NazaraEngine/src/Nazara/Shader/LangWriter.cpp

839 lines
20 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/LangWriter.hpp>
#include <Nazara/Core/Algorithm.hpp>
#include <Nazara/Core/CallOnExit.hpp>
#include <Nazara/Math/Algorithm.hpp>
#include <Nazara/Shader/ShaderBuilder.hpp>
#include <Nazara/Shader/Ast/AstCloner.hpp>
#include <Nazara/Shader/Ast/AstRecursiveVisitor.hpp>
#include <Nazara/Shader/Ast/AstUtils.hpp>
#include <Nazara/Shader/Ast/SanitizeVisitor.hpp>
#include <optional>
#include <stdexcept>
#include <Nazara/Shader/Debug.hpp>
namespace Nz
{
namespace
{
template<typename T> const T& Retrieve(const std::unordered_map<std::size_t, T>& map, std::size_t id)
{
auto it = map.find(id);
assert(it != map.end());
return it->second;
}
}
struct LangWriter::BindingAttribute
{
std::optional<unsigned int> bindingIndex;
inline bool HasValue() const { return bindingIndex.has_value(); }
};
struct LangWriter::BuiltinAttribute
{
std::optional<ShaderAst::BuiltinEntry> builtin;
inline bool HasValue() const { return builtin.has_value(); }
};
struct LangWriter::DepthWriteAttribute
{
std::optional<ShaderAst::DepthWriteMode> writeMode;
inline bool HasValue() const { return writeMode.has_value(); }
};
struct LangWriter::EarlyFragmentTestsAttribute
{
std::optional<bool> earlyFragmentTests;
inline bool HasValue() const { return earlyFragmentTests.has_value(); }
};
struct LangWriter::EntryAttribute
{
std::optional<ShaderStageType> stageType;
inline bool HasValue() const { return stageType.has_value(); }
};
struct LangWriter::LayoutAttribute
{
std::optional<StructLayout> layout;
inline bool HasValue() const { return layout.has_value(); }
};
struct LangWriter::LocationAttribute
{
std::optional<unsigned int> locationIndex;
inline bool HasValue() const { return locationIndex.has_value(); }
};
struct LangWriter::State
{
const States* states = nullptr;
std::stringstream stream;
std::unordered_map<std::size_t, std::string> optionNames;
std::unordered_map<std::size_t, ShaderAst::StructDescription> structs;
std::unordered_map<std::size_t, std::string> variableNames;
bool isInEntryPoint = false;
unsigned int indentLevel = 0;
};
std::string LangWriter::Generate(ShaderAst::StatementPtr& shader, const States& states)
{
State state;
m_currentState = &state;
CallOnExit onExit([this]()
{
m_currentState = nullptr;
});
ShaderAst::SanitizeVisitor::Options options;
options.removeOptionDeclaration = false;
ShaderAst::StatementPtr sanitizedAst = ShaderAst::Sanitize(shader, options);
AppendHeader();
sanitizedAst->Visit(*this);
return state.stream.str();
}
void LangWriter::SetEnv(Environment environment)
{
m_environment = std::move(environment);
}
void LangWriter::Append(const ShaderAst::ExpressionType& type)
{
std::visit([&](auto&& arg)
{
Append(arg);
}, type);
}
void LangWriter::Append(const ShaderAst::IdentifierType& /*identifierType*/)
{
throw std::runtime_error("unexpected identifier type");
}
void LangWriter::Append(const ShaderAst::MatrixType& matrixType)
{
if (matrixType.columnCount == matrixType.rowCount)
{
Append("mat");
Append(matrixType.columnCount);
}
else
{
Append("mat");
Append(matrixType.columnCount);
Append("x");
Append(matrixType.rowCount);
}
Append("<", matrixType.type, ">");
}
void LangWriter::Append(ShaderAst::PrimitiveType type)
{
switch (type)
{
case ShaderAst::PrimitiveType::Boolean: return Append("bool");
case ShaderAst::PrimitiveType::Float32: return Append("f32");
case ShaderAst::PrimitiveType::Int32: return Append("i32");
case ShaderAst::PrimitiveType::UInt32: return Append("ui32");
}
}
void LangWriter::Append(const ShaderAst::SamplerType& samplerType)
{
Append("sampler");
switch (samplerType.dim)
{
case ImageType::E1D: Append("1D"); break;
