Grid to editor

editor/client/public/common/chunkterrain.js

@@ -105,6 +105,46 @@ const ChunkTerrain = (() => {
     return new Float32Array(out);
   }
 
+  // Four edges (SW-SE, SE-NE, NE-NW, NW-SW) of a tile's quad as line
+  // segments, lifted slightly above the terrain surface to avoid
+  // z-fighting - same corner-height convention as pushTileQuad().
+  function pushTileGridLines(out, fx, fy, swZ, seZ, neZ, nwZ) {
+    const eps = 0.01;
+    const sw = [fx,     fy,     swZ + eps];
+    const se = [fx + 1, fy,     seZ + eps];
+    const ne = [fx + 1, fy + 1, neZ + eps];
+    const nw = [fx,     fy + 1, nwZ + eps];
+    const edges = [sw, se, se, ne, ne, nw, nw, sw];
+    for(const [x, y, z] of edges) out.push(0, 0, x, y, z);
+  }
+
+  // Generate grid-outline line segments for every non-null tile, following
+  // the same per-corner heights as buildTerrainVerts() so lines hug ramps
+  // instead of cutting through them. Returns a Float32Array of interleaved
+  // [u, v, x, y, z] vertices meant to be drawn with gl.LINES (pairs).
+  function buildGridLines(tiles) {
+    const out = [];
+    for(let z = 0; z < CHUNK_DEPTH; z++) {
+      for(let y = 0; y < CHUNK_HEIGHT; y++) {
+        for(let x = 0; x < CHUNK_WIDTH; x++) {
+          const type = tiles[tileIndex(x, y, z)] || TILE_SHAPE_NULL;
+          const corners = RAMP_CORNERS[type];
+          if(!corners) continue;
+
+          const [sw, se, ne, nw] = corners;
+          pushTileGridLines(
+            out, x, y,
+            (z + sw) * WORLD_LAYER_HEIGHT,
+            (z + se) * WORLD_LAYER_HEIGHT,
+            (z + ne) * WORLD_LAYER_HEIGHT,
+            (z + nw) * WORLD_LAYER_HEIGHT
+          );
+        }
+      }
+    }
+    return new Float32Array(out);
+  }
+
   return Object.freeze({
     CHUNK_WIDTH, CHUNK_HEIGHT, CHUNK_DEPTH, TILE_COUNT, WORLD_LAYER_HEIGHT,
     TILE_SHAPE_NULL, TILE_SHAPE_GROUND,
@@ -114,6 +154,6 @@ const ChunkTerrain = (() => {
     TILE_SHAPE_RAMP_SOUTHEAST, TILE_SHAPE_RAMP_SOUTHWEST,
     TILE_SHAPE_RAMP_NORTHEAST_INNER, TILE_SHAPE_RAMP_NORTHWEST_INNER,
     TILE_SHAPE_RAMP_SOUTHEAST_INNER, TILE_SHAPE_RAMP_SOUTHWEST_INNER,
-    RAMP_CORNERS, tileIndex, buildTerrainVerts,
+    RAMP_CORNERS, tileIndex, buildTerrainVerts, buildGridLines,
   });
 })();