From b2be356609ab92cd2154cfe936f7790e084a5b69 Mon Sep 17 00:00:00 2001
From: wmayer <wmayer@users.sourceforge.net>
Date: Tue, 3 Oct 2023 11:47:28 +0200
Subject: [PATCH] Import: Support of colors of the glTF format

---
 src/Mod/Import/App/ReaderGltf.cpp | 94 ++++++++++++++++++++++++++-----
 src/Mod/Import/App/ReaderGltf.h   |  4 ++
 2 files changed, 83 insertions(+), 15 deletions(-)

diff --git a/src/Mod/Import/App/ReaderGltf.cpp b/src/Mod/Import/App/ReaderGltf.cpp
index 47da47f2ce..4fd2449352 100644
--- a/src/Mod/Import/App/ReaderGltf.cpp
+++ b/src/Mod/Import/App/ReaderGltf.cpp
@@ -25,28 +25,36 @@
 #include "PreCompiled.h"
 #ifndef _PreComp_
 #include <Standard_Version.hxx>
+#if OCC_VERSION_HEX >= 0x070500
+#include <BRep_Builder.hxx>
+#include <Message_ProgressRange.hxx>
+#include <Quantity_ColorRGBA.hxx>
+#include <RWGltf_CafReader.hxx>
 #include <TDF_Label.hxx>
 #include <TDF_TagSource.hxx>
 #include <XCAFDoc_DocumentTool.hxx>
+#include <XCAFDoc_ColorTool.hxx>
 #include <XCAFDoc_ShapeTool.hxx>
-#if OCC_VERSION_HEX >= 0x070500
-#include <Message_ProgressRange.hxx>
-#include <RWGltf_CafReader.hxx>
+#include <XCAFDoc_VisMaterial.hxx>
+#include <XCAFDoc_VisMaterialTool.hxx>
 #endif
 #endif
 
 #include "ReaderGltf.h"
+#include "Tools.h"
 #include <Base/Exception.h>
 #include <Mod/Part/App/TopoShape.h>
 #include <Mod/Part/App/Tools.h>
 
 using namespace Import;
 
-ReaderGltf::ReaderGltf(const Base::FileInfo& file)  // NOLINT
+// NOLINTNEXTLINE
+ReaderGltf::ReaderGltf(const Base::FileInfo& file)
     : file {file}
 {}
 
-void ReaderGltf::read(Handle(TDocStd_Document) hDoc)  // NOLINT
+// NOLINTNEXTLINE
+void ReaderGltf::read(Handle(TDocStd_Document) hDoc)
 {
 #if OCC_VERSION_HEX >= 0x070500
     const double unit = 0.001;  // mm
@@ -62,16 +70,7 @@ void ReaderGltf::read(Handle(TDocStd_Document) hDoc)  // NOLINT
         throw Base::FileException("Cannot read from file: ", file);
     }
 
-    Handle(XCAFDoc_ShapeTool) aShapeTool = XCAFDoc_DocumentTool::ShapeTool(hDoc->Main());
-    TDF_LabelSequence labels;
-    aShapeTool->GetShapes(labels);
-    for (Standard_Integer i = 1; i <= labels.Length(); i++) {
-        auto label = labels.Value(i);
-        TopoDS_Shape shape = aShapeTool->GetShape(label);
-        if (!shape.IsNull()) {
-            aShapeTool->SetShape(label, fixShape(shape));
-        }
-    }
+    processDocument(hDoc);
 
 #else
     (void)hDoc;
@@ -79,6 +78,71 @@ void ReaderGltf::read(Handle(TDocStd_Document) hDoc)  // NOLINT
 #endif
 }
 
