OpenSceneGraph/src/osg/Billboard.cpp
2006-10-14 21:47:13 +00:00

341 lines
9.4 KiB
C++

/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2006 Robert Osfield
*
* This library is open source and may be redistributed and/or modified under
* the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or
* (at your option) any later version. The full license is in LICENSE file
* included with this distribution, and on the openscenegraph.org website.
*
* This library 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
* OpenSceneGraph Public License for more details.
*/
#include <stdio.h>
#include <math.h>
#include <osg/Billboard>
using namespace osg;
#define square(x) ((x)*(x))
Billboard::Billboard()
{
_mode = AXIAL_ROT;
_axis.set(0.0f,0.0f,1.0f);
//_normal.set(0.0f,-1.0f,0.0f);
setNormal(Vec3(0.0f,-1.0f,0.0f));
updateCache();
}
Billboard::Billboard(const Billboard& billboard,const CopyOp& copyop):
Geode(billboard,copyop),
_mode(billboard._mode),
_axis(billboard._axis),
_normal(billboard._normal),
_positionList(billboard._positionList),
_cachedMode(billboard._cachedMode),
_side(billboard._side) {}
Billboard::~Billboard()
{
}
void Billboard::setMode(Mode mode)
{
_mode = mode;
_cachedMode = CACHE_DIRTY;
updateCache();
}
void Billboard::setAxis(const Vec3& axis)
{
_axis = axis;
_axis.normalize();
updateCache();
}
void Billboard::setNormal(const Vec3& normal)
{
_normal = normal;
_normal.normalize();
updateCache();
// Build rotation from normal to z-axis,
// for use with POINT_ROT_EYE
Vec3 z(0.0, 0.0, 1.0);
Vec3 cp(z^_normal);
float dot = z*_normal;
float cp_len = cp.length();
if (cp_len != 0.0f)
{
cp /= cp_len;
float rotation_cp = acosf(dot);
Matrix rotateNormalToZ;
_rotateNormalToZAxis.makeRotate(-rotation_cp, cp);
}
else
_rotateNormalToZAxis.makeIdentity();
}
void Billboard::updateCache()
{
if (_mode==AXIAL_ROT)
{
if (_axis==Vec3(1.0f,0.0,0.0f) && _normal==Vec3(0.0f,-1.0,0.0f)) _cachedMode = AXIAL_ROT_X_AXIS;
else if (_axis==Vec3(0.0f,1.0,0.0f) && _normal==Vec3(1.0f, 0.0,0.0f)) _cachedMode = AXIAL_ROT_Y_AXIS;
else if (_axis==Vec3(0.0f,0.0,1.0f) && _normal==Vec3(0.0f,-1.0,0.0f)) _cachedMode = AXIAL_ROT_Z_AXIS;
else _cachedMode = AXIAL_ROT;
}
else if( _mode == POINT_ROT_WORLD )
{
if(_axis==Vec3(0.0f, 0.0, 1.0f) && _normal==Vec3(0.0f, -1.0f, 0.0f)) _cachedMode = POINT_ROT_WORLD_Z_AXIS;
else _cachedMode = _mode;
}
else _cachedMode = _mode;
_side = _axis^_normal;
_side.normalize();
}
bool Billboard::addDrawable(Drawable *gset)
{
if (Geode::addDrawable(gset))
{
Vec3 pos(0.0f,0.0f,0.0f);
while (_positionList.size()<_drawables.size())
{
_positionList.push_back(pos);
}
return true;
}
return false;
}
bool Billboard::addDrawable(Drawable *gset,const Vec3& pos)
{
if (Geode::addDrawable(gset))
{
while (_positionList.size()<_drawables.size())
{
_positionList.push_back(pos);
}
return true;
}
return false;
}
bool Billboard::removeDrawable( Drawable *gset )
{
PositionList::iterator pitr = _positionList.begin();
for (DrawableList::iterator itr=_drawables.begin();
itr!=_drawables.end();
++itr,++pitr)
{
if (itr->get()==gset)
{
// note ref_ptr<> automatically handles decrementing gset's reference count.