case ImageType::E1D_Array: Append("1DArray"); break;
case ImageType::E2D: Append("2D"); break;
case ImageType::E2D_Array: Append("2DArray"); break;
case ImageType::E3D: Append("3D"); break;
case ImageType::Cubemap: Append("Cube"); break;
}
Append("<", samplerType.sampledType, ">");
}
void LangWriter::Append(const ShaderAst::StructType& structType)
{
const auto& structDesc = Retrieve(m_currentState->structs, structType.structIndex);
Append(structDesc.name);
}
void LangWriter::Append(const ShaderAst::UniformType& uniformType)
{
Append("uniform<");
std::visit([&](auto&& arg)
{
Append(arg);
}, uniformType.containedType);
Append(">");
}
void LangWriter::Append(const ShaderAst::VectorType& vecType)
{
Append("vec", vecType.componentCount, "<", vecType.type, ">");
}
void LangWriter::Append(ShaderAst::NoType)
{
return Append("()");
}
template<typename T>
void LangWriter::Append(const T& param)
{
NazaraAssert(m_currentState, "This function should only be called while processing an AST");
m_currentState->stream << param;
}
template<typename T1, typename T2, typename... Args>
void LangWriter::Append(const T1& firstParam, const T2& secondParam, Args&&... params)
{
Append(firstParam);
Append(secondParam, std::forward<Args>(params)...);
}
template<typename ...Args>
void LangWriter::AppendAttributes(bool appendLine, Args&&... params)
{
bool hasAnyAttribute = (params.HasValue() || ...);
if (!hasAnyAttribute)
return;
Append("[");
(AppendAttribute(params), ...);
Append("]");
if (appendLine)
AppendLine();
else
Append(" ");
}
void LangWriter::AppendAttribute(BindingAttribute binding)
{
if (!binding.HasValue())
return;
Append("binding(", *binding.bindingIndex, ")");
}
void LangWriter::AppendAttribute(BuiltinAttribute builtin)
{
if (!builtin.HasValue())
return;
switch (*builtin.builtin)
{
case ShaderAst::BuiltinEntry::FragCoord:
Append("builtin(fragcoord)");
break;
case ShaderAst::BuiltinEntry::FragDepth:
Append("builtin(fragdepth)");
break;
case ShaderAst::BuiltinEntry::VertexPosition:
Append("builtin(position)");
break;
}
}
void LangWriter::AppendAttribute(DepthWriteAttribute depthWrite)
{
if (!depthWrite.HasValue())
return;
switch (*depthWrite.writeMode)
{
case ShaderAst::DepthWriteMode::Greater:
Append("depth_write(greater)");
break;
case ShaderAst::DepthWriteMode::Less:
Append("depth_write(less)");
break;
case ShaderAst::DepthWriteMode::Replace:
Append("depth_write(replace)");
break;
case ShaderAst::DepthWriteMode::Unchanged:
Append("depth_write(unchanged)");
break;
}
}
void LangWriter::AppendAttribute(EarlyFragmentTestsAttribute earlyFragmentTests)
{
if (!earlyFragmentTests.HasValue())
return;
if (*earlyFragmentTests.earlyFragmentTests)
Append("early_fragment_tests(on)");
else
Append("early_fragment_tests(off)");
}
void LangWriter::AppendAttribute(EntryAttribute entry)
{
if (!entry.HasValue())
return;
switch (*entry.stageType)
{
case ShaderStageType::Fragment:
Append("entry(frag)");
break;
case ShaderStageType::Vertex:
Append("entry(vert)");
break;
}
}
void LangWriter::AppendAttribute(LayoutAttribute entry)
{
if (!entry.HasValue())
return;
switch (*entry.layout)
{
case StructLayout::Std140:
Append("layout(std140)");
break;
}
}
void LangWriter::AppendAttribute(LocationAttribute location)
{
if (!location.HasValue())
return;
Append("location(", *location.locationIndex, ")");
}
void LangWriter::AppendCommentSection(const std::string& section)
{
NazaraAssert(m_currentState, "This function should only be called while processing an AST");
std::string stars((section.size() < 33) ? (36 - section.size()) / 2 : 3, '*');
m_currentState->stream << "/*" << stars << ' ' << section << ' ' << stars << "*/";
AppendLine();
}
void LangWriter::AppendField(std::size_t structIndex, const ShaderAst::ExpressionPtr* memberIndices, std::size_t remainingMembers)
