From f084f925252e99b4d7cdd2b19b52918b5306504e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bal=C3=A1zs=20Dukai?= <balazs.dukai@gmail.com>
Date: Mon, 9 Jan 2023 14:41:55 +0100
Subject: [PATCH] Gltf triangulate argument

---
 CHANGELOG.md     |  4 +++
 cjio/cityjson.py |  4 +--
 cjio/convert.py  | 66 +++++++++++++++++++++++++++++++-----------------
 3 files changed, 49 insertions(+), 25 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index f39c7fe..553768a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,10 @@
 - Added the `translate` paramter to `cityjson.compress` to manually set the tranlation properties instead of computing from the data.
 - The `cityjson.cityjson_for_features` and `cityjson.generate_features` methods.
 
+### Changed
+- The glb converter (`to_glb`) sets a root transformation matrix for z-up to y-up, instead of swapping the vertex coordinates directly.
+- The glb converter takes a `do_triangulate` argument to completely skip triangulation.
+
 ## [0.8.0] – 2022-11-28
 ### Added
 - added functions for reading/writing CityJSONL (CityJSONFeatures) from stdin/stdout, so cjio can be part of a pipeline of operators processing 3D city models 🚀
diff --git a/cjio/cityjson.py b/cjio/cityjson.py
index 0c0589a..1476b53 100644
--- a/cjio/cityjson.py
+++ b/cjio/cityjson.py
@@ -1571,9 +1571,9 @@ def export2b3dm(self):
         return b3dm
 
 
-    def export2glb(self):
+    def export2glb(self, do_triangulate=True):
         self.decompress()
-        glb = convert.to_glb(self)
+        glb = convert.to_glb(self, do_triangulate=do_triangulate)
         return glb
 
     def export2jsonl(self):
diff --git a/cjio/convert.py b/cjio/convert.py
index 3b5c607..cfab167 100644
--- a/cjio/convert.py
+++ b/cjio/convert.py
@@ -96,7 +96,7 @@ def to_b3dm(cm, glb):
 
     return b3dm_bin
 
-def to_glb(cm):
+def to_glb(cm, do_triangulate=True):
     """Convert to Binary glTF (.glb)
 
     Adapted from CityJSON2glTF: https://github.com/tudelft3d/CityJSON2glTF
@@ -188,35 +188,55 @@ def to_glb(cm):
                 matid = 9
             material_ids.append(matid)
 
-            # TODO: skip triangulation if already triangulated
-            for geom in cm.j['CityObjects'][theid]['geometry']:
-                poscount = poscount + 1
-                if geom['type'] == "Solid":
-                    triList = []
-                    for shell in geom['boundaries']:
-                        for face in shell:
+            if do_triangulate:
+                for geom in cm.j['CityObjects'][theid]['geometry']:
+                    poscount = poscount + 1
+                    if geom['type'] == "Solid":
+                        triList = []
+                        for shell in geom['boundaries']:
+                            for face in shell:
+                                tri, success = geom_help.triangulate_face(face, vertexlist)
+                                if success:
+                                    for t in tri:
+                                        triList.append(list(t))
+                                else:
+                                    # TODO: logging
+                                    print(f"Failed to triangulate face in CityObject {theid}")
+                        trigeom = (flatten(triList))
+
+                    elif (geom['type'] == 'MultiSurface') or (geom['type'] == 'CompositeSurface'):
+                        triList = []
+                        for face in geom['boundaries']:
                             tri, success = geom_help.triangulate_face(face, vertexlist)
                             if success:
                                 for t in tri:
-                                    triList.append(list(t))
+                                    triList.append(t)
                             else:
                                 # TODO: logging
                                 print(f"Failed to triangulate face in CityObject {theid}")
-                    trigeom = (flatten(triList))
-
-                elif (geom['type'] == 'MultiSurface') or (geom['type'] == 'CompositeSurface'):
-                    triList = []
-                    for face in geom['boundaries']:
-                        tri, success = geom_help.triangulate_face(face, vertexlist)
-                        if success:
-                            for t in tri:
+                        trigeom = (flatten(triList))
+            else:
+                # If the caller says it's triangulate, then we trust that it's
+                # triangulated.
+                for geom in cm.j['CityObjects'][theid]['geometry']:
+                    poscount = poscount + 1
+                    if geom['type'] == "Solid":
+                        triList = []
+                        for shell in geom['boundaries']:
+                            for face in shell:
+                                for t in face:
+                                    triList.append(list(t))
+                        trigeom = (flatten(triList))
+
+                    elif (geom['type'] == 'MultiSurface') or (
+                            geom['type'] == 'CompositeSurface'):
+                        triList = []
+                        for face in geom['boundaries']:
+                            for t in face:
                                 triList.append(t)
-                        else:
-                            # TODO: logging
-                            print(f"Failed to triangulate face in CityObject {theid}")
-                    trigeom = (flatten(triList))
-                flatgeom = trigeom
-                forimax.append(flatgeom)
+                        trigeom = (flatten(triList))
+            flatgeom = trigeom
+            forimax.append(flatgeom)
 
             #----- buffer and bufferView
             flatgeom = flatten(forimax)