NazaraEngine/src/Nazara/OpenGLRenderer/OpenGLUploadPool.cpp

84 lines
2.3 KiB
C++

// Copyright (C) 2022 Jérôme "Lynix" Leclercq (lynix680@gmail.com)
// This file is part of the "Nazara Engine - OpenGL renderer"
// For conditions of distribution and use, see copyright notice in Config.hpp
#include <Nazara/OpenGLRenderer/OpenGLUploadPool.hpp>
#include <cassert>
#include <stdexcept>
#include <Nazara/OpenGLRenderer/Debug.hpp>
namespace Nz
{
auto OpenGLUploadPool::Allocate(UInt64 size) -> Allocation&
{
return Allocate(size, 1); //< Alignment doesn't matter
}
auto OpenGLUploadPool::Allocate(UInt64 size, UInt64 /*alignment*/) -> Allocation&
{
// Try to minimize lost space
struct
{
Block* block = nullptr;
UInt64 offset = 0;
} bestBlock;
for (Block& block : m_blocks)
{
if (block.freeOffset + size > block.size)
continue; //< Not enough space
if (!bestBlock.block)
{
bestBlock.block = &block;
bestBlock.offset = block.freeOffset;
break; //< Since we have no alignment constraint, the first block is good
}
}
// No block found, allocate a new one
if (!bestBlock.block)
{
// Handle really big allocations (TODO: Handle them separately as they shouldn't be common and can consume a lot of memory)
UInt64 blockSize = std::max(m_blockSize, size);
Block newBlock;
newBlock.size = blockSize;
newBlock.memory.resize(blockSize);
bestBlock.block = &m_blocks.emplace_back(std::move(newBlock));
bestBlock.offset = 0;
}
// Now find the proper allocation buffer
std::size_t allocationBlockIndex = m_nextAllocationIndex / AllocationPerBlock;
std::size_t allocationIndex = m_nextAllocationIndex % AllocationPerBlock;
if (allocationBlockIndex >= m_allocationBlocks.size())
{
assert(allocationBlockIndex == m_allocationBlocks.size());
m_allocationBlocks.emplace_back(std::make_unique<AllocationBlock>());
}
auto& allocationBlock = *m_allocationBlocks[allocationBlockIndex];
Allocation& allocationData = allocationBlock[allocationIndex];
allocationData.mappedPtr = static_cast<UInt8*>(bestBlock.block->memory.data()) + bestBlock.offset;
allocationData.size = size;
bestBlock.block->freeOffset += size;
m_nextAllocationIndex++;
return allocationData;
}
void OpenGLUploadPool::Reset()
{
for (Block& block : m_blocks)
block.freeOffset = 0;
m_nextAllocationIndex = 0;
}
}