NazaraEngine/src/Nazara/Utility/TriangleIterator.cpp

81 lines
2.0 KiB
C++

// Copyright (C) 2014 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/TriangleIterator.hpp>
#include <Nazara/Utility/SubMesh.hpp>
#include <Nazara/Utility/Debug.hpp>
NzTriangleIterator::NzTriangleIterator(nzPrimitiveMode primitiveMode, const NzIndexBuffer* indexBuffer) :
m_primitiveMode(primitiveMode),
m_indexMapper(indexBuffer, nzBufferAccess_ReadOnly)
{
m_currentIndex = 3;
m_triangleIndices[0] = m_indexMapper.Get(0);
m_triangleIndices[1] = m_indexMapper.Get(1);
m_triangleIndices[2] = m_indexMapper.Get(2);
m_indexCount = indexBuffer->GetIndexCount();
}
NzTriangleIterator::NzTriangleIterator(NzSubMesh* subMesh) :
NzTriangleIterator(subMesh->GetPrimitiveMode(), subMesh->GetIndexBuffer())
{
}
bool NzTriangleIterator::Advance()
{
if (m_currentIndex >= m_indexCount)
{
Unmap();
return false;
}
switch (m_primitiveMode)
{
case nzPrimitiveMode_TriangleFan:
m_triangleIndices[1] = m_indexMapper.Get(m_currentIndex++);
m_triangleIndices[2] = m_indexMapper.Get(m_currentIndex++);
break;
case nzPrimitiveMode_TriangleList:
m_triangleIndices[0] = m_indexMapper.Get(m_currentIndex++);
m_triangleIndices[1] = m_indexMapper.Get(m_currentIndex++);
m_triangleIndices[2] = m_indexMapper.Get(m_currentIndex++);
break;
case nzPrimitiveMode_TriangleStrip:
m_triangleIndices[2] = m_indexMapper.Get(m_currentIndex++);
m_triangleIndices[1] = m_triangleIndices[2];
m_triangleIndices[0] = m_triangleIndices[1];
break;
default:
return false;
}
return true;
}
nzUInt32 NzTriangleIterator::operator[](unsigned int i) const
{
#if NAZARA_UTILITY_SAFE
if (i >= 3)
{
NzStringStream ss;
ss << "Index out of range: (" << i << " >= 3)";
NazaraError(ss);
throw std::domain_error(ss.ToString());
}
#endif
return m_triangleIndices[i];
}
void NzTriangleIterator::Unmap()
{
// Peut très bien être appellé plusieurs fois de suite, seul le premier appel sera pris en compte
m_indexMapper.Unmap();
}