+// NOLINTNEXTLINE
+void ReaderGltf::processDocument(Handle(TDocStd_Document) hDoc)
+{
+#if OCC_VERSION_HEX >= 0x070500
+    Handle(XCAFDoc_ShapeTool) aShapeTool = XCAFDoc_DocumentTool::ShapeTool(hDoc->Main());
+
+    TDF_LabelSequence shapeLabels;
+    aShapeTool->GetShapes(shapeLabels);
+    for (Standard_Integer i = 1; i <= shapeLabels.Length(); i++) {
+        auto topLevelshape = shapeLabels.Value(i);
+        TopoDS_Shape shape = aShapeTool->GetShape(topLevelshape);
+        if (!shape.IsNull()) {
+            TDF_LabelSequence subShapeLabels;
+            if (XCAFDoc_ShapeTool::GetSubShapes(topLevelshape, subShapeLabels)) {
+                TopoDS_Shape compound = processSubShapes(hDoc, subShapeLabels);
+                aShapeTool->SetShape(topLevelshape, compound);
+            }
+            else {
+                aShapeTool->SetShape(topLevelshape, fixShape(shape));
+            }
+        }
+    }
+#endif
+}
+
+// NOLINTNEXTLINE
+TopoDS_Shape ReaderGltf::processSubShapes(Handle(TDocStd_Document) hDoc,
+                                          const TDF_LabelSequence& subShapeLabels)
+{
+    TopoDS_Compound compound;
+#if OCC_VERSION_HEX >= 0x070500
+    Handle(XCAFDoc_ShapeTool) aShapeTool = XCAFDoc_DocumentTool::ShapeTool(hDoc->Main());
+    Handle(XCAFDoc_ColorTool) aColorTool = XCAFDoc_DocumentTool::ColorTool(hDoc->Main());
+    Handle(XCAFDoc_VisMaterialTool) aVisTool = XCAFDoc_DocumentTool::VisMaterialTool(hDoc->Main());
+
+    BRep_Builder builder;
+    builder.MakeCompound(compound);
+    for (Standard_Integer i = 1; i <= subShapeLabels.Length(); i++) {
+        auto faceLabel = subShapeLabels.Value(i);
+
+        // OCCT handles colors of a glTF with material labels but the ImportOCAF(2) class
+        // expects color labels. Thus, the material labels are converted into color labels.
+        Handle(XCAFDoc_VisMaterial) aVisMat = aVisTool->GetShapeMaterial(faceLabel);
+
+        Quantity_ColorRGBA rgba;
+        bool hasVisMat {false};
+        if (!aVisMat.IsNull()) {
+            rgba = aVisMat->BaseColor();
+            hasVisMat = true;
+        }
+
+        TopoDS_Shape face = aShapeTool->GetShape(faceLabel);
+        TopoDS_Shape fixed = fixShape(face);
+        builder.Add(compound, fixed);
+        aShapeTool->SetShape(faceLabel, fixed);
+
+        if (hasVisMat) {
+            aColorTool->SetColor(faceLabel, rgba, XCAFDoc_ColorSurf);
+        }
+    }
+#endif
+
+    return {std::move(compound)};
+}
+
 bool ReaderGltf::cleanup() const
 {
     return clean;
diff --git a/src/Mod/Import/App/ReaderGltf.h b/src/Mod/Import/App/ReaderGltf.h
index 5925100bba..2b6e9f9895 100644
--- a/src/Mod/Import/App/ReaderGltf.h
+++ b/src/Mod/Import/App/ReaderGltf.h
@@ -27,6 +27,7 @@
 #include <Mod/Import/ImportGlobal.h>
 #include <Base/FileInfo.h>
 #include <TDocStd_Document.hxx>
+#include <TDF_LabelSequence.hxx>
 #include <TopoDS_Shape.hxx>
 
 namespace Import
@@ -43,6 +44,9 @@ public:
 
 private:
     TopoDS_Shape fixShape(TopoDS_Shape);
+    void processDocument(Handle(TDocStd_Document) hDoc);
+    TopoDS_Shape processSubShapes(Handle(TDocStd_Document) hDoc,
+                                  const TDF_LabelSequence& subShapeLabels);
 
 private:
     Base::FileInfo file;