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