/*
* 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.

// Description : Calculate the reference frame for sub-object selections.

#include "StdAfx.h"
#include "SubObjectSelectionReferenceFrameCalculator.h"

SubObjectSelectionReferenceFrameCalculator::SubObjectSelectionReferenceFrameCalculator(ESubObjElementType selectionType)
    :   bAnySelected(false)
    , pos(0.0f, 0.0f, 0.0f)
    , normal(0.0f, 0.0f, 0.0f)
    , nNormals(0)
    , selectionType(selectionType)
    , bUseExplicitFrame(false)
    , bExplicitAnySelected(false)
{
}

void SubObjectSelectionReferenceFrameCalculator::SetExplicitFrame(bool bAnySelected, const Matrix34& refFrame)
{
    this->refFrame = refFrame;
    this->bUseExplicitFrame = true;
    this->bExplicitAnySelected = bAnySelected;
}

bool SubObjectSelectionReferenceFrameCalculator::GetFrame(Matrix34& refFrame)
{
    if (this->bUseExplicitFrame)
    {
        refFrame = this->refFrame;
        return this->bExplicitAnySelected;
    }
    else
    {
        refFrame.SetIdentity();

        if (this->nNormals > 0)
        {
            this->normal = this->normal / this->nNormals;
            if (!this->normal.IsZero())
            {
                this->normal.Normalize();
            }

            // Average position.
            this->pos = this->pos / this->nNormals;
            refFrame.SetTranslation(this->pos);
        }

        if (this->bAnySelected)
        {
            if (!this->normal.IsZero())
            {
                Vec3 xAxis(1, 0, 0), yAxis(0, 1, 0), zAxis(0, 0, 1);
                if (this->normal.IsEquivalent(zAxis) || normal.IsEquivalent(-zAxis))
                {
                    zAxis = xAxis;
                }
                xAxis = this->normal.Cross(zAxis).GetNormalized();
                yAxis = xAxis.Cross(this->normal).GetNormalized();
                refFrame.SetFromVectors(xAxis, yAxis, normal, pos);
            }
        }

        return bAnySelected;
    }
}