/*@z34.c:Rotation Service:Declarations@***************************************/
/* */
/* THE LOUT DOCUMENT FORMATTING SYSTEM (VERSION 3.27) */
/* COPYRIGHT (C) 1991, 2002 Jeffrey H. Kingston */
/* */
/* Jeffrey H. Kingston (jeff@it.usyd.edu.au) */
/* Basser Department of Computer Science */
/* The University of Sydney 2006 */
/* AUSTRALIA */
/* */
/* This program is free software; you can redistribute it and/or modify */
/* it under the terms of the GNU General Public License as published by */
/* the Free Software Foundation; either Version 2, or (at your option) */
/* any later version. */
/* */
/* This program is distributed in the hope that it will be useful, */
/* but WITHOUT ANY WARRANTY; without even the implied warranty of */
/* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the */
/* GNU General Public License for more details. */
/* */
/* You should have received a copy of the GNU General Public License */
/* along with this program; if not, write to the Free Software */
/* Foundation, Inc., 59 Temple Place, Suite 330, Boston MA 02111-1307 USA */
/* */
/* FILE: z34.c */
/* MODULE: Rotation Service */
/* EXTERNS: RotateSize() */
/* */
/*****************************************************************************/
#include <math.h>
#ifndef M_PI
#define M_PI 3.1415926535897931160E0
#endif
#include "externs.h"
typedef struct { double x, y; } rect_coord;
typedef struct { double angle, radius; } polar_coord;
#define rect_to_polar(rect, polar) \
polar.angle = atan2(rect.y, rect.x), \
polar.radius = sqrt(rect.x*rect.x + rect.y*rect.y)
#define polar_to_rect(polar, rect) \
rect.x = polar.radius * cos(polar.angle), \
rect.y = polar.radius * sin(polar.angle)
/*@::RotateSize()@************************************************************/
/* */
/* RotateSize(xcb, xcf, xrb, xrf, y, theta) */
/* */
/* Calculate the size of x, assuming that it is y rotated by theta degrees. */
/* */
/*****************************************************************************/
void RotateSize(FULL_LENGTH *xcb, FULL_LENGTH *xcf, FULL_LENGTH *xrb,
FULL_LENGTH *xrf, OBJECT y, FULL_LENGTH theta)
{ rect_coord ycorners[4], xcorner; polar_coord pol;
double maxx, maxy, minx, miny, ang; int i;
#if DEBUG_ON
char buff1[20], buff2[20];
#endif
/* calculate theta in radians */
ang = (double) theta * 2 * M_PI / (double) (DG * 360);
ifdebug(DRS, D, sprintf(buff2, "%.1f", ang));
debug2(DRS, D, "RotateSize( %s, %s )", EchoObject(y), buff2);
debug4(DRS, DD, " ycb %s, ycf %s, yrb %s, yrf %s",
EchoLength(back(y, COLM)), EchoLength(fwd(y, COLM)),
EchoLength(back(y, ROWM)), EchoLength(fwd(y, ROWM)));
/* set up coordinates of the four corners of y */
ycorners[0].x = (float) fwd(y, COLM);
ycorners[0].y = (float) back(y, ROWM);
ycorners[1].x = - (float) back(y, COLM);
ycorners[1].y = (float) back(y, ROWM);
ycorners[2].x = - (float) back(y, COLM);
ycorners[2].y = - (float) fwd(y, ROWM);
ycorners[3].x = (float) fwd(y, COLM);
ycorners[3].y = - (float) fwd(y, ROWM);
/* rotate these four corners by theta and store their extremes */
maxx = maxy = (float) - MAX_FULL_LENGTH;
minx = miny = (float) MAX_FULL_LENGTH;
for( i = 0; i < 4; i++ )
{
if( ycorners[i].x == 0 && ycorners[i].y == 0 )
{ pol.radius = 0; pol.angle = 0; }
else rect_to_polar(ycorners[i], pol);
ifdebug(DRS, DD, sprintf(buff1, "%.1f", pol.angle));
ifdebug(DRS, DD, sprintf(buff2, "%.1f", ang));
debug5(DRS, DD, " transforming (%s, %s) -> (%s, %s) + %s",
EchoLength( (int) ycorners[i].x), EchoLength( (int) ycorners[i].y),
EchoLength( (int) pol.radius), buff1, buff2);
pol.angle += ang;
polar_to_rect(pol, xcorner);
ifdebug(DRS, DD, sprintf(buff1, "%.1f", pol.angle));
debug4(DRS, DD, " transforming (%s, %s) -> (%s, %s)",
EchoLength( (int) pol.radius), buff1,
EchoLength( (int) xcorner.x), EchoLength( (int) xcorner.y) );
maxx = find_max(maxx, xcorner.x); minx = find_min(minx, xcorner.x);
maxy = find_max(maxy, xcorner.y); miny = find_min(miny, xcorner.y);
}
/* store sizes back into x and return */
*xcb = - (int) minx; *xcf = (int) maxx;
*xrb = (int) maxy; *xrf = - (int) miny;
debug0(DRS, D, "RotateSize returning.");
debug4(DRS, DD, " xcb %s, xcf %s, xrb %s, xrf %s",
EchoLength(*xcb), EchoLength(*xcf),
EchoLength(*xrb), EchoLength(*xrf));
} /* end RotateSize */
