// OpenGl transforms in C and mapped to C++


glMatrixMode ( GL_MODELVIEW );

glLoadIdentity ( );


glScaled ( sx, sy, 1.0 );   // 2D scale

glScaled ( sx, sy, sz );    // 3D


glTranslated ( dx, dy, 0 );   // 2D translate

glTranslated ( dx, dy, dz );   // 3D 


glRotated ( angle, 0.0, 0.0, 1.0 ); // 2D rotate

glRotated ( angle, ux, uy, uz ); // 3D 


// C++ mapping


// init CT
void Canvas :: initCT ( void )
{
     glMatrixMode ( GL_MODELVIEW );
     glLoadIdentity ( );
}

// 2D scale
void Canvas :: scale2D ( double sx, double sy )
{
     glMatrixMode ( GL_MODELVIEW );
     glScaled ( sx, sy, 1.0 );   // set CT to CT * ( 2D scale )
}

// 2D translate
void Canvas :: translate2D ( double dx, double dy )
{
     glMatrixMode ( GL_MODELVIEW );
     glTranslated ( dx, dy, 1.0 );   // set CT to CT * ( 2D xlate )
}

// 2D rotate
void Canvas :: rotate2D ( double angle )
{
     glMatrixMode ( GL_MODELVIEW );
     glRotated ( angle, 0.0, 0.0, 1.0 );   // set CT to CT * ( 2D rotate )
}

© 2006 G. Hill Price
All Rights Reserved