From 033fce26857b08f72f521e890b98ffb42a010610 Mon Sep 17 00:00:00 2001
From: wmayer <wmayer@users.sourceforge.net>
Date: Sat, 12 Jan 2019 15:06:25 +0100
Subject: [PATCH] support face colors when writing in OpenInventor format

---
 src/Mod/Part/App/TopoShape.cpp      | 22 ++++++++++++++++++----
 src/Mod/Part/App/TopoShape.h        |  6 +++++-
 src/Mod/Part/App/TopoShapePy.xml    |  2 +-
 src/Mod/Part/App/TopoShapePyImp.cpp | 20 ++++++++++++++++----
 4 files changed, 40 insertions(+), 10 deletions(-)

diff --git a/src/Mod/Part/App/TopoShape.cpp b/src/Mod/Part/App/TopoShape.cpp
index 6a4b22d391..72566eac3b 100644
--- a/src/Mod/Part/App/TopoShape.cpp
+++ b/src/Mod/Part/App/TopoShape.cpp
@@ -184,7 +184,7 @@
 #include <Base/Exception.h>
 #include <Base/Tools.h>
 #include <Base/Console.h>
-
+#include <App/Material.h>
 
 #include "TopoShape.h"
 #include "CrossSection.h"
@@ -826,13 +826,22 @@ void TopoShape::exportStl(const char *filename, double deflection) const
     writer.Write(this->_Shape,encodeFilename(filename).c_str());
 }
 
-void TopoShape::exportFaceSet(double dev, double ca, std::ostream& str) const
+void TopoShape::exportFaceSet(double dev, double ca,
+                              const std::vector<App::Color>& colors,
+                              std::ostream& str) const
 {
     Base::InventorBuilder builder(str);
     TopExp_Explorer ex;
-
-    BRepMesh_IncrementalMesh MESH(this->_Shape,dev);
+    std::size_t numFaces = 0;
     for (ex.Init(this->_Shape, TopAbs_FACE); ex.More(); ex.Next()) {
+        numFaces++;
+    }
+
+    bool supportFaceColors = (numFaces == colors.size());
+
+    std::size_t index=0;
+    BRepMesh_IncrementalMesh MESH(this->_Shape,dev);
+    for (ex.Init(this->_Shape, TopAbs_FACE); ex.More(); ex.Next(), index++) {
         // get the shape and mesh it
         const TopoDS_Face& aFace = TopoDS::Face(ex.Current());
         Standard_Integer nbNodesInFace,nbTriInFace;
@@ -898,6 +907,11 @@ void TopoShape::exportFaceSet(double dev, double ca, std::ostream& str) const
 
         builder.beginSeparator();
         builder.addShapeHints((float)ca);
+        if (supportFaceColors) {
+            App::Color c = colors[index];
+            builder.addMaterial(c.r, c.g, c.b, c.a);
+        }
+
         builder.beginPoints();
         builder.addPoints(vertices);
         builder.endPoints();
diff --git a/src/Mod/Part/App/TopoShape.h b/src/Mod/Part/App/TopoShape.h
index 1738cb8bd0..abb72591a4 100644
--- a/src/Mod/Part/App/TopoShape.h
+++ b/src/Mod/Part/App/TopoShape.h
@@ -35,6 +35,10 @@ class gp_Ax1;
 class gp_Ax2;
 class gp_Vec;
 
+namespace App {
+class Color;
+}
+
 namespace Part
 {
 
@@ -175,7 +179,7 @@ public:
     void exportBrep(std::ostream&) const;
     void exportBinary(std::ostream&);
     void exportStl (const char *FileName, double deflection) const;
-    void exportFaceSet(double, double, std::ostream&) const;
+    void exportFaceSet(double, double, const std::vector<App::Color>&, std::ostream&) const;
     void exportLineSet(std::ostream&) const;
     //@}
 
diff --git a/src/Mod/Part/App/TopoShapePy.xml b/src/Mod/Part/App/TopoShapePy.xml
index 798a99f02d..4399528d10 100644
--- a/src/Mod/Part/App/TopoShapePy.xml
+++ b/src/Mod/Part/App/TopoShapePy.xml
@@ -33,7 +33,7 @@ Sub-elements such as vertices, edges or faces are accessible as:
         <UserDocu>Read in an IGES, STEP or BREP file.</UserDocu>
       </Documentation>
     </Methode>
-    <Methode Name="writeInventor" Const="true">
+    <Methode Name="writeInventor" Const="true" Keyword="true">
       <Documentation>
         <UserDocu>Write the mesh in OpenInventor format to a string.</UserDocu>
       </Documentation>
diff --git a/src/Mod/Part/App/TopoShapePyImp.cpp b/src/Mod/Part/App/TopoShapePyImp.cpp
index 22c5ff3d3d..5255b92fb8 100644
--- a/src/Mod/Part/App/TopoShapePyImp.cpp
+++ b/src/Mod/Part/App/TopoShapePyImp.cpp
@@ -74,6 +74,7 @@
 #include <Base/MatrixPy.h>
 #include <Base/Vector3D.h>
 #include <Base/VectorPy.h>
+#include <App/PropertyStandard.h>
 #include <CXX/Extensions.hxx>
 
 #include "TopoShape.h"
@@ -286,21 +287,32 @@ PyObject*  TopoShapePy::read(PyObject *args)
     Py_Return;
 }
 
-PyObject* TopoShapePy::writeInventor(PyObject * args)
+PyObject* TopoShapePy::writeInventor(PyObject * args, PyObject * keywds)
 {
+    static char *kwlist[] = {"Mode", "Deviation", "Angle", "FaceColors", NULL};
+
     double dev=0.3, angle=0.4;
     int mode=2;
-    if (!PyArg_ParseTuple(args, "|idd", &mode,&dev,&angle))
+    PyObject* pylist=nullptr;
+    if (!PyArg_ParseTupleAndKeywords(args, keywds, "|iddO", kwlist,
+                                     &mode,&dev,&angle,&pylist))
         return NULL;
 
+    std::vector<App::Color> faceColors;
+    if (pylist) {
+        App::PropertyColorList prop;
+        prop.setPyObject(pylist);
+        faceColors = prop.getValues();
+    }
+
     std::stringstream result;
     BRepMesh_IncrementalMesh(getTopoShapePtr()->getShape(),dev);
     if (mode == 0)
-        getTopoShapePtr()->exportFaceSet(dev, angle, result);
+        getTopoShapePtr()->exportFaceSet(dev, angle, faceColors, result);
     else if (mode == 1)
         getTopoShapePtr()->exportLineSet(result);
     else {
-        getTopoShapePtr()->exportFaceSet(dev, angle, result);
+        getTopoShapePtr()->exportFaceSet(dev, angle, faceColors, result);
         getTopoShapePtr()->exportLineSet(result);
     }
     // NOTE: Cleaning the triangulation may cause problems on some algorithms like BOP