--- /dev/null
+/* Eruption, Copyright (c) 2002-2003 W.P. van Paassen <peter@paassen.tmfweb.nl>
+ *
+ * Permission to use, copy, modify, distribute, and sell this software and its
+ * documentation for any purpose is hereby granted without fee, provided that
+ * the above copyright notice appear in all copies and that both that
+ * copyright notice and this permission notice appear in supporting
+ * documentation. No representations are made about the suitability of this
+ * software for any purpose. It is provided "as is" without express or
+ * implied warranty.
+ *
+ * Module - "eruption.c"
+ *
+ * [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)
+ */
+
+#include <math.h>
+#include "screenhack.h"
+#include <X11/Xutil.h>
+
+/*#define VERBOSE*/
+
+char *progclass = "Eruption";
+
+char *defaults [] = {
+ ".background: black",
+ ".foreground: white",
+ "*cycles: 80",
+ "*ncolors: 256",
+ "*delay: 5000",
+ "*particles: 300",
+ "*cooloff: 2",
+ "*gravity: 1",
+ "*heat: 256",
+ 0
+};
+
+XrmOptionDescRec options [] = {
+ { "-ncolors", ".ncolors", XrmoptionSepArg, 0 },
+ { "-delay", ".delay", XrmoptionSepArg, 0 },
+ { "-cycles", ".cycles", XrmoptionSepArg, 0 },
+ { "-particles", ".particles", XrmoptionSepArg, 0 },
+ { "-cooloff", ".cooloff", XrmoptionSepArg, 0 },
+ { "-gravity", ".gravity", XrmoptionSepArg, 0 },
+ { "-heat", ".heat", XrmoptionSepArg, 0 },
+ { 0, 0, 0, 0 }
+};
+
+/*particle structure*/
+typedef struct
+{
+ short xpos, ypos, xdir, ydir;
+ unsigned char colorindex;
+ unsigned char dead;
+} PARTICLE;
+
+static PARTICLE *particles;
+static unsigned short iWinWidth, iWinHeight;
+static unsigned char **fire;
+static unsigned short nParticleCount;
+static unsigned char xdelta, ydelta, decay;
+static signed char gravity;
+static signed short heat;
+
+void init_particle(PARTICLE* particle, signed short iColorCount)
+{
+ /* 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));
+ particle->colorindex = iColorCount;
+ particle->dead = 0;
+}
+
+static void Execute( Display *pDisplay,
+ Window MainWindow,
+ GC *pGC, XImage *pImage,
+ signed short iColorCount, unsigned long *aiColorVals )
+{
+ int i, j;
+ unsigned int temp;
+
+ /* move and draw particles into fire array */
+
+ for (i = 0; i < nParticleCount; i++)
+ {
+ if (!particles[i].dead)
+ {
+ particles[i].xpos += particles[i].xdir;
+ particles[i].ypos += particles[i].ydir;
+
+ /* is particle dead? */
+
+ if (particles[i].colorindex == 0)
+ {
+ particles[i].dead = 1;
+ continue;
+ }
+
+ if (particles[i].xpos < 2)
+ {
+ particles[i].xpos = 2;
+ particles[i].xdir = -particles[i].xdir - 4;
+ particles[i].colorindex = iColorCount;
+ }
+ else if (particles[i].xpos > iWinWidth - 3)
+ {
+ particles[i].xpos = iWinWidth - 3;
+ particles[i].xdir = -particles[i].xdir + 4;
+ particles[i].colorindex = iColorCount;
+ }
+
+ if (particles[i].ypos < 2)
+ {
+ particles[i].ypos = 2;
+ particles[i].ydir = -particles[i].ydir;
+ particles[i].colorindex = iColorCount;
+ }
+ else if (particles[i].ypos > iWinHeight - 3)
+ {
+ particles[i].ypos = iWinHeight - 3;
+ particles[i].ydir = (-particles[i].ydir >> 2) - (random() % 4);
+ particles[i].colorindex = iColorCount;
+ }
+
+ /* gravity kicks in */
+ particles[i].ydir += gravity;
+
+ /* particle cools off */
+ particles[i].colorindex--;
+
+ /* draw particle */
+ fire[particles[i].ypos][particles[i].xpos] = particles[i].colorindex;
