/*
 * 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
 *
 */

#include <Atom/RPI/Math.azsli>

float4 ReconstructWorldPositionFromDepth(float2 screenCoords, uint sampleIndex)
{
    float depth = PassSrg::m_depth.Load(screenCoords, sampleIndex).r;

    uint2 dimensions;
    uint samples;
    PassSrg::m_depth.GetDimensions(dimensions.x, dimensions.y, samples);
    float2 UV = saturate(screenCoords / dimensions.xy);

    float x = UV.x * 2.0f - 1.0f;
    float y = (1.0f - UV.y) * 2.0f - 1.0f;
    float4 projectedPos = float4(x, y, depth, 1.0f);
    float4 positionVS = mul(ViewSrg::m_projectionMatrixInverse, projectedPos);
    positionVS /= positionVS.w;
    float4 positionWS = mul(ViewSrg::m_viewMatrixInverse, positionVS);
    return positionWS;
}