Add test hill

tools/asset/chunk/__main__.py

@@ -64,8 +64,16 @@ CHUNK_MESH_NAME_MAX  = 64
 TILE_SIZE   = 4
 VERTEX_SIZE = 20
 
-TILE_SHAPE_NULL   = 0
-TILE_SHAPE_GROUND = 1
+TILE_SHAPE_NULL      = 0
+TILE_SHAPE_GROUND    = 1
+TILE_SHAPE_RAMP_NORTH     = 2
+TILE_SHAPE_RAMP_EAST      = 3
+TILE_SHAPE_RAMP_SOUTH     = 4
+TILE_SHAPE_RAMP_WEST      = 5
+TILE_SHAPE_RAMP_NORTHEAST = 6
+TILE_SHAPE_RAMP_NORTHWEST = 7
+TILE_SHAPE_RAMP_SOUTHEAST = 8
+TILE_SHAPE_RAMP_SOUTHWEST = 9
 
 FILE_MAGIC  = b'DCF'
 DMF_MAGIC   = b'DMF\x00'
@@ -147,8 +155,42 @@ def write_v3(dcf_path, tiles, mesh_names, mesh_offsets=None):
 # JSON -> DCF + DMF
 # ---------------------------------------------------------------------------
 
+def _tile_quad(u0, u1, v0, v1, fx, fy, sw_z, se_z, ne_z, nw_z):
+    """Six vertices (2 CCW triangles) for a quad with per-corner Z heights.
+    Corner order: SW=(fx,fy), SE=(fx+1,fy), NE=(fx+1,fy+1), NW=(fx,fy+1).
+    NORTH=+Y, EAST=+X (matches entityDirGetRelative)."""
+    verts = [
+        (u0, v0, fx,   fy,   sw_z),
+        (u1, v0, fx+1, fy,   se_z),
+        (u1, v1, fx+1, fy+1, ne_z),
+        (u0, v0, fx,   fy,   sw_z),
+        (u1, v1, fx+1, fy+1, ne_z),
+        (u0, v1, fx,   fy+1, nw_z),
+    ]
+    buf = bytearray()
+    for v in verts:
+        buf += struct.pack('<5f', *v)
+    return bytes(buf)
+
+
+# Per-shape corner heights as (sw, se, ne, nw) offsets from tile base Z.
+# NORTH=+Y, EAST=+X.  Cardinal ramps: low face at 0, high face at 1.
+# Diagonal ramps: opposite corner at 0/1, adjacent corners at 0.5.
+_RAMP_CORNERS = {
+    TILE_SHAPE_GROUND:         (0.0, 0.0, 0.0, 0.0),
+    TILE_SHAPE_RAMP_NORTH:     (0.0, 0.0, 1.0, 1.0),  # south=low, north=high
+    TILE_SHAPE_RAMP_SOUTH:     (1.0, 1.0, 0.0, 0.0),  # south=high, north=low
+    TILE_SHAPE_RAMP_EAST:      (0.0, 1.0, 1.0, 0.0),  # west=low, east=high
+    TILE_SHAPE_RAMP_WEST:      (1.0, 0.0, 0.0, 1.0),  # west=high, east=low
+    TILE_SHAPE_RAMP_NORTHEAST: (0.0, 0.0, 1.0, 0.0),  # only NE raised
+    TILE_SHAPE_RAMP_NORTHWEST: (0.0, 0.0, 0.0, 1.0),  # only NW raised
+    TILE_SHAPE_RAMP_SOUTHEAST: (0.0, 1.0, 0.0, 0.0),  # only SE raised
+    TILE_SHAPE_RAMP_SOUTHWEST: (1.0, 0.0, 0.0, 0.0),  # only SW raised
+}
+
+
 def build_terrain_verts(tiles_bytes):
-    """Generate top-face quads for every TILE_SHAPE_GROUND tile."""
+    """Generate quads for every non-null tile, shaped to match tile type."""
     buf = bytearray()
     for z in range(CHUNK_DEPTH):
         for y in range(CHUNK_HEIGHT):
@@ -157,22 +199,19 @@ def build_terrain_verts(tiles_bytes):
                 tile_type = struct.unpack_from(
                     '<I', tiles_bytes, idx * TILE_SIZE
                 )[0]
-                if tile_type != TILE_SHAPE_GROUND:
+                corners = _RAMP_CORNERS.get(tile_type)
+                if corners is None:
                     continue
                 fx, fy, fz = float(x), float(y), float(z)
-                uv_u0 = x / CHUNK_WIDTH
-                uv_u1 = (x + 1) / CHUNK_WIDTH
-                uv_v0 = y / CHUNK_HEIGHT
-                uv_v1 = (y + 1) / CHUNK_HEIGHT
-                for v in [
-                    (uv_u0, uv_v0, fx,   fy,   fz),
-                    (uv_u1, uv_v0, fx+1, fy,   fz),
-                    (uv_u1, uv_v1, fx+1, fy+1, fz),
-                    (uv_u0, uv_v0, fx,   fy,   fz),
-                    (uv_u1, uv_v1, fx+1, fy+1, fz),
-                    (uv_u0, uv_v1, fx,   fy+1, fz),
-                ]:
-                    buf += struct.pack('<5f', *v)
+                u0 = x / CHUNK_WIDTH
+                u1 = (x + 1) / CHUNK_WIDTH
+                v0 = y / CHUNK_HEIGHT
+                v1 = (y + 1) / CHUNK_HEIGHT
+                sw, se, ne, nw = corners
+                buf += _tile_quad(
+                    u0, u1, v0, v1, fx, fy,
+                    fz + sw, fz + se, fz + ne, fz + nw
+                )
     return bytes(buf)