Display Class Reference

#include <Display.h>

Collaboration diagram for Display:


Public Member Functions
virtual	~Display ()
	Empty Display destructor.
void	init ()
	Initialize the OpenGL parameters for 3D rendering.
void	quit ()
	Actions to do before exiting the program.
void	timer (int value)
	The timer fonction that handle periodic iteration and redisplay.
void	draw ()
	Render the scene in OpenGL.
void	reshape (int width, int height)
	Recompute projection matrix after reshaping the window.
void	inputKey (unsigned char key, int x, int y)
	Associate treatments to the keyboard keys.
void	inputMouse (int button, int state, int x, int y)
	Associate treatments to the mouse.
Static Public Member Functions
static Display *	instance ()
	Return an instance of Display (use of singleton design pattern).
static void	destroy ()
	Destroy the instance of Display.
Protected Member Functions
	Display ()
	Empty Display constructor.
GLfloat	focal_distance ()
	Compute the focal distance (e.g. the distance to the object we are looking at).
void	translate_camera (GLfloat inc_x, GLfloat inc_z)
	Translate the camera.
void	move_camera (GLfloat inc_y)
	Move the camera up and down.
void	zoom_camera (GLfloat inc)
	Zoom or un-zoom to the center of the screen.
void	rotate_camera (GLfloat inc)
	Rotate the camera around the center of the screen point.
Protected Attributes
GLfloat	_camera_x
GLfloat	_camera_y
GLfloat	_camera_z
GLfloat	_center_x
GLfloat	_center_y
GLfloat	_center_z
GLfloat	_near
GLfloat	_far
GLfloat	_fovy
World	_world
bool	_timer
Static Protected Attributes
static Display *	_instance = NULL

Detailed Description

< The display class

Definition at line 35 of file Display.h.

Member Function Documentation

GLfloat Display::focal_distance ( ) [protected]

Compute the focal distance (e.g. the distance to the object we are looking at).

Returns:: the focal distance

Definition at line 68 of file Display.cpp.

References _camera_x, _camera_y, _center_x, and _center_y.

Referenced by zoom_camera().

00068                                 {
00069   return sqrt((_camera_x - _center_x) * (_camera_x - _center_x) +
00070               (_camera_y - _center_y) * (_camera_y - _center_y) +
00071               (_camera_y - _center_y) * (_camera_y - _center_y));
00072 }

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void Display::translate_camera	(	GLfloat	inc_x,
		GLfloat	inc_z
	)			`[protected]`

Translate the camera.

Parameters:

	inc_x	the relative movement of the camera in the x direction
	inc_z	the relative movement of the camera in the z direction

Definition at line 74 of file Display.cpp.

References _camera_x, _camera_z, _center_x, _center_z, _world, CELL_SIZE, World::getHeight(), and World::getWidth().

Referenced by inputKey().

00074                                                              {
00075   GLfloat tmp_x = _center_x + inc_x;
00076   GLfloat tmp_z = _center_z + inc_z;
00077 
00078   if(tmp_x > 0.0 && tmp_x < (_world.getWidth() - 1.0) * CELL_SIZE &&
00079       tmp_z > 0.0 && tmp_z < (_world.getHeight() - 1.0) * CELL_SIZE) {
00080     _camera_x += inc_x;
00081     _center_x = tmp_x;
00082     _camera_z += inc_z;
00083     _center_z = tmp_z;
00084     glutPostRedisplay();
00085   }
00086 }

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void Display::move_camera ( GLfloat inc_y ) [protected]

Move the camera up and down.

Parameters:

inc_y

the relative movement of the camera in the y direction

Definition at line 88 of file Display.cpp.

References _camera_y, HEIGHT_MAX, and HEIGHT_MIN.

Referenced by inputKey(), and inputMouse().

00088                                         {
00089   GLfloat tmp_y = _camera_y + inc_y;
00090 
00091   if(tmp_y >= HEIGHT_MIN && tmp_y <= HEIGHT_MAX) {
00092     _camera_y += inc_y;
00093     glutPostRedisplay();
00094   }
00095 }

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void Display::zoom_camera ( GLfloat inc ) [protected]

Zoom or un-zoom to the center of the screen.

Parameters:

inc

the relative movement of the camera in the center of the screen direction

Definition at line 97 of file Display.cpp.

References _camera_x, _camera_y, _camera_z, _center_x, _center_y, _center_z, focal_distance(), HEIGHT_MAX, and HEIGHT_MIN.

