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glt/project.cpp

Go to the documentation of this file.

#include "project.h"

#include <cassert>
#include <iosfwd>
using namespace std;

GltOrtho::GltOrtho()
: _left(-1.0), _right(1.0), _bottom(-1.0), _top(1.0), _zNear(-10.0), _zFar(10.0)
{
}

GltOrtho::~GltOrtho()
{
}

void 
GltOrtho::set()
{
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    glOrtho(_left,_right,_bottom,_top,_zNear,_zFar);
    glMatrixMode(GL_MODELVIEW);
}

void 
GltOrtho::set(int width,int height)
{
    GLdouble x = 1.0;
    GLdouble y = 1.0;

    if (width!=0 && height!=0)
    {
        if (width>height)
            x = GLdouble(width)/GLdouble(height);
        else
            y = GLdouble(height)/GLdouble(width);
    }

    _left   = -x;
    _right  =  x;
    _bottom = -y;
    _top    =  y;
    set();
}

GLdouble &GltOrtho::left()   { return _left;   }
GLdouble &GltOrtho::right()  { return _right;  }
GLdouble &GltOrtho::bottom() { return _bottom; }
GLdouble &GltOrtho::top()    { return _top;    }
GLdouble &GltOrtho::zNear()  { return _zNear;  }
GLdouble &GltOrtho::zFar()   { return _zFar;   }

const GLdouble &GltOrtho::left()   const { return _left;   }
const GLdouble &GltOrtho::right()  const { return _right;  }
const GLdouble &GltOrtho::bottom() const { return _bottom; }
const GLdouble &GltOrtho::top()    const { return _top;    }
const GLdouble &GltOrtho::zNear()  const { return _zNear;  }
const GLdouble &GltOrtho::zFar()   const { return _zFar;   }

bool 
GltOrtho::tile(GltOrtho &frust,const int dx,const int dy,const int n) const
{
    if (dx<1 || dy<1 || n<0 || n>=dx*dy)
    {
        frust = *this;
        return false;
    }

    const int px = n%dx;
    const int py = n/dx;

    const GLdouble width  = (_right-_left)/dx;
    const GLdouble height = (_top-_bottom)/dy;
    
    assert(py<=dy);

    if (py<dy)
    {
        frust._left = frust._right  = _left   + width*px;
        frust._top  = frust._bottom = _bottom + height*py;
    
        frust._right += width;
        frust._top   += height;

        frust._zNear = _zNear;
        frust._zFar  = _zFar;

        return true;
    }
    else
        return false;
}



GltFrustum::GltFrustum()
: _left(-1.0), _right(1.0), _bottom(-1.0), _top(1.0), _zNear(1.0), _zFar(10.0)
{
}

GltFrustum::~GltFrustum()
{
}

void 
GltFrustum::set()
{
    assert(_zNear>0.0);
    assert(_zFar>0.0);

    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    glFrustum(_left,_right,_bottom,_top,_zNear,_zFar);
    glMatrixMode(GL_MODELVIEW);
}

void 
GltFrustum::set(int width,int height)
{
    GLdouble x = 1.0;
    GLdouble y = 1.0;

    if (width!=0 && height!=0)
    {
        if (width>height)
            x = GLdouble(width)/GLdouble(height);
        else
            y = GLdouble(height)/GLdouble(width);
    }

    _left   = -x;
    _right  =  x;
    _bottom = -y;
    _top    =  y;
    set();
}

GLdouble &GltFrustum::left()   { return _left;   }
GLdouble &GltFrustum::right()  { return _right;  }
GLdouble &GltFrustum::bottom() { return _bottom; }
GLdouble &GltFrustum::top()    { return _top;    }
GLdouble &GltFrustum::zNear()  { return _zNear;  }
GLdouble &GltFrustum::zFar()   { return _zFar;   }

const GLdouble &GltFrustum::left()   const { return _left;   }
const GLdouble &GltFrustum::right()  const { return _right;  }
const GLdouble &GltFrustum::bottom() const { return _bottom; }
const GLdouble &GltFrustum::top()    const { return _top;    }
const GLdouble &GltFrustum::zNear()  const { return _zNear;  }
const GLdouble &GltFrustum::zFar()   const { return _zFar;   }

bool 
GltFrustum::tile(GltFrustum &frust,const int dx,const int dy,const int n) const
{
    if (dx<1 || dy<1 || n<0 || n>=dx*dy)
    {
        frust = *this;
        return false;
    }

    const int px = n%dx;
    const int py = n/dx;

    const GLdouble width  = (_right-_left)/dx;
    const GLdouble height = (_top-_bottom)/dy;
    
    assert(py<=dy);

    if (py<dy)
    {
        frust._left = frust._right  = _left   + width*px;
        frust._top  = frust._bottom = _bottom + height*py;
    
        frust._right += width;
        frust._top   += height;

        frust._zNear = _zNear;
        frust._zFar  = _zFar;

        return true;
    }
    else
        return false;
}

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