -EINVAL;
+
+    return boundary_def[loc].coord_idx;
+}
+
+int mg2d_bnd_is_upper(enum MG2DBoundaryLoc loc)
+{
+    if (loc < 0 || loc >= ARRAY_ELEMS(boundary_def))
+        return -EINVAL;
+
+    return boundary_def[loc].is_upper;
+}
+
+int mg2d_bnd_out_dir(enum MG2DBoundaryLoc loc)
+{
+    int ret = mg2d_bnd_is_upper(loc);
+
+    if (ret < 0)
+        return 0;
+
+    return ret ? 1 : -1;
+}
+
+enum MG2DBoundaryLoc mg2d_bnd_id(int coord_idx, int is_upper)
+{
+    for (int i = 0; i < ARRAY_ELEMS(boundary_def); i++) {
+        if (boundary_def[i].coord_idx == coord_idx &&
+            boundary_def[i].is_upper  == is_upper)
+            return i;
+    }
+    return MG2D_BOUNDARY_NONE;
+}