Category : C Source Code
Archive   : FRAC151S.ZIP
Filename : ZOOM.C

 
Output of file : ZOOM.C contained in archive : FRAC151S.ZIP

/*
zoom.c - routines for zoombox manipulation and for panning

*/

#include
#include "fractint.h"

/* screen dimensions here are (1.0,1.0) corresponding to (xdots-1,ydots-1) */
extern double zbx,zby; /* topleft of unrotated zoombox */
extern double zwidth,zdepth,zskew; /* zoombox size & shape */
extern int zrotate; /* * 2.5 degree increments */
extern int boxcount,boxx[],boxy[]; /* co-ords of each zoombox pixel */
extern int xdots,ydots,sxdots,sydots,sxoffs,syoffs;
extern double dxsize,dysize; /* xdots-1, ydots-1 */
extern double xxmin,yymin,xxmax,yymax,xx3rd,yy3rd;
extern double sxmin,symin,sxmax,symax,sx3rd,sy3rd;
/* top left corner of screen is (xxmin,yymax) */
/* bottom left corner of screen is (xx3rd,yy3rd) */
/* bottom right corner of screen is (xxmax,yymin) */
extern double plotmx1,plotmx2,plotmy1,plotmy2;

extern int calc_status; /* status of calculations */
extern int fractype; /* fractal type */
extern char stdcalcmode; /* '1', '2', 'g', 'b' */
extern int num_worklist; /* resume worklist for standard engine */
extern struct workliststuff worklist[MAXCALCWORK];
extern char dstack[4096]; /* common temp, used for get_line/put_line */
extern int StandardFractal();
extern int calcmand();
extern int potflag;
extern int pot16bit;
extern float finalaspectratio;

struct coords {
int x,y;
};

#define PIXELROUND 0.00001

static void drawlines(struct coords, struct coords, int, int);
static void addbox(struct coords);
static void zmo_calc(double, double, double *, double *);
static int check_pan();
static void fix_worklist();

void drawbox(int drawit)
{ struct coords tl,bl,tr,br; /* dot addr of topleft, botleft, etc */
double tmpx,tmpy,dx,dy,rotcos,rotsin,ftemp1,ftemp2;
double fxwidth,fxskew,fydepth,fyskew,fxadj;

if (zwidth==0) { /* no box to draw */
if (boxcount!=0) { /* remove the old box from display */
clearbox(); /* asm routine */
boxcount = 0; }
xxmin = sxmin; /* set corners to full screen and return */
xxmax = sxmax;
xx3rd = sx3rd;
yymin = symin;
yymax = symax;
yy3rd = sy3rd;
return; }

ftemp1 = PI*zrotate/72; /* convert to radians */
rotcos = cos(ftemp1); /* sin & cos of rotation */
rotsin = sin(ftemp1);

/* do some calcs just once here to reduce fp work a bit */
fxwidth = sxmax-sx3rd;
fxskew = sx3rd-sxmin;
fydepth = sy3rd-symax;
fyskew = symin-sy3rd;
fxadj = zwidth*zskew;

/* calc co-ords of topleft & botright corners of box */
tmpx = zwidth/-2+fxadj; /* from zoombox center as origin, on xdots scale */
tmpy = zdepth*finalaspectratio/2;
dx = (rotcos*tmpx - rotsin*tmpy) - tmpx; /* delta x to rotate topleft */
dy = tmpy - (rotsin*tmpx + rotcos*tmpy); /* delta y to rotate topleft */
/* calc co-ords of topleft */
ftemp1 = zbx + dx + fxadj;
ftemp2 = zby + dy/finalaspectratio;
tl.x = ftemp1*(dxsize+PIXELROUND); /* screen co-ords */
tl.y = ftemp2*(dysize+PIXELROUND);
xxmin = sxmin + ftemp1*fxwidth + ftemp2*fxskew; /* real co-ords */
yymax = symax + ftemp2*fydepth + ftemp1*fyskew;
/* calc co-ords of bottom right */
ftemp1 = zbx + zwidth - dx - fxadj;
ftemp2 = zby - dy/finalaspectratio + zdepth;
br.x = ftemp1*(dxsize+PIXELROUND);
br.y = ftemp2*(dysize+PIXELROUND);
xxmax = sxmin + ftemp1*fxwidth + ftemp2*fxskew;
yymin = symax + ftemp2*fydepth + ftemp1*fyskew;

