static void _fastcall zmo_calcbf(bf_t bfdx, bf_t bfdy,
bf_t bfnewx, bf_t bfnewy,bf_t bfplotmx1, bf_t bfplotmx2, bf_t bfplotmy1,
bf_t bfplotmy2, bf_t bfftemp)
{
bf_t btmp1, btmp2, btmp3, btmp4, btempx, btempy ;
bf_t btmp2a, btmp4a;
int saved; saved = save_stack();
btmp1 = alloc_stack(rbflength+2);
btmp2 = alloc_stack(rbflength+2);
btmp3 = alloc_stack(rbflength+2);
btmp4 = alloc_stack(rbflength+2);
btmp2a = alloc_stack(rbflength+2);
btmp4a = alloc_stack(rbflength+2);
btempx = alloc_stack(rbflength+2);
btempy = alloc_stack(rbflength+2);
/* 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; */
mult_bf(btmp1,bfdy,bfplotmx1);
mult_bf(btmp2,bfdx,bfplotmx2);
sub_bf(btempx,btmp1,btmp2);
/* tempy = dx * plotmy1 - dy * plotmy2; */
mult_bf(btmp1,bfdx,bfplotmy1);
mult_bf(btmp2,bfdy,bfplotmy2);
sub_bf(btempy,btmp1,btmp2);
/* calc new corner by extending from current screen corners */
/* *newx = sxmin + tempx*(sxmax-sx3rd)/ftemp + tempy*(sx3rd-sxmin)/ftemp; */
sub_bf(btmp1,bfsxmax,bfsx3rd);
mult_bf(btmp2,btempx,btmp1);
/* show_three_bf("fact1",btempx,"fact2",btmp1,"prod ",btmp2,70); */
div_bf(btmp2a,btmp2,bfftemp);
/* show_three_bf("num ",btmp2,"denom",bfftemp,"quot ",btmp2a,70); */
sub_bf(btmp3,bfsx3rd,bfsxmin);
mult_bf(btmp4,btempy,btmp3);
div_bf(btmp4a,btmp4,bfftemp);
add_bf(bfnewx,bfsxmin,btmp2a);
add_a_bf(bfnewx,btmp4a);
/* *newy = symax + tempy*(sy3rd-symax)/ftemp + tempx*(symin-sy3rd)/ftemp; */
sub_bf(btmp1,bfsy3rd,bfsymax);
mult_bf(btmp2,btempy,btmp1);
div_bf(btmp2a,btmp2,bfftemp);
sub_bf(btmp3,bfsymin,bfsy3rd);
mult_bf(btmp4,btempx,btmp3);
div_bf(btmp4a,btmp4,bfftemp);
add_bf(bfnewy,bfsymax,btmp2a);
add_a_bf(bfnewy,btmp4a);
restore_stack(saved);
}
// for aspect ratio debugging
void showaspect(char *s)
{
bf_t bt1, bt2, aspect;
char msg[100], str[100];
int saved;
saved = save_stack();
bt1 = alloc_stack(rbflength+2);
bt2 = alloc_stack(rbflength+2);
aspect = alloc_stack(rbflength+2);
sub_bf(bt1, bfxmax, bfxmin);
sub_bf(bt2, bfymax, bfymin);
div_bf(aspect, bt2, bt1);
bftostr(str, 10, aspect);
sprintf(msg, "aspect %s\nfloat %13.10f\nbf %s\n\n",
s,
(yymax-yymin)/(xxmax-xxmin),
str);
if (stopmsg(STOPMSG_NONE, msg) == -1)
goodbye();
restore_stack(saved);
}