{
const auto& structDesc = Retrieve(m_currentState->structs, structIndex);
assert((*memberIndices)->GetType() == ShaderAst::NodeType::ConstantExpression);
auto& constantValue = static_cast<ShaderAst::ConstantExpression&>(**memberIndices);
Int32 index = std::get<Int32>(constantValue.value);
const auto& member = structDesc.members[index];
Append(".");
Append(member.name);
if (remainingMembers > 1)
{
assert(IsStructType(member.type));
AppendField(std::get<ShaderAst::StructType>(member.type).structIndex, memberIndices + 1, remainingMembers - 1);
}
}
void LangWriter::AppendLine(const std::string& txt)
{
NazaraAssert(m_currentState, "This function should only be called while processing an AST");
m_currentState->stream << txt << '\n' << std::string(m_currentState->indentLevel, '\t');
}
template<typename... Args>
void LangWriter::AppendLine(Args&&... params)
{
(Append(std::forward<Args>(params)), ...);
AppendLine();
}
void LangWriter::AppendStatementList(std::vector<ShaderAst::StatementPtr>& statements)
{
bool first = true;
for (const ShaderAst::StatementPtr& statement : statements)
{
if (!first && statement->GetType() != ShaderAst::NodeType::NoOpStatement)
AppendLine();
statement->Visit(*this);
first = false;
}
}
void LangWriter::EnterScope()
{
NazaraAssert(m_currentState, "This function should only be called while processing an AST");
m_currentState->indentLevel++;
AppendLine("{");
}
void LangWriter::LeaveScope(bool skipLine)
{
NazaraAssert(m_currentState, "This function should only be called while processing an AST");
m_currentState->indentLevel--;
AppendLine();
if (skipLine)
AppendLine("}");
else
Append("}");
}
void LangWriter::RegisterOption(std::size_t optionIndex, std::string optionName)
{
assert(m_currentState->optionNames.find(optionIndex) == m_currentState->optionNames.end());
m_currentState->optionNames.emplace(optionIndex, std::move(optionName));
}
void LangWriter::RegisterStruct(std::size_t structIndex, ShaderAst::StructDescription desc)
{
assert(m_currentState->structs.find(structIndex) == m_currentState->structs.end());
m_currentState->structs.emplace(structIndex, std::move(desc));
}
void LangWriter::RegisterVariable(std::size_t varIndex, std::string varName)
{
assert(m_currentState->variableNames.find(varIndex) == m_currentState->variableNames.end());
m_currentState->variableNames.emplace(varIndex, std::move(varName));
}
void LangWriter::Visit(ShaderAst::ExpressionPtr& expr, bool encloseIfRequired)
{
bool enclose = encloseIfRequired && (GetExpressionCategory(*expr) != ShaderAst::ExpressionCategory::LValue);
if (enclose)
Append("(");
expr->Visit(*this);
if (enclose)
Append(")");
}
void LangWriter::Visit(ShaderAst::AccessIndexExpression& node)
{
Visit(node.expr, true);
const ShaderAst::ExpressionType& exprType = GetExpressionType(*node.expr);
// For structs, convert indices to field names
if (IsStructType(exprType))
AppendField(std::get<ShaderAst::StructType>(exprType).structIndex, node.indices.data(), node.indices.size());
else
{
// Array access
for (ShaderAst::ExpressionPtr& expr : node.indices)
{
Append("[");
Visit(expr);
Append("]");
}
}
}
void LangWriter::Visit(ShaderAst::AssignExpression& node)
{
node.left->Visit(*this);
switch (node.op)
{
case ShaderAst::AssignType::Simple:
Append(" = ");
break;
}
node.right->Visit(*this);
}
void LangWriter::Visit(ShaderAst::BranchStatement& node)
{
bool first = true;
for (const auto& statement : node.condStatements)
{
if (!first)
Append("else ");
Append("if (");
statement.condition->Visit(*this);
AppendLine(")");
EnterScope();
statement.statement->Visit(*this);
LeaveScope();
first = false;
}
if (node.elseStatement)
{
AppendLine("else");
EnterScope();
