// This file is part of the FidelityFX SDK.
//
// Copyright (C) 2024 Advanced Micro Devices, Inc.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files(the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and /or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions :
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.

// @defgroup OpticalFlow

#pragma once

// Include the interface for the backend of the OpticalFlow API.
#include "ffx_interface.h"

namespace Fsr31
{
/// FidelityFX OpticalFlow major version.
///
/// @ingroup ffxOpticalflow
#define FFX_OPTICALFLOW_VERSION_MAJOR (1)

/// FidelityFX OpticalFlow minor version.
///
/// @ingroup ffxOpticalflow
#define FFX_OPTICALFLOW_VERSION_MINOR (1)

/// FidelityFX OpticalFlow patch version.
///
/// @ingroup ffxOpticalflow
#define FFX_OPTICALFLOW_VERSION_PATCH (1)

/// FidelityFX Optical Flow context count
///
/// Defines the number of internal effect contexts required by Optical Flow
///
/// @ingroup ffxOpticalFlow
#define FFX_OPTICALFLOW_CONTEXT_COUNT (1)

/// The size of the context specified in 32bit size units.
///
/// @ingroup ffxOpticalflow
#define FFX_OPTICALFLOW_CONTEXT_SIZE (FFX_SDK_DEFAULT_CONTEXT_SIZE)

#if defined(__cplusplus)
extern "C"
{
#endif // #if defined(__cplusplus)

    /// An enumeration of all the passes which constitute the OpticalFlow algorithm.
    ///
    /// @ingroup ffxOpticalflow
    typedef enum FfxOpticalflowPass
    {
        FFX_OPTICALFLOW_PASS_PREPARE_LUMA = 0,
        FFX_OPTICALFLOW_PASS_GENERATE_OPTICAL_FLOW_INPUT_PYRAMID,
        FFX_OPTICALFLOW_PASS_GENERATE_SCD_HISTOGRAM,
        FFX_OPTICALFLOW_PASS_COMPUTE_SCD_DIVERGENCE,
        FFX_OPTICALFLOW_PASS_COMPUTE_OPTICAL_FLOW_ADVANCED_V5,
        FFX_OPTICALFLOW_PASS_FILTER_OPTICAL_FLOW_V5,
        FFX_OPTICALFLOW_PASS_SCALE_OPTICAL_FLOW_ADVANCED_V5,

        FFX_OPTICALFLOW_PASS_COUNT
    } FfxOpticalflowPass;

    /// An enumeration of bit flags used when creating a
    /// <c><i>FfxOpticalflowContext</i></c>. See <c><i>FfxOpticalflowDispatchDescription</i></c>.
    ///
    /// @ingroup ffxOpticalflow
    typedef enum FfxOpticalflowInitializationFlagBits
    {
        FFX_OPTICALFLOW_ENABLE_TEXTURE1D_USAGE = (1 << 0),

    } FfxOpticalflowInitializationFlagBits;

    /// A structure encapsulating the parameters required to initialize
    /// FidelityFX OpticalFlow.
    ///
    /// @ingroup ffxOpticalflow
    typedef struct FfxOpticalflowContextDescription
    {

        FfxInterface backendInterface; ///< A set of pointers to the backend implementation for FidelityFX SDK
        uint32_t flags;                ///< A collection of <c><i>FfxOpticalflowInitializationFlagBits</i></c>.
        FfxDimensions2D resolution;
    } FfxOpticalflowContextDescription;

    /// A structure encapsulating the parameters for dispatching the various passes
    /// of FidelityFX Opticalflow.
    ///
    /// @ingroup ffxOpticalflow
    typedef struct FfxOpticalflowDispatchDescription
    {
        FfxCommandList commandList;    ///< The <c><i>FfxCommandList</i></c> to record rendering commands into.
        FfxResource color;             ///< A <c><i>FfxResource</i></c> containing the input color buffer
        FfxResource opticalFlowVector; ///< A <c><i>FfxResource</i></c> containing the output motion buffer
        FfxResource opticalFlowSCD; ///< A <c><i>FfxResource</i></c> containing the output scene change detection buffer
        bool reset; ///< A boolean value which when set to true, indicates the camera has moved discontinuously.
        int backbufferTransferFunction;
        FfxFloatCoords2D minMaxLuminance;
    } FfxOpticalflowDispatchDescription;

    typedef struct FfxOpticalflowSharedResourceDescriptions
    {

        FfxCreateResourceDescription opticalFlowVector;
        FfxCreateResourceDescription opticalFlowSCD;

    } FfxOpticalflowSharedResourceDescriptions;