_drawables.erase(itr);
_positionList.erase(pitr);
dirtyBound();
return true;
}
}
return false;
}
bool Billboard::computeMatrix(Matrix& modelview, const Vec3& eye_local, const Vec3& pos_local) const
{
//Vec3 up_local(matrix(0,1),matrix(1,1),matrix(2,1));
Matrix matrix;
Vec3 ev(eye_local-pos_local);
switch(_cachedMode)
{
case(AXIAL_ROT_Z_AXIS):
{
ev.z() = 0.0f;
float ev_length = ev.length();
if (ev_length>0.0f)
{
//float rotation_zrotation_z = atan2f(ev.x(),ev.y());
//mat.makeRotate(inRadians(rotation_z),0.0f,0.0f,1.0f);
float inv = 1.0f/ev_length;
float s = ev.x()*inv;
float c = -ev.y()*inv;
matrix(0,0) = c;
matrix(1,0) = -s;
matrix(0,1) = s;
matrix(1,1) = c;
}
break;
}
case(AXIAL_ROT_Y_AXIS):
{
ev.y() = 0.0f;
float ev_length = ev.length();
if (ev_length>0.0f)
{
//float rotation_zrotation_z = atan2f(ev.x(),ev.y());
//mat.makeRotate(inRadians(rotation_z),0.0f,0.0f,1.0f);
float inv = 1.0f/ev_length;
float s = -ev.z()*inv;
float c = ev.x()*inv;
matrix(0,0) = c;
matrix(2,0) = s;
matrix(0,2) = -s;
matrix(2,2) = c;
}
break;
}
case(AXIAL_ROT_X_AXIS):
{
ev.x() = 0.0f;
float ev_length = ev.length();
if (ev_length>0.0f)
{
//float rotation_zrotation_z = atan2f(ev.x(),ev.y());
//mat.makeRotate(inRadians(rotation_z),0.0f,0.0f,1.0f);
float inv = 1.0f/ev_length;
float s = -ev.z()*inv;
float c = -ev.y()*inv;
matrix(1,1) = c;
matrix(2,1) = -s;
matrix(1,2) = s;
matrix(2,2) = c;
}
break;
}
case(AXIAL_ROT): // need to implement
{
float ev_side = ev*_side;
float ev_normal = ev*_normal;
float rotation = atan2f(ev_side,ev_normal);
matrix.makeRotate(rotation,_axis);
break;
}
case(POINT_ROT_WORLD):
{
float ev_len = ev.length();
if (ev_len != 0.0f)
{
ev /= ev_len;
Vec3 cp(ev^_normal);
float dot = ev*_normal;
float cp_len = cp.length();
if (cp_len != 0.0f)
{
cp /= cp_len;
float rotation_cp = acosf(dot);
matrix.makeRotate(-inRadians(rotation_cp),cp[0],cp[1],cp[2]);
}
}
break;
}
case(POINT_ROT_EYE):
{
float ev_len = ev.length();
if (ev_len != 0.0f)
{
ev /= ev_len;
Vec3 up(modelview(0,1), modelview(1,1), modelview(2,1));
Vec3 right(up^ev);
right.normalize();
up = ev^right;
up.normalize();
matrix(0,0) = right.x();
matrix(0,1) = right.y();
matrix(0,2) = right.z();
matrix(1,0) = up.x();
matrix(1,1) = up.y();
matrix(1,2) = up.z();
matrix(2,0) = ev.x();
matrix(2,1) = ev.y();
matrix(2,2) = ev.z();
matrix.preMult(_rotateNormalToZAxis);
}
break;
}
case(POINT_ROT_WORLD_Z_AXIS):
{
// float rotation_about_z = atan2( -ev.y(), ev.x() );
// float xy_distance = sqrt( ev.x()*ev.x() + ev.y()*ev.y() );
// float rotation_from_xy = atan2( xy_distance, -ev.z() );
Vec2 about_z( -ev.y(), ev.x() );
if( about_z.normalize() == 0.0f ) about_z.x() = 1.0f;
float xy_distance = sqrt( ev.x()*ev.x() + ev.y()*ev.y() );
Vec2 from_xy( xy_distance, -ev.z() );
if( from_xy.normalize() == 0.0f ) from_xy.x() = 1.0f;
matrix(0,0) = about_z.x();
matrix(0,1) = about_z.y();
matrix(1,0) = -about_z.y()*from_xy.x();
matrix(1,1) = about_z.x()*from_xy.x();
matrix(1,2) = from_xy.y();
matrix(2,0) = about_z.y()*from_xy.y();
matrix(2,1) = -about_z.x()*from_xy.y();
matrix(2,2) = from_xy.x();
break;
}
}
matrix.setTrans(pos_local);
modelview.preMult(matrix);
return true;
}
BoundingSphere Billboard::computeBound() const
{
int i;
int ngsets = _drawables.size();
if( ngsets == 0 ) return BoundingSphere();
BoundingSphere bsphere;
bsphere._center.set(0.0f,0.0f,0.0f);
for( i = 0; i < ngsets; i++ )
{
const Drawable *gset = _drawables[i].get();
const BoundingBox& bbox = gset->getBound();
bsphere._center += bbox.center();
bsphere._center += _positionList[i];
}
bsphere._center /= (float)(ngsets);
float maxd = 0.0;
for( i = 0; i < ngsets; ++i )
{
const Drawable *gset = _drawables[i].get();
const BoundingBox& bbox = gset->getBound();
Vec3 local_center = bsphere._center-_positionList[i];
for(unsigned int c=0;c<8;++c)
{
float d = (bbox.corner(c)-local_center).length2();
if( d > maxd ) maxd = d;
}
}
bsphere._radius = sqrtf(maxd);
return bsphere;
}