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#include <stdio.h>
#include <math.h>
#include <stdlib.h>
#ifndef vms
#include <malloc.h>
#endif
/* use this to change if you want ripples with more than 256 colors */
#define RIPPLE_USES char
#include <X11/Xlib.h>
#include <X11/Xutil.h>
#include "xb_config.h"
#include "xbanner.h"
static XImage *ximg;
static unsigned RIPPLE_USES *rimg;
/* Ripple routines */
#define rputpixel(ARRAY,XL,YL,PIXEL) (ARRAY)[(XL)+((YL)*(ri->width))]=(PIXEL)
#define rgetpixel(ARRAY,XL,YL) (ARRAY)[(XL)+((YL)*(ri->width))]
/* define frand() */
#ifdef linux
#define frand() drand48()
#else
#ifdef OTHER_FRAND
#define frand() OTHER_FRAND()
#else
#define frand() (((double)rand())/(double)RAND_MAX)
#endif
#endif
static _inline int PDist(XPoint p, int x, int y,float scale)
{
return (int) (
sqrt(
(float)
(
(p.x-x) * (p.x-x) +
(p.y-y) * (p.y-y)
)
)*scale + frand()
);
}
/* main ripple drawing thingy */
Stat DoRipples(Display *disp, Ripple_Info *ri)
{
int p, x, y, v, scrn_no, depth, bpp;
float *scales;
XPoint *pt_list;
scrn_no = DefaultScreen(disp);
depth = DisplayPlanes(disp,scrn_no);
bpp = (depth/sizeof(char)) + (depth%sizeof(char)>0?1:0);
/* first create an XImage by copying the root window */
ximg = XCreateImage(disp,DefaultVisual(disp,0),DefaultDepth(disp,0),
ZPixmap,0,(char*)malloc(bpp*(ri->width)*(ri->height)),
ri->width,ri->height,BitmapPad(disp),0);
if(ximg == NULL)
{
error(disp,mgc,"Could not get XImage for Ripples effect",False);
return XIMAGE;
}
/* now get an image where the ripples take place */
rimg = (unsigned char *)calloc(ri->width,ri->height);
if(rimg == NULL)
{
error(disp,mgc,"Could not allocate memory for Ripples effect RImage",False);
XDestroyImage(ximg);
return NOMEM;
}
/* now create the ripple centers list */
pt_list = (XPoint*)calloc(ri->ripples,sizeof(XPoint));
if(pt_list == NULL)
{
error(disp,mgc,"Could not allocate memory for Ripple centers list",False);
XDestroyImage(ximg);
free(rimg);
return NOMEM;
}
/* now create the ripple "speeds" list */
scales = (float*)calloc(ri->ripples,sizeof(float));
if(scales == NULL)
{
error(disp,mgc,"Could not allocate memory for Ripple speeds list",False);
XDestroyImage(ximg);
free(rimg);
free(pt_list);
return NOMEM;
}
/* choose the centers by random and random speeds */
for(x=0;x<ri->ripples;x++)
{
scales[x] = (x+frand()+0.5)/3.0;
pt_list[x].x = rand()%ri->width;
pt_list[x].y = rand()%ri->height;
}
/* main loop */
for(y=0;y<ri->height;y++) /* for every pixel in the drawable */
for(x=0;x<ri->width;x++)
{
p = rand()%ri->ripples;
v = PDist(pt_list[p],x,y,scales[p]);
rputpixel(rimg,x,y,((ri->colors)-1-(v%ri->colors)));
}
/* copy the RImage to the XImage... */
for(y=0;y<ri->height;y++)
for(x=0;x<ri->width;x++)
XPutPixel(ximg,x,y,(ri->grad)->grad[rgetpixel(rimg,x,y)].pixel);
/* copy the XImage back to the drawable */
XPutImage(disp,ri->d,ri->gc,ximg,0,0,0,0,ri->width,ri->height);
/* free the resources */
XDestroyImage(ximg);
return OK;
}
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