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sheet06.cpp File Reference

#include <GL/glut.h>
#include <GL/glu.h>
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include "config.h"
#include "torus.h"
#include "texture.h"
#include "heightfield.h"

Go to the source code of this file.

Enumerations

enum  {
  MENU_LIGHTING = 1, MENU_POLYMODE, MENU_TEXTURING, MENU_FRAMERATE,
  MENU_EXIT
}

Functions

void glutString (char *pstr)
void computeCameraPosition (float *eyePoint)
void computeLightPosition (const float *lightPosWorld, float *lightPosEye)
void setupCamera ()
void renderScene ()
void display ()
void reshape (GLint width, GLint height)
void initGL ()
void timerCallback (int)
void selectFromMenu (int idCommand)
float sExpFunc (int n)
void keyboard (unsigned char key, int, int)
void keyboardUp (unsigned char key, int, int)
void special (int key, int, int)
void specialUp (int key, int, int)
int buildPopupMenu ()
int main (int argc, char **argv)

Variables

int g_nLastTime = 0
float g_fFPS = 0
float g_nearPlane = 1
float g_farPlane = 10
const double VIEWING_DISTANCE_MIN = 1
float g_fViewDistance = 5*VIEWING_DISTANCE_MIN
int g_Width = 256
int g_Height = 256
bool g_bFillPolygons = true
bool g_bRotateLeft = false
bool g_bRotateRight = false
bool g_bRotateDown = false
bool g_bRotateUp = false
bool g_bCameraUp = false
bool g_bCameraDown = false
bool g_bCameraLeft = false
bool g_bCameraRight = false
float g_fCameraX = 0
float g_fCameraY = 0
float g_eyePoint [4]

Enumeration Type Documentation

anonymous enum
 

Enumeration values:
MENU_LIGHTING 
MENU_POLYMODE 
MENU_TEXTURING 
MENU_FRAMERATE 
MENU_EXIT 

Definition at line 21 of file sheet06.cpp. 

00021      {
00022   MENU_LIGHTING = 1,
00023   MENU_POLYMODE,
00024   MENU_TEXTURING,
00025   MENU_FRAMERATE,
00026   MENU_EXIT
00027 };

Function Documentation

int buildPopupMenu (   ) 
 

Definition at line 497 of file sheet06.cpp.

References MENU_EXIT, MENU_FRAMERATE, MENU_POLYMODE, and selectFromMenu().

Referenced by main(). 

00498 {
00499   printf( "Keys:\n" );
00500 
00501 //  printf( "  F1 - Per Pixel Lighting ON\n" );
00502 //  printf( "  F2 - Per Pixel Lighting OFF\n" );
00503 
00504 //  printf( "  F3 - Specular Term ON\n" );
00505 //  printf( "  F4 - Specular Tern OFF\n\n" );
00506 
00507 //  printf( "  0-9 - Set specular exponent to n^2/4\n\n" );
00508 
00509 //  printf( "  Cursor keys - rotate camera\n" );
00510 //  printf( "  A,S,D,W     - rotate Torus\n\n" );
00511 
00512   printf( "  p - Toggle polygon fill\n" );
00513   printf( "  f   - Display frame rate\n" );
00514   printf( "  ESC - Exit demo\n" );
00515 
00516 
00517   int menu = glutCreateMenu (selectFromMenu);
00518   glutAddMenuEntry ("Toggle polygon fill\tp", MENU_POLYMODE);
00519   glutAddMenuEntry ("Display frame rate\tf", MENU_FRAMERATE);
00520   glutAddMenuEntry ("Exit demo\tEsc", MENU_EXIT);
00521   return menu;
00522 }

void computeCameraPosition (  float *  eyePoint  ) 
 

Definition at line 89 of file sheet06.cpp.

References g_farPlane, and g_nearPlane. 