/* do the same for botleft & topright */
tmpx = zwidth/-2 - fxadj;
tmpy = 0.0-tmpy;
dx = (rotcos*tmpx - rotsin*tmpy) - tmpx;
dy = tmpy - (rotsin*tmpx + rotcos*tmpy);
ftemp1 = zbx + dx - fxadj;
ftemp2 = zby + dy/finalaspectratio + zdepth;
bl.x = ftemp1*(dxsize+PIXELROUND);
bl.y = ftemp2*(dysize+PIXELROUND);
xx3rd = sxmin + ftemp1*fxwidth + ftemp2*fxskew;
yy3rd = symax + ftemp2*fydepth + ftemp1*fyskew;
ftemp1 = zbx + zwidth - dx + fxadj;
ftemp2 = zby - dy/finalaspectratio;
tr.x = ftemp1*(dxsize+PIXELROUND);
tr.y = ftemp2*(dysize+PIXELROUND);

if (boxcount!=0) { /* remove the old box from display */
clearbox(); /* asm routine */
boxcount = 0; }

if (drawit) { /* caller wants box drawn as well as co-ords calc'd */
/* build the list of zoom box pixels */
addbox(tl); addbox(tr); /* corner pixels */
addbox(bl); addbox(br);
drawlines(tl,tr,bl.x-tl.x,bl.y-tl.y); /* top & bottom lines */
drawlines(tl,bl,tr.x-tl.x,tr.y-tl.y); /* left & right lines */
dispbox(); /* asm routine to paint it */
}
}

static void drawlines(struct coords fr, struct coords to, int dx, int dy)
{ int xincr,yincr,ctr;
int altctr,altdec,altinc;
struct coords tmpp,line1,line2;

if (abs(to.x-fr.x) > abs(to.y-fr.y)) { /* delta.x > delta.y */
if (fr.x>to.x) { /* swap so from.x is < to.x */
tmpp = fr; fr = to; to = tmpp; }
xincr = (to.x-fr.x)*4/sxdots+1; /* do every 1st, 2nd, 3rd, or 4th dot */
ctr = (to.x-fr.x-1)/xincr;
altdec = abs(to.y-fr.y)*xincr;
altinc = to.x-fr.x;
altctr = altinc/2;
yincr = (to.y>fr.y)?1:-1;
line2.x = (line1.x = fr.x) + dx;
line2.y = (line1.y = fr.y) + dy;
while (--ctr>=0) {
line1.x += xincr;
line2.x += xincr;
altctr -= altdec;
while (altctr<0) {
altctr += altinc;
line1.y += yincr;
line2.y += yincr;
}
addbox(line1);
addbox(line2);
}
}

else { /* delta.y > delta.x */
if (fr.y>to.y) { /* swap so from.y is < to.y */
tmpp = fr; fr = to; to = tmpp; }
yincr = (to.y-fr.y)*4/sydots+1; /* do every 1st, 2nd, 3rd, or 4th dot */
ctr = (to.y-fr.y-1)/yincr;
altdec = abs(to.x-fr.x)*yincr;
altinc = to.y-fr.y;
altctr = altinc/2;
xincr = (to.x>fr.x) ? 1 : -1;
line2.x = (line1.x = fr.x) + dx;
line2.y = (line1.y = fr.y) + dy;
while (--ctr>=0) {
line1.y += yincr;
line2.y += yincr;
altctr -= altdec;
while (altctr<0) {
altctr += altinc;
line1.x += xincr;
line2.x += xincr;
}
addbox(line1);
addbox(line2);
}
}
}

static void addbox(struct coords point)
{
point.x += sxoffs;
point.y += syoffs;
if (point.x >= 0 && point.x < sxdots && point.y >= 0 && point.y < sydots) {
boxx[boxcount] = point.x;
boxy[boxcount] = point.y;
++boxcount;
}
}

