From 9c76c78c0c2b0de42191a602e48c97c679ad200e Mon Sep 17 00:00:00 2001
From: Lynix <lynix680@gmail.com>
Date: Thu, 3 Jan 2013 21:26:51 +0100
Subject: [PATCH] Added IndexMapper

Former-commit-id: 994b30f41161855827d920b6c128a5bbd480929b
---
 include/Nazara/Utility/IndexMapper.hpp | 39 +++++++++++
 src/Nazara/Utility/IndexMapper.cpp     | 96 ++++++++++++++++++++++++++
 2 files changed, 135 insertions(+)
 create mode 100644 include/Nazara/Utility/IndexMapper.hpp
 create mode 100644 src/Nazara/Utility/IndexMapper.cpp

diff --git a/include/Nazara/Utility/IndexMapper.hpp b/include/Nazara/Utility/IndexMapper.hpp
new file mode 100644
index 000000000..b681a49b1
--- /dev/null
+++ b/include/Nazara/Utility/IndexMapper.hpp
@@ -0,0 +1,39 @@
+// 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
+
+#pragma once
+
+#ifndef NAZARA_VERTEXITERATOR_HPP
+#define NAZARA_VERTEXITERATOR_HPP
+
+#include <Nazara/Prerequesites.hpp>
+#include <Nazara/Utility/BufferMapper.hpp>
+
+class NzIndexBuffer;
+class NzSubMesh;
+
+using NzIndexMapperGetter = nzUInt32 (*)(const void* buffer, unsigned int i);
+using NzIndexMapperSetter = void (*)(void* buffer, unsigned int i, nzUInt32 value);
+
+class NAZARA_API NzIndexMapper
+{
+	public:
+		NzIndexMapper(NzIndexBuffer* indexBuffer, nzBufferAccess access = nzBufferAccess_ReadWrite);
+		NzIndexMapper(const NzIndexBuffer* indexBuffer);
+		NzIndexMapper(const NzSubMesh* subMesh);
+		~NzIndexMapper() = default;
+
+		nzUInt32 Get(unsigned int i) const;
+
+		void Set(unsigned int i, nzUInt32 value);
+
+		void Unmap();
+
+	private:
+		NzBufferMapper<NzIndexBuffer> m_mapper;
+		NzIndexMapperGetter m_getter;
+		NzIndexMapperSetter m_setter;
+};
+
+#endif // NAZARA_VERTEXITERATOR_HPP
diff --git a/src/Nazara/Utility/IndexMapper.cpp b/src/Nazara/Utility/IndexMapper.cpp
new file mode 100644
index 000000000..cb389e3ba
--- /dev/null
+++ b/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();
+}