progs/demos/rain.cxx

   1 /*
   2  * This program is under the GNU GPL.
   3  * Use at your own risk.
   4  *
   5  * written by David Bucciarelli (humanware@plus.it)
   6  *            Humanware s.r.l.
   7  */
   8
   9 #include <stdio.h>
  10 #include <stdlib.h>
  11 #include <math.h>
  12 #include <time.h>
  13 #include <GL/glut.h>
  14
  15 #include "particles.h"
  16 extern "C" {
  17 #include "image.h"
  18 }
  19
  20 #ifdef WIN32
  21 #include <windows.h>
  22 #include <mmsystem.h>
  23 #endif
  24
  25 #ifdef XMESA
  26 #include "GL/xmesa.h"
  27 static int fullscreen=1;
  28 #endif
  29
  30 static int WIDTH=640;
  31 static int HEIGHT=480;
  32 static int NUMPART=7500;
  33
  34 #define FRAME 50
  35
  36 static float fogcolor[4]={1.0,1.0,1.0,1.0};
  37
  38 #define DIMP 40.0
  39 #define DIMTP 32.0
  40
  41 static float q[4][3]={
  42   {-DIMP,0.0,-DIMP},
  43   {DIMP,0.0,-DIMP},
  44   {DIMP,0.0,DIMP},
  45   {-DIMP,0.0,DIMP}
  46 };
  47
  48 static float qt[4][2]={
  49   {-DIMTP,-DIMTP},
  50   {DIMTP,-DIMTP},
  51   {DIMTP,DIMTP},
  52   {-DIMTP,DIMTP}
  53 };
  54
  55 static int win=0;
  56
  57 static int fog=1;
  58 static int help=1;
  59
  60 static GLuint groundid;
  61
  62 static float obs[3]={2.0,1.0,0.0};
  63 static float dir[3];
  64 static float v=0.0;
  65 static float alpha=-90.0;
  66 static float beta=90.0;
  67
  68 static particleSystem *ps;
  69
  70 static float gettime()
  71 {
  72   static clock_t told=0;
  73   clock_t tnew,ris;
  74
  75   tnew=clock();
  76
  77   ris=tnew-told;
  78
  79   told=tnew;
  80
  81   return(ris/(float)CLOCKS_PER_SEC);
  82 }
  83
  84 static float gettimerain()
  85 {
  86   static clock_t told=0;
  87   clock_t tnew,ris;
  88
  89   tnew=clock();
  90
  91   ris=tnew-told;
  92
  93   told=tnew;
  94
  95   return(ris/(float)CLOCKS_PER_SEC);
  96 }
  97
  98 static void calcposobs(void)
  99 {
 100   dir[0]=sin(alpha*M_PI/180.0);
 101   dir[2]=cos(alpha*M_PI/180.0)*sin(beta*M_PI/180.0);
 102   dir[1]=cos(beta*M_PI/180.0);
 103
 104   obs[0]+=v*dir[0];
 105   obs[1]+=v*dir[1];
 106   obs[2]+=v*dir[2];
 107
 108   rainParticle::setRainingArea(obs[0]-7.0f,-0.2f,obs[2]-7.0f,obs[0]+7.0f,8.0f,obs[2]+7.0f);
 109 }
 110
 111 static void printstring(void *font, char *string)
 112 {
 113   int len,i;
 114
 115   len=(int)strlen(string);
 116   for(i=0;i<len;i++)
 117     glutBitmapCharacter(font,string[i]);
 118 }
 119
 120 static void reshape(int width, int height)
 121 {
 122   WIDTH=width;
 123   HEIGHT=height;
 124   glViewport(0,0,(GLint)width,(GLint)height);
 125   glMatrixMode(GL_PROJECTION);
 126   glLoadIdentity();
 127   gluPerspective(70.0,width/(float)height,0.1,30.0);
 128
 129   glMatrixMode(GL_MODELVIEW);
 130 }
 131
 132 static void printhelp(void)
 133 {
 134   glEnable(GL_BLEND);
 135   glColor4f(0.0,0.0,0.0,0.5);
 136   glRecti(40,40,600,440);
 137   glDisable(GL_BLEND);
 138
 139   glColor3f(1.0,0.0,0.0);
 140   glRasterPos2i(300,420);
 141   printstring(GLUT_BITMAP_TIMES_ROMAN_24,"Help");
 142
 143   glRasterPos2i(60,390);
 144   printstring(GLUT_BITMAP_TIMES_ROMAN_24,"h - Togle Help");
