CCylinder.cpp

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/* +------------------------------------------------------------------------+
   |                     Mobile Robot Programming Toolkit (MRPT)            |
   |                          http://www.mrpt.org/                          |
   |                                                                        |
   | Copyright (c) 2005-2018, Individual contributors, see AUTHORS file     |
   | See: http://www.mrpt.org/Authors - All rights reserved.                |
   | Released under BSD License. See details in http://www.mrpt.org/License |
   +------------------------------------------------------------------------+ */

#include "opengl-precomp.h"  // Precompiled header
#include <mrpt/opengl/CCylinder.h>
#include <mrpt/math/geometry.h>
#include <mrpt/serialization/CArchive.h>

#include "opengl_internals.h"

using namespace mrpt;
using namespace mrpt::opengl;
using namespace mrpt::math;

using namespace std;

IMPLEMENTS_SERIALIZABLE(CCylinder, CRenderizableDisplayList, mrpt::opengl)

/*---------------------------------------------------------------
                            render
  ---------------------------------------------------------------*/
void CCylinder::render_dl() const
{
#if MRPT_HAS_OPENGL_GLUT
    glEnable(GL_BLEND);
    checkOpenGLError();
    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
    checkOpenGLError();
    GLUquadricObj* obj = gluNewQuadric();

    // This is required to draw cylinders of negative height.
    const float absHeight = std::abs(mHeight);
    if (mHeight < 0)
    {
        glPushMatrix();
        glTranslatef(0, 0, mHeight);
    }

    gluCylinder(obj, mBaseRadius, mTopRadius, absHeight, mSlices, mStacks);

    if (mHeight < 0) glPopMatrix();

    if (mHasBottomBase) gluDisk(obj, 0, mBaseRadius, mSlices, 1);
    if (mHasTopBase && mTopRadius > 0)
    {
        glPushMatrix();
        glTranslatef(0, 0, mHeight);
        gluDisk(obj, 0, mTopRadius, mSlices, 1);
        glPopMatrix();
    }
    gluDeleteQuadric(obj);
    glDisable(GL_BLEND);

#endif
}

uint8_t CCylinder::serializeGetVersion() const { return 0; }
void CCylinder::serializeTo(mrpt::serialization::CArchive& out) const
{
    writeToStreamRender(out);
    // version 0
    out << mBaseRadius << mTopRadius << mHeight << mSlices << mStacks
        << mHasBottomBase << mHasTopBase;
}
void CCylinder::serializeFrom(
    mrpt::serialization::CArchive& in, uint8_t version)
{
    switch (version)
    {
        case 0:
            readFromStreamRender(in);
            in >> mBaseRadius >> mTopRadius >> mHeight >> mSlices >> mStacks >>
                mHasBottomBase >> mHasTopBase;
            break;
        default:
            MRPT_THROW_UNKNOWN_SERIALIZATION_VERSION(version)
    };
    CRenderizableDisplayList::notifyChange();
}

bool solveEqn(double a, double b, double c, double& t)
{  // Actually, the b from the quadratic equation is the DOUBLE of this. But
    // this way, operations are simpler.
    if (a < 0)
    {
        a = -a;
        b = -b;
        c = -c;
    }
    if (a >= mrpt::math::getEpsilon())
    {
        double delta = square(b) - a * c;
        if (delta == 0)
            return (t = -b / a) >= 0;
        else if (delta >= 0)
        {
            delta = sqrt(delta);
            if (-b - delta > 0)
            {
                t = (-b - delta) / a;
                return true;
            }
            else if (-b + delta > 0)
            {
                t = (-b + delta) / a;
                return true;
            }  // else return false;    Both solutions are negative
        }  // else return false;    Both solutions are complex
    }
    else if (abs(b) >= mrpt::math::getEpsilon())
    {
        t = -c / (b + b);
        return t >= 0;
    }  // else return false;    This actually isn't an equation
    return false;
}

bool CCylinder::traceRay(const mrpt::poses::CPose3D& o, double& dist) const
{
    TLine3D lin;
    mrpt::math::createFromPoseX((o - this->m_pose).asTPose(), lin);
    lin.unitarize();  // By adding this line, distance from any point of the
    // line to its base is exactly equal to the "t".
    if (abs(lin.director[2]) < getEpsilon())
    {
        if (!reachesHeight(lin.pBase.z)) return false;
        float r;
        return getRadius(static_cast<float>(lin.pBase.z), r)
                   ? solveEqn(
                         square(lin.director[0]) + square(lin.director[1]),
                         lin.director[0] * lin.pBase.x +
                             lin.director[1] * lin.pBase.y,
                         square(lin.pBase.x) + square(lin.pBase.y) - square(r),
                         dist)
                   : false;
    }
    bool fnd = false;
    double nDist, tZ0;
    if (mHasBottomBase && (tZ0 = -lin.pBase.z / lin.director[2]) > 0)
    {
        nDist = sqrt(
            square(lin.pBase.x + tZ0 * lin.director[0]) +
            square(lin.pBase.y + tZ0 * lin.director[1]));
        if (nDist <= mBaseRadius)
        {
            fnd = true;
            dist = tZ0;
        }
    }
    if (mHasTopBase)
    {
        tZ0 = (mHeight - lin.pBase.z) / lin.director[2];
        if (tZ0 > 0 && (!fnd || tZ0 < dist))
        {
            nDist = sqrt(
                square(lin.pBase.x + tZ0 * lin.director[0]) +
                square(lin.pBase.y + tZ0 * lin.director[1]));
            if (nDist <= mTopRadius)
            {
                fnd = true;
                dist = tZ0;
            }
        }
    }
    if (mBaseRadius == mTopRadius)
    {
        if (solveEqn(
                square(lin.director[0]) + square(lin.director[1]),
                lin.director[0] * lin.pBase.x + lin.director[1] * lin.pBase.y,
                square(lin.pBase.x) + square(lin.pBase.y) - square(mBaseRadius),
                nDist))
            if ((!fnd || nDist < dist) &&
                reachesHeight(lin.pBase.z + nDist * lin.director[2]))
            {
                dist = nDist;
                fnd = true;
            }
    }
    else
    {
        double slope = (mTopRadius - mBaseRadius) / mHeight;
        if (solveEqn(
                square(lin.director[0]) + square(lin.director[1]) -
                    square(lin.director[2] * slope),
                lin.pBase.x * lin.director[0] + lin.pBase.y * lin.director[1] -
                    (mBaseRadius + slope * lin.pBase.z) * slope *
                        lin.director[2],
                square(lin.pBase.x) + square(lin.pBase.y) -
                    square(mBaseRadius + slope * lin.pBase.z),
                nDist))
            if ((!fnd || nDist < dist) &&
                reachesHeight(lin.pBase.z + nDist * lin.director[2]))
            {
                dist = nDist;
                fnd = true;
            }
    }
    return fnd;
}

void CCylinder::getBoundingBox(
    mrpt::math::TPoint3D& bb_min, mrpt::math::TPoint3D& bb_max) const
{
    bb_min.x = -std::max(mBaseRadius, mTopRadius);
    bb_min.y = bb_min.x;
    bb_min.z = 0;

    bb_max.x = std::max(mBaseRadius, mTopRadius);
    bb_max.y = bb_max.x;
    bb_max.z = mHeight;

    // Convert to coordinates of my parent:
    m_pose.composePoint(bb_min, bb_min);
    m_pose.composePoint(bb_max, bb_max);
}