agar: Re-entrant Abstract Graph Algorithms

[ccan] / ccan / agar / test / grid.c

diff --git a/ccan/agar/test/grid.c b/ccan/agar/test/grid.c
new file mode 100644 (file)
index 0000000..3b59c38
--- /dev/null
+++ b/ccan/agar/test/grid.c
@@ -0,0 +1,81 @@
+#include "config.h"
+
+#include <assert.h>
+
+#include <ccan/container_of/container_of.h>
+#include <ccan/ptrint/ptrint.h>
+
+#include <ccan/agar/agar.h>
+
+#include "simple-graphr.h"
+
+static const void *grid_first_edge_r(const struct agar_graph *gr,
+                                    const void *nr)
+{
+       return int2ptr(1);
+}
+
+static const void *grid_next_edge_r(const struct agar_graph *gr,
+                                   const void *nr, const void *e)
+{
+       int index = ptr2int(e);
+
+       if (index < 4)
+               return int2ptr(index + 1);
+       else
+               return NULL;           
+}
+
+static int grid_edge_info_r(const struct agar_graph *gr,
+                           const void *nr, const void *e,
+                           struct agar_edge_info *eir)
+{
+       struct grid_graphr *ggr = container_of(gr, struct grid_graphr, gr);
+       int ni = ptr2int(nr);
+       int x = ((ni - 1) % ggr->nx) + 1;
+       int y = ((ni - 1) / ggr->nx) + 1;
+       int i = ptr2int(e);
+
+       assert((x >= 1) && (x <= ggr->nx));
+       assert((y >= 1) && (y <= ggr->ny));
+
+       switch (i) {
+       case 1: /* right */
+               if (ggr->right && (x != ggr->nx))
+                       eir->to = int2ptr(ni + 1);
+               break;
+
+       case 2: /* down */
+               if (ggr->down && (y != ggr->ny))
+                       eir->to = int2ptr(ni + ggr->nx);
+               break;
+               
+       case 3: /* left */
+               if (ggr->left && (x != 1))
+                       eir->to = int2ptr(ni - 1);
+               break;
+
+       case 4: /* up */
+               if (ggr->up && (y != 1))
+                       eir->to = int2ptr(ni - ggr->nx);
+               break;
+
+       default:
+               assert(0);
+       }
+       return 0;
+}
+
+void grid_graphr_init(struct grid_graphr *ggr, int nx, int ny,
+                    bool right, bool down, bool left, bool up)
+{
+       ggr->nx = nx;
+       ggr->ny = ny;
+       ggr->right = right;
+       ggr->down = down;
+       ggr->left = left;
+       ggr->up = up;
+
+       agar_init_graph(&ggr->gr, grid_first_edge_r, grid_next_edge_r,
+                       grid_edge_info_r);
+}