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 <string.h>
  12 #include <math.h>
  13 #include <time.h>
  14 #include <GL/glut.h>
  15 #ifndef M_PI
  16 #define M_PI 3.14159265
  17 #endif
  18
  19 #include "particles.h"
  20 extern "C" {
  21 #include "readtex.h"
  22 }
  23
  24 #ifdef _WIN32
  25 #include <windows.h>
  26 #include <mmsystem.h>
  27 #include "particles.cxx"
  28 #include "readtex.c"
  29 #endif
  30
  31 #ifdef XMESA
  32 #include "GL/xmesa.h"
  33 static int fullscreen=1;
  34 #endif
  35
  36 static int WIDTH=640;
  37 static int HEIGHT=480;
  38 static int NUMPART=7500;
  39
  40 #define FRAME 50
  41
  42 static float fogcolor[4]={1.0,1.0,1.0,1.0};
  43
  44 #define DIMP 40.0
  45 #define DIMTP 32.0
  46
  47 static float q[4][3]={
  48   {-DIMP,0.0,-DIMP},
  49   {DIMP,0.0,-DIMP},
  50   {DIMP,0.0,DIMP},
  51   {-DIMP,0.0,DIMP}
  52 };
  53
  54 static float qt[4][2]={
  55   {-DIMTP,-DIMTP},
  56   {DIMTP,-DIMTP},
  57   {DIMTP,DIMTP},
  58   {-DIMTP,DIMTP}
  59 };
  60
  61 static int win=0;
  62
  63 static int fog=1;
  64 static int help=1;
  65
  66 static GLuint groundid;
  67
  68 static float obs[3]={2.0,1.0,0.0};
  69 static float dir[3];
  70 static float v=0.0;
  71 static float alpha=-90.0;
  72 static float beta=90.0;
  73
  74 static particleSystem *ps;
  75
  76 static float gettime()
  77 {
  78   static clock_t told=0;
  79   clock_t tnew,ris;
  80
  81   tnew=clock();
  82
  83   ris=tnew-told;
  84
  85   told=tnew;
  86
  87   return(ris/(float)CLOCKS_PER_SEC);
  88 }
  89
  90 static float gettimerain()
  91 {
  92   static clock_t told=0;
  93   clock_t tnew,ris;
  94
  95   tnew=clock();
  96
  97   ris=tnew-told;
  98
  99   told=tnew;
 100
 101   return(ris/(float)CLOCKS_PER_SEC);
 102 }
 103
 104 static void calcposobs(void)
 105 {
 106   dir[0]=sin(alpha*M_PI/180.0);
 107   dir[2]=cos(alpha*M_PI/180.0)*sin(beta*M_PI/180.0);
 108   dir[1]=cos(beta*M_PI/180.0);
 109
 110   obs[0]+=v*dir[0];
 111   obs[1]+=v*dir[1];
 112   obs[2]+=v*dir[2];
 113
 114   rainParticle::setRainingArea(obs[0]-7.0f,-0.2f,obs[2]-7.0f,obs[0]+7.0f,8.0f,obs[2]+7.0f);
 115 }
 116
 117 static void printstring(void *font, const char *string)
 118 {
 119   int len,i;
 120
 121   len=(int)strlen(string);
 122   for(i=0;i<len;i++)
 123     glutBitmapCharacter(font,string[i]);
 124 }
 125
 126 static void reshape(int width, int height)
 127 {
 128   WIDTH=width;
 129   HEIGHT=height;
 130   glViewport(0,0,(GLint)width,(GLint)height);
 131   glMatrixMode(GL_PROJECTION);
 132   glLoadIdentity();
 133   gluPerspective(70.0,width/(float)height,0.1,30.0);
 134
 135   glMatrixMode(GL_MODELVIEW);
 136 }
 137
 138 static void printhelp(void)
 139 {
 140   glEnable(GL_BLEND);
 141   glColor4f(0.0,0.0,0.0,0.5);
 142   glRecti(40,40,600,440);
 143   glDisable(GL_BLEND);
 144
 145   glColor3f(1.0,0.0,0.0);
 146   glRasterPos2i(300,420);
 147   printstring(GLUT_BITMAP_TIMES_ROMAN_24,"Help");
 148
 149   glRasterPos2i(60,390);
 150   printstring(GLUT_BITMAP_TIMES_ROMAN_24,"h - Toggle Help");
 151
 152   glRasterPos2i(60,360);
