/* Copyright 1986, 1988, 1989, 1990 by Abacus Research and
 * Development, Inc.  All rights reserved.
 */

#if !defined (OMIT_RCSID_STRINGS)
char ROMlib_rcsid_qStdArc[] =
	    "$Id: qStdArc.c 63 2004-12-24 18:19:43Z ctm $";
#endif

/* Forward declarations in QuickDraw.h (DO NOT DELETE THIS LINE) */

#include "rsys/common.h"
#include "QuickDraw.h"
#include "CQuickDraw.h"
#include "MemoryMgr.h"
#include "ToolboxUtil.h"

#include "rsys/cquick.h"
#include "rsys/picture.h"

#define returnhv(hh, vv)    { ptp->h = hh; ptp->v = vv; return; }

A3(PRIVATE, void, getpoint, INTEGER, angle, Rect *, r, Point *, ptp)
{
    INTEGER left  = CW(r->left),  top    = CW(r->top),
            right = CW(r->right), bottom = CW(r->bottom);
    INTEGER radh = (right - left) / 2,
            radv = (bottom - top) / 2;
    INTEGER centh = left + radh,
            centv = top  + radv;
    
    MoveTo(centh, centv);
    if (angle == 0) {
/*-->*/ returnhv(centh, top)
    } else if (angle == 90) {
/*-->*/ returnhv(right, centv)
    } else if (angle == 180) {
/*-->*/ returnhv(centh, bottom)
    } else if (angle == 270) {
/*-->*/ returnhv(left, centv)
    } else if (angle >=  45 && angle <= 135) {
/*-->*/ returnhv(right, centv - (INTEGER)(FixMul(SlopeFromAngle(90-angle),
                                    -(LONGINT) radv << 16) >> 16))
    } else if (angle >= 225 && angle <= 315) {
/*-->*/ returnhv(left, centv + (INTEGER)(FixMul(SlopeFromAngle(90-angle),
                                    -(LONGINT) radv << 16) >> 16))
    } else if (angle < 45 || angle > 315) {
/*-->*/ returnhv(centh + (INTEGER)(FixMul(SlopeFromAngle(angle),
                                    -(LONGINT) radh << 16) >> 16), top)
    } else {
/*-->*/ returnhv(centh - (INTEGER)(FixMul(SlopeFromAngle(angle),
                                    -(LONGINT) radh << 16) >> 16), bottom)
    }
}

#define RTop    0
#define RRight  1
#define RBottom 2
#define RLeft   3

A3(PRIVATE, INTEGER, findwall, Rect *, r, INTEGER, h, INTEGER, v)
{
    if (v == CW(r->top))            /* the order of tests is important */
        return(RTop);           /* don't change them if you don't see */
    else if (h == CW(r->right))     /* why */
        return(RRight);
    else if (v == CW(r->bottom))
        return(RBottom);
    else
        return(RLeft);
}

P4 (PUBLIC pascal trap, void, StdArc, GrafVerb, verb, Rect *, r,
    INTEGER, starta, INTEGER, arca)
{
  INTEGER left  = CW(r->left),  top    = CW(r->top),
          right = CW(r->right), bottom = CW(r->bottom);
  INTEGER ewall;
  Point spt, ept;
  register INTEGER h, v;
  INTEGER enda;
  INTEGER done;
  RgnHandle saveclip, rh;
  Point saveloc;
  INTEGER tmpvis;
  INTEGER swappedarca, swappedstarta;
  PAUSEDECL;
  
  if (EmptyRect(r))
/*-->*/	return;

  if (arca <= -360 || arca >= 360)
    {
      StdOval(verb, r);
/*-->*/ return;
    }

  PIC_SAVE_EXCURSION
    ({
      ROMlib_drawingverbrectpicupdate( verb, r );
      PICOP(OP_frameArc + (int) verb);
      PICWRITE(r, sizeof(*r));
      swappedstarta = CW(starta);
      PICWRITE(&swappedstarta, sizeof(swappedstarta));
      swappedarca = CW(arca);
      PICWRITE(&swappedarca, sizeof(swappedarca));
    });
  
  if (PORT_PEN_VIS (thePort) < 0)
/*-->*/ return;
  saveloc = PORT_PEN_LOC (thePort);
  PAUSERECORDING;
  tmpvis = PORT_PEN_VIS_X (thePort);
  PORT_PEN_VIS_X (thePort) = CWC (0);
  OpenRgn ();
    enda = starta + arca;
    if (arca < 0) {
        arca = starta;  /* use arca as a temp... not needed anymore */
        starta = enda;
        enda = arca;
    }
    while (starta < 0)
        starta += 360;
    while (enda   < 0)
        enda   += 360;
    starta %= 360;
    enda   %= 360;
    
    getpoint(starta, r, &spt);
    getpoint(enda,   r, &ept);

    MoveTo(left + (right - left) / 2, top + (bottom - top) / 2);
            
    ewall = findwall(r, ept.h, ept.v);
    LineTo(h = spt.h, v = spt.v);

    for (done = FALSE; !done;)  
        switch (findwall(r, h, v)) {
        case RTop:
            if (ewall == RTop && h <= ept.h) {
                LineTo(ept.h, top);
                done = TRUE;
                break;
            }
            LineTo(h = right, v = top);
        case RRight:
            if (ewall == RRight && v <= ept.v) {
                LineTo(right, ept.v);
                done = TRUE;
                break;
            }
            LineTo(h = right, v = bottom);
        case RBottom:
            if (ewall == RBottom && h >= ept.h) {
                LineTo(ept.h, bottom);
                done = TRUE;
                break;
            }
            LineTo(h = left, v = bottom);
        case RLeft:
            if (ewall == RLeft && v >= ept.v) {
                LineTo(left, ept.v);
                done = TRUE;
                break;
            }
            LineTo(h = left, v = top);
        }
        
  LineTo (left + (right - left) / 2, top + (bottom - top) / 2);
  rh = NewRgn();
  CloseRgn (rh);
  PORT_PEN_VIS_X (thePort) = tmpvis;
  saveclip = PORT_CLIP_REGION_X (thePort);
  SectRgn (MR (saveclip), rh, rh);
  PORT_CLIP_REGION_X (thePort) = RM (rh);
  StdOval (verb, r);
  PORT_CLIP_REGION_X (thePort) = saveclip;
  DisposeRgn (rh);
  RESUMERECORDING;
  PORT_PEN_LOC (thePort) = saveloc;
}