00090 {
00091   // Projected eye position:
00092   //   In the projection step (gluProject(), the eye position is mapped from (0,0,0) to
00093   //   (0,0, - (n*f) / (f-n)), where n and f are near and far plane.
00094   float eyeProject[4];
00095   eyeProject[0] = 0;
00096   eyeProject[1] = 0;
00097   eyeProject[2] = - (g_nearPlane * g_farPlane) / (g_farPlane - g_nearPlane);
00098   eyeProject[3] = 0;
00099 
00100   // Multiply projected eye position with inverse projection to get
00101   // eye point of the camera in world coordinates
00102   float modelviewT[16];
00103   glGetFloatv( GL_TRANSPOSE_MODELVIEW_MATRIX, modelviewT );
00104   float projectionT[16];
00105   glGetFloatv( GL_TRANSPOSE_PROJECTION_MATRIX, projectionT );
00106 
00107   // Compute inverse matrices
00108   float inverse_projection[16];
00109   float inverse_modelview[16];
00110   Invert<float> (projectionT, inverse_projection);
00111   Invert<float> (modelviewT, inverse_modelview);
00112 
00113   float eyeCamera[4];
00114   Multiply<float> (inverse_projection, eyeProject, eyeCamera );
00115   Multiply<float> (inverse_modelview,  eyeCamera, eyePoint );
00116 }

void computeLightPosition (  const float *  lightPosWorld,
float *  lightPosEye
) 
 

Definition at line 122 of file sheet06.cpp. 

00123 {
00124   // Now that the camera transformation is set up, the current modelview
00125   // matrix transforms world coordinates to eye coordinates, and is
00126   // the correct transformation matrix for the light sources
00127   float projection[16];
00128   glGetFloatv( GL_TRANSPOSE_MODELVIEW_MATRIX, projection );
00129   Multiply<float> (projection, lightPosWorld, lightPosEye );
00130 }

void display (   ) 
 

Definition at line 191 of file sheet06.cpp.

References colorDarkGrey, colorSky, colorWhite, g_bFrameRate, g_farPlane, g_fFPS, g_Height, g_lightPos, g_Width, glutString(), ModelViewMatrix, renderScene(), and setupCamera().

Referenced by main(). 

00192 {
00193   // Clear frame buffer and depth buffer
00194   glClearColor( colorSky[0], colorSky[1], colorSky[2], colorSky[3] );
00195   glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
00196   
00197   // Setup camera and initialize modelview matrix stack
00198   setupCamera();
00199 glGetFloatv(GL_MODELVIEW_MATRIX, ModelViewMatrix);
00200   
00201   glViewport(0, 0, g_Width, g_Height);
00202   
00203   // Set up the stationary light (after camera transform)
00204   glLightfv(GL_LIGHT0, GL_POSITION, g_lightPos);
00205   glLightfv(GL_LIGHT0, GL_DIFFUSE, colorWhite );
00206   glLightfv(GL_LIGHT0, GL_AMBIENT, colorDarkGrey );
00207   glLightfv(GL_LIGHT0, GL_SPECULAR, colorWhite );
00208   
00209   // Fog from 0.6*visibility to visibility range
00210   glFogi( GL_FOG_MODE, GL_LINEAR );
00211   glFogf( GL_FOG_START, g_farPlane * 0.6f );
00212   glFogf( GL_FOG_END, g_farPlane );
00213   glFogfv( GL_FOG_COLOR, colorSky );
00214   glEnable( GL_FOG );
00215 
00216   // Render the scene
00217   renderScene();
00218 
00219 
00220   // Display framerate
00221   if (g_bFrameRate) {
00222     char buf[100];
00223     sprintf( buf, "%0.2f fps", g_fFPS );
00224     glMatrixMode( GL_PROJECTION );
00225     glLoadIdentity();
00226     glMatrixMode( GL_MODELVIEW );
00227     glLoadIdentity();
00228     glDisable( GL_DEPTH_TEST );
00229     glDisable( GL_LIGHTING );
00230     glColor3f( 1.0f, 1.0f, 1.0f );
00231     glRasterPos2f( -1,-1 );
00232     glutString( buf );
00233     glEnable( GL_DEPTH_TEST );
00234   }
00235 
00236   // Make sure changes appear onscreen
00237   glutSwapBuffers();
00238 }

void glutString (  char *  pstr  ) 
 

Definition at line 75 of file sheet06.cpp.