    /// A structure encapsulating the FidelityFX OpticalFlow context.
    ///
    /// This sets up an object which contains all persistent internal data and
    /// resources that are required by OpticalFlow.
    ///
    /// The <c><i>FfxOpticalflowContext</i></c> object should have a lifetime matching
    /// your use of OpticalFlow. Before destroying the OpticalFlow context care should be taken
    /// to ensure the GPU is not accessing the resources created or used by OpticalFlow.
    /// It is therefore recommended that the GPU is idle before destroying OpticalFlow
    /// OpticalFlow context.
    ///
    /// @ingroup ffxOpticalflow
    typedef struct FfxOpticalflowContext
    {
        uint32_t data[FFX_OPTICALFLOW_CONTEXT_SIZE]; ///< An opaque set of <c>uint32_t</c> which contain the data for
                                                     ///< the context.
    } FfxOpticalflowContext;

    /// Create a FidelityFX OpticalFlow context from the parameters
    /// programmed to the <c><i>FfxOpticalflowContextDescription</i></c> structure.
    ///
    /// The context structure is the main object used to interact with the OpticalFlow
    /// API, and is responsible for the management of the internal resources used
    /// by the OpticalFlow algorithm. When this API is called, multiple calls will be
    /// made via the pointers contained in the <c><i>callbacks</i></c> structure.
    /// These callbacks will attempt to retreive the device capabilities, and
    /// create the internal resources, and pipelines required by OpticalFlow's
    /// frame-to-frame function. Depending on the precise configuration used when
    /// creating the <c><i>FfxOpticalflowContext</i></c> a different set of resources and
    /// pipelines might be requested via the callback functions.
    ///
    /// The flags included in the <c><i>flags</i></c> field of
    /// <c><i>FfxOpticalflowContext</i></c> how match the configuration of your
    /// application as well as the intended use of OpticalFlow. It is important that these
    /// flags are set correctly (as well as a correct programmed
    /// <c><i>FfxOpticalflowContextDescription</i></c>) to ensure correct operation. It is
    /// recommended to consult the overview documentation for further details on
    /// how OpticalFlow should be integerated into an application.
    ///
    /// When the <c><i>FfxOpticalflowContext</i></c> is created, you should use the
    /// <c><i>ffxOpticalflowContextDispatch</i></c> function each frame where FSR3
    /// upscaling should be applied. See the documentation of
    /// <c><i>ffxOpticalflowContextDispatch</i></c> for more details.
    ///
    /// The <c><i>FfxOpticalflowContext</i></c> should be destroyed when use of it is
    /// completed, typically when an application is unloaded or OpticalFlow is
    /// disabled by a user. To destroy the OpticalFlow context you should call
    /// <c><i>ffxOpticalflowContextDestroy</i></c>.
    ///
    /// @param [out] context                A pointer to a <c><i>FfxOpticalflowContext</i></c> structure to populate.
    /// @param [in]  contextDescription     A pointer to a <c><i>FfxOpticalflowContextDescription</i></c> structure.
    ///
    /// @retval
    /// FFX_OK                              The operation completed successfully.
    /// @retval
    /// FFX_ERROR_CODE_NULL_POINTER         The operation failed because either <c><i>context</i></c> or
    /// <c><i>contextDescription</i></c> was <c><i>NULL</i></c>.
    /// @retval
    /// FFX_ERROR_INCOMPLETE_INTERFACE      The operation failed because the
    /// <c><i>FfxOpticalflowContextDescription.callbacks</i></c>  was not fully specified.
    /// @retval
    /// FFX_ERROR_BACKEND_API_ERROR         The operation failed because of an error returned from the backend.
    ///
    /// @ingroup ffxOpticalflow
    FFX_API FfxErrorCode ffxOpticalflowContextCreate(FfxOpticalflowContext* context,
                                                     FfxOpticalflowContextDescription* contextDescription);

    FFX_API FfxErrorCode ffxOpticalflowGetSharedResourceDescriptions(
        FfxOpticalflowContext* context, FfxOpticalflowSharedResourceDescriptions* SharedResources);

    FFX_API FfxErrorCode ffxOpticalflowContextDispatch(FfxOpticalflowContext* context,
                                                       const FfxOpticalflowDispatchDescription* dispatchDescription);

    /// Destroy the FidelityFX OpticalFlow context.
    ///
    /// @param [out] context                A pointer to a <c><i>FfxOpticalflowContext</i></c> structure to destroy.
    ///
    /// @retval
    /// FFX_OK                              The operation completed successfully.
    /// @retval
    /// FFX_ERROR_CODE_NULL_POINTER         The operation failed because either <c><i>context</i></c> was
    /// <c><i>NULL</i></c>.
    ///
    /// @ingroup ffxOpticalflow
    FFX_API FfxErrorCode ffxOpticalflowContextDestroy(FfxOpticalflowContext* context);

#if defined(__cplusplus)
}
#endif // #if defined(__cplusplus)
} // namespace Fsr31