 153   printstring(GLUT_BITMAP_TIMES_ROMAN_24,"f - Toggle Fog");
 154   glRasterPos2i(60,330);
 155   printstring(GLUT_BITMAP_TIMES_ROMAN_24,"Arrow Keys - Rotate");
 156   glRasterPos2i(60,300);
 157   printstring(GLUT_BITMAP_TIMES_ROMAN_24,"a - Increase velocity");
 158   glRasterPos2i(60,270);
 159   printstring(GLUT_BITMAP_TIMES_ROMAN_24,"z - Decrease velocity");
 160   glRasterPos2i(60,240);
 161   printstring(GLUT_BITMAP_TIMES_ROMAN_24,"l - Increase rain length");
 162   glRasterPos2i(60,210);
 163   printstring(GLUT_BITMAP_TIMES_ROMAN_24,"k - Increase rain length");
 164 }
 165
 166 static void drawrain(void)
 167 {
 168   static int count=0;
 169   static char frbuf[80];
 170   float fr;
 171
 172   glEnable(GL_DEPTH_TEST);
 173
 174   if(fog)
 175     glEnable(GL_FOG);
 176   else
 177     glDisable(GL_FOG);
 178
 179   glDepthMask(GL_TRUE);
 180   glClearColor(1.0,1.0,1.0,1.0);
 181   glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
 182
 183   glPushMatrix();
 184   calcposobs();
 185   gluLookAt(obs[0],obs[1],obs[2],
 186             obs[0]+dir[0],obs[1]+dir[1],obs[2]+dir[2],
 187             0.0,1.0,0.0);
 188
 189   glColor4f(1.0,1.0,1.0,1.0);
 190
 191   glEnable(GL_TEXTURE_2D);
 192
 193   glBindTexture(GL_TEXTURE_2D,groundid);
 194   glBegin(GL_QUADS);
 195   glTexCoord2fv(qt[0]);
 196   glVertex3fv(q[0]);
 197   glTexCoord2fv(qt[1]);
 198   glVertex3fv(q[1]);
 199   glTexCoord2fv(qt[2]);
 200   glVertex3fv(q[2]);
 201   glTexCoord2fv(qt[3]);
 202   glVertex3fv(q[3]);
 203   glEnd();
 204
 205   // Particle System
 206
 207   glDisable(GL_TEXTURE_2D);
 208   glShadeModel(GL_SMOOTH);
 209   glEnable(GL_BLEND);
 210
 211   ps->draw();
 212   ps->addTime(gettimerain());
 213
 214   glShadeModel(GL_FLAT);
 215
 216
 217   if((count % FRAME)==0) {
 218     fr=gettime();
 219     sprintf(frbuf,"Frame rate: %f",FRAME/fr);
 220   }
 221
 222   glDisable(GL_TEXTURE_2D);
 223   glDisable(GL_DEPTH_TEST);
 224   glDisable(GL_FOG);
 225
 226   glMatrixMode(GL_PROJECTION);
 227   glLoadIdentity();
 228   glOrtho(-0.5,639.5,-0.5,479.5,-1.0,1.0);
 229   glMatrixMode(GL_MODELVIEW);
 230   glLoadIdentity();
 231
 232   glColor3f(1.0,0.0,0.0);
 233   glRasterPos2i(10,10);
 234   printstring(GLUT_BITMAP_HELVETICA_18,frbuf);
 235   glRasterPos2i(350,470);
 236   printstring(GLUT_BITMAP_HELVETICA_10,"Rain V1.0 Written by David Bucciarelli (humanware@plus.it)");
 237
 238   if(help)
 239     printhelp();
 240
 241   reshape(WIDTH,HEIGHT);
 242   glPopMatrix();
 243
 244   glutSwapBuffers();
 245
 246   count++;
 247 }
 248
 249
 250 static void special(int key, int x, int y)
 251 {
 252   switch (key) {
 253   case GLUT_KEY_LEFT:
 254     alpha+=2.0;
 255     break;
 256   case GLUT_KEY_RIGHT:
 257     alpha-=2.0;
 258     break;
 259   case GLUT_KEY_DOWN:
 260     beta-=2.0;
 261     break;
 262   case GLUT_KEY_UP:
 263     beta+=2.0;
 264     break;
 265   }
 266 }
 267
 268 static void key(unsigned char key, int x, int y)
 269 {
 270   switch (key) {
 271   case 27:
 272     exit(0);
 273     break;
 274
 275   case 'a':
 276     v+=0.01;
 277     break;
 278   case 'z':
