Add FieldOffsets class

2020-08-04 01:33:52 +02:00
parent 7736312c2f
commit 7fd3264d08
4 changed files with 356 additions and 0 deletions
--- a/src/Nazara/Utility/FieldOffsets.cpp
+++ b/src/Nazara/Utility/FieldOffsets.cpp
@@ -0,0 +1,101 @@
+// Copyright (C) 2019 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/FieldOffsets.hpp>
+#include <algorithm>
+#include <cassert>
+#include <Nazara/Utility/Debug.hpp>
+
+namespace Nz
+{
+	std::size_t FieldOffsets::AddField(StructFieldType type)
+	{
+		std::size_t fieldAlignement = GetAlignement(m_layout, type);
+
+		m_largestFieldAlignment = std::max(m_largestFieldAlignment, fieldAlignement);
+
+		std::size_t offset = Align(m_size, Align(fieldAlignement, m_offsetRounding));
+		m_size = offset + GetSize(type);
+
+		m_offsetRounding = 1;
+
+		return offset;
+	}
+
+	std::size_t FieldOffsets::AddFieldArray(StructFieldType type, std::size_t arraySize)
+	{
+		std::size_t fieldAlignement = GetAlignement(m_layout, type);
+		if (m_layout == StructLayout_Std140)
+			fieldAlignement = Align(fieldAlignement, GetAlignement(StructLayout_Std140, StructFieldType_Float4));
+
+		m_largestFieldAlignment = std::max(fieldAlignement, m_largestFieldAlignment);
+
+		std::size_t offset = Align(m_size, Align(fieldAlignement, m_offsetRounding));
+		m_size = offset + GetSize(type) * arraySize;
+
+		m_offsetRounding = 1;
+
+		return offset;
+	}
+
+	std::size_t FieldOffsets::AddMatrix(StructFieldType cellType, unsigned int columns, unsigned int rows, bool columnMajor)
+	{
+		assert(GetCount(cellType) == 1);
+		assert(columns >= 2 && columns <= 4);
+		assert(rows >= 2 && rows <= 4);
+
+		if (columnMajor)
+			return AddFieldArray(static_cast<StructFieldType>(cellType + rows - 1), columns);
+		else
+			return AddFieldArray(static_cast<StructFieldType>(cellType + columns - 1), rows);
+	}
+
+	std::size_t FieldOffsets::AddMatrixArray(StructFieldType cellType, unsigned int columns, unsigned int rows, bool columnMajor, std::size_t arraySize)
+	{
+		assert(GetCount(cellType) == 1);
+		assert(columns >= 2 && columns <= 4);
+		assert(rows >= 2 && rows <= 4);
+
+		if (columnMajor)
+			return AddFieldArray(static_cast<StructFieldType>(cellType + rows - 1), columns * arraySize);
+		else
+			return AddFieldArray(static_cast<StructFieldType>(cellType + columns - 1), rows * arraySize);
+	}
+
+	std::size_t FieldOffsets::AddStruct(const FieldOffsets& fieldStruct)
+	{
+		std::size_t fieldAlignement = fieldStruct.GetLargestFieldAlignement();
+		if (m_layout == StructLayout_Std140)
+			fieldAlignement = Align(fieldAlignement, GetAlignement(StructLayout_Std140, StructFieldType_Float4));
+
+		m_largestFieldAlignment = std::max(m_largestFieldAlignment, fieldAlignement);
+
+		std::size_t offset = Align(m_size, Align(fieldAlignement, m_offsetRounding));
+		m_size = offset + fieldStruct.GetSize();
+
+		m_offsetRounding = std::max<std::size_t>(Align(fieldStruct.GetSize(), fieldAlignement) - fieldStruct.GetSize(), 1);
+
+		return offset;
+	}
+
+	std::size_t FieldOffsets::AddStructArray(const FieldOffsets& fieldStruct, std::size_t arraySize)
+	{
+		assert(arraySize > 0);
+
+		std::size_t fieldAlignement = fieldStruct.GetLargestFieldAlignement();
+		if (m_layout == StructLayout_Std140)
+			fieldAlignement = Align(fieldAlignement, GetAlignement(StructLayout_Std140, StructFieldType_Float4));
+
+		m_largestFieldAlignment = std::max(m_largestFieldAlignment, fieldAlignement);
+
+		std::size_t offset = Align(m_size, Align(fieldAlignement, m_offsetRounding));
+		m_size = offset
+		       + fieldStruct.GetSize() * arraySize
+		       + (Align(fieldStruct.GetSize(), fieldAlignement) - fieldStruct.GetSize()) * (arraySize - 1);
+
+		m_offsetRounding = fieldAlignement;
+
+		return offset;
+	}
+}