axmol/extensions/Particle3D/PU/CCPUUtil.cpp

/****************************************************************************
 Copyright (C) 2013 Henry van Merode. All rights reserved.
 Copyright (c) 2015-2016 Chukong Technologies Inc.
 Copyright (c) 2017-2018 Xiamen Yaji Software Co., Ltd.

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#include "CCPUUtil.h"
#include "base/ccMacros.h"

NS_CC_BEGIN

cocos2d::Vec3 PUUtil::randomDeviant(const Vec3& src, float angle, const Vec3& up /*= Vec3::ZERO*/)
{
    Vec3 newUp;

    if (up == Vec3::ZERO)
    {
        // Generate an up vector
        newUp = perpendicular(src);
    }
    else
    {
        newUp = up;
    }

    // Rotate up vector by random amount around this
    // Quaternion q;
    // q.FromAngleAxis( Radian(Math::UnitRandom() * Math::TWO_PI), *this );
    // newUp = q * newUp;

    //// Finally rotate this by given angle around randomised up
    // q.FromAngleAxis( angle, newUp );
    // return q * (*this);

    Quaternion q;
    Mat4 mat;
    Quaternion::createFromAxisAngle(src, CCRANDOM_0_1() * M_PI * 2.0f, &q);
    Mat4::createRotation(q, &mat);

    //{
    //	Vec3 uv, uuv;
    //	Vec3 qvec(q.x, q.y, q.z);
    //	Vec3::cross(qvec, newUp, &uv);
    //	Vec3::cross(qvec, uv, &uuv);
    //	uv *= (2.0f * q.w);
    //	uuv *= 2.0f;
    //	newUp = newUp + uv + uuv;
    //}

    newUp = mat * newUp;
    Quaternion::createFromAxisAngle(newUp, angle, &q);
    Mat4::createRotation(q, &mat);
    return mat * src;

    //{
    //	Vec3 uv, uuv;
    //	Vec3 qvec(q.x, q.y, q.z);
    //	Vec3::cross(qvec, src, &uv);
    //	Vec3::cross(qvec, uv, &uuv);
    //	uv *= (2.0f * q.w);
    //	uuv *= 2.0f;
    //	return src + uv + uuv;
    //}
}

cocos2d::Vec3 PUUtil::perpendicular(const Vec3& src)
{
    // static const float fSquareZero = (float)(1e-06 * 1e-06);

    // Vector3 perp = this->crossProduct( Vector3::UNIT_X );

    //// Check length
    // if( perp.squaredLength() < fSquareZero )
    //{
    //	/* This vector is the Y axis multiplied by a scalar, so we have
    //		to use another axis.
    //	*/
    //	perp = this->crossProduct( Vector3::UNIT_Y );
    // }
    // perp.normalise();

    // return perp;

    static const float fSquareZero = (float)(1e-06 * 1e-06);
    Vec3 perp;
    Vec3::cross(src, Vec3::UNIT_X, &perp);
    // Check length
    if (perp.lengthSquared() < fSquareZero)
    {
        /* This vector is the Y axis multiplied by a scalar, so we have
            to use another axis.
        */
        Vec3::cross(src, Vec3::UNIT_Y, &perp);
    }
    perp.normalize();
    return perp;
}

NS_CC_END