*
* Module - "eruption.c"
*
+ * [02-2003] - W.P. van Paassen: Improvements, added some code of jwz from the pyro hack for a spherical distribution of the particles
* [01-2003] - W.P. van Paassen: Port to X for use with XScreenSaver, the shadebob hack by Shane Smit was used as a template
* [04-2002] - W.P. van Paassen: Creation for the Demo Effects Collection (http://demo-effects.sourceforge.net)
*/
{ 0, 0, 0, 0 }
};
+/* Slightly whacked, for better explosions
+ */
+#define PI_2000 6284
+#define SPREAD 15
+
+static int sin_cache[PI_2000];
+static int cos_cache[PI_2000];
+
/*particle structure*/
typedef struct
{
static signed char gravity;
static signed short heat;
-void init_particle(PARTICLE* particle, signed short iColorCount)
+static void
+cache(void) /* jwz */
+{ /*needs to be run once. Could easily be */
+ int i; /*reimplemented to run and cache at compile-time,*/
+ double dA;
+ for (i=0; i<PI_2000; i++)
+ {
+ dA=sin(((double) (random() % (PI_2000/2)))/1000.0);
+ /*Emulation of spherical distribution*/
+ dA+=asin(frand(1.0))/M_PI_2*0.1;
+ /*Approximating the integration of the binominal, for
+ well-distributed randomness*/
+ cos_cache[i]=-abs((int) (cos(((double)i)/1000.0)*dA*ydelta));
+ sin_cache[i]=(int) (sin(((double)i)/1000.0)*dA*xdelta);
+ }
+}
+
+void init_particle(PARTICLE* particle, signed short iColorCount, unsigned short xcenter, unsigned short ycenter)
{
- /* randomly init particles, generate them in the center of the screen */
- particle->xpos = (iWinWidth >> 1) - 15 + (int)(14.0 * frand(2.0));
- particle->ypos = (iWinHeight >> 1) - 15 + (int)(16.0 * frand(2.0));
- particle->xdir = -xdelta + (int)(xdelta * frand(2.0));
- particle->ydir = -ydelta + (int)((ydelta / 2) * frand(2.0));
+ int v = random() % PI_2000;
+ particle->xpos = xcenter - SPREAD + (random() % (SPREAD * 2));
+ particle->ypos = ycenter - SPREAD + (random() % (SPREAD * 2));;
+ particle->xdir = sin_cache[v];
+ particle->ydir = cos_cache[v];
particle->colorindex = iColorCount;
particle->dead = 0;
}
continue;
}
- if (particles[i].xpos < 2)
+ if (particles[i].xpos < 1)
{
- particles[i].xpos = 2;
+ particles[i].xpos = 1;
particles[i].xdir = -particles[i].xdir - 4;
particles[i].colorindex = iColorCount;
}
- else if (particles[i].xpos > iWinWidth - 3)
+ else if (particles[i].xpos >= iWinWidth - 2)
{
- particles[i].xpos = iWinWidth - 3;
+ particles[i].xpos = iWinWidth - 2;
particles[i].xdir = -particles[i].xdir + 4;
particles[i].colorindex = iColorCount;
}
- if (particles[i].ypos < 2)
+ if (particles[i].ypos < 1)
{
- particles[i].ypos = 2;
+ particles[i].ypos = 1;
particles[i].ydir = -particles[i].ydir;
particles[i].colorindex = iColorCount;
}
- else if (particles[i].ypos > iWinHeight - 3)
+ else if (particles[i].ypos >= iWinHeight - 3)
{
- particles[i].ypos = iWinHeight - 3;
- particles[i].ydir = (-particles[i].ydir >> 2) - (random() % 4);
+ particles[i].ypos = iWinHeight- 3;
+ particles[i].ydir = (-particles[i].ydir >> 2) - (random() % 2);
particles[i].colorindex = iColorCount;
}
XGetWindowAttributes( pDisplay, Win, &XWinAttribs );
*piColorCount = get_integer_resource( "ncolors", "Integer" );
- if( *piColorCount < 16 ) *piColorCount = 16;
+ if( *piColorCount < 16 ) *piColorCount = 16;
if( *piColorCount > 255 ) *piColorCount = 256;
aColors = calloc( *piColorCount, sizeof(XColor) );
free( aColors );
free( aiColorVals );
(*piColorCount)--;
-
- if (*piColorCount < 6)
- {
- fprintf (stderr, "%s: insufficient colors!\n", progname);
- exit (1);
- }
-
aColors = calloc( *piColorCount, sizeof(XColor) );
aiColorVals = calloc( *piColorCount, sizeof(unsigned long) );
iColor = -1;
iWinHeight = XWinAttribs.height;
/* create fire array */
- fire = malloc( iWinHeight * sizeof(unsigned char*));
+ fire = calloc( iWinHeight, sizeof(unsigned char*));
for (i = 0; i < iWinHeight; ++i)
- fire[i] = malloc( iWinWidth * sizeof(unsigned char));
+ fire[i] = calloc( iWinWidth, sizeof(unsigned char));
/*create particles */
particles = malloc (nParticleCount * sizeof(PARTICLE));
Initialize( pDisplay, Win, &gc, &pImage );
ydelta = 0;
- while (sum < (iWinHeight >> 1) - 15)
+ while (sum < (iWinHeight >> 1) - SPREAD)
{
ydelta++;
sum += ydelta;
cycles = get_integer_resource( "cycles", "Integer" );
i = cycles;
+ cache();
+
XGetWindowAttributes( pDisplay, Win, &XWinAttribs );
XFreeColors( pDisplay, XWinAttribs.colormap, aiColorVals, iColorCount, 0 );
free( aiColorVals );
aiColorVals = SetPalette( pDisplay, Win, &iColorCount );
XClearWindow( pDisplay, Win );
+ memset( pImage->data, 0, pImage->bytes_per_line * pImage->height );
while( 1 )
- {
- screenhack_handle_events( pDisplay );
-
- if( i++ >= cycles )
- {
- for (i = 0; i < nParticleCount; i++)
- init_particle(particles + i, iColorCount - 1);
- i = 0;
- }
-
- Execute( pDisplay, Win, &gc, pImage, iColorCount - 1, aiColorVals );
-
- if( delay && !(i % 4) )
- usleep(delay);
-
+ {
+ screenhack_handle_events( pDisplay );
+
+ if( i++ >= cycles )
+ {
+ /* compute random center */
+ unsigned short xcenter, ycenter;
+ xcenter = random() % iWinWidth;
+ ycenter = random() % iWinHeight;
+
+ for (i = 0; i < nParticleCount; i++)
+ init_particle(particles + i, iColorCount - 1, xcenter, ycenter);
+ i = 0;
+ }
+
+ Execute( pDisplay, Win, &gc, pImage, iColorCount - 1, aiColorVals );
+
+ if( delay && !(i % 4) )
+ usleep(delay);
+
#ifdef VERBOSE
- iFrame++;
- if( nTime - time( NULL ) )
- {
- printf( "%s: %d FPS\n", progclass, iFrame );
- nTime = time( NULL );
- iFrame = 0;
- }
+ iFrame++;
+ if( nTime - time( NULL ) )
+ {
+ printf( "%s: %d FPS\n", progclass, iFrame );
+ nTime = time( NULL );
+ iFrame = 0;
+ }
#endif /* VERBOSE */
- }
-
+ }
+
free( pImage->data );
XDestroyImage( pImage );
free( aiColorVals );
projects / xscreensaver / blobdiff