OpenSceneGraph/src/osg/ImpostorSprite.cpp
2003-04-09 21:53:09 +00:00

325 lines
7.7 KiB
C++

/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2003 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.
*/
#if defined(_MSC_VER)
#pragma warning( disable : 4786 )
#endif
#include <stdio.h>
#include <math.h>
#include <float.h>
#include <osg/Geometry>
#include <osg/ImpostorSprite>
#include <osg/Texture2D>
#include <osg/TexEnv>
#include <osg/AlphaFunc>
#include <osg/Notify>
using namespace osg;
ImpostorSprite::ImpostorSprite()
{
// don't use display list since we will be updating the geometry.
_useDisplayList = false;
_parent = NULL;
_ism = NULL;
_previous = NULL;
_next = NULL;
_texture = NULL;
_s = 0;
_t = 0;
_color.set(1.0f, 1.0f, 1.0f, 1.0f );
}
ImpostorSprite::~ImpostorSprite()
{
if (_ism)
{
_ism->remove(this);
}
}
float ImpostorSprite::calcPixelError(const Matrix& MVPW) const
{
// find the maximum screen space pixel error between the control coords and the quad coners.
float max_error_sqrd = 0.0f;
for(int i=0;i<4;++i)
{
Vec3 projected_coord = _coords[i]*MVPW;
Vec3 projected_control = _controlcoords[i]*MVPW;
float dx = (projected_coord.x()-projected_control.x());
float dy = (projected_coord.y()-projected_control.y());
float error_sqrd = dx*dx+dy*dy;
if (error_sqrd > max_error_sqrd) max_error_sqrd = error_sqrd;
}
return sqrtf(max_error_sqrd);
}
void ImpostorSprite::drawImplementation(State&) const
{
// when the tex env is set to REPLACE, and the
// texture is set up correctly the color has no effect.
glColor4fv( _color.ptr() );
glBegin( GL_QUADS );
glTexCoord2fv( (GLfloat *)&_texcoords[0] );
glVertex3fv( (GLfloat *)&_coords[0] );
glTexCoord2fv( (GLfloat *)&_texcoords[1] );
glVertex3fv( (GLfloat *)&_coords[1] );
glTexCoord2fv( (GLfloat *)&_texcoords[2] );
glVertex3fv( (GLfloat *)&_coords[2] );
glTexCoord2fv( (GLfloat *)&_texcoords[3] );
glVertex3fv( (GLfloat *)&_coords[3] );
glEnd();
}
bool ImpostorSprite::computeBound() const
{
_bbox.init();
_bbox.expandBy(_coords[0]);
_bbox.expandBy(_coords[1]);
_bbox.expandBy(_coords[2]);
_bbox.expandBy(_coords[3]);
_bbox_computed=true;
if (!_bbox.valid())
{
notify(WARN) << "******* ImpostorSprite::computeBound() problem"<<std::endl;
notify(WARN) << "******* = "<<_coords[0]<<std::endl;
notify(WARN) << "******* = "<<_coords[1]<<std::endl;
notify(WARN) << "******* = "<<_coords[2]<<std::endl;
notify(WARN) << "******* = "<<_coords[3]<<std::endl;
}
return true;
}
void ImpostorSprite::setTexture(Texture2D* tex,int s,int t)
{
_texture = tex;
_s = s;
_t = t;
}
void ImpostorSprite::accept(AttributeFunctor& af)
{
af.apply(VERTICES,4,_coords);
af.apply(TEXTURE_COORDS_0,4,_texcoords);
}
void ImpostorSprite::accept(ConstAttributeFunctor& af) const
{
af.apply(VERTICES,4,_coords);
af.apply(TEXTURE_COORDS_0,4,_texcoords);
}
void ImpostorSprite::accept(PrimitiveFunctor& functor) const
{
functor.setVertexArray(4,_coords);
functor.drawArrays( GL_QUADS, 0, 4);
}
///////////////////////////////////////////////////////////////////////////
// Helper class for managing the reuse of ImpostorSprite resources.