node.elseStatement->Visit(*this);
LeaveScope();
}
}
void LangWriter::Visit(ShaderAst::BinaryExpression& node)
{
Visit(node.left, true);
switch (node.op)
{
case ShaderAst::BinaryType::Add: Append(" + "); break;
case ShaderAst::BinaryType::Subtract: Append(" - "); break;
case ShaderAst::BinaryType::Multiply: Append(" * "); break;
case ShaderAst::BinaryType::Divide: Append(" / "); break;
case ShaderAst::BinaryType::CompEq: Append(" == "); break;
case ShaderAst::BinaryType::CompGe: Append(" >= "); break;
case ShaderAst::BinaryType::CompGt: Append(" > "); break;
case ShaderAst::BinaryType::CompLe: Append(" <= "); break;
case ShaderAst::BinaryType::CompLt: Append(" < "); break;
case ShaderAst::BinaryType::CompNe: Append(" != "); break;
}
Visit(node.right, true);
}
void LangWriter::Visit(ShaderAst::CastExpression& node)
{
Append(node.targetType);
Append("(");
bool first = true;
for (const auto& exprPtr : node.expressions)
{
if (!exprPtr)
break;
if (!first)
m_currentState->stream << ", ";
exprPtr->Visit(*this);
first = false;
}
Append(")");
}
void LangWriter::Visit(ShaderAst::ConditionalExpression& node)
{
Append("select_opt(", Retrieve(m_currentState->optionNames, node.optionIndex), ", ");
node.truePath->Visit(*this);
Append(", ");
node.falsePath->Visit(*this);
Append(")");
}
void LangWriter::Visit(ShaderAst::ConditionalStatement& node)
{
Append("[opt(", Retrieve(m_currentState->optionNames, node.optionIndex), ")]");
node.statement->Visit(*this);
}
void LangWriter::Visit(ShaderAst::ConstantExpression& node)
{
std::visit([&](auto&& arg)
{
using T = std::decay_t<decltype(arg)>;
if constexpr (std::is_same_v<T, bool>)
Append((arg) ? "true" : "false");
else if constexpr (std::is_same_v<T, float> || std::is_same_v<T, Int32> || std::is_same_v<T, UInt32>)
Append(std::to_string(arg));
else if constexpr (std::is_same_v<T, Vector2f>)
Append("vec2<f32>(" + std::to_string(arg.x) + ", " + std::to_string(arg.y) + ")");
else if constexpr (std::is_same_v<T, Vector2i32>)
Append("vec2<i32>(" + std::to_string(arg.x) + ", " + std::to_string(arg.y) + ")");
else if constexpr (std::is_same_v<T, Vector3f>)
Append("vec3<f32>(" + std::to_string(arg.x) + ", " + std::to_string(arg.y) + ", " + std::to_string(arg.z) + ")");
else if constexpr (std::is_same_v<T, Vector3i32>)
Append("vec3<i32>(" + std::to_string(arg.x) + ", " + std::to_string(arg.y) + ", " + std::to_string(arg.z) + ")");
else if constexpr (std::is_same_v<T, Vector4f>)
Append("vec4<f32>(" + std::to_string(arg.x) + ", " + std::to_string(arg.y) + ", " + std::to_string(arg.z) + ", " + std::to_string(arg.w) + ")");
else if constexpr (std::is_same_v<T, Vector4i32>)
Append("vec4<i32>(" + std::to_string(arg.x) + ", " + std::to_string(arg.y) + ", " + std::to_string(arg.z) + ", " + std::to_string(arg.w) + ")");
else
static_assert(AlwaysFalse<T>::value, "non-exhaustive visitor");
}, node.value);
}
void LangWriter::Visit(ShaderAst::DeclareExternalStatement& node)
{
assert(node.varIndex);
std::size_t varIndex = *node.varIndex;
AppendLine("external");
EnterScope();
bool first = true;
for (const auto& externalVar : node.externalVars)
{
if (!first)
AppendLine(",");
first = false;
AppendAttributes(false, BindingAttribute{ externalVar.bindingIndex });
Append(externalVar.name, ": ", externalVar.type);
RegisterVariable(varIndex++, externalVar.name);
}
LeaveScope();
}
void LangWriter::Visit(ShaderAst::DeclareFunctionStatement& node)
{
NazaraAssert(m_currentState, "This function should only be called while processing an AST");
std::optional<std::size_t> varIndexOpt = node.varIndex;
AppendAttributes(true, EntryAttribute{ node.entryStage }, EarlyFragmentTestsAttribute{ node.earlyFragmentTests }, DepthWriteAttribute{ node.depthWrite });
