ssgKeyframeTransform.cpp

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/*
 * ssgKeyframeTransform.cpp
 *
 * Part of Fly! Legacy project
 *
 * Copyright 2003 Chris Wallace
 *
 * Fly! Legacy is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 * Fly! Legacy is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 *   along with Fly! Legacy; if not, write to the Free Software
 *    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */

#include "ssgLocal.h"
#include "../Include/FlyLegacy.h"

//
// ssgKeyframeTransform
//
/*
void ssgKeyframeTransform::copy_from ( ssgKeyframeTransform *src, int clone_flags ) 
{
  ssgBaseTransform::copy_from ( src, clone_flags ) ;

  nFrames = src->nFrames;
  min = src->min;
  max = src->max;
  next = src->next;
  memcpy (data, src->data, nFrames * sizeof(SKeyframe));
}

ssgBase *ssgKeyframeTransform::clone ( int clone_flags )
{
  ssgKeyframeTransform *b = new ssgKeyframeTransform (nFrames, min, max);
  b -> copy_from ( this, clone_flags ) ;
  return b;
}
*/


//
// Constructor
//
ssgKeyframeTransform::ssgKeyframeTransform (int n,
                      float minValue,
                      float maxValue)
{
  type = ssgTypeKeyframeTransform();

  // Allocate storage for keyframe data table and init 'next entry' index
  nFrames = n;
  data = new SKeyframe[nFrames];
  next = 0;

  min = minValue;
  max = maxValue;
}


//
// Destructor
//
ssgKeyframeTransform::~ssgKeyframeTransform (void)
{
  delete data;
}


void ssgKeyframeTransform::addKeyframe (float frame, sgCoord *xform)
{
  if (next < nFrames) {
    // Store keyframe value
    data[next].frame = frame;

    // Convert sgCoord to mat4
    sgCopyCoord (&data[next].transform, xform);

    // Increment index of next keyframe
    next++;
  }
}


void ssgKeyframeTransform::setKeyframe (float frame)
{
  // Search for keyframes before and after the frame value
  SKeyframe *pPre = NULL;
  SKeyframe *pPost = NULL;
  SKeyframe *pMatch = NULL;

  if (frame <= min) {
    pMatch = &data[0];
  } else if (frame >= max) {
    pMatch = &data[nFrames-1];
  } else
    for (int i=0; i<nFrames; i++) {
      SKeyframe *f = &data[i];

      if (f->frame == frame) {
        // Exact match
        pMatch = f;
        break;
      } else {
        if (f->frame < frame) {
          // Replace 'pre' with this keyframe
          pPre = f;
        } else {
          if ((f->frame > frame) && (pPost == NULL)) {
            pPost = f;
          }
        }
      }
    }

  // If an exact match was found then just use the matching values
  if (pMatch) {
    setTransform (&pMatch->transform);
  } else {
    if ((pPre == NULL) || (pPost == NULL)) {
      gtfo ("ssgKeyframeTransform::setKeyframe : Could not find pre/post entries");
    } else {
      // Interpolate between pre and post
      float scale = (frame - pPre->frame) / (pPost->frame - pPre->frame);
      float dx = pPost->transform.xyz[0] - pPre->transform.xyz[0];
      float dy = pPost->transform.xyz[1] - pPre->transform.xyz[1];
      float dz = pPost->transform.xyz[2] - pPre->transform.xyz[2];
      float dh = pPost->transform.hpr[0] - pPre->transform.hpr[0];
      float dp = pPost->transform.hpr[1] - pPre->transform.hpr[1];
      float dr = pPost->transform.hpr[2] - pPre->transform.hpr[2];

      sgCoord coord;
      coord.xyz[0] = pPre->transform.xyz[0] + (scale * dx);
      coord.xyz[1] = pPre->transform.xyz[1] + (scale * dy);
      coord.xyz[2] = pPre->transform.xyz[2] + (scale * dz);
      coord.hpr[0] = pPre->transform.hpr[0] + (scale * dh);
      coord.hpr[1] = pPre->transform.hpr[1] + (scale * dp);
      coord.hpr[2] = pPre->transform.hpr[2] + (scale * dr);
      setTransform (&coord);
    }
  }
}

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