+
+#ifndef LEVEL_EDITOR
+
+static int get_cell_type(struct level *lvl, int x, int y)
+{
+ if(x < 0 || x >= lvl->width || y < 0 || y >= lvl->height) {
+ return CELL_SOLID;
+ }
+ return lvl->cells[y * lvl->width + x].type;
+}
+
+static int detect_cell_tile(struct level *lvl, int x, int y, int *rot)
+{
+ int i, j, bit;
+ unsigned int adj = 0;
+
+ bit = 0;
+ for(i=0; i<3; i++) {
+ for(j=0; j<3; j++) {
+ if(get_cell_type(lvl, x + j - 1, y + i - 1) == CELL_SOLID) {
+ adj |= 1 << bit;
+ }
+ bit++;
+ }
+ }
+
+ *rot = 0;
+
+ switch(adj) {
+ case 0:
+ case 0757:
+ /* really we'd need a separate tile type for "all neighbors solid", but we
+ * probably never going to need that in practice, so fuck it.
+ */
+ return TILE_OPEN;
+
+ case 0745:
+ case 0645:
+ case 0741:
+ case 0641:
+ return TILE_CORNER;
+
+ case 0744:
+ case 0644:
+ case 0740:
+ case 0640:
+ return TILE_OPENCORNER;
+
+ case 0715:
+ case 0315:
+ case 0714:
+ case 0314:
+ *rot = 1;
+ return TILE_CORNER;
+
+ case 0711:
+ case 0311:
+ case 0710:
+ case 0310:
+ *rot = 1;
+ return TILE_OPENCORNER;
+
+ case 0547:
+ case 0147:
+ case 0546:
+ case 0146:
+ *rot = 3;
+ return TILE_CORNER;
+
+ case 0447:
+ case 0047:
+ case 0446:
+ case 0046:
+ *rot = 3;
+ return TILE_OPENCORNER;
+
+ case 0517:
+ case 0417:
+ case 0513:
+ case 0413:
+ *rot = 2;
+ return TILE_CORNER;
+
+ case 0117:
+ case 0017:
+ case 0113:
+ case 0013:
+ *rot = 2;
+ return TILE_OPENCORNER;
+
+ case 0507: /* N tee */
+ *rot = 3;
+ return TILE_TEE;
+ case 0515: /* W tee */
+ *rot = 2;
+ return TILE_TEE;
+ case 0705: /* S tee */
+ *rot = 1;
+ return TILE_TEE;
+ case 0545: /* E tee */
+ return TILE_TEE;
+
+ case 0505: /* cross */
+ return TILE_CROSS;
+
+ case 0404: /* E str2open */
+ return TILE_STR2OPEN;
+ case 0005: /* N str2open */
+ *rot = 1;
+ return TILE_STR2OPEN;
+ case 0101: /* W str2open */
+ *rot = 2;
+ return TILE_STR2OPEN;
+ case 0500: /* S str2open */
+ *rot = 3;
+ return TILE_STR2OPEN;
+
+ default:
+ if((adj & 0222) == 0200) {
+ return TILE_STROPEN;
+ }
+ if((adj & 0222) == 0002) {
+ *rot = 2;
+ return TILE_STROPEN;
+ }
+ if((adj & 0070) == 0040) {
+ *rot = 3;
+ return TILE_STROPEN;
+ }
+ if((adj & 0070) == 0010) {
+ *rot = 1;
+ return TILE_STROPEN;
+ }
+
+ if((adj & 0070) == 0050) {
+ *rot = 1; /* straight N-S */
+ return TILE_STR;
+ }
+ if((adj & 0202) == 0202) {
+ return TILE_STR; /* straight E-W */
+ }
+ }
+
+ return TILE_OPEN;
+}
+
+#endif /* !LEVEL_EDITOR */