//
// Copyright 2019 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_HGI_GL_GRAPHICS_CMDS_H
#define PXR_IMAGING_HGI_GL_GRAPHICS_CMDS_H

#include "pxr/pxr.h"
#include "pxr/base/gf/vec4i.h"
#include "pxr/imaging/hgi/graphicsCmds.h"
#include "pxr/imaging/hgiGL/api.h"
#include "pxr/imaging/hgiGL/hgi.h"
#include <cstdint>

PXR_NAMESPACE_OPEN_SCOPE

struct HgiGraphicsCmdsDesc;


/// \class HgiGLGraphicsCmds
///
/// OpenGL implementation of HgiGraphicsCmds.
///
class HgiGLGraphicsCmds final : public HgiGraphicsCmds
{
public:
    HGIGL_API
    ~HgiGLGraphicsCmds() override;

    /// XXX This function is exposed temporarily for Hgi transition.
    /// It allows code that is not yet converted to Hgi (e.g. HdSt) to insert
    /// its opengl calls into the ops-stack of HgiGL to ensure that all commands
    /// execute in the correct order. Once HdSt has transition fully to Hgi we
    /// should remove this function.
    HGIGL_API
    void InsertFunctionOp(std::function<void(void)> const& fn);

    HGIGL_API
    void PushDebugGroup(const char* label) override;

    HGIGL_API
    void PopDebugGroup() override;

    HGIGL_API
    void SetViewport(GfVec4i const& vp) override;

    HGIGL_API
    void SetScissor(GfVec4i const& sc) override;

    HGIGL_API
    void BindPipeline(HgiGraphicsPipelineHandle pipeline) override;

    HGIGL_API
    void BindResources(HgiResourceBindingsHandle resources) override;

    HGIGL_API
    void SetConstantValues(
        HgiGraphicsPipelineHandle pipeline,
        HgiShaderStage stages,
        uint32_t bindIndex,
        uint32_t byteSize,
        const void* data) override;
    
    HGIGL_API
    void BindVertexBuffers(
        uint32_t firstBinding,
        HgiBufferHandleVector const& buffers,
        std::vector<uint32_t> const& byteOffsets) override;

    HGIGL_API
    void DrawIndexed(
        HgiBufferHandle const& indexBuffer,
        uint32_t indexCount,
        uint32_t indexBufferByteOffset,
        uint32_t firstIndex,
        uint32_t vertexOffset,
        uint32_t instanceCount) override;

protected:
    friend class HgiGL;

    HGIGL_API
    HgiGLGraphicsCmds(
        HgiGLDevice* device,
        HgiGraphicsCmdsDesc const& desc);

    HGIGL_API
    bool _Submit(Hgi* hgi) override;

private:
    HgiGLGraphicsCmds() = delete;
    HgiGLGraphicsCmds & operator=(const HgiGLGraphicsCmds&) = delete;
    HgiGLGraphicsCmds(const HgiGLGraphicsCmds&) = delete;

    /// This performs multisample resolve when needed at the end of recording.
    void _Resolve();

    bool _recording;
    HgiGraphicsCmdsDesc _descriptor;
    HgiGLOpsVector _ops;

    // Cmds is used only one frame so storing multi-frame state on will not
    // survive.
};

PXR_NAMESPACE_CLOSE_SCOPE

#endif