OpenRaider/src/ViewVolume.cpp

/* -*- Mode: C++; tab-width: 3; indent-tabs-mode: t; c-basic-offset: 3 -*- */
/*================================================================
 *
 * Project : hel
 * Author  : Terry 'Mongoose' Hendrix II
 * Website : http://www.westga.edu/~stu7440/
 * Email   : stu7440@westga.edu
 * Object  : ViewVolume
 * License : No use w/o permission (C) 2002 Mongoose
 * Comments: This is the viewing volume for culling use
 *
 *           Thanks Mark Morley for the article I used
 *           to get several algorithms.
 *
 *           This file was generated using Mongoose's C++
 *           template generator script.  <stu7440@westga.edu>
 *
 *-- History -------------------------------------------------
 *
 * 2002.12.15:
 * Mongoose - Created
 =================================================================*/

#include <math.h>

#include <ViewVolume.h>


////////////////////////////////////////////////////////////
// Constructors
////////////////////////////////////////////////////////////

ViewVolume::ViewVolume()
{
    mFrustum[0][0] = mFrustum[0][1] = mFrustum[0][2] = mFrustum[0][3] = 0.0f;
    mFrustum[1][0] = mFrustum[1][1] = mFrustum[1][2] = mFrustum[1][3] = 0.0f;
    mFrustum[2][0] = mFrustum[2][1] = mFrustum[2][2] = mFrustum[2][3] = 0.0f;
    mFrustum[3][0] = mFrustum[3][1] = mFrustum[3][2] = mFrustum[3][3] = 0.0f;
    mFrustum[4][0] = mFrustum[4][1] = mFrustum[4][2] = mFrustum[4][3] = 0.0f;
    mFrustum[5][0] = mFrustum[5][1] = mFrustum[5][2] = mFrustum[5][3] = 0.0f;
}


ViewVolume::~ViewVolume()
{
}


////////////////////////////////////////////////////////////
// Public Accessors
////////////////////////////////////////////////////////////

bool ViewVolume::isBoundingVolumeInFrustum(BoundingVolume bvol)
{
    return (isBoundingSphereInFrustum(bvol.mSphere) &&
            isBoundingBoxInFrustum(bvol.mBox));
}


bool ViewVolume::isBoundingSphereInFrustum(BoundingSphere bvol)
{
    return (isSphereInFrustum(bvol.mCenter[0],
                bvol.mCenter[1],
                bvol.mCenter[2],
                bvol.mRadius));
}


bool ViewVolume::isBoundingBoxInFrustum(BoundingBox bvol)
{
    return (isBboxInFrustum(bvol.mMin, bvol.mMax));
}


bool ViewVolume::isPointInFrustum(vec_t x, vec_t y, vec_t z)
{
    unsigned int p;


    for (p = 0; p < 6; ++p)
    {
        if (mFrustum[p][0] * x + mFrustum[p][1] * y + mFrustum[p][2] * z +
                mFrustum[p][3] <= 0)
        {
            return false;
        }
    }

    return true;
}


bool ViewVolume::isSphereInFrustum(vec_t x, vec_t y, vec_t z, vec_t radius)
{
    unsigned int p;
    vec_t d;


    for (p = 0; p < 6; ++p)
    {
        d = mFrustum[p][0] * x + mFrustum[p][1] * y + mFrustum[p][2] * z + mFrustum[p][3];
        if (d <= -radius)
            return false;
    }

    return true;
}


bool ViewVolume::isBboxInFrustum(vec3_t min, vec3_t max)
{
    unsigned int p;


    for (p = 0; p < 6; ++p)
    {
        if (mFrustum[p][0] * min[0] +
                mFrustum[p][1] * min[1] +
                mFrustum[p][2] * min[2] + mFrustum[p][3] > 0)
            continue;

        if (mFrustum[p][0] * max[0] +
                mFrustum[p][1] * max[1] +
                mFrustum[p][2] * max[2] + mFrustum[p][3] > 0)
            continue;

        if (mFrustum[p][0] * min[0] +
                mFrustum[p][1] * max[1] +
                mFrustum[p][2] * max[2] + mFrustum[p][3] > 0)
            continue;

