Orthogonal view goes upside down

[macsam]

Hi,

I have been using a perspective view but changed to an orthogonal view. When I used the perspective view I was able to walk through the model. Now with the Orthogonal when I walk through it seems to turn upside down!

Any clue as to what I might be doing wrong? Any help gratefully appreciated.

[Agent_D]

How do you compute the projection matrix?

[macsam]

Thanks for your reply.

I presume this is what you would like to see:
Lvoid initializeGL(HWND hwnd, GLsizei width, GLsizei height)
{
GLfloat fmaxObjectSize, faspect;
GLdouble dnear_plane, dfar_plane,
glEmin = 0.0,
glEmax = 0.0,
glNmin = 0.0,
glNmax = 0.0,
glFar = 0.0 ;

GLfloat mat_specular[] = { 1.0, 1.0, 1.0, 1.0 };

GLfloat mat_shininess[] = { 50.0 };
GLfloat light_position[] = { 1.0, 1.0, 1.0, 0.0 };

/* glEnable(GL_LIGHTING);
glEnable(GL_LIGHT0);*/

glClearIndex( (GLfloat)BLACK_INDEX); //specify the clear value for the color index buffers BLACK_INDEX = black back ground
glClearDepth( 1.0 ); //clears the depth buffer


glEnable(GL_DEPTH_TEST); //enable or disable server-side GL capabilities, GL_DEPTH_TEST = do depth comparisons and update the depth buffer
///transparent stuff/////////////
glEnable( GL_BLEND);//for transparent
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
////end of transparent stuff///////

glMatrixMode( GL_PROJECTION ); //sets the current matrix mode. GL_PROJECTION Applies subsequent matrix operations to the projection matrix stack. 

glClearColor (0.0, 0.0, 0.0, 0.0);//this is also required for transparent stuff

glShadeModel (GL_FLAT);

glMaterialfv(GL_FRONT, GL_SPECULAR, mat_specular);
glMaterialfv(GL_FRONT, GL_SHININESS, mat_shininess);
glLightfv(GL_LIGHT0, GL_POSITION, light_position);

glEmin = (GLdouble)e_3dMin -(GLdouble)(glfZoom - (GLfloat)radius ) ;
glEmax = (GLdouble)e_3dMax + (GLdouble)(glfZoom - (GLfloat)radius ) ;
glNmin = (GLdouble)n_3dMin - (GLdouble)(glfZoom - (GLfloat)radius ) ;
glNmax = (GLdouble)n_3dMax + (GLdouble)(glfZoom - (GLfloat)radius );
glFar = (GLdouble)(4.0 * mf_3d);

glOrtho( glEmin, glEmax, glNmin, glNmax, -glFar, glFar);




glMatrixMode( GL_MODELVIEW ); //specify which matrix is the current matrix. GL_MODELVIEW Applies subsequent matrix operations to the modelview matrix stack.

if( cUseOpenGL != 'u' )//ie do not reset everything, just update the objects
{
    dnear_plane = 5.0; 
    dfar_plane = 2.0 * mf_3d;//700.0; 
    fmaxObjectSize = (float)mf_3d;//mf_d;//100.0F;//3.0F; 
    //radius =  mf_3d * 1.5;//mf_d * 1.5;///200;//radius = near_plane + maxObjectSize/2.0; 

    if( cAllowWottieFiles == 'n' )
    {
        flatitude = 0.0F; 
        flongitude = 0.0F; 
        flatinc = 6.0F; 
        flonginc = 2.5F; 
    }
    else
    {
        flatitude = 90.0F; 
        flongitude = 0.0F; 
        flatinc = 6.0F; 
        flonginc = 2.5F; 
    }
}

glPixelStorei( GL_UNPACK_ALIGNMENT, 1 );//part of zoom initialisation OpenGL p 357
createObjects( hwnd ); 

}