 145
 146   glRasterPos2i(60,360);
 147   printstring(GLUT_BITMAP_TIMES_ROMAN_24,"f - Togle Fog");
 148   glRasterPos2i(60,330);
 149   printstring(GLUT_BITMAP_TIMES_ROMAN_24,"Arrow Keys - Rotate");
 150   glRasterPos2i(60,300);
 151   printstring(GLUT_BITMAP_TIMES_ROMAN_24,"a - Increase velocity");
 152   glRasterPos2i(60,270);
 153   printstring(GLUT_BITMAP_TIMES_ROMAN_24,"z - Decrease velocity");
 154   glRasterPos2i(60,240);
 155   printstring(GLUT_BITMAP_TIMES_ROMAN_24,"l - Increase rain length");
 156   glRasterPos2i(60,210);
 157   printstring(GLUT_BITMAP_TIMES_ROMAN_24,"k - Increase rain length");
 158 }
 159
 160 static void drawrain(void)
 161 {
 162   static int count=0;
 163   static char frbuf[80];
 164   float fr;
 165
 166   glEnable(GL_DEPTH_TEST);
 167
 168   if(fog)
 169     glEnable(GL_FOG);
 170   else
 171     glDisable(GL_FOG);
 172
 173   glDepthMask(GL_TRUE);
 174   glClearColor(1.0,1.0,1.0,1.0);
 175   glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
 176
 177   glPushMatrix();
 178   calcposobs();
 179   gluLookAt(obs[0],obs[1],obs[2],
 180             obs[0]+dir[0],obs[1]+dir[1],obs[2]+dir[2],
 181             0.0,1.0,0.0);
 182
 183   glColor4f(1.0,1.0,1.0,1.0);
 184
 185   glEnable(GL_TEXTURE_2D);
 186
 187   glBindTexture(GL_TEXTURE_2D,groundid);
 188   glBegin(GL_QUADS);
 189   glTexCoord2fv(qt[0]);
 190   glVertex3fv(q[0]);
 191   glTexCoord2fv(qt[1]);
 192   glVertex3fv(q[1]);
 193   glTexCoord2fv(qt[2]);
 194   glVertex3fv(q[2]);
 195   glTexCoord2fv(qt[3]);
 196   glVertex3fv(q[3]);
 197   glEnd();
 198
 199   // Particle System
 200
 201   glDisable(GL_TEXTURE_2D);
 202   glShadeModel(GL_SMOOTH);
 203   glEnable(GL_BLEND);
 204
 205   ps->draw();
 206   ps->addTime(gettimerain());
 207
 208   glShadeModel(GL_FLAT);
 209
 210
 211   if((count % FRAME)==0) {
 212     fr=gettime();
 213     sprintf(frbuf,"Frame rate: %f",FRAME/fr);
 214   }
 215
 216   glDisable(GL_TEXTURE_2D);
 217   glDisable(GL_DEPTH_TEST);
 218   glDisable(GL_FOG);
 219
 220   glMatrixMode(GL_PROJECTION);
 221   glLoadIdentity();
 222   glOrtho(-0.5,639.5,-0.5,479.5,-1.0,1.0);
 223   glMatrixMode(GL_MODELVIEW);
 224   glLoadIdentity();
 225
 226   glColor3f(1.0,0.0,0.0);
 227   glRasterPos2i(10,10);
 228   printstring(GLUT_BITMAP_HELVETICA_18,frbuf);
 229   glRasterPos2i(350,470);
 230   printstring(GLUT_BITMAP_HELVETICA_10,"Rain V1.0 Written by David Bucciarelli (humanware@plus.it)");
 231
 232   if(help)
 233     printhelp();
 234
 235   reshape(WIDTH,HEIGHT);
 236   glPopMatrix();
 237
 238   glutSwapBuffers();
 239
 240   count++;
 241 }
 242
 243
 244 static void special(int key, int x, int y)
 245 {
 246   switch (key) {
 247   case GLUT_KEY_LEFT:
 248     alpha+=2.0;
 249     break;
 250   case GLUT_KEY_RIGHT:
 251     alpha-=2.0;
 252     break;
 253   case GLUT_KEY_DOWN:
 254     beta-=2.0;
 255     break;
 256   case GLUT_KEY_UP:
 257     beta+=2.0;
 258     break;
 259   }
 260 }
 261
 262 static void key(unsigned char key, int x, int y)
 263 {
 264   switch (key) {
 265   case 27:
 266     exit(0);
 267     break;
 268
