Rube Goldberg Machine 1.0
This is the base code for Rube Goldberg designed for the CS296 Software Systems Lab
Static Public Member Functions
cs296::callbacks_t Class Reference

#include <callbacks.hpp>

List of all members.

Static Public Member Functions

static b2Vec2 convert_screen_to_world (int32 x, int32 y)
 Helper function for coordinates system conversion Note the function is a static function. Read about C++ static functions.
static void resize_cb (int32 w, int32 h)
 GLUT resize callback. This is set via GLUI. Why is this so? This gets called when the window is resized. Passed as parameters are the current window width and height.
static void keyboard_cb (unsigned char key, int x, int y)
 GLUT keyboard callback This gets called whenever a key is pressed.
static void keyboard_special_cb (int key, int x, int y)
 GLUT keyboard callback for keys with special keycodes.
static void keyboard_up_cb (unsigned char key, int x, int y)
 Another keyboard callback? Why is this necessary? Is this used?
static void mouse_cb (int32 button, int32 state, int32 x, int32 y)
 GLUT mouse callback This is called when a mouse button is pressed.
static void mouse_motion_cb (int32 x, int32 y)
 GLUT Mouse motion callback This is called when the mouse is moved/dragged.
static void timer_cb (int)
 GLUT timer callback. This is used to control the frame rate - figure out how by reading the GLUT manual.
static void display_cb (void)
 GLUT display callback This draws every time a draw event is posted. It also xecutes the main simulation loop by calling test->step(...)
static void restart_cb (int)
 GLUI callback - Called when the restart button is pressed.
static void pause_cb (int)
 GLUI callback - Called when the pause button is pressed.
static void single_step_cb (int)
 GLUI callback - Called when the single-step button is pressed.
static void exit_cb (int code)
 GLUI callback - Called when the exit button is pressed.

Detailed Description

Definition at line 29 of file callbacks.hpp.

Member Function Documentation

b2Vec2 cs296::callbacks_t::convert_screen_to_world ( int32  x,
int32  y 
) [static]

Helper function for coordinates system conversion Note the function is a static function. Read about C++ static functions.

Definition at line 39 of file callbacks.cpp.

  {
    float32 u = x / static_cast<float32>(tw);
    float32 v = (th - y) / float32(th);
    
    float32 ratio = static_cast<float32>(tw) / static_cast<float32>(th);
    b2Vec2 extents(ratio * 25.0f, 25.0f);
    extents *= view_zoom;
    
    b2Vec2 lower = settings.view_center - extents;
    b2Vec2 upper = settings.view_center + extents;
  
    b2Vec2 p;
    p.x = (1.0f - u) * lower.x + u * upper.x;
    p.y = (1.0f - v) * lower.y + v * upper.y;
    return p;
  }
void cs296::callbacks_t::display_cb ( void  ) [static]

GLUT display callback This draws every time a draw event is posted. It also xecutes the main simulation loop by calling test->step(...)

Definition at line 246 of file callbacks.cpp.

  {
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
    
    test->set_text_line(30);
    b2Vec2 old_center = settings.view_center;
    settings.hz = settings_hz;
    
    test->step(&settings);
    
    if (old_center.x != settings.view_center.x || old_center.y != settings.view_center.y)
      {
    resize_cb(width, height);
      }
    
    test->draw_title(5, 15, entry->name);
    
    glutSwapBuffers();
    
    if (test_selection != test_index)
      {
    test_index = test_selection;
    delete test;
    entry = cs296::sim;
    test = entry->create_fcn();
    view_zoom = 1.0f;
    settings.view_center.Set(0.0f, 20.0f);
      resize_cb(width, height);
      }
  }
void cs296::callbacks_t::exit_cb ( int  code) [static]

GLUI callback - Called when the exit button is pressed.

Definition at line 295 of file callbacks.cpp.

  {
    exit(code);
  }
void cs296::callbacks_t::keyboard_cb ( unsigned char  key,
int  x,
int  y 
) [static]

GLUT keyboard callback This gets called whenever a key is pressed.

What are these?

Press 'z' to zoom out.

Press 'x' to zoom in.

Press 'r' to reset.

Press 'p' to pause.

The default case. Why is this needed?

Definition at line 85 of file callbacks.cpp.

  {
    B2_NOT_USED(x);
    B2_NOT_USED(y);
    
    switch (key)
    {
    case 27:
      exit(0);
      break;
      
    case 'z':
      view_zoom = b2Min(1.1f * view_zoom, 20.0f);
      resize_cb(width, height);
      break;
      
    case 'x':
      view_zoom = b2Max(0.9f * view_zoom, 0.02f);
      resize_cb(width, height);
      break;
      
    case 'r':
      delete test;
      test = entry->create_fcn();
      break;
      
    case 'p':
      settings.pause = !settings.pause;
      break;
      
    default:
      if (test)
    {
      test->keyboard(key);
    }
    }
  }
void cs296::callbacks_t::keyboard_special_cb ( int  key,
int  x,
int  y 
) [static]

GLUT keyboard callback for keys with special keycodes.

Press left to pan left.

Press right to pan right.

Press down to pan down.

Press up to pan up.

Press home to reset the view.

Definition at line 130 of file callbacks.cpp.