///////////////////////////////////////////////////////////////////////////
ImpostorSpriteManager::ImpostorSpriteManager():
_first(NULL),
_last(NULL)
{
_texenv = new TexEnv;
_texenv->setMode(TexEnv::REPLACE);
_alphafunc = new osg::AlphaFunc;
_alphafunc->setFunction( AlphaFunc::GREATER, 0.000f );
_reuseStateSetIndex = 0;
}
ImpostorSpriteManager::~ImpostorSpriteManager()
{
while (_first)
{
ImpostorSprite* next = _first->_next;
_first->_ism = NULL;
_first->_previous = NULL;
_first->_next = NULL;
_first = next;
}
}
void ImpostorSpriteManager::push_back(ImpostorSprite* is)
{
if (is==NULL || is==_last) return;
// remove entry for exisiting position in linked list
// if it is already inserted.
if (is->_previous)
{
(is->_previous)->_next = is->_next;
}
if (is->_next)
{
(is->_next)->_previous = is->_previous;
}
if (_first==is) _first = is->_next;
if (empty())
{
_first = is;
_last = is;
is->_ism = this;
is->_previous = NULL;
is->_next = NULL;
}
else
{
// now add the element into the list.
ImpostorSprite* previous_last = _last;
previous_last->_next = is;
_last = is;
_last->_ism = this;
_last->_previous = previous_last;
_last->_next = NULL;
}
}
void ImpostorSpriteManager::remove(ImpostorSprite* is)
{
if (is==NULL) return;
// remove entry for exisiting position in linked list
// if it is already inserted.
if (is->_previous)
{
(is->_previous)->_next = is->_next;
}
if (is->_next)
{
(is->_next)->_previous = is->_previous;
}
if (_first==is) _first = is->_next;
if (_last==is) _last = is->_previous;
}
ImpostorSprite* ImpostorSpriteManager::createOrReuseImpostorSprite(int s,int t,int frameNumber)
{
if (!empty())
{
// search for a valid impostor to reuse.
ImpostorSprite* curr = _first;
while (curr)
{
if (curr->getLastFrameUsed()<=frameNumber &&
curr->s()==s &&
curr->t()==t)
{
push_back(curr);
return curr;
}
else
{
curr = curr->_next;
}
}
}
// creating new impostor sprite.
StateSet* stateset = new StateSet;
stateset->setMode(GL_CULL_FACE,osg::StateAttribute::OFF);
stateset->setMode(GL_LIGHTING,osg::StateAttribute::OFF);
stateset->setMode(GL_BLEND,osg::StateAttribute::ON);
stateset->setRenderingHint( StateSet::TRANSPARENT_BIN );
stateset->setAttributeAndModes( _alphafunc.get(), StateAttribute::ON );
Texture2D* texture = new Texture2D;
texture->setFilter(Texture2D::MIN_FILTER,Texture2D::LINEAR);
texture->setFilter(Texture2D::MAG_FILTER,Texture2D::LINEAR);
stateset->setTextureAttributeAndModes(0,texture,StateAttribute::ON);
stateset->setTextureAttribute(0,_texenv.get());
/*
TexEnv* texenv = new TexEnv;
texenv->setMode(TexEnv::REPLACE);
stateset->setAttribute(texenv);
AlphaFunc* alphafunc = new osg::AlphaFunc;
alphafunc->setFunction( AlphaFunc::GREATER, 0.000f );
stateset->setAttributeAndModes( alphafunc, StateAttribute::ON );
*/
// stateset->setMode( GL_ALPHA_TEST, StateAttribute::OFF );
ImpostorSprite* is = new ImpostorSprite;
is->setStateSet(stateset);
is->setTexture(texture,s,t);
push_back(is);
return is;
}
StateSet* ImpostorSpriteManager::createOrReuseStateSet()
{
if (_reuseStateSetIndex<_stateSetList.size())
{
return _stateSetList[_reuseStateSetIndex++].get();
}
_stateSetList.push_back(new StateSet);
_reuseStateSetIndex=_stateSetList.size();
return _stateSetList.back().get();
}
void ImpostorSpriteManager::reset()
{
_reuseStateSetIndex = 0;
}