Files
NazaraEngine/src/Nazara/Shader/SpirvExpressionLoad.cpp

122 lines
3.2 KiB
C++

// Copyright (C) 2020 Jérôme Leclercq
// This file is part of the "Nazara Engine - Shader generator"
// For conditions of distribution and use, see copyright notice in Config.hpp
#include <Nazara/Shader/SpirvExpressionLoad.hpp>
#include <Nazara/Core/StackVector.hpp>
#include <Nazara/Shader/SpirvBlock.hpp>
#include <Nazara/Shader/SpirvWriter.hpp>
#include <Nazara/Shader/Debug.hpp>
namespace Nz
{
namespace
{
template<class... Ts> struct overloaded : Ts... { using Ts::operator()...; };
template<class... Ts> overloaded(Ts...) -> overloaded<Ts...>;
}
UInt32 SpirvExpressionLoad::Evaluate(ShaderNodes::Expression& node)
{
node.Visit(*this);
return std::visit(overloaded
{
[this](const Pointer& pointer) -> UInt32
{
UInt32 resultId = m_writer.AllocateResultId();
m_block.Append(SpirvOp::OpLoad, pointer.pointedTypeId, resultId, pointer.resultId);
return resultId;
},
[](const Value& value) -> UInt32
{
return value.resultId;
},
[](std::monostate) -> UInt32
{
throw std::runtime_error("an internal error occurred");
}
}, m_value);
}
void SpirvExpressionLoad::Visit(ShaderNodes::AccessMember& node)
{
Visit(node.structExpr);
std::visit(overloaded
{
[&](const Pointer& pointer)
{
UInt32 resultId = m_writer.AllocateResultId();
UInt32 pointerType = m_writer.RegisterPointerType(node.exprType, pointer.storage); //< FIXME
UInt32 typeId = m_writer.GetTypeId(node.exprType);
m_block.AppendVariadic(SpirvOp::OpAccessChain, [&](const auto& appender)
{
appender(pointerType);
appender(resultId);
appender(pointer.resultId);
for (std::size_t index : node.memberIndices)
appender(m_writer.GetConstantId(Int32(index)));
});
m_value = Pointer { pointer.storage, resultId, typeId };
},
[&](const Value& value)
{
UInt32 resultId = m_writer.AllocateResultId();
UInt32 typeId = m_writer.GetTypeId(node.exprType);
m_block.AppendVariadic(SpirvOp::OpCompositeExtract, [&](const auto& appender)
{
appender(typeId);
appender(resultId);
appender(value.resultId);
for (std::size_t index : node.memberIndices)
appender(m_writer.GetConstantId(Int32(index)));
});
m_value = Value { resultId };
},
[](std::monostate)
{
throw std::runtime_error("an internal error occurred");
}
}, m_value);
}
void SpirvExpressionLoad::Visit(ShaderNodes::Identifier& node)
{
Visit(node.var);
}
void SpirvExpressionLoad::Visit(ShaderNodes::InputVariable& var)
{
auto inputVar = m_writer.GetInputVariable(var.name);
if (auto resultIdOpt = m_writer.ReadVariable(inputVar, SpirvWriter::OnlyCache{}))
m_value = Value{ *resultIdOpt };
else
m_value = Pointer{ SpirvStorageClass::Input, inputVar.varId, inputVar.typeId };
}
void SpirvExpressionLoad::Visit(ShaderNodes::LocalVariable& var)
{
m_value = Value{ m_writer.ReadLocalVariable(var.name) };
}
void SpirvExpressionLoad::Visit(ShaderNodes::UniformVariable& var)
{
auto uniformVar = m_writer.GetUniformVariable(var.name);
if (auto resultIdOpt = m_writer.ReadVariable(uniformVar, SpirvWriter::OnlyCache{}))
m_value = Value{ *resultIdOpt };
else
m_value = Pointer{ SpirvStorageClass::Uniform, uniformVar.varId, uniformVar.typeId };
}
}