Referenced by display(). 

00076 {
00077   while (*pstr!=char(0)) {
00078     glutBitmapCharacter( GLUT_BITMAP_8_BY_13, int( *pstr ));
00079     pstr++;
00080   }
00081 }

void initGL (   ) 
 

Definition at line 250 of file sheet06.cpp.

References g_hfH, g_hfW, g_strHeightFieldFile, initHeightField(), initTextures(), and initTorus().

Referenced by main(). 

00251 {
00252   glEnable(GL_DEPTH_TEST);
00253   glDepthFunc(GL_LESS);
00254   glShadeModel(GL_SMOOTH);
00255   glEnable(GL_LIGHTING);
00256   glEnable(GL_LIGHT0);
00257   glEnable( GL_CULL_FACE );
00258   glCullFace( GL_BACK );
00259   glEnable( GL_NORMALIZE );
00260 
00261   // Init Cg
00262   initTorus();
00263   // Load the textures
00264   initTextures();
00265 
00266   // Load the height field
00267   printf( "Loading height field %s, size %i x %i ... ",
00268           g_strHeightFieldFile, g_hfW, g_hfH );
00269   initHeightField();
00270   printf( "success.\n" );
00271 }

void keyboard (  unsigned char  key,
int  ,
int 
) 
 

Definition at line 365 of file sheet06.cpp.

References g_bRotateDown, g_bRotateLeft, g_bRotateRight, g_bRotateUp, g_specularExponent, MENU_FRAMERATE, MENU_LIGHTING, MENU_POLYMODE, selectFromMenu(), and sExpFunc().

Referenced by main(). 

00366 {
00367   switch (key) {
00368   case 27:             // ESCAPE key
00369     exit (0);
00370     break;
00371   case 'l':
00372     selectFromMenu(MENU_LIGHTING);
00373     break;
00374   case 'f':
00375     selectFromMenu(MENU_FRAMERATE);
00376     break;
00377   case 'p':
00378     selectFromMenu(MENU_POLYMODE);
00379     break;
00380   case '1':
00381     g_specularExponent = sExpFunc( 1 );
00382     break;
00383   case '2':
00384     g_specularExponent = sExpFunc( 2 );
00385     break;
00386   case '3':
00387     g_specularExponent = sExpFunc( 3 );
00388     break;
00389   case '4':
00390     g_specularExponent = sExpFunc( 4 );
00391     break;
00392   case '5':
00393     g_specularExponent = sExpFunc( 5 );
00394     break;
00395   case '6':
00396     g_specularExponent = sExpFunc( 6 );
00397     break;
00398   case '7':
00399     g_specularExponent = sExpFunc( 7 );
00400     break;
00401   case '8':
00402     g_specularExponent = sExpFunc( 8 );
00403     break;
00404   case '9':
00405     g_specularExponent = sExpFunc( 9 );
00406     break;
00407   case '0':
00408     g_specularExponent = sExpFunc( 0 );
00409     break;
00410   case 'a':
00411     g_bRotateLeft = true;
00412     break;
00413   case 'd':
00414     g_bRotateRight = true;
00415     break;
00416   case 's':
00417     g_bRotateUp = true;
00418     break;
00419   case 'w':
00420     g_bRotateDown = true;
00421     break;
00422   }
00423 }

void keyboardUp (  unsigned char  key,
int  ,
int 
) 
 

Definition at line 425 of file sheet06.cpp.

References g_bRotateDown, g_bRotateLeft, g_bRotateRight, and g_bRotateUp.

Referenced by main(). 

00426 {
00427   switch( key ) {
00428   case 'a':
00429     g_bRotateLeft = false;
00430     break;
00431   case 'd':
00432     g_bRotateRight = false;
00433     break;
00434   case 's':
00435     g_bRotateUp = false;
00436     break;
00437   case 'w':
00438     g_bRotateDown = false;
00439     break;
00440   }
00441 }

int main (  int  argc,
char **  argv
) 
 

Definition at line 534 of file sheet06.cpp.