+ fire[particles[i].ypos][particles[i].xpos - 1] = particles[i].colorindex;
+ fire[particles[i].ypos + 1][particles[i].xpos] = particles[i].colorindex;
+ fire[particles[i].ypos - 1][particles[i].xpos] = particles[i].colorindex;
+ fire[particles[i].ypos][particles[i].xpos + 1] = particles[i].colorindex;
+ }
+ }
+
+ /* create fire effect */
+ for (i = 0; i < iWinHeight; i++)
+ {
+ for (j = 0; j < iWinWidth; j++)
+ {
+ if (j + 1 >= iWinWidth)
+ temp = 0;
+ else
+ temp = fire[i][j + 1];
+
+ if (j - 1 >= 0)
+ temp += fire[i][j - 1];
+
+ if (i - 1 >= 0)
+ {
+ temp += fire[i - 1][j];
+ if (j - 1 >= 0)
+ temp += fire[i - 1][j - 1];
+ if (j + 1 < iWinWidth)
+ temp += fire[i - 1][j + 1];
+ }
+
+ if (i + 1 < iWinHeight)
+ {
+ temp += fire[i + 1][j];
+ if (j + 1 < iWinWidth)
+ temp += fire[i + 1][j + 1];
+ if (j - 1 >= 0)
+ temp += fire[i + 1][j - 1];
+ }
+
+ temp >>= 3;
+
+ if (temp > decay)
+ {
+ temp -= decay;
+ }
+ else
+ temp = 0;
+
+ fire[i][j] = temp;
+ }
+ }
+
+ memset( pImage->data, 0, pImage->bytes_per_line * pImage->height );
+
+ /* draw fire array to screen */
+ for (i = 0; i < iWinHeight; ++i)
+ {
+ for (j = 0; j < iWinWidth; ++j)
+ {
+ if (fire[i][j] > 0)
+ XPutPixel( pImage, j, i, aiColorVals[ fire[i][j] ] );
+ }
+ }
+ XPutImage( pDisplay, MainWindow, *pGC, pImage,
+ 0,0,0,0, iWinWidth, iWinHeight );
+ XSync( pDisplay, False );
+}
+
+static unsigned long * SetPalette(Display *pDisplay, Window Win, signed short *piColorCount )
+{
+ XWindowAttributes XWinAttribs;
+ XColor Color, *aColors;
+ unsigned long *aiColorVals;
+ signed short iColor;
+
+ XGetWindowAttributes( pDisplay, Win, &XWinAttribs );
+
+ *piColorCount = get_integer_resource( "ncolors", "Integer" );
+ if( *piColorCount < 16 ) *piColorCount = 16;
+ if( *piColorCount > 255 ) *piColorCount = 256;
+
+ aColors = calloc( *piColorCount, sizeof(XColor) );
+ aiColorVals = calloc( *piColorCount, sizeof(unsigned long) );
+
+ Color.red = Color.green = Color.blue = 65535 / *piColorCount;
+
+ /* create fire palette */
+ for( iColor=0; iColor < *piColorCount; iColor++ )
+ {
+ if (iColor < *piColorCount >> 3)
+ {
+ /* black to blue */
+ aColors[iColor].red = 0;
+ aColors[iColor].green = 0;
+ aColors[iColor].blue = Color.blue * (iColor << 1);
+ }
+ else if (iColor < *piColorCount >> 2)
+ {
+ /* blue to red */
+ signed short temp = (iColor - (*piColorCount >> 3));
+ aColors[iColor].red = Color.red * (temp << 3);
+ aColors[iColor].green = 0;
+ aColors[iColor].blue = 16383 - Color.blue * (temp << 1);
+ }
+ else if (iColor < (*piColorCount >> 2) + (*piColorCount >> 3))
+ {
+ /* red to yellow */
+ signed short temp = (iColor - (*piColorCount >> 2)) << 3;
+ aColors[iColor].red = 65535;
+ aColors[iColor].green = Color.green * temp;
+ aColors[iColor].blue = 0;
+ }
+ else if (iColor < *piColorCount >> 1)
+ {
+ /* yellow to white */
+ signed int temp = (iColor - ((*piColorCount >> 2) + (*piColorCount >> 3))) << 3;
+ aColors[iColor].red = 65535;
+ aColors[iColor].green = 65535;
+ aColors[iColor].blue = Color.blue * temp;
+ }
+ else
+ {
+ /* white */
+ aColors[iColor].red = aColors[iColor].green = aColors[iColor].blue = 65535;
+ }
+
+ if( !XAllocColor( pDisplay, XWinAttribs.colormap, &aColors[ iColor ] ) )
+ {
+ /* start all over with less colors */
+ XFreeColors( pDisplay, XWinAttribs.colormap, aiColorVals, iColor, 0 );
+ 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;
