output.h

//
// Copyright 2016 Pixar
//
// Licensed under the Apache License, Version 2.0 (the "Apache License")
// with the following modification; you may not use this file except in
// compliance with the Apache License and the following modification to it:
// Section 6. Trademarks. is deleted and replaced with:
//
// 6. Trademarks. This License does not grant permission to use the trade
//    names, trademarks, service marks, or product names of the Licensor
//    and its affiliates, except as required to comply with Section 4(c) of
//    the License and to reproduce the content of the NOTICE file.
//
// You may obtain a copy of the Apache License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the Apache License with the above modification is
// distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, either express or implied. See the Apache License for the specific
// language governing permissions and limitations under the Apache License.
//
#ifndef PXR_USD_USD_SHADE_OUTPUT_H
#define PXR_USD_USD_SHADE_OUTPUT_H

#include "pxr/pxr.h"
#include "pxr/usd/usdShade/api.h"
#include "pxr/usd/usdShade/types.h"
#include "pxr/usd/usdShade/utils.h"
#include "pxr/usd/usd/attribute.h"
#include "pxr/usd/ndr/declare.h"

#include <vector>

PXR_NAMESPACE_OPEN_SCOPE

class UsdShadeConnectableAPI;
struct UsdShadeConnectionSourceInfo;
class UsdShadeInput;

class UsdShadeOutput
{
public:
    UsdShadeOutput()
    {
        // nothing
    }

    TfToken const &GetFullName() const { 
        return _attr.GetName(); 
    }

    USDSHADE_API
    TfToken GetBaseName() const;

    UsdPrim GetPrim() const {
        return _attr.GetPrim();
    }

    USDSHADE_API
    SdfValueTypeName GetTypeName() const;
    
    USDSHADE_API
    bool Set(const VtValue& value, 
             UsdTimeCode time = UsdTimeCode::Default()) const;

    template <typename T>
    bool Set(const T& value, UsdTimeCode time = UsdTimeCode::Default()) const {
        if (UsdAttribute attr = GetAttr()) {
            return attr.Set(value, time);
        }
        return false;
    }


    USDSHADE_API
    bool SetRenderType(TfToken const& renderType) const;

    USDSHADE_API
    TfToken GetRenderType() const;

    USDSHADE_API
    bool HasRenderType() const;



    USDSHADE_API
    NdrTokenMap GetSdrMetadata() const;
    
    USDSHADE_API
    std::string GetSdrMetadataByKey(const TfToken &key) const;
        
    USDSHADE_API
    void SetSdrMetadata(const NdrTokenMap &sdrMetadata) const;

    USDSHADE_API
    void SetSdrMetadataByKey(
        const TfToken &key, 
        const std::string &value) const;

    USDSHADE_API
    bool HasSdrMetadata() const;

    USDSHADE_API
    bool HasSdrMetadataByKey(const TfToken &key) const;

    USDSHADE_API
    void ClearSdrMetadata() const;

    USDSHADE_API
    void ClearSdrMetadataByKey(const TfToken &key) const;


    // ---------------------------------------------------------------
    // ---------------------------------------------------------------


    USDSHADE_API
    explicit UsdShadeOutput(const UsdAttribute &attr);

    USDSHADE_API
    static bool IsOutput(const UsdAttribute &attr);

    UsdAttribute GetAttr() const { return _attr; }
    
    operator UsdAttribute () const { return GetAttr(); }

    bool IsDefined() const {
        return IsOutput(_attr);
    }


    // -------------------------------------------------------------------------
    // -------------------------------------------------------------------------

    USDSHADE_API
    bool CanConnect(const UsdAttribute &source) const;

    USDSHADE_API
    bool CanConnect(const UsdShadeInput &sourceInput) const;

    USDSHADE_API
    bool CanConnect(const UsdShadeOutput &sourceOutput) const;

    using ConnectionModification = UsdShadeConnectionModification;

    USDSHADE_API
    bool ConnectToSource(
        UsdShadeConnectionSourceInfo const &source,
        ConnectionModification const mod =
            ConnectionModification::Replace) const;

    USDSHADE_API
    bool ConnectToSource(
        UsdShadeConnectableAPI const &source, 
        TfToken const &sourceName, 
        UsdShadeAttributeType const sourceType=UsdShadeAttributeType::Output,
        SdfValueTypeName typeName=SdfValueTypeName()) const;

    USDSHADE_API
    bool ConnectToSource(SdfPath const &sourcePath) const;

    USDSHADE_API
    bool ConnectToSource(UsdShadeInput const &sourceInput) const;

    USDSHADE_API
    bool ConnectToSource(UsdShadeOutput const &sourceOutput) const;

    USDSHADE_API
    bool SetConnectedSources(
        std::vector<UsdShadeConnectionSourceInfo> const &sourceInfos) const;

    // XXX move to new header
    using SourceInfoVector = TfSmallVector<UsdShadeConnectionSourceInfo, 1>;

    USDSHADE_API
    SourceInfoVector GetConnectedSources(
        SdfPathVector *invalidSourcePaths = nullptr) const;

    USDSHADE_API
    bool GetConnectedSource(UsdShadeConnectableAPI *source, 
                            TfToken *sourceName,
                            UsdShadeAttributeType *sourceType) const;

    USDSHADE_API
    bool GetRawConnectedSourcePaths(SdfPathVector *sourcePaths) const;

    USDSHADE_API
    bool HasConnectedSource() const;

    USDSHADE_API
    bool IsSourceConnectionFromBaseMaterial() const;

    USDSHADE_API
    bool DisconnectSource(UsdAttribute const &sourceAttr = UsdAttribute()) const;

    USDSHADE_API
    bool ClearSources() const;

    USDSHADE_API
    bool ClearSource() const;


    // -------------------------------------------------------------------------
    // -------------------------------------------------------------------------

    USDSHADE_API
    UsdShadeAttributeVector GetValueProducingAttributes(
        bool shaderOutputsOnly = false) const;


    explicit operator bool() const { 
        return IsDefined(); 
    }

    friend bool operator==(const UsdShadeOutput &lhs, const UsdShadeOutput &rhs) {
        return lhs.GetAttr() == rhs.GetAttr();
    }

    friend bool operator!=(const UsdShadeOutput &lhs, const UsdShadeOutput &rhs) {
        return !(lhs == rhs);
    }

private:
    friend class UsdShadeConnectableAPI;

    // Constructor that creates a UsdShadeOutput with the given name on the 
    // given prim.
    // \p name here is the unnamespaced name of the output.
    UsdShadeOutput(UsdPrim prim,
                   TfToken const &name,
                   SdfValueTypeName const &typeName);

    UsdAttribute _attr;
};


PXR_NAMESPACE_CLOSE_SCOPE

#endif // PXR_USD_USD_SHADE_OUTPUT_H