 279     v-=0.01;
 280     break;
 281
 282   case 'l':
 283     rainParticle::setLength(rainParticle::getLength()+0.025f);
 284     break;
 285   case 'k':
 286     rainParticle::setLength(rainParticle::getLength()-0.025f);
 287     break;
 288
 289   case 'h':
 290     help=(!help);
 291     break;
 292   case 'f':
 293     fog=(!fog);
 294     break;
 295 #ifdef XMESA
 296   case ' ':
 297     XMesaSetFXmode(fullscreen ? XMESA_FX_FULLSCREEN : XMESA_FX_WINDOW);
 298     fullscreen=(!fullscreen);
 299     break;
 300 #endif
 301   }
 302 }
 303
 304 static void inittextures(void)
 305 {
 306   GLubyte *img;
 307   GLint width,height;
 308   GLenum format;
 309   GLenum gluerr;
 310
 311   glGenTextures(1,&groundid);
 312   glBindTexture(GL_TEXTURE_2D,groundid);
 313
 314   if(!(img=LoadRGBImage("../images/s128.rgb",&width,&height,&format))){
 315         fprintf(stderr,"Error reading a texture.\n");
 316         exit(-1);
 317   }
 318   glPixelStorei(GL_UNPACK_ALIGNMENT,4);
 319   if((gluerr=(GLenum)gluBuild2DMipmaps(GL_TEXTURE_2D, 3, width, height,GL_RGB,
 320                                GL_UNSIGNED_BYTE, (GLvoid *)(img)))) {
 321     fprintf(stderr,"GLULib%s\n",gluErrorString(gluerr));
 322     exit(-1);
 323   }
 324
 325   glTexParameterf(GL_TEXTURE_2D,GL_TEXTURE_WRAP_S,GL_REPEAT);
 326   glTexParameterf(GL_TEXTURE_2D,GL_TEXTURE_WRAP_T,GL_REPEAT);
 327
 328   glTexParameterf(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR_MIPMAP_LINEAR);
 329   glTexParameterf(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR);
 330
 331   glTexEnvf(GL_TEXTURE_ENV,GL_TEXTURE_ENV_MODE,GL_DECAL);
 332 }
 333
 334 static void initparticle(void)
 335 {
 336   ps=new particleSystem;
 337
 338   rainParticle::setRainingArea(-7.0f,-0.2f,-7.0f,7.0f,8.0f,7.0f);
 339
 340   for(int i=0;i<NUMPART;i++) {
 341     rainParticle *p=new rainParticle;
 342     p->randomHeight();
 343
 344     ps->addParticle((particle *)p);
 345   }
 346 }
 347
 348 int main(int ac,char **av)
 349 {
 350   fprintf(stderr,"Rain V1.0\nWritten by David Bucciarelli (humanware@plus.it)\n");
 351
 352   /* Default settings */
 353
 354   WIDTH=640;
 355   HEIGHT=480;
 356
 357   glutInitWindowPosition(0,0);
 358   glutInitWindowSize(WIDTH,HEIGHT);
 359   glutInit(&ac,av);
 360
 361   glutInitDisplayMode(GLUT_RGB|GLUT_DEPTH|GLUT_DOUBLE);
 362
 363   if(!(win=glutCreateWindow("Rain"))) {
 364     fprintf(stderr,"Error opening a window.\n");
 365     exit(-1);
 366   }
 367
 368   reshape(WIDTH,HEIGHT);
 369
 370   inittextures();
 371
 372   glShadeModel(GL_FLAT);
 373   glEnable(GL_DEPTH_TEST);
 374
 375   glBlendFunc(GL_SRC_ALPHA,GL_ONE_MINUS_SRC_ALPHA);
 376
 377   glEnable(GL_FOG);
 378   glFogi(GL_FOG_MODE,GL_EXP);
 379   glFogfv(GL_FOG_COLOR,fogcolor);
 380   glFogf(GL_FOG_DENSITY,0.1);
 381 #ifdef FX
 382   glHint(GL_FOG_HINT,GL_NICEST);
 383 #endif
 384
 385   initparticle();
 386
 387   glutKeyboardFunc(key);
 388   glutSpecialFunc(special);
 389   glutDisplayFunc(drawrain);
 390   glutIdleFunc(drawrain);
 391   glutReshapeFunc(reshape);
 392   glutMainLoop();
 393
 394   return(0);
 395 }