Append("fn ", node.name, "(");
for (std::size_t i = 0; i < node.parameters.size(); ++i)
{
if (i != 0)
Append(", ");
Append(node.parameters[i].name);
Append(": ");
Append(node.parameters[i].type);
assert(varIndexOpt);
std::size_t& varIndex = *varIndexOpt;
RegisterVariable(varIndex++, node.parameters[i].name);
}
Append(")");
if (!IsNoType(node.returnType))
Append(" -> ", node.returnType);
AppendLine();
EnterScope();
{
AppendStatementList(node.statements);
}
LeaveScope();
}
void LangWriter::Visit(ShaderAst::DeclareOptionStatement& node)
{
assert(node.optIndex);
RegisterOption(*node.optIndex, node.optName);
Append("option ", node.optName, ": ", node.optType);
if (node.initialValue)
{
Append(" = ");
node.initialValue->Visit(*this);
}
Append(";");
}
void LangWriter::Visit(ShaderAst::DeclareStructStatement& node)
{
assert(node.structIndex);
RegisterStruct(*node.structIndex, node.description);
AppendAttributes(true, LayoutAttribute{ node.description.layout });
Append("struct ");
AppendLine(node.description.name);
EnterScope();
{
bool first = true;
for (const auto& member : node.description.members)
{
if (!first)
AppendLine(",");
first = false;
AppendAttributes(false, LocationAttribute{ member.locationIndex }, BuiltinAttribute{ member.builtin });
Append(member.name, ": ", member.type);
}
}
LeaveScope();
}
void LangWriter::Visit(ShaderAst::DeclareVariableStatement& node)
{
assert(node.varIndex);
RegisterVariable(*node.varIndex, node.varName);
Append("let ", node.varName, ": ", node.varType);
if (node.initialExpression)
{
Append(" = ");
node.initialExpression->Visit(*this);
}
Append(";");
}
void LangWriter::Visit(ShaderAst::DiscardStatement& /*node*/)
{
Append("discard;");
}
void LangWriter::Visit(ShaderAst::ExpressionStatement& node)
{
node.expression->Visit(*this);
Append(";");
}
void LangWriter::Visit(ShaderAst::IntrinsicExpression& node)
{
switch (node.intrinsic)
{
case ShaderAst::IntrinsicType::CrossProduct:
Append("cross");
break;
case ShaderAst::IntrinsicType::DotProduct:
Append("dot");
break;
case ShaderAst::IntrinsicType::Length:
Append("length");
break;
case ShaderAst::IntrinsicType::Max:
Append("max");
break;
case ShaderAst::IntrinsicType::Min:
Append("min");
break;
case ShaderAst::IntrinsicType::SampleTexture:
Append("texture");
break;
}
Append("(");
for (std::size_t i = 0; i < node.parameters.size(); ++i)
{
if (i != 0)
Append(", ");
node.parameters[i]->Visit(*this);
}
Append(")");
}
void LangWriter::Visit(ShaderAst::MultiStatement& node)
{
AppendStatementList(node.statements);
}
void LangWriter::Visit(ShaderAst::NoOpStatement& /*node*/)
{
/* nothing to do */
}
void LangWriter::Visit(ShaderAst::ReturnStatement& node)
{
if (node.returnExpr)
{
Append("return ");
node.returnExpr->Visit(*this);
Append(";");
}
else
Append("return;");
}
void LangWriter::Visit(ShaderAst::SwizzleExpression& node)
{
Visit(node.expression, true);
Append(".");
for (std::size_t i = 0; i < node.componentCount; ++i)
{
switch (node.components[i])
{
case ShaderAst::SwizzleComponent::First:
Append("x");
break;
case ShaderAst::SwizzleComponent::Second:
Append("y");
break;
case ShaderAst::SwizzleComponent::Third:
Append("z");
break;
case ShaderAst::SwizzleComponent::Fourth:
Append("w");
break;
}
}
}
void LangWriter::Visit(ShaderAst::VariableExpression& node)
{
const std::string& varName = Retrieve(m_currentState->variableNames, node.variableId);
Append(varName);
}
void LangWriter::Visit(ShaderAst::UnaryExpression& node)
{
switch (node.op)
{
case ShaderAst::UnaryType::LogicalNot:
Append("!");
break;
case ShaderAst::UnaryType::Minus:
Append("-");
break;
case ShaderAst::UnaryType::Plus:
Append("+");
break;
}
node.expression->Visit(*this);
}
void LangWriter::AppendHeader()
{
// Nothing yet
}
}