References buildPopupMenu(), display(), g_Height, g_nLastTime, g_nTimerDelay, g_Width, initGL(), keyboard(), keyboardUp(), reshape(), special(), specialUp(), and timerCallback(). 

00535 {
00536   // GLUT Window Initialization:
00537   glutInit(&argc, argv);
00538   glutInitWindowSize(g_Width, g_Height);
00539   glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH );
00540   glutCreateWindow("CG-I GLUT example");
00541 
00542   glutSetKeyRepeat( GLUT_KEY_REPEAT_ON );
00543   glutIgnoreKeyRepeat(0);
00544 
00545   // Initialize OpenGL graphics state
00546   initGL();
00547 
00548   // Register callbacks:
00549   glutDisplayFunc(display);
00550   glutReshapeFunc(reshape);
00551   glutKeyboardFunc(keyboard);
00552   glutKeyboardUpFunc(keyboardUp);
00553   glutSpecialFunc(special);
00554   glutSpecialUpFunc(specialUp);
00555 
00556 
00557   // Create popup menu
00558   buildPopupMenu();
00559   glutAttachMenu(GLUT_RIGHT_BUTTON);
00560 
00561   // Start display timer
00562   g_nLastTime = glutGet( GLUT_ELAPSED_TIME );
00563   glutTimerFunc( g_nTimerDelay, timerCallback, 0);
00564 
00565   // Turn the flow of control over to GLUT
00566   glutMainLoop();
00567   return 0;
00568 }

void renderScene (   ) 
 

Definition at line 164 of file sheet06.cpp.

References drawHeightField(), drawTorus(), g_bLighting, g_eyePoint, and g_farPlane.

Referenced by display(). 

00165 {
00166   if (g_bLighting) {
00167     glEnable(GL_LIGHTING);
00168   }
00169   else {
00170     glDisable(GL_LIGHTING);
00171   }
00172 
00173   // Draw torus
00174   glPushMatrix();
00175 //  glRotatef( g_fTorusX, 0,1,0 );
00176 //  glRotatef( g_fTorusY, 1,0,0 );
00177   drawTorus( g_eyePoint );
00178   glPopMatrix();
00179 
00180 
00181 
00182   // Draw ground
00183   glPushMatrix();
00184   glTranslatef( 0,-5,0 );
00185   glRotatef( -90, 1,0,0 );
00186   drawHeightField( 0,0, (int)g_farPlane, (int)g_farPlane );
00187   glPopMatrix();
00188 }

void reshape (  GLint  width,
GLint  height
) 
 

Definition at line 242 of file sheet06.cpp.

References g_Height, and g_Width.

Referenced by main(). 

00243 {
00244   g_Width = width;
00245   g_Height = height;
00246 }

void selectFromMenu (  int  idCommand  ) 
 

Definition at line 333 of file sheet06.cpp.

References g_bFillPolygons, g_bFrameRate, g_bLighting, MENU_EXIT, MENU_FRAMERATE, MENU_LIGHTING, and MENU_POLYMODE.

Referenced by buildPopupMenu(), and keyboard(). 

00334 {
00335   switch (idCommand) {
00336   case MENU_LIGHTING:
00337     g_bLighting = !g_bLighting;
00338     break;
00339   case MENU_FRAMERATE:
00340     g_bFrameRate = !g_bFrameRate;
00341     break;
00342   case MENU_POLYMODE:
00343     g_bFillPolygons = !g_bFillPolygons;
00344     glPolygonMode (GL_FRONT_AND_BACK, g_bFillPolygons ? GL_FILL : GL_LINE);
00345     break;      
00346   case MENU_EXIT:
00347     printf( "Exiting.\n" );
00348     glutSetKeyRepeat( GLUT_KEY_REPEAT_ON );
00349     exit (0);
00350     break;
00351   }
00352 
00353   // Almost any menu selection requires a redraw
00354   glutPostRedisplay();
00355 }

void setupCamera (   ) 
 

Definition at line 140 of file sheet06.cpp.

