/* zoom.c: * * zoom an image * * jim frost 10.11.89 * * Copyright 1989 Jim Frost.  See included file "copyright.h" for complete * copyright information. */#ifdef SCCS    static char *sccs_id = "@(#)zoom.c	1.1  10/13/90";#endif#include "copyright.h"#include "image.h"static unsigned int *buildIndex(width, zoom, rwidth)     unsigned int  width;     unsigned int  zoom;     unsigned int *rwidth;{ float         fzoom;  unsigned int *index;  unsigned int  a;  if (!zoom) {    fzoom= 100.0;    *rwidth= width;  }  else {    fzoom= (float)zoom / 100.0;    *rwidth= fzoom * width;  }  index= (unsigned int *)lmalloc(sizeof(unsigned int) * *rwidth);  for (a= 0; a < *rwidth; a++)    if (zoom)      *(index + a)= (float)a / fzoom;    else      *(index + a)= a;  return(index);}Image *zoom(oimage, xzoom, yzoom, verbose)     Image        *oimage;     unsigned int  xzoom, yzoom;{ char          buf[BUFSIZ];  Image        *image;  unsigned int *xindex, *yindex;  unsigned int  xwidth, ywidth;  unsigned int  x, y, xsrc, ysrc;  unsigned int  pixlen;  unsigned int  srclinelen;  unsigned int  destlinelen;  byte         *srcline, *srcptr;  byte         *destline, *destptr;  byte          srcmask, destmask, bit;  Pixel         value;  goodImage(oimage, "zoom");  if (!xzoom && !yzoom) /* stupid user */    return(NULL);  if (!xzoom) {    if (verbose)      printf("  Zooming image Y axis by %d%%...", yzoom);      sprintf(buf, "%s (Y zoom %d%%)", oimage->title, yzoom);  }  else if (!yzoom) {    if (verbose)      printf("  Zooming image X axis by %d%%...", xzoom);    sprintf(buf, "%s (X zoom %d%%)", oimage->title, xzoom);  }  else if (xzoom == yzoom) {    if (verbose)      printf("  Zooming image by %d%%...", xzoom);    sprintf(buf, "%s (%d%% zoom)", oimage->title, xzoom);  }  else {    if (verbose)      printf("  Zooming image X axis by %d%% and Y axix by %d%%...",	     xzoom, yzoom);    sprintf(buf, "%s (X zoom %d%% Y zoom %d%%)", oimage->title,	    xzoom, yzoom);  }  if (verbose)    fflush(stdout);  xindex= buildIndex(oimage->width, xzoom, &xwidth);  yindex= buildIndex(oimage->height, yzoom, &ywidth);  switch (oimage->type) {  case IBITMAP:    image= newBitImage(xwidth, ywidth);    for (x= 0; x < oimage->rgb.used; x++) {      *(image->rgb.red + x)= *(oimage->rgb.red + x);      *(image->rgb.green + x)= *(oimage->rgb.green + x);      *(image->rgb.blue + x)= *(oimage->rgb.blue + x);    }    image->rgb.used= oimage->rgb.used;    destline= image->data;    destlinelen= (xwidth / 8) + (xwidth % 8 ? 1 : 0);    srcline= oimage->data;    srclinelen= (oimage->width / 8) + (oimage->width % 8 ? 1 : 0);    for (y= 0, ysrc= *(yindex + y); y < ywidth; y++) {      while (ysrc != *(yindex + y)) {	ysrc++;	srcline += srclinelen;      }      srcptr= srcline;      destptr= destline;      srcmask= 0x80;      destmask= 0x80;      bit= srcmask & *srcptr;      for (x= 0, xsrc= *(xindex + x); x < xwidth; x++) {	if (xsrc != *(xindex + x)) {	  do {	    xsrc++;	    if (!(srcmask >>= 1)) {	      srcmask= 0x80;	      srcptr++;	    }	  } while (xsrc != *(xindex + x));	  bit= srcmask & *srcptr;	}	if (bit)	  *destptr |= destmask;	if (!(destmask >>= 1)) {	  destmask= 0x80;	  destptr++;	}      }      destline += destlinelen;    }    break;  case IRGB:    image= newRGBImage(xwidth, ywidth, oimage->depth);    for (x= 0; x < oimage->rgb.used; x++) {      *(image->rgb.red + x)= *(oimage->rgb.red + x);      *(image->rgb.green + x)= *(oimage->rgb.green + x);      *(image->rgb.blue + x)= *(oimage->rgb.blue + x);    }    image->rgb.used= oimage->rgb.used;    pixlen= oimage->pixlen;    destptr= image->data;    srcline= oimage->data;    srclinelen= oimage->width * pixlen;    for (y= 0, ysrc= *(yindex + y); y < ywidth; y++) {      while (ysrc != *(yindex + y)) {	ysrc++;	srcline += srclinelen;      }      srcptr= srcline;      value= memToVal(srcptr, pixlen);      for (x= 0, xsrc= *(xindex + x); x < xwidth; x++) {	if (xsrc != *(xindex + x)) {	  do {	    xsrc++;	    srcptr += image->pixlen;	  } while (xsrc != *(xindex + x));	  value= memToVal(srcptr, pixlen);	}	valToMem(value, destptr++, pixlen);      }    }    break;  }  image->title= dupString(buf);  lfree((byte *)xindex);  lfree((byte *)yindex);  if (verbose)    printf("done\n");  return(image);}