void moveboxf(double dx, double dy)
{ int align,row,col;
align = check_pan();
if (dx!=0.0) {
if ((zbx += dx) + zwidth/2 < 0) /* center must stay onscreen */
zbx = zwidth/-2;
if (zbx + zwidth/2 > 1)
zbx = 1.0 - zwidth/2;
if (align != 0
&& ((col = zbx*(dxsize+PIXELROUND)) & (align-1)) != 0) {
if (dx > 0) col += align;
col -= col & (align-1); /* adjust col to pass alignment */
zbx = (double)col/dxsize; }
}
if (dy!=0.0) {
if ((zby += dy) + zdepth/2 < 0)
zby = zdepth/-2;
if (zby + zdepth/2 > 1)
zby = 1.0 - zdepth/2;
if (align != 0
&& ((row = zby*(dysize+PIXELROUND)) & (align-1)) != 0) {
if (dy > 0) row += align;
row -= row & (align-1);
zby = (double)row/dysize; }
}
}

static void chgboxf(double dwidth, double ddepth)
{
if (zwidth+dwidth > 1)
dwidth = 1.0-zwidth;
if (zwidth+dwidth < 0.05)
dwidth = 0.05-zwidth;
zwidth += dwidth;
if (zdepth+ddepth > 1)
ddepth = 1.0-zdepth;
if (zdepth+ddepth < 0.05)
ddepth = 0.05-zdepth;
zdepth += ddepth;
moveboxf(dwidth/-2,ddepth/-2); /* keep it centered & check limits */
}

void resizebox(int steps)
{
double deltax,deltay;
if (zdepth*SCREENASPECT > zwidth) { /* box larger on y axis */
deltay = steps * 0.036 / SCREENASPECT;
deltax = zwidth * deltay / zdepth;
}
else { /* box larger on x axis */
deltax = steps * 0.036;
deltay = zdepth * deltax / zwidth;
}
chgboxf(deltax,deltay);
}

void chgboxi(int dw, int dd)
{ /* change size by pixels */
chgboxf( (double)dw/dxsize, (double)dd/dysize );
}

void zoomout() /* for ctl-enter, calc corners for zooming out */
{ double savxxmin,savyymax,ftemp;
/* (xxmin,yymax), etc, are already set to zoombox corners;
(sxmin,symax), etc, are still the screen's corners;
use the same logic as plot_orbit stuff to first calculate current screen
corners relative to the zoombox, as if the zoombox were a square with
upper left (0,0) and width/depth 1; ie calc the current screen corners
as if plotting them from the zoombox;
then extend these co-ords from current real screen corners to get
new actual corners
*/
ftemp = (yymin-yy3rd)*(xx3rd-xxmin) - (xxmax-xx3rd)*(yy3rd-yymax);
plotmx1 = (xx3rd-xxmin) / ftemp; /* reuse the plotxxx vars is safe */
plotmx2 = (yy3rd-yymax) / ftemp;
plotmy1 = (yymin-yy3rd) / ftemp;
plotmy2 = (xxmax-xx3rd) / ftemp;
savxxmin = xxmin; savyymax = yymax;
zmo_calc(sxmin-savxxmin,symax-savyymax,&xxmin,&yymax); /* new xxmin/xxmax */
zmo_calc(sxmax-savxxmin,symin-savyymax,&xxmax,&yymin);
zmo_calc(sx3rd-savxxmin,sy3rd-savyymax,&xx3rd,&yy3rd);
}

static void zmo_calc(double dx, double dy, double *newx, double *newy)
{ double tempx,tempy;
/* calc cur screen corner relative to zoombox, when zoombox co-ords
are taken as (0,0) topleft thru (1,1) bottom right */
tempx = dy * plotmx1 - dx * plotmx2;
tempy = dx * plotmy1 - dy * plotmy2;
/* calc new corner by extending from current screen corners */
*newx = sxmin + tempx*(sxmax-sx3rd) + tempy*(sx3rd-sxmin);
*newy = symax + tempy*(sy3rd-symax) + tempx*(symin-sy3rd);
}

void aspectratio_crop(float oldaspect,float newaspect)
{
double ftemp,xmargin,ymargin;
if (newaspect > oldaspect) { /* new ratio is taller, crop x */
ftemp = (1.0 - oldaspect / newaspect) / 2;
xmargin = (xxmax - xx3rd) * ftemp;
ymargin = (yymin - yy3rd) * ftemp;
xx3rd += xmargin;
yy3rd += ymargin;
}
else { /* new ratio is wider, crop y */
ftemp = (1.0 - newaspect / oldaspect) / 2;
xmargin = (xx3rd - xxmin) * ftemp;
ymargin = (yy3rd - yymax) * ftemp;
xx3rd -= xmargin;
yy3rd -= ymargin;
}
xxmin += xmargin;
yymax += ymargin;
xxmax -= xmargin;
yymin -= ymargin;
}

