src/compiler/translator/EmulatePrecision.h

//
// Copyright (c) 2002-2014 The ANGLE Project Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
//

#ifndef COMPILER_TRANSLATOR_EMULATE_PRECISION_H_
#define COMPILER_TRANSLATOR_EMULATE_PRECISION_H_

#include "common/angleutils.h"
#include "compiler/translator/InfoSink.h"
#include "compiler/translator/IntermNode.h"
#include "GLSLANG/ShaderLang.h"

// This class gathers all compound assignments from the AST and can then write
// the functions required for their precision emulation. This way there is no
// need to write a huge number of variations of the emulated compound assignment
// to every translated shader with emulation enabled.

class EmulatePrecision : public TIntermTraverser
{
  public:
    EmulatePrecision();

    virtual void visitSymbol(TIntermSymbol *node);
    virtual bool visitBinary(Visit visit, TIntermBinary *node);
    virtual bool visitUnary(Visit visit, TIntermUnary *node);
    virtual bool visitAggregate(Visit visit, TIntermAggregate *node);

    void writeEmulationHelpers(TInfoSinkBase& sink, ShShaderOutput outputLanguage);

  private:
    DISALLOW_COPY_AND_ASSIGN(EmulatePrecision);

    struct TypePair
    {
        TypePair(const char *l, const char *r)
            : lType(l), rType(r) { }

        const char *lType;
        const char *rType;
    };

    struct TypePairComparator
    {
        bool operator() (const TypePair& l, const TypePair& r) const
        {
            if (l.lType == r.lType)
                return l.rType < r.rType;
            return l.lType < r.lType;
        }
    };

    typedef std::set<TypePair, TypePairComparator> EmulationSet;
    EmulationSet mEmulateCompoundAdd;
    EmulationSet mEmulateCompoundSub;
    EmulationSet mEmulateCompoundMul;
    EmulationSet mEmulateCompoundDiv;

    // Stack of function call parameter iterators
    std::vector<TIntermSequence::const_iterator> mSeqIterStack;

    bool mDeclaringVariables;
    bool mInLValue;
    bool mInFunctionCallOutParameter;

    struct TStringComparator
    {
        bool operator() (const TString& a, const TString& b) const { return a.compare(b) < 0; }
    };

    // Map from function names to their parameter sequences
    std::map<TString, TIntermSequence*, TStringComparator> mFunctionMap;
};

#endif  // COMPILER_TRANSLATOR_EMULATE_PRECISION_H_