  {
    B2_NOT_USED(x);
    B2_NOT_USED(y);
    
    switch (key)
    {
    case GLUT_ACTIVE_SHIFT:
      
    case GLUT_KEY_LEFT:
      settings.view_center.x -= 0.5f;
      resize_cb(width, height);
      break;
      
    case GLUT_KEY_RIGHT:
      settings.view_center.x += 0.5f;
      resize_cb(width, height);
      break;
      
    case GLUT_KEY_DOWN:
      settings.view_center.y -= 0.5f;
      resize_cb(width, height);
      break;
      
    case GLUT_KEY_UP:
      settings.view_center.y += 0.5f;
      resize_cb(width, height);
      break;
      
    case GLUT_KEY_HOME:
      view_zoom = 1.0f;
      settings.view_center.Set(0.0f, 20.0f);
      callbacks_t::resize_cb(width, height);
      break;
    }
  }
void cs296::callbacks_t::keyboard_up_cb ( unsigned char  key,
int  x,
int  y 
) [static]

Another keyboard callback? Why is this necessary? Is this used?

Definition at line 172 of file callbacks.cpp.

  {
    B2_NOT_USED(x);
    B2_NOT_USED(y);
    
    if (test)
      {
    test->keyboard_up(key);
      }
  }
void cs296::callbacks_t::mouse_cb ( int32  button,
int32  state,
int32  x,
int32  y 
) [static]

GLUT mouse callback This is called when a mouse button is pressed.

Use the mouse to move things around - figure out how this works?

Definition at line 183 of file callbacks.cpp.

  {
    if (button == GLUT_LEFT_BUTTON)
      {
    int mod = glutGetModifiers();
    b2Vec2 p = convert_screen_to_world(x, y);
    if (state == GLUT_DOWN)
      {
        b2Vec2 p = convert_screen_to_world(x, y);
        if (mod == GLUT_ACTIVE_SHIFT)
          {
        test->shift_mouse_down(p);
          }
        else
          {
        test->mouse_down(p);
          }
      }
    
    if (state == GLUT_UP)
      {
        test->mouse_up(p);
      }
      }
    else if (button == GLUT_RIGHT_BUTTON)
      {
    if (state == GLUT_DOWN)
      { 
        lastp = convert_screen_to_world(x, y);
        r_mouse_down = true;
      }
    
    if (state == GLUT_UP)
      {
      r_mouse_down = false;
      }
      }
  }
void cs296::callbacks_t::mouse_motion_cb ( int32  x,
int32  y 
) [static]

GLUT Mouse motion callback This is called when the mouse is moved/dragged.

Definition at line 224 of file callbacks.cpp.

  {
    b2Vec2 p = convert_screen_to_world(x, y);
    test->mouse_move(p);
    
    if (r_mouse_down)
      {
    b2Vec2 diff = p - lastp;
    settings.view_center.x -= diff.x;
    settings.view_center.y -= diff.y;
    resize_cb(width, height);
    lastp = convert_screen_to_world(x, y);
      }
  }
void cs296::callbacks_t::pause_cb ( int  ) [static]

GLUI callback - Called when the pause button is pressed.

Definition at line 290 of file callbacks.cpp.

  {
    settings.pause = !settings.pause;
  }
void cs296::callbacks_t::resize_cb ( int32  w,
int32  h 
) [static]

GLUT resize callback. This is set via GLUI. Why is this so? This gets called when the window is resized. Passed as parameters are the current window width and height.

Notice the type casting Read about explicit/implicit type casting in C++

L/R/B/T extents of the view frustum Find where this function is defined

Definition at line 58 of file callbacks.cpp.

  {
    width = w;
    height = h;
    
    GLUI_Master.get_viewport_area(&tx, &ty, &tw, &th);
    glViewport(tx, ty, tw, th);
    
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    
    float32 ratio = static_cast<float32>(tw) / static_cast<float32>(th);
    
    b2Vec2 extents(ratio * 25.0f, 25.0f);
    extents *= view_zoom;
    
    b2Vec2 lower = settings.view_center - extents;
    b2Vec2 upper = settings.view_center + extents;
  
    gluOrtho2D(lower.x, upper.x, lower.y, upper.y);
  }
void cs296::callbacks_t::restart_cb ( int  ) [static]

GLUI callback - Called when the restart button is pressed.

Definition at line 282 of file callbacks.cpp.

  {
    delete test;
    entry = cs296::sim;
    test = entry->create_fcn();
    resize_cb(width, height);
  }
void cs296::callbacks_t::single_step_cb ( int  ) [static]

GLUI callback - Called when the single-step button is pressed.

Definition at line 300 of file callbacks.cpp.

  {
    settings.pause = 1;
    settings.single_step = 1;
  }
void cs296::callbacks_t::timer_cb ( int  ) [static]

GLUT timer callback. This is used to control the frame rate - figure out how by reading the GLUT manual.

Definition at line 239 of file callbacks.cpp.

  {
    glutSetWindow(main_window);
    glutPostRedisplay();
    glutTimerFunc(frame_period, timer_cb, 0);
  }
The documentation for this class was generated from the following files:
 All Classes Namespaces Files Functions Variables Typedefs Friends Defines
Generated on Thu Apr 11 2013 00:02:34 for Rube Goldberg Machine by  doxygen 1.7.4