References computeLightPosition(), g_farPlane, g_fCameraX, g_fCameraY, g_fViewDistance, g_Height, g_lightPos, g_lightPosEye, g_nearPlane, and g_Width.

Referenced by display(). 

00141 {
00142   // Setup projection with field of view of 65 degrees
00143   glMatrixMode(GL_PROJECTION);
00144   glLoadIdentity();
00145   gluPerspective(65.0, (float)g_Width / g_Height, g_nearPlane, g_farPlane);
00146 
00147   // Initializa modelview
00148   glMatrixMode(GL_MODELVIEW);
00149   glLoadIdentity();
00150 
00151   // Set up viewing transformation, looking down -Z axis
00152   gluLookAt(0, 0, -g_fViewDistance, 0, 0, -1, 0, 1, 0);
00153 
00154   // Free camera mode
00155   glRotatef( g_fCameraX, 1,0,0 );
00156   glRotatef( g_fCameraY, 0,1,0 );
00157 
00158   // Compute the position of the light source in eye coordinates
00159   computeLightPosition( g_lightPos, g_lightPosEye );
00160 }

float sExpFunc (  int  n  ) 
 

Definition at line 358 of file sheet06.cpp.

Referenced by keyboard(). 

00359 {
00360   return float(n*n) / 2.0f + 0.01f;
00361 }

void special (  int  key,
int  ,
int 
) 
 

Definition at line 443 of file sheet06.cpp.

References g_bBlinnPhong, g_bCameraDown, g_bCameraLeft, g_bCameraRight, g_bCameraUp, and g_bPerPixelLighting.

Referenced by main(). 

00444 {
00445   switch( key ) {
00446   case GLUT_KEY_F1:
00447     g_bPerPixelLighting = true;
00448     break;
00449   case GLUT_KEY_F2:
00450     g_bPerPixelLighting = false;
00451     break;
00452   case GLUT_KEY_F3:
00453     g_bBlinnPhong = true;
00454     break;
00455   case GLUT_KEY_F4:
00456     g_bBlinnPhong = false;
00457     break;
00458   case GLUT_KEY_UP:
00459     g_bCameraUp = true;
00460     break;
00461   case GLUT_KEY_DOWN:
00462     g_bCameraDown = true;
00463     break;
00464   case GLUT_KEY_LEFT:
00465     g_bCameraLeft = true;
00466     break;
00467   case GLUT_KEY_RIGHT:
00468     g_bCameraRight = true;
00469     break;
00470   }
00471 }

void specialUp (  int  key,
int  ,
int 
) 
 

Definition at line 474 of file sheet06.cpp.

References g_bCameraDown, g_bCameraLeft, g_bCameraRight, and g_bCameraUp.

Referenced by main(). 

00475 {
00476   switch( key ) {
00477   case GLUT_KEY_UP:
00478     g_bCameraUp = false;
00479     break;
00480   case GLUT_KEY_DOWN:
00481     g_bCameraDown = false;
00482     break;
00483   case GLUT_KEY_LEFT:
00484     g_bCameraLeft = false;
00485     break;
00486   case GLUT_KEY_RIGHT:
00487     g_bCameraRight = false;
00488     break;
00489   }
00490 }

void timerCallback (  int   )  [static]
 

Definition at line 283 of file sheet06.cpp.

References g_bRotateDown, g_bRotateLeft, g_bRotateRight, g_bRotateUp, g_fFPS, g_fTorusX, g_fTorusY, g_nLastTime, g_nTimerDelay, and timerCallback().

Referenced by main(), and timerCallback(). 