static int check_pan() /* return 0 if can't, alignment requirement if can */
{ int i,j;
if (calc_status != 2 && calc_status != 4)
return(0); /* not resumable, not complete */
if ( fractalspecific[fractype].calctype != StandardFractal
&& fractalspecific[fractype].calctype != calcmand)
return(0); /* not a worklist-driven type */
if (zwidth != 1.0 || zdepth != 1.0 || zskew != 0.0 || zrotate != 0.0)
return(0); /* not a full size unrotated unskewed zoombox */
/* can pan if we get this far */
if (calc_status == 4)
return(1); /* image completed, align on any pixel */
if (potflag && pot16bit)
return(1); /* 1 pass forced so align on any pixel */
if (stdcalcmode == 'b')
return(1); /* btm, align on any pixel */
if (stdcalcmode != 'g' || (fractalspecific[fractype].flags&NOGUESS)) {
if (stdcalcmode == '2') /* align on even pixel for 2pass */
return(2);
return(1); /* assume 1pass */
}
/* solid guessing */
start_resume();
get_resume(sizeof(int),&num_worklist,sizeof(worklist),worklist,0);
/* don't do end_resume! we're just looking */
i = 9;
for (j=0; j if (worklist[j].pass < i)
i = worklist[j].pass;
j = ssg_blocksize(); /* worst-case alignment requirement */
while (--i >= 0)
j = j>>1; /* reduce requirement */
return(j);
}

static void move_row(fromrow,torow,col) /* move a row on the screen */
{ int startcol,endcol,tocol;
memset(dstack,0,xdots); /* use dstack as a temp for the row; clear it */
if (fromrow >= 0 && fromrow < ydots) {
tocol = startcol = 0;
endcol = xdots-1;
if (col < 0) {
tocol -= col;
endcol += col; }
if (col > 0)
startcol += col;
get_line(fromrow,startcol,endcol,&dstack[tocol]);
}
put_line(torow,0,xdots-1,dstack);
}

init_pan_or_recalc(zoomout) /* decide to recalc, or to chg worklist & pan */
{ int i,j,row,col,y,alignmask,direction,listfull;
if (zwidth == 0.0)
return(0); /* no zoombox, leave calc_status as is */
/* got a zoombox */
if ((alignmask=check_pan()-1) < 0) {
calc_status = 0; /* can't pan, trigger recalc */
return(0); }
if (zbx == 0.0 && zby == 0.0) {
clearbox();
return(0); } /* box is full screen, leave calc_status as is */
col = zbx*(dxsize+PIXELROUND); /* calc dest col,row of topleft pixel */
row = zby*(dysize+PIXELROUND);
if (zoomout) { /* invert row and col */
row = 0-row;
col = 0-col; }
if ((row&alignmask) != 0 || (col&alignmask) != 0) {
calc_status = 0; /* not on useable pixel alignment, trigger recalc */
return(0); }
/* pan */
num_worklist = 0;
if (calc_status == 2) {
start_resume();
get_resume(sizeof(int),&num_worklist,sizeof(worklist),worklist,0);
} /* don't do end_resume! we might still change our mind */
/* adjust existing worklist entries */
for (i=0; i worklist[i].yystart -= row;
worklist[i].yystop -= row;
worklist[i].yybegin -= row;
worklist[i].xxstart -= col;
worklist[i].xxstop -= col;
}
/* add worklist entries for the new edges */
listfull = i = 0;
j = ydots-1;
if (row < 0) {
listfull |= add_worklist(0,xdots-1,0,0-row-1,0,0,0);
i = 0 - row; }
if (row > 0) {
listfull |= add_worklist(0,xdots-1,ydots-row,ydots-1,ydots-row,0,0);
j = ydots - row - 1; }
if (col < 0)
listfull |= add_worklist(0,0-col-1,i,j,i,0,0);
if (col > 0)
listfull |= add_worklist(xdots-col,xdots-1,i,j,i,0,0);
if (listfull != 0) {
if (stopmsg(2,"\
Tables full, can't pan current image.\n\
Cancel resumes old image, continue pans and calculates a new one.")) {
zwidth = 0; /* cancel the zoombox */
drawbox(1); }
else
calc_status = 0; /* trigger recalc */
return(0); }
/* now we're committed */
calc_status = 2;
clearbox();
if (row > 0) /* move image up */
for (y=0; y else /* move image down */
for (y=ydots; --y>=0;) move_row(y+row,y,col);
fix_worklist(); /* fixup any out of bounds worklist entries */
alloc_resume(sizeof(worklist)+10,1); /* post the new worklist */
put_resume(sizeof(int),&num_worklist,sizeof(worklist),worklist,0);
return(0);
}

