Usenet 1994 January/usenetsourcesnewsgroupsinfomagicjanuary1994.iso/sources/unix/volume10/lemming/part02/lemspecial.c

C/C++ Source or Header | 1987-08-05 | 4.3 KB | 221 lines

/*
 * lemspecial.c - extra functions for random applications
 *
 * copyright (c) by Alan W. Paeth, 1987. All rights reserved.
 */

#include "lem.h"
#include <math.h>

specialfunc()
    {
    char ch;
    msgpost("<F>lip <C>cw <M>agnify <R>otate <S>tretch <A>lign: ");
    ch = getstroke();
    switch(UC(ch))
    {
    case 'F': flip(); break;
    case 'C': ccw(); break;
    case 'M': magnify(); break;
    case 'R': rotate(); break;
    case 'S': stretch(); break;
    case 'A': align(); break;
    default: msgpost("unknown transformation"); break;
    }
    }

transform(m11, m12, m21, m22)
    float m11, m12, m21, m22;
    {
    int i;
/*
 * record inverse transformation and set undo flag for undoing
 */
    undo = UNDOAFF;
    unx = markx;
    uny = marky;
    un11 = m11;
    un12 = m12;
    un21 = m21;
    un22 = m22;
/*
 * now do the transformations
 */
 forobjects
    {
    if (Osel)
        {
        objectop(i, SEL, DEL);
        objmove(i, -markx, -marky);
        objaffine(i, m11, m12, m21, m22);
        objmove(i,  markx,  marky);
        objresize(i);
        objectop(i, DEL, SEL);
        }
    }
    }

flip()
    {
    if (markon)
    {
    transform(-1.0, 0.0, 0.0, 1.0, 1);
    msgpost("flip done");
    }
    else msgpost("flip -- no mark present");
    }

ccw()
    {
    if (markon)
    {
    transform(0.0, -1.0, 1.0, 0.0, 0);
    msgpost("ccw turn done");
    }
    else msgpost("ccw -- no mark present");
    }

magnify()
    {
    int x1, y1, x2, y2, xs, ys, xe, ye;
    float mag, outlen;
    if (findmark(&x1, &y1, &x2, &y2))
    {
    xs = x2-markx;
    ys = y2-marky;
    xe = x1-markx;
    ye = y1-marky;
    outlen = xs*xs+ys*ys;
    if (outlen != 0.0)
        {
        mag = sqrt((float)(xe*xe+ye*ye)/outlen);
        mag = (mag < 0.1) ? 0.1 : (mag > 10.0 ? 10.0 : mag);
        transform(mag, 0.0, 0.0, mag, 1);
        msgpost("magnify done");
        }
    msgpost("null magnify ignored");
    }
    }

stretch()
    {
    int x1, y1, x2, y2, xs, ys, xe, ye;
    float xmag, ymag;
    if (findmark(&x1, &y1, &x2, &y2))
    {
    xs = x2-markx;
    ys = y2-marky;
    xe = x1-markx;
    ye = y1-marky;
    xmag = (xs == 0) ? 1.0 : (float)(xe)/xs;
    ymag = (ys == 0) ? 1.0 : (float)(ye)/ys;
    xmag = (xmag < 0.1) ? 0.1 : (xmag > 10.0 ? 10.0 : xmag);
    ymag = (ymag < 0.1) ? 0.1 : (ymag > 10.0 ? 10.0 : ymag);
    transform(xmag, 0.0, 0.0, ymag, 1);
    msgpost("stretch done");
    }
    }

rotate()
    {
    int x1, y1, x2, y2, xs, ys, xe, ye;
    float s, c, hy;
    if (findmark(&x1, &y1, &x2, &y2))
    {
    xs = x2-markx;
    ys = y2-marky;
    xe = x1-markx;
    ye = y1-marky;
    hy = sqrt((float)( (xs*xs + ys*ys) * (xe*xe + ye*ye) ));
    if (hy != 0.0)
        {
        c =  (xs*xe+ys*ye)/hy;
        s =  (xs*ye-xe*ys)/hy;
        transform(c, -s, s, c, 0);
        msgpost("rotate done");
        }
    else msgpost("null rotation ignored");
    }
    }

align()
    {
    int x1, y1, x2, y2, xs, ys, xe, ye, scale;
    float m11, m12, m21, m22, det;
    if (findmark(&x1, &y1, &x2, &y2))
    {
    xs = x2-markx;
    ys = y2-marky;
    xe = x1-markx;
    ye = y1-marky;
    scale = MAX(MAX(ABS(xs),ABS(ys)),MAX(ABS(xe),ABS(ye)));
    det = xe*ys - xs*ye;
    m11 = (float)( ys*scale)/det;
    m12 = (float)(-xs*scale)/det;
    m21 = (float)(-ye*scale)/det;
    m22 = (float)( xe*scale)/det;
    transform(m11, m12, m21, m22, 1);
    msgpost("align done");
    }
    }

findmark(x1, y1, x2, y2)
    int *x1, *y1, *x2, *y2;
    {
    int i, s, e, arrow, straight;
    arrow = straight = 0;
    if (!markon)
    {
    msgpost("transform: no mark present");
    return(0);
    }
    else
    {
    forobjects
        {
        if (Otype != LINE) continue;
        s = (Oxs == markx) && (Oys == marky);
        e = (Oxe == markx) && (Oye == marky);
        if (s || e)
        {
        switch (Oalign)
            {
case ALIGNCENT:        *x1 = s ? Oxe : Oxs;
            *y1 = s ? Oye : Oys;
            straight++;
            break;
case ALIGNLEFT:        if (s)
            {
            msgpost("transform: arrowhead at origin");
            return(0);
            }
            *x2 = Oxs;
            *y2 = Oys;
            arrow++;
            break;
case ALIGNRGHT:        if (e)
            {
            msgpost("transform: arrowhead at origin");
            return(0);
            }
            *x2 = Oxe;
            *y2 = Oye;
            arrow++;
            break;
            }
        }
        }
    }
    if ((arrow == 1) && (straight == 1)) return(1);
/*
 * errors
 */
    if (arrow+straight == 0)
    msgpost("transform: no basis vectors at mark");
    else if (arrow != 1)
    msgpost("transform: exactly one arrow basis vector needed");
    else if (straight != 1)
    msgpost("transform: exactly one non-arrow basis vector needed");
    return(0);
    }