shaderCode.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_IMAGING_HD_ST_SHADER_CODE_H
#define PXR_IMAGING_HD_ST_SHADER_CODE_H

#include "pxr/pxr.h"
#include "pxr/imaging/hdSt/api.h"
#include "pxr/imaging/hdSt/resourceRegistry.h"
#include "pxr/imaging/hd/version.h"
#include "pxr/imaging/hd/enums.h"

#include "pxr/usd/sdf/path.h"

#include "pxr/base/tf/token.h"

#include <memory>
#include <string>
#include <vector>

PXR_NAMESPACE_OPEN_SCOPE


using HdBindingRequestVector = std::vector<class HdBindingRequest>;

using HdStShaderCodeSharedPtr =
    std::shared_ptr<class HdStShaderCode>;
using HdStShaderCodeSharedPtrVector =
    std::vector<HdStShaderCodeSharedPtr>;

using HdSt_MaterialParamVector =
    std::vector<class HdSt_MaterialParam>;
using HdBufferSourceSharedPtr =
    std::shared_ptr<class HdBufferSource>;
using HdBufferSourceSharedPtrVector =
    std::vector<HdBufferSourceSharedPtr>;
using HdBufferArrayRangeSharedPtr =
    std::shared_ptr<class HdBufferArrayRange>;
using HdStTextureHandleSharedPtr =
    std::shared_ptr<class HdStTextureHandle>;
using HdComputationSharedPtr =
    std::shared_ptr<class HdComputation>;

class HioGlslfx;
class HdSt_ResourceBinder;
class HdStResourceRegistry;

class HdStShaderCode : public std::enable_shared_from_this<HdStShaderCode>
{
public:
    typedef size_t ID;

    HDST_API
    HdStShaderCode();
    HDST_API
    virtual ~HdStShaderCode();

    virtual ID ComputeHash() const = 0;

    HDST_API
    static ID ComputeHash(HdStShaderCodeSharedPtrVector const &shaders);

    virtual ID ComputeTextureSourceHash() const;

    virtual std::string GetSource(TfToken const &shaderStageKey) const = 0;

    HDST_API
    VtDictionary GetLayout(TfTokenVector const &shaderStageKeys) const;

    // XXX: Should be pure-virtual
    HDST_API
    virtual HdSt_MaterialParamVector const& GetParams() const;

    HDST_API
    virtual bool IsEnabledPrimvarFiltering() const;

    HDST_API
    virtual TfTokenVector const& GetPrimvarNames() const;



    struct NamedTextureHandle {
        TfToken name;
        HdTextureType type;
        HdStTextureHandleSharedPtr handle;

        size_t hash;
    };
    using NamedTextureHandleVector = std::vector<NamedTextureHandle>;

    HDST_API
    virtual NamedTextureHandleVector const & GetNamedTextureHandles() const;


    // XXX: Should be pure-virtual
    HDST_API
    virtual HdBufferArrayRangeSharedPtr const& GetShaderData() const;

    virtual void BindResources(int program,
                               HdSt_ResourceBinder const &binder) = 0;

    virtual void UnbindResources(int program,
                                 HdSt_ResourceBinder const &binder) = 0;

    virtual void AddBindings(HdBindingRequestVector* customBindings) = 0;

    HDST_API
    virtual TfToken GetMaterialTag() const;

    class ResourceContext {
    public:
        HDST_API
        void AddSource(HdBufferArrayRangeSharedPtr const &range,
                       HdBufferSourceSharedPtr const &source);

        HDST_API
        void AddSources(HdBufferArrayRangeSharedPtr const &range,
                        HdBufferSourceSharedPtrVector &&sources);

        HDST_API
        void AddComputation(HdBufferArrayRangeSharedPtr const &range,
                            HdComputationSharedPtr const &computation,
                            HdStComputeQueue const queue);
        
        HdStResourceRegistry * GetResourceRegistry() const {
            return _registry;
        }

    private:
        friend class HdStResourceRegistry;
        ResourceContext(HdStResourceRegistry *);
        HdStResourceRegistry *_registry;
    };

    HDST_API
    virtual void AddResourcesFromTextures(ResourceContext &ctx) const;

private:

    // No copying
    HdStShaderCode(const HdStShaderCode &)                      = delete;
    HdStShaderCode &operator =(const HdStShaderCode &)          = delete;

    // Returns the HioGlslfx instance used to configure this shader.
    // This can return nullptr for shaders without a GLSLFX instance.
    virtual HioGlslfx const * _GetGlslfx() const;
};


PXR_NAMESPACE_CLOSE_SCOPE

#endif //HDST_SHADER_H