Referenced by inputKey(), and inputMouse().

00097                                       {
00098   GLfloat tmp = focal_distance();
00099 
00100   if(_camera_y + inc >= HEIGHT_MIN && _camera_y + inc <= HEIGHT_MAX) {
00101     _camera_x = ((_camera_x - _center_x) * (1 + inc / tmp)) + _center_x;
00102     _camera_y = ((_camera_y - _center_y) * (1 + inc / tmp)) + _center_y;
00103     _camera_z = ((_camera_z - _center_z) * (1 + inc / tmp)) + _center_z;
00104     glutPostRedisplay();
00105   }
00106 }

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void Display::rotate_camera ( GLfloat inc ) [protected]

Rotate the camera around the center of the screen point.

Parameters:

inc

the angle of the rotation to do

Definition at line 108 of file Display.cpp.

References _camera_x, _camera_z, _center_x, and _center_z.

Referenced by inputKey(), and inputMouse().

00108                                         {
00109   GLfloat tmp = _camera_x;
00110   _camera_x = ((_camera_x - _center_x) * cos(inc) -
00111     (_camera_z - _center_z) * sin(inc)) + _center_x;
00112   _camera_z = ((tmp - _center_x) * sin(inc) +
00113     (_camera_z - _center_z) * cos(inc)) + _center_z;
00114   glutPostRedisplay();
00115 }

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Display * Display::instance ( ) [static]

Return an instance of Display (use of singleton design pattern).

Returns:: the instance of Display

Definition at line 121 of file Display.cpp.

References _instance, and Display().

Referenced by display_draw(), display_init(), display_inputKey(), display_inputMouse(), display_quit(), display_reshape(), and display_timer().

00121                            {
00122   if(_instance == NULL) {
00123     _instance = new Display();
00124   }
00125 
00126   return _instance;
00127 }

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void Display::timer ( int value )

The timer fonction that handle periodic iteration and redisplay.

Parameters:

value

(unused)

Definition at line 188 of file Display.cpp.

References _timer, _world, display_timer(), World::iteration(), and REDISPLAY_NB_MILLI_SEC.

Referenced by display_timer().

00188                              {
00189   _world.iteration();
00190   glutPostRedisplay();
00191   if(_timer) {
00192     // on relance le timer pour ré-appeler automatiquement la fonction plus tard
00193     glutTimerFunc(REDISPLAY_NB_MILLI_SEC, display_timer, 0);
00194   }
00195 }

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void Display::reshape	(	int	width,
		int	height
	)

Recompute projection matrix after reshaping the window.

Parameters:

	width	the new width of the window
	height	the new height of the window

Definition at line 254 of file Display.cpp.

References _far, _fovy, and _near.

Referenced by display_reshape().

00254                                            {
00255   // division par 0 : pas bô, alors autant l'éviter...
00256   if (height == 0)
00257     height = 1;
00258 
00259   // modification de la taille de la zone d'affichage
00260   glViewport(0, 0, width, height);
00261 
00262   // passage en mode projection
00263   glMatrixMode(GL_PROJECTION);
00264 
00265   // création de la nouvelle transformation de projection
00266   glLoadIdentity();
00267   gluPerspective(_fovy, (float) width / height, _near, _far);
00268 
00269   // réactivation du mode dessin
00270   glMatrixMode(GL_MODELVIEW);
00271 }

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void Display::inputKey	(	unsigned char	key,
		int	x,
		int	y
	)

Associate treatments to the keyboard keys.

Parameters:

	key	the key pressed
	x	the x mouse coordinate
	y	the y mouse coordinate

Definition at line 273 of file Display.cpp.

References _center_x, _center_z, _timer, _world, World::addGodsGift(), CELL_SIZE, display_timer(), move_camera(), MOVE_UP_SPEED, PAUSE, REDISPLAY_NB_MILLI_SEC, ROTATE_ANGLE, rotate_camera(), ROTATE_LEFT, ROTATE_RIGHT, translate_camera(), TRANSLATE_DOWN, TRANSLATE_LEFT, TRANSLATE_RIGHT, TRANSLATE_UP, VALIDATE, zoom_camera(), ZOOM_IN, ZOOM_OUT, and ZOOM_SPEED.

Referenced by display_inputKey().

