OpenSceneGraph/include/osg/Viewport
2002-07-16 20:07:32 +00:00

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//C++ header - Open Scene Graph - Copyright (C) 1998-2002 Robert Osfield
//Distributed under the terms of the GNU Library General Public License (LGPL)
//as published by the Free Software Foundation.
#ifndef OSG_VIEWPORT
#define OSG_VIEWPORT 1
#include <osg/StateAttribute>
#include <osg/Types>
#include <osg/Matrix>
namespace osg {
/** Encapsulte OpenGL glViewport.
*/
class SG_EXPORT Viewport : public StateAttribute
{
public :
Viewport();
/** Copy constructor using CopyOp to manage deep vs shallow copy.*/
Viewport(const Viewport& vp,const CopyOp& copyop=CopyOp::SHALLOW_COPY):
StateAttribute(vp,copyop),
_x(vp._x),
_y(vp._y),
_width(vp._width),
_height(vp._height) {}
META_StateAttribute(osg, Viewport,VIEWPORT);
/** return -1 if *this < *rhs, 0 if *this==*rhs, 1 if *this>*rhs.*/
virtual int compare(const StateAttribute& sa) const
{
// check the types are equal and then create the rhs variable
// used by the COMPARE_StateAttribute_Paramter macro's below.
COMPARE_StateAttribute_Types(Viewport,sa)
// compare each paramter in turn against the rhs.
COMPARE_StateAttribute_Parameter(_x)
COMPARE_StateAttribute_Parameter(_y)
COMPARE_StateAttribute_Parameter(_width)
COMPARE_StateAttribute_Parameter(_height)
return 0; // passed all the above comparison macro's, must be equal.
}
inline void setViewport(const int x,const int y,const int width,const int height)
{
_x = x;
_y = y;
_width = width;
_height = height;
}
void getViewport(int& x,int& y,int& width,int& height) const
{
x = _x;
y = _y;
width = _width;
height = _height;
}
inline const int x() const { return _x; }
inline const int y() const { return _y; }
inline const int width() const { return _width; }
inline const int height() const { return _height; }
inline const bool valid() const { return _width!=0 && _height!=0; }
/** Return the aspcetRatio of the viewport, which is equal to width/height.
* If height is zero, the potental division by zero is avoid by simply returning 1.0f.*/
inline const float aspectRatio() const { if (_height!=0) return (float)_width/(float)_height; else return 1.0f; }
/** Compute the Window Matrix which takes projected coords into Window coordinates.
* To converted local coodinates into window coordinates use v_window = v_local * MVPW matrix,
* where the MVPW matrix is ModelViewMatrix * ProjectionMatrix * WindowMatrix, the later supplied by
* viewport::computeWindowMatrix(), the ModelView and Projection Matrix can either be sourced from the
* current osg::State object, via osgUtil::SceneView or CullVisitor.*/
inline const osg::Matrix computeWindowMatrix() const
{
return osg::Matrix::translate(1.0f,1.0f,1.0f)*osg::Matrix::scale(0.5f*width(),0.5f*height(),0.5f);
}
virtual void apply(State& state) const;
protected:
virtual ~Viewport();
int _x;
int _y;
int _width;
int _height;
};
}
#endif