example2.cpp

c++源程序

/****************************************************************************

  example2.cpp

  A simple GLUT program using the GLUI User Interface Library

  -----------------------------------------------------------------------
	   
  9/9/98 Paul Rademacher ([e-mail])

****************************************************************************/

#include <string.h>
#include <GL/glut.h>
#include "glui.h"

float xy_aspect;
int   last_x, last_y;
float rotationX = 0.0, rotationY = 0.0;
int   main_window;


/** These are the live variables passed into GLUI ***/
int   wireframe = 0;
int   obj = 0;
int   segments = 8;
char  text[200] = {"Hello World!"};

GLUI_Checkbox   *checkbox;
GLUI_Spinner    *spinner;
GLUI_RadioGroup *radio;
GLUI_EditText   *edittext;

/**************************************** control_cb() *******************/
/* GLUI control callback                                                 */

void control_cb( int control )
{
  /********************************************************************
    Here we'll print the user id of the control that generated the
    callback, and we'll also explicitly get the values of each control.
    Note that we really didn't have to explicitly get the values, since
    they are already all contained within the live variables:
    'wireframe',  'segments',  'obj',  and 'text'  
    ********************************************************************/

  printf( "callback: %d\n", control );
  printf( "             checkbox: %d\n", checkbox->get_int_val() );
  printf( "              spinner: %d\n", spinner->get_int_val() );
  printf( "          radio group: %d\n", radio->get_int_val() );
  printf( "                 text: %s\n", edittext->get_text() );
  
}

/**************************************** myGlutKeyboard() **********/

void myGlutKeyboard(unsigned char Key, int x, int y)
{
  switch(Key)
  {
  case 27: 
  case 'q':
    exit(0);
    break;
  };
  
  glutPostRedisplay();
}


/***************************************** myGlutMenu() ***********/

void myGlutMenu( int value )
{
  myGlutKeyboard( value, 0, 0 );
}


/***************************************** myGlutIdle() ***********/

void myGlutIdle( void )
{
  /* According to the GLUT specification, the current window is 
     undefined during an idle callback.  So we need to explicitly change
     it if necessary */
  if ( glutGetWindow() != main_window) 
    glutSetWindow(main_window);  

  glutPostRedisplay();
}

/***************************************** myGlutMouse() **********/

void myGlutMouse(int button, int button_state, int x, int y )
{
  if ( button == GLUT_LEFT_BUTTON && button_state == GLUT_DOWN ) {
    last_x = x;
    last_y = y;
  }
}


/***************************************** myGlutMotion() **********/

void myGlutMotion(int x, int y )
{
  rotationX += (float) (y - last_y);
  rotationY += (float) (x - last_x);

  last_x = x;
  last_y = y;

  glutPostRedisplay(); 
}

/**************************************** myGlutReshape() *************/

void myGlutReshape( int x, int y )
{
  xy_aspect = (float)x / (float)y;
  glViewport( 0, 0, x, y );

  glutPostRedisplay();
}

/***************************************** myGlutDisplay() *****************/

void myGlutDisplay( void )
{
  glClearColor( .9f, .9f, .9f, 1.0f );
  glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );

  glMatrixMode( GL_PROJECTION );
  glLoadIdentity();
  glFrustum( -xy_aspect*.08, xy_aspect*.08, -.08, .08, .1, 15.0 );

  glMatrixMode( GL_MODELVIEW );
  glLoadIdentity();
  glTranslatef( 0.0f, 0.0f, -1.6f );
  glRotatef( rotationY, 0.0, 1.0, 0.0 );
  glRotatef( rotationX, 1.0, 0.0, 0.0 );

  /*** Now we render object, using the variables 'obj', 'segments', and
    'wireframe'.  These are _live_ variables, which are transparently 
    updated by GLUI ***/
  
  if ( obj == 0 ) {
    if ( wireframe )      
      glutWireSphere( .6, segments, segments );
    else                  
      glutSolidSphere( .6, segments, segments );
  }
  else if ( obj == 1 ) {
    if ( wireframe )
      glutWireTorus( .2,.5,16,segments );
    else
      glutSolidTorus( .2,.5,16,segments );
  }

  glDisable( GL_LIGHTING );  /* Disable lighting while we render text */
  glMatrixMode( GL_PROJECTION );
  glLoadIdentity();
  gluOrtho2D( 0.0, 100.0, 0.0, 100.0  );
  glMatrixMode( GL_MODELVIEW );
  glLoadIdentity();
  glColor3ub( 0, 0, 0 );
  glRasterPos2i( 10, 10 );

  //  printf( "text: %s\n", text );

  /*** Render the live character array 'text' ***/
  int i;
  for( i=0; i<(int)strlen( text ); i++ )
    glutBitmapCharacter( GLUT_BITMAP_HELVETICA_18, text[i] );

  glEnable( GL_LIGHTING );

  glutSwapBuffers(); 
}


/**************************************** main() ********************/

void main(int argc, char* argv[])
{
  /****************************************/
  /*   Initialize GLUT and create window  */
  /****************************************/

  glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH );
  glutInitWindowPosition( 50, 50 );
  glutInitWindowSize( 300, 300 );
 
  main_window = glutCreateWindow( "GLUI Example 2" );
  glutDisplayFunc( myGlutDisplay );
  glutReshapeFunc( myGlutReshape );  
  glutKeyboardFunc( myGlutKeyboard );
  glutMotionFunc( myGlutMotion );
  glutMouseFunc( myGlutMouse );

  /****************************************/
  /*       Set up OpenGL lights           */
  /****************************************/

  GLfloat light0_ambient[] =  {0.1f, 0.1f, 0.3f, 1.0f};
  GLfloat light0_diffuse[] =  {.6f, .6f, 1.0f, 1.0f};
  GLfloat light0_position[] = {1.0f, 1.0f, 1.0f, 0.0f};

  glEnable(GL_LIGHTING);
  glEnable(GL_LIGHT0);
  glLightfv(GL_LIGHT0, GL_AMBIENT, light0_ambient);
  glLightfv(GL_LIGHT0, GL_DIFFUSE, light0_diffuse);
  glLightfv(GL_LIGHT0, GL_POSITION, light0_position);

  /****************************************/
  /*          Enable z-buferring          */
  /****************************************/

  glEnable(GL_DEPTH_TEST);

  /****************************************/
  /*         Here's the GLUI code         */
  /****************************************/

  GLUI *glui = GLUI_Master.create_glui( "GLUI", 0, 400, 50 ); /* name, flags,
								 x, and y */
  glui->add_statictext( "GLUI Example 2" );
  glui->add_separator();
  checkbox = glui->add_checkbox( "Wireframe", &wireframe, 1, control_cb );
  spinner  = glui->add_spinner( "Segments:",GLUI_SPINNER_INT, &segments,
				2, control_cb );
  spinner->set_int_limits( 3, 60 );
  edittext = glui->add_edittext( "Text:", GLUI_EDITTEXT_TEXT, text, 
				 3, control_cb );
  GLUI_Panel *obj_panel = glui->add_panel( "Object Type" );
  radio = glui->add_radiogroup_to_panel(obj_panel,&obj,4,control_cb);
  glui->add_radiobutton_to_group( radio, "Sphere" );
  glui->add_radiobutton_to_group( radio, "Torus" );
  glui->add_button( "Quit", 0,(GLUI_Update_CB)exit );
 
  glui->set_main_gfx_window( main_window );

  /* We register the idle callback with GLUI, *not* with GLUT */
  GLUI_Master.set_glutIdleFunc( myGlutIdle );

  glutMainLoop();
}