3 files changed, 15 insertions, 6 deletions

diff --git a/demos/checkerboard/checkerboard.c b/demos/checkerboard/checkerboard.c
index 467da61..243f7a8 100644
--- a/demos/checkerboard/checkerboard.c
+++ b/demos/checkerboard/checkerboard.c
@@ -86,7 +86,8 @@ static bool init(GfxApp* app, GfxAppState* state, int argc, const char** argv) {
                       .tile_height  = TILE_HEIGHT,
                       .world_width  = WORLD_WIDTH,
                       .world_height = WORLD_HEIGHT,
-                      .num_tiles    = NUM_TILES});
+                      .num_tiles    = NUM_TILES,
+                      .orientation  = MapIsometric});
 
   const Tile black = gfx2d_make_tile(iso, &tile_set[Black]);
   const Tile white = gfx2d_make_tile(iso, &tile_set[White]);
diff --git a/include/isogfx/gfx2d.h b/include/isogfx/gfx2d.h
index 59566f3..a3ddbb6 100644
--- a/include/isogfx/gfx2d.h
+++ b/include/isogfx/gfx2d.h
@@ -37,12 +37,18 @@ typedef struct TileDesc {
   };
 } TileDesc;
 
+typedef enum MapOrientation {
+  MapOrthogonal,
+  MapIsometric,
+} MapOrientation;
+
 typedef struct MapDesc {
-  int tile_width;   // Base tile width in pixels.
-  int tile_height;  // Base tile height in pixels.
-  int world_width;  // World width in tiles.
-  int world_height; // World height in tiles.
-  int num_tiles;    // Number of tiles to allocate memory for.
+  int            tile_width;   // Base tile width in pixels.
+  int            tile_height;  // Base tile height in pixels.
+  int            world_width;  // World width in tiles.
+  int            world_height; // World height in tiles.
+  int            num_tiles;    // Number of tiles to allocate memory for.
+  MapOrientation orientation;  // Map orientation.
 } MapDesc;
 
 typedef struct IsoGfxDesc {
diff --git a/src/gfx2d.c b/src/gfx2d.c
index 266a5f7..f609c98 100644
--- a/src/gfx2d.c
+++ b/src/gfx2d.c
@@ -263,6 +263,8 @@ void gfx2d_make_map(Gfx2d* gfx, const MapDesc* desc) {
       .base_tile_width  = desc->tile_width,
       .base_tile_height = desc->tile_height,
       .num_layers       = 1,
+      .flags =
+          (desc->orientation == MapOrthogonal) ? Tm_Orthogonal : Tm_Isometric,
   };
 
   gfx->tileset  = memstack_alloc_aligned(&gfx->stack, tileset_size_bytes, 4);