Added IndexMapper

Former-commit-id: 994b30f41161855827d920b6c128a5bbd480929b

src/Nazara/Utility/IndexMapper.cpp

@@ -0,0 +1,96 @@
+// Copyright (C) 2012 Jérôme Leclercq
+// This file is part of the "Nazara Engine - Utility module"
+// For conditions of distribution and use, see copyright notice in Config.hpp
+
+#include <Nazara/Utility/IndexMapper.hpp>
+#include <Nazara/Utility/IndexBuffer.hpp>
+#include <Nazara/Utility/SubMesh.hpp>
+#include <Nazara/Utility/Debug.hpp>
+
+namespace
+{
+	nzUInt32 Getter16(const void* buffer, unsigned int i)
+	{
+		const nzUInt16* ptr = reinterpret_cast<const nzUInt16*>(buffer);
+		return ptr[i];
+	}
+
+	nzUInt32 Getter32(const void* buffer, unsigned int i)
+	{
+		const nzUInt32* ptr = reinterpret_cast<const nzUInt32*>(buffer);
+		return ptr[i];
+	}
+
+	void Setter16(void* buffer, unsigned int i, nzUInt32 value)
+	{
+		nzUInt16* ptr = reinterpret_cast<nzUInt16*>(buffer);
+		ptr[i] = static_cast<nzUInt16>(value);
+	}
+
+	void Setter32(void* buffer, unsigned int i, nzUInt32 value)
+	{
+		nzUInt32* ptr = reinterpret_cast<nzUInt32*>(buffer);
+		ptr[i] = value;
+	}
+
+	void SetterError(void*, unsigned int, nzUInt32)
+	{
+		NazaraError("Index buffer opened with read-only access");
+	}
+}
+
+NzIndexMapper::NzIndexMapper(NzIndexBuffer* indexBuffer, nzBufferAccess access) :
+m_mapper(indexBuffer, access)
+{
+	if (indexBuffer->HasLargeIndices())
+	{
+		m_getter = Getter32;
+		if (access != nzBufferAccess_ReadOnly)
+			m_setter = Setter32;
+		else
+			m_setter = SetterError;
+	}
+	else
+	{
+		m_getter = Getter16;
+		if (access != nzBufferAccess_ReadOnly)
+			m_setter = Setter16;
+		else
+			m_setter = SetterError;
+	}
+}
+
+NzIndexMapper::NzIndexMapper(const NzIndexBuffer* indexBuffer) :
+m_mapper(indexBuffer, nzBufferAccess_ReadOnly)
+{
+	if (indexBuffer->HasLargeIndices())
+	{
+		m_getter = Getter32;
+		m_setter = SetterError;
+	}
+	else
+	{
+		m_getter = Getter16;
+		m_setter = SetterError;
+	}
+}
+
+NzIndexMapper::NzIndexMapper(const NzSubMesh* subMesh) :
+NzIndexMapper(subMesh->GetIndexBuffer())
+{
+}
+
+nzUInt32 NzIndexMapper::Get(unsigned int i) const
+{
+	return m_getter(m_mapper.GetPointer(), i);
+}
+
+void NzIndexMapper::Set(unsigned int i, nzUInt32 value)
+{
+	m_setter(m_mapper.GetPointer(), i, value);
+}
+
+void NzIndexMapper::Unmap()
+{
+	m_mapper.Unmap();
+}