From 88dfa6a264a8da65bb38b86dd49a93c33013844b Mon Sep 17 00:00:00 2001
From: Wentao Kuang <wkuang@linz.govt.nz>
Date: Thu, 14 Nov 2024 14:55:25 +1300
Subject: [PATCH 1/2] Fix NZTM terrain exaggeration been multiplyed twice/

---
 packages/lambda-tiler/src/util/nztm.style.ts | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/packages/lambda-tiler/src/util/nztm.style.ts b/packages/lambda-tiler/src/util/nztm.style.ts
index d297617f1..b3ca78cff 100644
--- a/packages/lambda-tiler/src/util/nztm.style.ts
+++ b/packages/lambda-tiler/src/util/nztm.style.ts
@@ -37,8 +37,5 @@ export function convertStyleToNztmStyle(inputStyle: StyleJson, clone: boolean =
     }
   }
 
-  /** Based on {@link DefaultExaggeration} offsetting by 2 two levels changes the exaggeration needed by approx 4x */
-  if (style.terrain) style.terrain.exaggeration = style.terrain.exaggeration * 4;
-
   return style;
 }

From c19dd8bf09fa4a115ece29d8dca6a4e295c00fdf Mon Sep 17 00:00:00 2001
From: Wentao Kuang <wkuang@linz.govt.nz>
Date: Thu, 14 Nov 2024 15:40:49 +1300
Subject: [PATCH 2/2] Fix the broken tests

---
 .../routes/__tests__/tile.style.json.test.ts  |  5 ++--
 .../src/routes/tile.style.json.ts             |  2 +-
 .../src/util/__test__/nztm.style.test.ts      | 26 +++++++++++++------
 3 files changed, 22 insertions(+), 11 deletions(-)

diff --git a/packages/lambda-tiler/src/routes/__tests__/tile.style.json.test.ts b/packages/lambda-tiler/src/routes/__tests__/tile.style.json.test.ts
index d15ec5f91..edec5c4fa 100644
--- a/packages/lambda-tiler/src/routes/__tests__/tile.style.json.test.ts
+++ b/packages/lambda-tiler/src/routes/__tests__/tile.style.json.test.ts
@@ -2,7 +2,8 @@ import assert from 'node:assert';
 import { afterEach, before, beforeEach, describe, it } from 'node:test';
 
 import { ConfigProviderMemory, SourceRaster, StyleJson } from '@basemaps/config';
-import { Terrain } from '@basemaps/config/src/config/vector.style.js';
+import { DefaultExaggeration, Terrain } from '@basemaps/config/build/config/vector.style.js';
+import { Nztm2000QuadTms } from '@basemaps/geo';
 import { Env } from '@basemaps/shared';
 import { createSandbox } from 'sinon';
 
@@ -441,7 +442,7 @@ describe('/v1/styles', () => {
           },
         ],
         terrain: {
-          exaggeration: 1.1,
+          exaggeration: DefaultExaggeration[Nztm2000QuadTms.identifier],
         },
       },
     };
diff --git a/packages/lambda-tiler/src/routes/tile.style.json.ts b/packages/lambda-tiler/src/routes/tile.style.json.ts
index efa7c7044..327a8ef3e 100644
--- a/packages/lambda-tiler/src/routes/tile.style.json.ts
+++ b/packages/lambda-tiler/src/routes/tile.style.json.ts
@@ -90,7 +90,7 @@ export interface StyleConfig {
 /**
  * Turn on the terrain setting in the style json
  */
-function setStyleTerrain(style: StyleJson, terrain: string, tileMatrix: TileMatrixSet): void {
+export function setStyleTerrain(style: StyleJson, terrain: string, tileMatrix: TileMatrixSet): void {
   const source = Object.keys(style.sources).find((s) => s === terrain);
   if (source == null) throw new LambdaHttpResponse(400, `Terrain: ${terrain} does not exists in the style source.`);
   style.terrain = {
diff --git a/packages/lambda-tiler/src/util/__test__/nztm.style.test.ts b/packages/lambda-tiler/src/util/__test__/nztm.style.test.ts
index ba907ee14..622d42bc7 100644
--- a/packages/lambda-tiler/src/util/__test__/nztm.style.test.ts
+++ b/packages/lambda-tiler/src/util/__test__/nztm.style.test.ts
@@ -2,7 +2,9 @@ import assert from 'node:assert';
 import { describe, it } from 'node:test';
 
 import { StyleJson } from '@basemaps/config';
+import { GoogleTms, Nztm2000QuadTms } from '@basemaps/geo';
 
+import { setStyleTerrain } from '../../routes/tile.style.json.js';
 import { convertStyleToNztmStyle } from '../nztm.style.js';
 
 describe('NZTM2000QuadStyle', () => {
@@ -25,9 +27,6 @@ describe('NZTM2000QuadStyle', () => {
 
     convertStyleToNztmStyle(baseStyle);
     assert.equal(baseStyle.terrain?.exaggeration, 1.1);
-
-    convertStyleToNztmStyle(baseStyle, false);
-    assert.equal(baseStyle.terrain?.exaggeration, 4.4);
   });
 
   it('should convert min/maxzooms', () => {
@@ -39,13 +38,24 @@ describe('NZTM2000QuadStyle', () => {
     assert.deepEqual(newStyle.layers[0], { minzoom: 3, maxzoom: 8, id: 'something', type: '' });
   });
 
-  it('should offset terrain', () => {
-    const newStyle = convertStyleToNztmStyle({
+  it('should not offset terrain for WebMecator', () => {
+    const testStyle: StyleJson = {
       ...fakeStyle,
-      terrain: { exaggeration: 1.1, source: 'abc' },
-    });
+      sources: { 'LINZ-Terrain': { type: 'raster-dem', tiles: ['https://example.com/{z}/{x}/{y}.png'] } },
+    };
+    setStyleTerrain(testStyle, 'LINZ-Terrain', GoogleTms);
+
+    assert.deepEqual(testStyle.terrain, { exaggeration: 1.2, source: 'LINZ-Terrain' });
+  });
+
+  it('should offset terrain for NZTM', () => {
+    const testStyle: StyleJson = {
+      ...fakeStyle,
+      sources: { 'LINZ-Terrain': { type: 'raster-dem', tiles: ['https://example.com/{z}/{x}/{y}.png'] } },
+    };
+    setStyleTerrain(testStyle, 'LINZ-Terrain', Nztm2000QuadTms);
 
-    assert.deepEqual(newStyle.terrain, { exaggeration: 4.4, source: 'abc' });
+    assert.deepEqual(testStyle.terrain, { exaggeration: 4.4, source: 'LINZ-Terrain' });
   });
 
   it('should convert stops inside of paint and layout', () => {