00273                                                       {
00274   GLint specialKey = glutGetModifiers();
00275 
00276   switch(key) {
00277     case TRANSLATE_LEFT :
00278       translate_camera(-CELL_SIZE, 0.0);
00279       break;
00280     case TRANSLATE_RIGHT :
00281       translate_camera(CELL_SIZE, 0.0);;
00282       break;
00283     case TRANSLATE_UP :
00284       translate_camera(0.0, -CELL_SIZE);
00285       break;
00286     case TRANSLATE_DOWN :
00287       translate_camera(0.0, CELL_SIZE);
00288       break;
00289     case ZOOM_IN :
00290       if(specialKey == GLUT_ACTIVE_CTRL) {
00291         move_camera(MOVE_UP_SPEED);
00292       } else {
00293         zoom_camera(-ZOOM_SPEED);
00294       }
00295       break;
00296     case ZOOM_OUT :
00297       if(specialKey == GLUT_ACTIVE_CTRL) {
00298         move_camera(-MOVE_UP_SPEED);
00299       } else {
00300         zoom_camera(ZOOM_SPEED);
00301       }
00302       break;
00303     case ROTATE_LEFT :
00304       rotate_camera(-ROTATE_ANGLE);
00305       break;
00306     case ROTATE_RIGHT :
00307       rotate_camera(ROTATE_ANGLE);
00308       break;
00309     case PAUSE :
00310       if(_timer) {
00311         _timer = false;
00312       } else {
00313         _timer = true;
00314         // relance le timer
00315         glutTimerFunc(REDISPLAY_NB_MILLI_SEC, display_timer, 0);
00316       }
00317       break;
00318     case VALIDATE :
00319       _world.addGodsGift((unsigned int) _center_z / CELL_SIZE,
00320         (unsigned int) _center_x / CELL_SIZE);
00321       glutPostRedisplay();
00322       break;
00323   }
00324 }

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void Display::inputMouse	(	int	button,
		int	state,
		int	x,
		int	y
	)

Associate treatments to the mouse.

Parameters:

	button	the button pressed
	state	the state of the button (up or down)
	x	the x mouse coordinate
	y	the y mouse coordinate

Definition at line 326 of file Display.cpp.

References _world, GLUT_DOWN_BUTTON, GLUT_UP_BUTTON, World::iteration(), move_camera(), MOVE_UP_SPEED, ROTATE_ANGLE, rotate_camera(), zoom_camera(), and ZOOM_SPEED.

Referenced by display_inputMouse().

00326                                                             {
00327   GLint specialKey = glutGetModifiers();
00328 
00329   /*
00330   GLint viewport[4];
00331   GLdouble modelview[16];
00332   GLdouble projection[16];
00333   GLfloat win_x, win_y, win_z;
00334   GLdouble obj_x, obj_y, obj_z;
00335 
00336   glGetIntegerv(GL_VIEWPORT, viewport);
00337   glGetDoublev(GL_MODELVIEW_MATRIX, modelview);
00338   glGetDoublev(GL_PROJECTION_MATRIX, projection);
00339 
00340   win_x = (GLfloat) x;
00341   win_y = (GLfloat) viewport[3] - (GLfloat) y;
00342   glReadPixels(win_x, win_y , 1, 1, GL_DEPTH_COMPONENT, GL_FLOAT, &win_z);
00343 
00344   gluUnProject((GLdouble) win_x, (GLdouble) win_y, 0.0, modelview, projection,
00345     viewport, &obj_x, &obj_y, &obj_z);
00346   */
00347 
00348   if(state == GLUT_DOWN) {
00349     switch(button) {
00350       case GLUT_UP_BUTTON :
00351         if(specialKey == GLUT_ACTIVE_CTRL) {
00352           move_camera(MOVE_UP_SPEED);
00353         } else {
00354           zoom_camera(-ZOOM_SPEED);
00355         }
00356         break;
00357       case GLUT_DOWN_BUTTON :
00358         if(specialKey == GLUT_ACTIVE_CTRL) {
00359           move_camera(-MOVE_UP_SPEED);
00360         } else {
00361           zoom_camera(ZOOM_SPEED);
00362         }
00363         break;
00364       case GLUT_LEFT_BUTTON :
00365         if(specialKey == GLUT_ACTIVE_CTRL) {
00366           rotate_camera(-ROTATE_ANGLE);
00367         } else {
00368           _world.iteration();
00369           glutPostRedisplay();
00370         }
00371         break;
00372       case GLUT_RIGHT_BUTTON :
00373         if(specialKey == GLUT_ACTIVE_CTRL) {
00374           rotate_camera(ROTATE_ANGLE);
00375         }
00376         break;
00377     }
00378   }
00379 }