Added [Sub]Mesh::GetTriangleCount()

Former-commit-id: e365bd3aa57d487186a0be5cde1d5b0ba78d740c

include/Nazara/Utility/Mesh.hpp

@@ -76,6 +76,7 @@ class NAZARA_API NzMesh : public NzResource, NzResourceListener
 		const NzSubMesh* GetSubMesh(unsigned int index) const;
 		unsigned int GetSubMeshCount() const;
 		int GetSubMeshIndex(const NzString& identifier) const;
+		unsigned int GetTriangleCount() const;
 		unsigned int GetVertexCount() const;
 
 		bool HasSubMesh(const NzString& identifier) const;

include/Nazara/Utility/SubMesh.hpp

@@ -40,6 +40,7 @@ class NAZARA_API NzSubMesh : public NzResource
 		unsigned int GetMaterialIndex() const;
 		const NzMesh* GetParent() const;
 		nzPrimitiveType GetPrimitiveType() const;
+		unsigned int GetTriangleCount() const;
 		virtual unsigned int GetVertexCount() const = 0;
 
 		virtual bool IsAnimated() const = 0;

src/Nazara/Utility/Mesh.cpp

@@ -472,6 +472,23 @@ int NzMesh::GetSubMeshIndex(const NzString& identifier) const
 	return it->second;
 }
 
+unsigned int NzMesh::GetTriangleCount() const
+{
+	#if NAZARA_UTILITY_SAFE
+	if (!m_impl)
+	{
+		NazaraError("Mesh not created");
+		return 0;
+	}
+	#endif
+
+	unsigned int triangleCount = 0;
+	for (NzSubMesh* subMesh : m_impl->subMeshes)
+		triangleCount += subMesh->GetTriangleCount();
+
+	return triangleCount;
+}
+
 unsigned int NzMesh::GetVertexCount() const
 {
 	#if NAZARA_UTILITY_SAFE

src/Nazara/Utility/SubMesh.cpp

@@ -151,6 +151,36 @@ nzPrimitiveType NzSubMesh::GetPrimitiveType() const
 	return m_primitiveType;
 }
 
+unsigned int NzSubMesh::GetTriangleCount() const
+{
+	const NzIndexBuffer* indexBuffer = GetIndexBuffer();
+	unsigned int indexCount;
+	if (indexBuffer)
+		indexCount = indexBuffer->GetIndexCount();
+	else
+		indexCount = GetVertexCount();
+
+	switch (m_primitiveType)
+	{
+		case nzPrimitiveType_LineList:
+		case nzPrimitiveType_LineStrip:
+		case nzPrimitiveType_PointList:
+			return 0;
+
+		case nzPrimitiveType_TriangleFan:
+			return (indexCount - 1) / 2;
+
+		case nzPrimitiveType_TriangleList:
+			return indexCount / 3;
+
+		case nzPrimitiveType_TriangleStrip:
+			return indexCount - 2;
+	}
+
+	NazaraError("Primitive type not handled (0x" + NzString::Number(m_primitiveType, 16) + ')');
+	return 0;
+}
+
 unsigned int NzSubMesh::GetMaterialIndex() const
 {
 	return m_matIndex;