        if (mFrustum[p][0] * min[0] +
                mFrustum[p][1] * min[1] +
                mFrustum[p][2] * max[2] + mFrustum[p][3] > 0)
            continue;

        if (mFrustum[p][0] * min[0] +
                mFrustum[p][1] * max[1] +
                mFrustum[p][2] * min[2] + mFrustum[p][3] > 0)
            continue;

        if (mFrustum[p][0] * max[0] +
                mFrustum[p][1] * min[1] +
                mFrustum[p][2] * min[2] + mFrustum[p][3] > 0)
            continue;

        if (mFrustum[p][0] * max[0] +
                mFrustum[p][1] * max[1] +
                mFrustum[p][2] * min[2] + mFrustum[p][3] > 0)
            continue;

        if (mFrustum[p][0] * max[0] +
                mFrustum[p][1] * min[1] +
                mFrustum[p][2] * max[2] + mFrustum[p][3] > 0)
            continue;

        return false;
    }

    return true;
}


vec_t ViewVolume::getDistToSphereFromNear(vec_t x, vec_t y, vec_t z,
        vec_t radius)
{
    unsigned int p;
    vec_t d = 0.0;

    for (p = 0; p < 6; ++p)
    {
        d = mFrustum[p][0] * x + mFrustum[p][1] * y + mFrustum[p][2] * z + mFrustum[p][3];
        if (d <= -radius)
            return 0;
    }

    return d + radius;
}


vec_t ViewVolume::getDistToBboxFromNear(vec3_t min, vec3_t max)
{
    vec3_t center;
    vec_t d, radius;


    helMidpoint3v(min, max, center);

    // 5 should be near plane
    d = (mFrustum[5][0] * center[0] +
            mFrustum[5][1] * center[1] +
            mFrustum[5][2] * center[2] +
            mFrustum[5][3]);

    radius = helDist3v(max, center);

    if (d <= -radius)
        return 0;

    return d + radius;
}


void ViewVolume::getFrustum(vec_t frustum[6][4])
{
    unsigned int plane;


    for (plane = 0; plane < 6; ++plane)
    {
        frustum[plane][0] = mFrustum[plane][0];
        frustum[plane][1] = mFrustum[plane][1];
        frustum[plane][2] = mFrustum[plane][2];
        frustum[plane][3] = mFrustum[plane][3];
    }
}


void ViewVolume::getPlane(ViewVolumeSide p, vec4_t plane)
{
    plane[0] =  mFrustum[p][0];
    plane[1] =  mFrustum[p][1];
    plane[2] =  mFrustum[p][2];
    plane[3] =  mFrustum[p][3];
}


////////////////////////////////////////////////////////////
// Public Mutators
////////////////////////////////////////////////////////////

void ViewVolume::updateFrame(matrix_t proj, matrix_t mdl)
{
    setModel(mdl);
    setProjection(proj);
    updateClip();
    updateFrustum();
}


void ViewVolume::updateFrame()
{
    updateClip();
    updateFrustum();
}


void ViewVolume::setModel(matrix_t mdl)
{
    mModel.setMatrix(mdl);
}


void ViewVolume::setProjection(matrix_t proj)
{
    /*void setProjection(viewAngle, aspectRatio, near, far)
     ****************************
     *float far = 4000.0f;
     *float near = 4.0f;
     *float viewAngle = 45.0f;
     *float aspectRatio = 800.0f/600.0f;
     ****************************
     *float top = near * tan(PI/180 * viewAngle/2)
     *float bottom = -top
     *float right = top * aspectRatio
     *float left = - right
     */

    mProjection.setMatrix(proj);
}



////////////////////////////////////////////////////////////
// Private Accessors
////////////////////////////////////////////////////////////


////////////////////////////////////////////////////////////
// Private Mutators
////////////////////////////////////////////////////////////

void ViewVolume::updateClip()
{
    //mClip = mModel * mProjection;
    mClip = mProjection * mModel;
}


void ViewVolume::updateFrustum()
{
    matrix_t clip;
    vec_t t;


    mClip.getMatrix(clip);

