/*
 * Copyright (c) Contributors to the Open 3D Engine Project.
 * For complete copyright and license terms please see the LICENSE at the root of this distribution.
 *
 * SPDX-License-Identifier: Apache-2.0 OR MIT
 *
 */

#ifndef AZ_COLLECTING_PARTIAL_SRGS
#error Do not include this file directly. Include the main .srgi file instead.
#endif

partial ShaderResourceGroup ViewSrg
{
    row_major float4x4 m_viewProjectionMatrix;
    row_major float4x4 m_viewMatrix;
    row_major float4x4 m_viewMatrixInverse;
    row_major float4x4 m_projectionMatrix;
    row_major float4x4 m_projectionMatrixInverse;
    row_major float4x4 m_viewProjectionInverseMatrix;

    // view projection matrix of last frame
    row_major float4x4 m_viewProjectionPrevMatrix;

    float3 m_worldPosition;

    float4 m_nearZ_farZ_farZTimesNearZ_farZMinusNearZ;

    // Constants used to unproject depth values and reconstruct the view-space position (Z-forward & Y-up)
    // See the GetViewSpacePosition( ) function below
    float4 m_unprojectionConstants;

    float GetNearZ()
    {
        return ViewSrg::m_nearZ_farZ_farZTimesNearZ_farZMinusNearZ.x;
    }

    float GetFarZ()
    {
        return ViewSrg::m_nearZ_farZ_farZTimesNearZ_farZMinusNearZ.y;
    }

    float GetFarZTimesNearZ()
    {
        return ViewSrg::m_nearZ_farZ_farZTimesNearZ_farZMinusNearZ.z;
    }

    float GetFarZMinusNearZ()
    {
        return ViewSrg::m_nearZ_farZ_farZTimesNearZ_farZMinusNearZ.w;
    }

    // Uses linearDepth value at screenUV to reconstruct view-space position (Z-forward & Y-up)
    float3 GetViewSpacePosition(float2 screenUV, float linearDepth)
    {
        float2 screenRay = (screenUV * ViewSrg::m_unprojectionConstants.xy + ViewSrg::m_unprojectionConstants.zw);
        return float3(screenRay * linearDepth, linearDepth);
    }
}

#include <Atom/Feature/Common/Assets/ShaderResourceGroups/Decals/ViewSrg.azsli>
#include <Atom/Feature/Common/Assets/ShaderResourceGroups/CoreLights/ViewSrg.azsli>
#include <Atom/Feature/Common/Assets/ShaderResourceGroups/PostProcessing/ViewSrg.azsli>