/*
* All or portions of this file Copyright (c) Amazon.com, Inc. or its affiliates or
* its licensors.
*
* For complete copyright and license terms please see the LICENSE at the root of this
* distribution (the "License"). All use of this software is governed by the License,
* or, if provided, by the license below or the license accompanying this file. Do not
* remove or modify any license notices. This file is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
*
*/
// Original file Copyright Crytek GMBH or its affiliates, used under license.

#include "StdAfx.h"
#include "../Common/RendElements/OpticsElement.h"
#include "../Common/RendElements/RootOpticsElement.h"
#include "../Common/RendElements/FlareSoftOcclusionQuery.h"
#include "../Common/RendElements/OpticsPredef.hpp"
#include "DriverD3D.h"
#include "I3DEngine.h"

static CSoftOcclusionManager g_SoftOcclusionManager;

CRELensOptics::CRELensOptics(void)
{
    mfSetType(eDATA_LensOptics);
    mfUpdateFlags(FCEF_TRANSFORM);
}

CRELensOptics::~CRELensOptics(void)
{
}

bool CRELensOptics::mfCompile(CParserBin& Parser, SParserFrame& Frame)
{
    return true;
}

void CRELensOptics::mfPrepare(bool bCheckOverflow)
{
    if (bCheckOverflow)
    {
        gRenDev->FX_CheckOverflow(0, 0, this);
    }

    gRenDev->m_RP.m_pRE = this;
    gRenDev->m_RP.m_RendNumIndices = 0;
    gRenDev->m_RP.m_RendNumVerts = 0;
}

void CRELensOptics::ProcessGlobalAction()
{
    PROFILE_LABEL_SCOPE("Soft Occlusion Query");

    CFlareSoftOcclusionQuery::InitGlobalResources();
    CFlareSoftOcclusionQuery::BatchReadResults(); // copy to system memory previous frame

    CShader* pShader = CShaderMan::s_ShaderSoftOcclusionQuery;
    static CCryNameTSCRC sTechName("Main");

    uint32 nPass = 0;
    pShader->FXSetTechnique(sTechName);
    pShader->FXBegin(&nPass, FEF_DONTSETTEXTURES);

    g_SoftOcclusionManager.ComputeVisibility();
    g_SoftOcclusionManager.GatherOcclusions();

    pShader->FXEnd();

    CFlareSoftOcclusionQuery::ReadbackSoftOcclQuery(); // update current frame to staging buffer
    for (int i = 0, iSize(g_SoftOcclusionManager.GetSize()); i < iSize; ++i)
    {
        CFlareSoftOcclusionQuery* pSoftOcclusion = g_SoftOcclusionManager.GetSoftOcclusionQuery(i);
        if (pSoftOcclusion == NULL)
        {
            continue;
        }
        pSoftOcclusion->UpdateCachedResults();
    }
}

static int prevFrameID = 0;

bool CRELensOptics::mfDraw(CShader* pShader, SShaderPass* pass)
{
    if (!CRenderer::CV_r_flares || !CRenderer::CV_r_PostProcess)
    {
        return false;
    }

    CD3D9Renderer* pRD = gcpRendD3D;
    CRenderObject* pObj = pRD->m_RP.m_pCurObject;
    SRenderObjData* pOD = pObj->GetObjData();
    const CameraViewParameters* cam = &pRD->GetViewParameters();

    // Basically LensOptics should be rendered in only FB_TRANSPARENT phase currently so FB_GENERAL is ignored until it's needed.
    if (pRD->m_RP.m_nBatchFilter == FB_GENERAL)
    {
        return false;
    }

    SRenderLight* pLight = pOD ? pRD->EF_GetDeferredLightByID(pOD->m_nLightID) : NULL;
    RootOpticsElement* pRootElem = pLight ? (RootOpticsElement*)pLight->GetLensOpticsElement() : NULL;

    if (!pRootElem || pRootElem->GetType() != eFT_Root)
    {
        return false;
    }

    CFlareSoftOcclusionQuery* pOcc = static_cast<CFlareSoftOcclusionQuery*>(pLight->m_pSoftOccQuery);
    if (!pOcc)
    {
        return false;
    }

#if !defined(_RELEASE)
    PROFILE_LABEL_SCOPE(pLight->m_sName);
#endif

    pRootElem->SetOcclusionQuery(pOcc);
    pOcc->SetOccPlaneSizeRatio(pRootElem->GetOccSize());

    RootOpticsElement::SFlareLight flareLight;
    if (pLight->m_Flags & DLF_ATTACH_TO_SUN)
    {
        const float sunHeight = 20000.0f;
        Vec3 sunDirNorm = gEnv->p3DEngine->GetSunDir();
        sunDirNorm.Normalize();

        flareLight.m_vPos = cam->vOrigin + sunDirNorm * sunHeight;
        flareLight.m_cLdrClr = gEnv->p3DEngine->GetSunAnimColor();
        flareLight.m_fRadius = sunHeight;
        flareLight.m_bAttachToSun = true;
        pLight->SetPosition(flareLight.m_vPos);
    }
    else
    {
        flareLight.m_vPos = pObj->GetTranslation();
        ColorF& c = pLight->m_Color;
        flareLight.m_cLdrClr.Set(c.r, c.g, c.b);
        flareLight.m_fRadius = pLight->m_fRadius;
        flareLight.m_bAttachToSun = false;
    }

    ColorF cNorm;
    flareLight.m_fClrMultiplier = flareLight.m_cLdrClr.NormalizeCol(cNorm);
    flareLight.m_cLdrClr = cNorm;

    flareLight.m_opticsParams = pLight->GetOpticsParams();

    flareLight.m_fViewAngleFalloff = 1.0;
    if (pLight->m_LensOpticsFrustumAngle != 0)
    {
        Vec3 vDirLight2Camera = (cam->vOrigin - flareLight.m_vPos).GetNormalizedFast();
        float viewCos = pLight->m_ProjMatrix.GetColumn(0).Dot(vDirLight2Camera) * 0.5f + 0.5f;
        if (pLight->m_LensOpticsFrustumAngle < 255)
        {
            int angle = (int)((float)pLight->m_LensOpticsFrustumAngle * (360.0f / 255.0f));
            float radAngle = DEG2RAD(angle);
            float halfFrustumCos = cos_tpl(radAngle * 0.5f) * 0.5f + 0.5f;
            float quarterFrustumCos = cos_tpl(radAngle * 0.25f) * 0.5f + 0.5f;
            if (viewCos < quarterFrustumCos)
            {
                flareLight.m_fViewAngleFalloff = max(1.0f - (float)((quarterFrustumCos - viewCos) / (quarterFrustumCos - halfFrustumCos)), 0.0f);
            }
            else
            {
                flareLight.m_fViewAngleFalloff = 1;
            }
        }
    }
    else
    {
        flareLight.m_fViewAngleFalloff = 0.0;
    }

    int curFID = gRenDev->GetFrameID(false);
    if (curFID != prevFrameID)
    {
        if (g_SoftOcclusionManager.Begin())
        {
            ProcessGlobalAction();
            g_SoftOcclusionManager.End();
        }
        prevFrameID = curFID;
    }

    if (pRootElem->ProcessAll(pShader, flareLight))
    {
        g_SoftOcclusionManager.AddSoftOcclusionQuery(pOcc, pLight->GetPosition());
    }

    pRootElem->SetOcclusionQuery(NULL);

    return true;
}

void CRELensOptics::ClearResources()
{
    g_SoftOcclusionManager.ClearResources();
}