    /* Extract the numbers for the RIGHT plane */
    mFrustum[0][0] = clip[ 3] - clip[ 0];
    mFrustum[0][1] = clip[ 7] - clip[ 4];
    mFrustum[0][2] = clip[11] - clip[ 8];
    mFrustum[0][3] = clip[15] - clip[12];

    /* Normalize the result */
    t = sqrtf(mFrustum[0][0] * mFrustum[0][0] +
            mFrustum[0][1] * mFrustum[0][1] +
            mFrustum[0][2] * mFrustum[0][2]);
    mFrustum[0][0] /= t;
    mFrustum[0][1] /= t;
    mFrustum[0][2] /= t;
    mFrustum[0][3] /= t;

    /* Extract the numbers for the LEFT plane */
    mFrustum[1][0] = clip[ 3] + clip[ 0];
    mFrustum[1][1] = clip[ 7] + clip[ 4];
    mFrustum[1][2] = clip[11] + clip[ 8];
    mFrustum[1][3] = clip[15] + clip[12];

    /* Normalize the result */
    t = sqrtf(mFrustum[1][0] * mFrustum[1][0] +
            mFrustum[1][1] * mFrustum[1][1] +
            mFrustum[1][2] * mFrustum[1][2]);
    mFrustum[1][0] /= t;
    mFrustum[1][1] /= t;
    mFrustum[1][2] /= t;
    mFrustum[1][3] /= t;

    /* Extract the BOTTOM plane */
    mFrustum[2][0] = clip[ 3] + clip[ 1];
    mFrustum[2][1] = clip[ 7] + clip[ 5];
    mFrustum[2][2] = clip[11] + clip[ 9];
    mFrustum[2][3] = clip[15] + clip[13];

    /* Normalize the result */
    t = sqrtf(mFrustum[2][0] * mFrustum[2][0] +
            mFrustum[2][1] * mFrustum[2][1] +
            mFrustum[2][2] * mFrustum[2][2]);
    mFrustum[2][0] /= t;
    mFrustum[2][1] /= t;
    mFrustum[2][2] /= t;
    mFrustum[2][3] /= t;

    /* Extract the TOP plane */
    mFrustum[3][0] = clip[ 3] - clip[ 1];
    mFrustum[3][1] = clip[ 7] - clip[ 5];
    mFrustum[3][2] = clip[11] - clip[ 9];
    mFrustum[3][3] = clip[15] - clip[13];

    /* Normalize the result */
    t = sqrtf(mFrustum[3][0] * mFrustum[3][0] +
            mFrustum[3][1] * mFrustum[3][1] +
            mFrustum[3][2] * mFrustum[3][2]);
    mFrustum[3][0] /= t;
    mFrustum[3][1] /= t;
    mFrustum[3][2] /= t;
    mFrustum[3][3] /= t;

    /* Extract the FAR plane */
    mFrustum[4][0] = clip[ 3] - clip[ 2];
    mFrustum[4][1] = clip[ 7] - clip[ 6];
    mFrustum[4][2] = clip[11] - clip[10];
    mFrustum[4][3] = clip[15] - clip[14];

    /* Normalize the result */
    t = sqrtf(mFrustum[4][0] * mFrustum[4][0] +
            mFrustum[4][1] * mFrustum[4][1] +
            mFrustum[4][2] * mFrustum[4][2]);
    mFrustum[4][0] /= t;
    mFrustum[4][1] /= t;
    mFrustum[4][2] /= t;
    mFrustum[4][3] /= t;

    /* Extract the NEAR plane */
    mFrustum[5][0] = clip[ 3] + clip[ 2];
    mFrustum[5][1] = clip[ 7] + clip[ 6];
    mFrustum[5][2] = clip[11] + clip[10];
    mFrustum[5][3] = clip[15] + clip[14];

    /* Normalize the result */
    t = sqrtf(mFrustum[5][0] * mFrustum[5][0] +
            mFrustum[5][1] * mFrustum[5][1] +
            mFrustum[5][2] * mFrustum[5][2]);
    mFrustum[5][0] /= t;
    mFrustum[5][1] /= t;
    mFrustum[5][2] /= t;
    mFrustum[5][3] /= t;
}