From 585f3c34b1925111652484c9c07a25f75b9358d8 Mon Sep 17 00:00:00 2001
From: Azgaar <azgaar.fmg@yandex.com>
Date: Fri, 31 Oct 2025 02:55:02 +0100
Subject: [PATCH] feat: 3d mode - improve water bodies mesh

---
 index.html            |  5 +++++
 modules/ui/3d.js      | 41 +++++++++++++++++++++++++++++++++++++++--
 modules/ui/options.js |  8 ++++----
 3 files changed, 48 insertions(+), 6 deletions(-)

diff --git a/index.html b/index.html
index 80241d98..d2d184b4 100644
--- a/index.html
+++ b/index.html
@@ -5993,6 +5993,11 @@
             >
           </div>
 
+          <div data-tip="Toggle wireframe mode" style="margin: 0.6em 0 0.3em -0.2em">
+            <input id="options3dMeshWireframeMode" class="checkbox" type="checkbox" />
+            <label for="options3dMeshWireframeMode" class="checkbox-label"><i>Show wireframe</i></label>
+          </div>
+
           <div data-tip="Set sky and water color" id="options3dColorSection" style="display: none">
             <span>Sky:</span
             ><input
diff --git a/modules/ui/3d.js b/modules/ui/3d.js
index 4981caca..fb23da7b 100644
--- a/modules/ui/3d.js
+++ b/modules/ui/3d.js
@@ -39,6 +39,7 @@ window.ThreeD = (function () {
   let labels = [];
   let icons = [];
   let lines = [];
+  let gridToPackCellMap = null; // Map from grid cell index to pack cell index
 
   const context2d = document.createElement("canvas").getContext("2d");
 
@@ -486,8 +487,20 @@ window.ThreeD = (function () {
       };
     });
   }
+
   // create a mesh from pixel data
   async function createMesh(width, height, segmentsX, segmentsY) {
+    // Build lookup map from grid cell index to pack cell index
+    gridToPackCellMap = new Map();
+    if (pack.cells?.g && pack.cells?.i) {
+      for (const packCellIndex of pack.cells.i) {
+        const gridCellIndex = pack.cells.g[packCellIndex];
+        if (!gridToPackCellMap.has(gridCellIndex)) {
+          gridToPackCellMap.set(gridCellIndex, packCellIndex);
+        }
+      }
+    }
+
     if (texture) texture.dispose();
     if (!options.wireframe) {
       texture = new THREE.TextureLoader().load(await createMeshTextureUrl(), render);
@@ -541,9 +554,32 @@ window.ThreeD = (function () {
     }
   }
 
+  const LOWER_BY_WATER = 18;
+  const DIVIDER = 100 - LOWER_BY_WATER;
+
   function getMeshHeight(i) {
-    const h = grid.cells.h[i];
-    return h < 20 ? 0 : ((h - 18) / 82) * options.scale;
+    const height = grid.cells.h[i];
+
+    let waterCellId = null;
+    if (height < 20) {
+      waterCellId = i;
+    } else if (grid.cells.c[i]) {
+      waterCellId = grid.cells.c[i].find(c => grid.cells.h[c] < 20) ?? null;
+    }
+
+    // If water vertex, get uniform elevation
+    if (waterCellId !== null) {
+      const packCellIndex = gridToPackCellMap.get(waterCellId);
+      const featureId = pack.cells.f[packCellIndex];
+      if (featureId === undefined) return 0;
+
+      const feature = pack.features[featureId];
+      const waterHeight = feature.type === "lake" && feature.height ? feature.height : 20;
+      return ((waterHeight - LOWER_BY_WATER) / DIVIDER) * options.scale;
+    }
+
+    // Land vertex
+    return ((height - LOWER_BY_WATER) / DIVIDER) * options.scale;
   }
 
   function extendWater(width, height) {
@@ -699,6 +735,7 @@ window.ThreeD = (function () {
       script.onerror = () => resolve(false);
     });
   }
+
   function OrbitControls(camera, domElement) {
     if (THREE.OrbitControls) return new THREE.OrbitControls(camera, domElement);
 
diff --git a/modules/ui/options.js b/modules/ui/options.js
index 84c1a6a0..551a78e6 100644
--- a/modules/ui/options.js
+++ b/modules/ui/options.js
@@ -1051,7 +1051,7 @@ function toggle3dOptions() {
   byId("options3dMeshSky").addEventListener("input", changeColors);
   byId("options3dMeshWater").addEventListener("input", changeColors);
   byId("options3dGlobeResolution").addEventListener("change", changeResolution);
-  // byId("options3dMeshWireframeMode").addEventListener("change",toggleWireframe3d);
+  byId("options3dMeshWireframeMode").addEventListener("change", toggleWireframe3d);
   byId("options3dSunColor").addEventListener("input", changeSunColor);
   byId("options3dSubdivide").addEventListener("change", toggle3dSubdivision);
 
@@ -1116,9 +1116,9 @@ function toggle3dOptions() {
     ThreeD.toggle3dSubdivision();
   }
 
-  // function toggleWireframe3d() {
-  //   ThreeD.toggleWireframe();
-  // }
+  function toggleWireframe3d() {
+    ThreeD.toggleWireframe();
+  }
 
   function toggleSkyMode() {
     const hide = ThreeD.options.extendedWater;