static void restart_window(int wknum) /* force a worklist entry to restart */
{ int i,yfrom,yto,xfrom,xto;
if ((yfrom = worklist[wknum].yystart) < 0) yfrom = 0;
if ((xfrom = worklist[wknum].xxstart) < 0) xfrom = 0;
if ((yto = worklist[wknum].yystop) >= ydots) yto = ydots - 1;
if ((xto = worklist[wknum].xxstop) >= xdots) xto = xdots - 1;
memset(dstack,0,xdots); /* use dstack as a temp for the row; clear it */
while (yfrom <= yto)
put_line(yfrom++,xfrom,xto,dstack);
worklist[wknum].sym = worklist[wknum].pass = 0;
worklist[wknum].yybegin = worklist[wknum].yystart;
}

static void fix_worklist() /* fix out of bounds and symmetry related stuff */
{ int i,j,k;
struct workliststuff *wk;
for (i=0; i wk = &worklist[i];
if ( wk->yystart >= ydots || wk->yystop < 0
|| wk->xxstart >= xdots || wk->xxstop < 0) { /* offscreen, delete */
for (j=i+1; j worklist[j-1] = worklist[j];
--num_worklist;
--i;
continue; }
if (wk->yystart < 0) /* partly off top edge */
if ((wk->sym&1) == 0) /* no sym, easy */
wk->yystart = 0;
else { /* xaxis symmetry */
if ((j = wk->yystop + wk->yystart) > 0
&& num_worklist < MAXCALCWORK) { /* split the sym part */
worklist[num_worklist] = worklist[i];
worklist[num_worklist].yystart = 0;
worklist[num_worklist++].yystop = j;
wk->yystart = j+1; }
else
wk->yystart = 0;
restart_window(i); /* restart the no-longer sym part */
}
if (wk->yystop >= ydots) { /* partly off bottom edge */
j = ydots-1;
if ((wk->sym&1) != 0) { /* uses xaxis symmetry */
if ((k = wk->yystart + (wk->yystop - j)) < j)
if (num_worklist >= MAXCALCWORK) /* no room to split */
restart_window(i);
else { /* split it */
worklist[num_worklist] = worklist[i];
worklist[num_worklist].yystart = k;
worklist[num_worklist++].yystop = j;
j = k-1; }
wk->sym &= -1 - 1; }
wk->yystop = j; }
if (wk->xxstart < 0) /* partly off left edge */
if ((wk->sym&2) == 0) /* no sym, easy */
wk->xxstart = 0;
else { /* yaxis symmetry */
if ((j = wk->xxstop + wk->xxstart) > 0
&& num_worklist < MAXCALCWORK) { /* split the sym part */
worklist[num_worklist] = worklist[i];
worklist[num_worklist].xxstart = 0;
worklist[num_worklist++].xxstop = j;
wk->xxstart = j+1; }
else
wk->xxstart = 0;
restart_window(i); /* restart the no-longer sym part */
}
if (wk->xxstop >= xdots) { /* partly off right edge */
j = xdots-1;
if ((wk->sym&2) != 0) { /* uses xaxis symmetry */
if ((k = wk->xxstart + (wk->xxstop - j)) < j)
if (num_worklist >= MAXCALCWORK) /* no room to split */
restart_window(i);
else { /* split it */
worklist[num_worklist] = worklist[i];
worklist[num_worklist].xxstart = k;
worklist[num_worklist++].xxstop = j;
j = k-1; }
wk->sym &= -1 - 2; }
wk->xxstop = j; }
if (wk->yybegin < wk->yystart) wk->yybegin = wk->yystart;
if (wk->yybegin > wk->yystop) wk->yybegin = wk->yystop;
}
tidy_worklist(); /* combine where possible, re-sort */
}