+ }
+ else
+ aiColorVals[ iColor ] = aColors[ iColor ].pixel;
+ }
+
+ if (heat < *piColorCount)
+ *piColorCount = heat;
+
+ free( aColors );
+
+ XSetWindowBackground( pDisplay, Win, aiColorVals[ 0 ] );
+
+ return aiColorVals;
+}
+
+
+static void Initialize( Display *pDisplay, Window Win, GC *pGC, XImage **ppImage )
+{
+ XGCValues gcValues;
+ XWindowAttributes XWinAttribs;
+ int iBitsPerPixel, i;
+
+ /* Create the Image for drawing */
+ XGetWindowAttributes( pDisplay, Win, &XWinAttribs );
+
+ /* Find the preferred bits-per-pixel. (jwz) */
+ {
+ int i, pfvc = 0;
+ XPixmapFormatValues *pfv = XListPixmapFormats( pDisplay, &pfvc );
+ for( i=0; i<pfvc; i++ )
+ if( pfv[ i ].depth == XWinAttribs.depth )
+ {
+ iBitsPerPixel = pfv[ i ].bits_per_pixel;
+ break;
+ }
+ if( pfv )
+ XFree (pfv);
+ }
+
+ /* Create the GC. */
+ *pGC = XCreateGC( pDisplay, Win, 0, &gcValues );
+
+ *ppImage = XCreateImage( pDisplay, XWinAttribs.visual, XWinAttribs.depth, ZPixmap, 0, NULL,
+ XWinAttribs.width, XWinAttribs.height, BitmapPad( pDisplay ), 0 );
+ (*ppImage)->data = calloc((*ppImage)->bytes_per_line, (*ppImage)->height);
+
+ iWinWidth = XWinAttribs.width;
+ iWinHeight = XWinAttribs.height;
+
+ /* create fire array */
+ fire = malloc( iWinHeight * sizeof(unsigned char*));
+ for (i = 0; i < iWinHeight; ++i)
+ fire[i] = malloc( iWinWidth * sizeof(unsigned char));
+
+ /*create particles */
+ particles = malloc (nParticleCount * sizeof(PARTICLE));
+}
+
+void screenhack(Display *pDisplay, Window Win )
+{
+ XWindowAttributes XWinAttribs;
+ GC gc;
+ signed short iColorCount = 0;
+ unsigned long *aiColorVals = NULL;
+ unsigned short sum = 0;
+ XImage *pImage = NULL;
+#ifdef VERBOSE
+ time_t nTime = time( NULL );
+ unsigned short iFrame = 0;
+#endif /* VERBOSE */
+ int delay, cycles, i;
+
+ nParticleCount = get_integer_resource( "particles", "Integer" );
+ if (nParticleCount < 100)
+ nParticleCount = 100;
+ if (nParticleCount > 2000)
+ nParticleCount = 2000;
+
+ decay = get_integer_resource( "cooloff", "Integer" );
+ if (decay <= 0)
+ decay = 0;
+ if (decay > 10)
+ decay = 10;
+
+ gravity = get_integer_resource( "gravity", "Integer" );
+ if (gravity < -5)
+ gravity = -5;
+ if (gravity > 5)
+ gravity = 5;
+
+ heat = get_integer_resource( "heat", "Integer" );
+ if (heat < 64)
+ heat = 64;
+ if (heat > 256)
+ heat = 256;
+
+#ifdef VERBOSE
+ printf( "%s: Allocated %d particles\n", progclass, nParticleCount );
+#endif /* VERBOSE */
+
+ Initialize( pDisplay, Win, &gc, &pImage );
+
+ ydelta = 0;
+ while (sum < (iWinHeight >> 1) - 15)
+ {
+ ydelta++;
+ sum += ydelta;
+ }
+
+ sum = 0;
+ while (sum < (iWinWidth >> 3))
+ {
+ xdelta++;
+ sum += xdelta;
+ }
+
+ delay = get_integer_resource( "delay", "Integer" );
+ cycles = get_integer_resource( "cycles", "Integer" );
+ i = cycles;
+
+ XGetWindowAttributes( pDisplay, Win, &XWinAttribs );
+ XFreeColors( pDisplay, XWinAttribs.colormap, aiColorVals, iColorCount, 0 );
+ free( aiColorVals );
+ aiColorVals = SetPalette( pDisplay, Win, &iColorCount );
+ XClearWindow( pDisplay, Win );
+
+ 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);
+
+#ifdef VERBOSE
+ 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 );
+ for (i = 0; i < iWinHeight; ++i)
+ free( fire[i] );
+ free( fire );
+ free( particles );
+}
+
+/* End of Module - "eruption.c" */
+
projects / xscreensaver / blobdiff