 269   case 'a':
 270     v+=0.01;
 271     break;
 272   case 'z':
 273     v-=0.01;
 274     break;
 275
 276   case 'l':
 277     rainParticle::setLength(rainParticle::getLength()+0.025f);
 278     break;
 279   case 'k':
 280     rainParticle::setLength(rainParticle::getLength()-0.025f);
 281     break;
 282
 283   case 'h':
 284     help=(!help);
 285     break;
 286   case 'f':
 287     fog=(!fog);
 288     break;
 289 #ifdef XMESA
 290   case ' ':
 291     XMesaSetFXmode(fullscreen ? XMESA_FX_FULLSCREEN : XMESA_FX_WINDOW);
 292     fullscreen=(!fullscreen);
 293     break;
 294 #endif
 295   }
 296 }
 297
 298 static void inittextures(void)
 299 {
 300   IMAGE *img;
 301   GLenum gluerr;
 302
 303   glGenTextures(1,&groundid);
 304   glBindTexture(GL_TEXTURE_2D,groundid);
 305
 306   if(!(img=ImageLoad("s128.rgb"))) {
 307     fprintf(stderr,"Error reading a texture.\n");
 308     exit(-1);
 309   }
 310
 311   glPixelStorei(GL_UNPACK_ALIGNMENT,4);
 312   if((gluerr=(GLenum)gluBuild2DMipmaps(GL_TEXTURE_2D, 3, img->sizeX, img->sizeY, GL_RGB,
 313                                GL_UNSIGNED_BYTE, (GLvoid *)(img->data)))) {
 314     fprintf(stderr,"GLULib%s\n",gluErrorString(gluerr));
 315     exit(-1);
 316   }
 317
 318   glTexParameterf(GL_TEXTURE_2D,GL_TEXTURE_WRAP_S,GL_REPEAT);
 319   glTexParameterf(GL_TEXTURE_2D,GL_TEXTURE_WRAP_T,GL_REPEAT);
 320
 321   glTexParameterf(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR_MIPMAP_LINEAR);
 322   glTexParameterf(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR);
 323
 324   glTexEnvf(GL_TEXTURE_ENV,GL_TEXTURE_ENV_MODE,GL_DECAL);
 325 }
 326
 327 static void initparticle(void)
 328 {
 329   ps=new particleSystem;
 330
 331   rainParticle::setRainingArea(-7.0f,-0.2f,-7.0f,7.0f,8.0f,7.0f);
 332
 333   for(int i=0;i<NUMPART;i++) {
 334     rainParticle *p=new rainParticle;
 335     p->randomHeight();
 336
 337     ps->addParticle((particle *)p);
 338   }
 339 }
 340
 341 int main(int ac,char **av)
 342 {
 343   fprintf(stderr,"Rain V1.0\nWritten by David Bucciarelli (humanware@plus.it)\n");
 344
 345   /* Default settings */
 346
 347   WIDTH=640;
 348   HEIGHT=480;
 349
 350   glutInitWindowPosition(0,0);
 351   glutInitWindowSize(WIDTH,HEIGHT);
 352   glutInit(&ac,av);
 353
 354   glutInitDisplayMode(GLUT_RGB|GLUT_DEPTH|GLUT_DOUBLE);
 355
 356   if(!(win=glutCreateWindow("Rain"))) {
 357     fprintf(stderr,"Error opening a window.\n");
 358     exit(-1);
 359   }
 360
 361   reshape(WIDTH,HEIGHT);
 362
 363   inittextures();
 364
 365   glShadeModel(GL_FLAT);
 366   glEnable(GL_DEPTH_TEST);
 367
 368   glBlendFunc(GL_SRC_ALPHA,GL_ONE_MINUS_SRC_ALPHA);
 369
 370   glEnable(GL_FOG);
 371   glFogi(GL_FOG_MODE,GL_EXP);
 372   glFogfv(GL_FOG_COLOR,fogcolor);
 373   glFogf(GL_FOG_DENSITY,0.1);
 374 #ifdef FX
 375   glHint(GL_FOG_HINT,GL_NICEST);
 376 #endif
 377
 378   initparticle();
 379
 380   glutKeyboardFunc(key);
 381   glutSpecialFunc(special);
 382   glutDisplayFunc(drawrain);
 383   glutIdleFunc(drawrain);
 384   glutReshapeFunc(reshape);
 385   glutMainLoop();
 386
 387   return(0);
 388 }