Visible Surface

glutInitDisplayMode ( GLUT_SINGLE | GLUT_RGB | GLUT_DEPTH );

glClear ( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );

glEnable ( GL_DEPTH_TEST );
glColor3f ( 1.0, 0.0, 0.0 );
drawDisc ( 20.0, 100.0, 100.0, 0.0 );
glColor3f ( 0.0, 0.0, 1.0 );
drawDisc ( 10.0, 100.0, 100.0, 0.5 );
glDisable ( GL_DEPTH_TEST );





Mouse Operations ( need GLUT or FreeGLUT ) 


void mouse ( int button, int state, int x, int y )
{
   if ( button == GLUT_LEFT_BUTTON && state == GLUT_DOWN )
          drawSomething ( x, y );

   if ( button == GLUT_RIGHT_BUTTON && state == GLUT_DOWN )
          exit ( );
}


-- and in main ( )

glutMouseFunc ( mouse );




Similar Keyboard Ops


void myKey ( unsigned char key, int x, int y )
{
   if ( key == 'q' || key == 'Q' )
          exit ( );
}


-- and in main ( )

glutKeyboardFunc ( myKey );




Images ( bitblt hardware )

glBitmap ( width, height, xo, yo, xi, yi, bitmap );



GLubyte myimage [ 512 ] [ 512 ] [ 3 ];

glReadPixels ( GLint x, GLint y, GLsizei width, Glsizei height,
               GLenum format, GLenum type, GLvoid *image );

glDrawPixels ( GLsizei width, Glsizei height, GLenum format, GLenum type,
               GLvoid *image );

glCopyPixels ( GLint x, GLint y, GLsizei width, Glsizei height, GLenum type );


glRasterPos2i ( startx, starty );

glDrawPixels ( 512, 512, GL_RGB, GL_UNSIGNED_BYTE, myimage );

© 2019 G. Hill Price
All Rights Reserved