00284 {
00285   // Get time in seconds after last call to the timer
00286   int nc = glutGet(GLUT_ELAPSED_TIME);
00287   float fSec = float(nc-g_nLastTime) / 1000.0f;
00288   // Compute average frame rate from the last twenty frames
00289   g_fFPS = (19.0f*g_fFPS + 1.0f / fSec) / 20.0f;
00290   g_nLastTime = nc;
00291 
00292   // Perform all animations
00293   // Camera movement at 1/2 rounds per second
00294 /*  float fCamArc = fSec * 180.0f;
00295   if (g_bCameraUp && g_fCameraX < 90) g_fCameraX += fCamArc;
00296   if (g_bCameraDown && g_fCameraX > -90) g_fCameraX -= fCamArc;
00297   if (g_bCameraLeft) g_fCameraY += fCamArc;
00298   if (g_bCameraRight) g_fCameraY -= fCamArc;
00299 */
00300   // Plane rotation
00301   if (g_bRotateLeft) {
00302     g_fTorusX += fSec * 360.0f / 5.0f;
00303   }
00304   else if (g_bRotateRight) {
00305     g_fTorusX -= fSec * 360.0f / 5.0f;
00306   }
00307   if (g_bRotateUp) {
00308     g_fTorusY += fSec * 360.0f / 5.0f;
00309   }
00310   else if (g_bRotateDown) {
00311     g_fTorusY -= fSec * 360.0f / 5.0f;
00312   }
00313 
00314 
00315   // Redraw and restart timer
00316   glutPostRedisplay();
00317   glutTimerFunc( g_nTimerDelay, timerCallback, 0);
00318 }

Variable Documentation

bool g_bCameraDown = false [static]
 

Definition at line 58 of file sheet06.cpp.

Referenced by special(), and specialUp().

bool g_bCameraLeft = false [static]
 

Definition at line 59 of file sheet06.cpp.

Referenced by special(), and specialUp().

bool g_bCameraRight = false [static]
 

Definition at line 60 of file sheet06.cpp.

Referenced by special(), and specialUp().

bool g_bCameraUp = false [static]
 

Definition at line 57 of file sheet06.cpp.

Referenced by special(), and specialUp().

bool g_bFillPolygons = true [static]
 

Definition at line 47 of file sheet06.cpp.

Referenced by selectFromMenu().

bool g_bRotateDown = false [static]
 

Definition at line 53 of file sheet06.cpp.

Referenced by keyboard(), keyboardUp(), and timerCallback().

bool g_bRotateLeft = false [static]
 

Definition at line 51 of file sheet06.cpp.

Referenced by keyboard(), keyboardUp(), and timerCallback().

bool g_bRotateRight = false [static]
 

Definition at line 52 of file sheet06.cpp.

Referenced by keyboard(), keyboardUp(), and timerCallback().

bool g_bRotateUp = false [static]
 

Definition at line 54 of file sheet06.cpp.

Referenced by keyboard(), keyboardUp(), and timerCallback().

float g_eyePoint[4] [static]
 

Definition at line 65 of file sheet06.cpp.

Referenced by renderScene().

float g_farPlane = 10 [static]
 

Definition at line 36 of file sheet06.cpp.

Referenced by computeCameraPosition(), display(), renderScene(), and setupCamera().

float g_fCameraX = 0 [static]
 

Definition at line 61 of file sheet06.cpp.

Referenced by setupCamera().

float g_fCameraY = 0 [static]
 

Definition at line 62 of file sheet06.cpp.

Referenced by setupCamera().

float g_fFPS = 0 [static]
 

Definition at line 32 of file sheet06.cpp.

Referenced by display(), and timerCallback().

float g_fViewDistance = 5*VIEWING_DISTANCE_MIN
 

Definition at line 39 of file sheet06.cpp.

Referenced by setupCamera().

int g_Height = 256 [static]
 

Definition at line 44 of file sheet06.cpp.

Referenced by display(), main(), reshape(), and setupCamera().

float g_nearPlane = 1 [static]
 

Definition at line 35 of file sheet06.cpp.

Referenced by computeCameraPosition(), and setupCamera().

int g_nLastTime = 0 [static]
 

Definition at line 30 of file sheet06.cpp.

Referenced by main(), and timerCallback().

int g_Width = 256 [static]
 

Definition at line 43 of file sheet06.cpp.

Referenced by display(), main(), reshape(), and setupCamera().

const double VIEWING_DISTANCE_MIN = 1 [static]
 

Definition at line 38 of file sheet06.cpp.

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