#5115: Convert patch surface to indexed model surface before passing …

…them to the exporter.

This way the polygons are not separated and the normals can be smoothed.

radiantcore/model/export/ModelExporter.cpp

@@ -13,6 +13,8 @@
 #include <stdexcept>
 #include <fstream>
 
+#include "PatchSurface.h"
+
 namespace model
 {
 
@@ -196,7 +198,9 @@ void ModelExporter::processPatch(const scene::INodePtr& node)
 	if (!isExportableMaterial(materialName)) return;
 
 	PatchMesh mesh = patch->getTesselatedPatchMesh();
+    Matrix4 exportTransform = node->localToWorld().getPremultipliedBy(_centerTransform);
 
+#if 0
 	std::vector<model::ModelPolygon> polys;
 
 	for (std::size_t h = 0; h < mesh.height - 1; ++h)
@@ -219,9 +223,12 @@ void ModelExporter::processPatch(const scene::INodePtr& node)
 		}
 	}
 
-	Matrix4 exportTransform = node->localToWorld().getPremultipliedBy(_centerTransform);
-
 	_exporter->addPolygons(materialName, polys, exportTransform);
+#else
+    // Convert the patch mesh to an indexed surface
+    PatchSurface surface(materialName, mesh);
+    _exporter->addSurface(surface, exportTransform);
+#endif
 }
 
 void ModelExporter::processBrush(const scene::INodePtr& node)

radiantcore/model/export/PatchSurface.h

@@ -0,0 +1,111 @@
+#pragma once
+
+#include "ipatch.h"
+#include "imodelsurface.h"
+
+namespace model
+{
+
+// Adapter methods to convert patch vertices to ArbitraryMeshVertex type
+inline ArbitraryMeshVertex convertPatchVertex(const VertexNT& in)
+{
+    // Colour will be set to 1,1,1 by the constructor
+    return ArbitraryMeshVertex(in.vertex, in.normal, in.texcoord);
+}
+
+/**
+ * Adapter class converting a PatchTesselation object into
+ * a surface suitable for exporting it to a model file.
+ * The PatchSurface class will generate the triangle indices
+ * (clockwise) as expeced by the IModelExporter interface.
+ */
+class PatchSurface : 
+    public IIndexedModelSurface
+{
+private:
+    std::vector<ArbitraryMeshVertex> _vertices;
+    std::vector<unsigned int> _indices;
+    std::string _materialName;
+
+public:
+    PatchSurface(const std::string& materialName, PatchMesh& mesh) :
+        _materialName(materialName)
+    {
+        assert(mesh.width >= 2 && mesh.height >= 2);
+
+        _vertices.reserve(mesh.vertices.size());
+        _indices.reserve((mesh.height - 1) * (mesh.width- 1) * 6); // 6 => 2 triangles per quad
+
+        // Load all the vertices into the target vector
+        std::transform(mesh.vertices.begin(), mesh.vertices.end(),
+            std::back_inserter(_vertices), convertPatchVertex);
+
+        // Generate the indices to define the triangles in clockwise order
+        for (std::size_t h = 0; h < mesh.height - 1; ++h)
+        {
+            auto rowOffset = h * mesh.width;
+
+            for (std::size_t w = 0; w < mesh.width - 1; ++w)
+            {
+                _indices.push_back(rowOffset + w + mesh.width);
+                _indices.push_back(rowOffset + w + 1);
+                _indices.push_back(rowOffset + w);
+
+                _indices.push_back(rowOffset + w + mesh.width);
+                _indices.push_back(rowOffset + w + mesh.width + 1);
+                _indices.push_back(rowOffset + w + 1);
+            }
+        }
+    }
+
+    // Inherited via IIndexedModelSurface
+    int getNumVertices() const override
+    {
+        return static_cast<int>(_vertices.size());
+    }
+
+    int getNumTriangles() const override
+    {
+        return static_cast<int>(_indices.size() / 3); // 3 indices per triangle
+    }
+
+    const ArbitraryMeshVertex& getVertex(int vertexNum) const override
+    {
+        return _vertices[vertexNum];
+    }
+
+    ModelPolygon getPolygon(int polygonIndex) const override
+    {
+        assert(polygonIndex >= 0 && polygonIndex * 3 < static_cast<int>(_indices.size()));
+
+        ModelPolygon poly;
+
+        poly.a = _vertices[_indices[polygonIndex * 3]];
+        poly.b = _vertices[_indices[polygonIndex * 3 + 1]];
+        poly.c = _vertices[_indices[polygonIndex * 3 + 2]];
+
+        return poly;
+    }
+
+    const std::string& getDefaultMaterial() const override
+    {
+        return _materialName;
+    }
+
+    const std::string& getActiveMaterial() const override
+    {
+        return _materialName;
+    }
+
+    const std::vector<ArbitraryMeshVertex>& getVertexArray() const override
+    {
+        return _vertices;
+    }
+
+    const std::vector<unsigned int>& getIndexArray() const override
+    {
+        return _indices;
+    }
+};
+
+}

tools/msvc/DarkRadiantCore.vcxproj

@@ -857,6 +857,7 @@
     <ClInclude Include="..\..\radiantcore\model\export\ModelExporter.h" />
     <ClInclude Include="..\..\radiantcore\model\export\ModelExporterBase.h" />
     <ClInclude Include="..\..\radiantcore\model\export\ModelScalePreserver.h" />
+    <ClInclude Include="..\..\radiantcore\model\export\PatchSurface.h" />
     <ClInclude Include="..\..\radiantcore\model\export\ScaledModelExporter.h" />
     <ClInclude Include="..\..\radiantcore\model\export\WavefrontExporter.h" />
     <ClInclude Include="..\..\radiantcore\model\md5\MD5Anim.h" />

tools/msvc/DarkRadiantCore.vcxproj.filters

@@ -2034,5 +2034,8 @@
     <ClInclude Include="..\..\radiantcore\camera\CameraManager.h">
       <Filter>src\camera</Filter>
     </ClInclude>
+    <ClInclude Include="..\..\radiantcore\model\export\PatchSurface.h">
+      <Filter>src\model\export</Filter>
+    </ClInclude>
   </ItemGroup>
 </Project>