borgware-2d/simulator/trackball.h

/**
 * \addtogroup unixsimulator
 */
/*@{*/

/**
 *  Simple trackball-like motion adapted (ripped off) from projtex.c
 *  (written by David Yu and David Blythe).  See the SIGGRAPH '96
 *  Advanced OpenGL course notes.
 *
 *
 *  Usage:
 *
 *  o  call tbInit() in before any other tb call
 *  o  call tbReshape() from the reshape callback
 *  o  call tbMatrix() to get the trackball matrix rotation
 *  o  call tbStartMotion() to begin trackball movememt
 *  o  call tbStopMotion() to stop trackball movememt
 *  o  call tbMotion() from the motion callback
 *  o  call tbAnimate(GL_TRUE) if you want the trackball to continue
 *     spinning after the mouse button has been released
 *  o  call tbAnimate(GL_FALSE) if you want the trackball to stop
 *     spinning after the mouse button has been released
 *
 *  Typical setup:
 *
 *
 *  void
 *  init(void)
 *  {
 *    tbInit(GLUT_MIDDLE_BUTTON);
 *    tbAnimate(GL_TRUE);
 *    . . .
 *  }
 *
 *  void
 *  reshape(int width, int height)
 *  {
 *    tbReshape(width, height);
 *    . . .
 *  }
 *
 *  void
 *  display(void)
 *  {
 *    glPushMatrix();
 *
 *    tbMatrix();
 *    . . . draw the scene . . .
 *
 *    glPopMatrix();
 *  }
 *
 *  void
 *  mouse(int button, int state, int x, int y)
 *  {
 *    tbMouse(button, state, x, y);
 *    . . .
 *  }
 *
 *  void
 *  motion(int x, int y)
 *  {
 *    tbMotion(x, y);
 *    . . .
 *  }
 *
 *  int
 *  main(int argc, char** argv)
 *  {
 *    . . .
 *    init();
 *    glutReshapeFunc(reshape);
 *    glutDisplayFunc(display);
 *    glutMouseFunc(mouse);
 *    glutMotionFunc(motion);
 *    . . .
 *  }
 *
 * @file trackball.h
 * @brief Header file for helper functions for the UNIX platform Borg simulator.
 * @author Martin Ongsiek, David Yu, David Blythe
 */


 /* functions */
 void tbInit(GLuint button);

 void tbMatrix(void);

 void tbReshape(int width, int height);

 void tbMouse(int button, int state, int x, int y);

 void tbMotion(int x, int y);

 void tbAnimate(GLboolean animate);

 /*@}*/