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/* Copyright (c) 1986 Regents of the University of California */ |
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|
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#ifndef lint |
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static char SCCSid[] = "$SunId$ LBL"; |
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#endif |
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|
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/* |
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* cone.c - routines for making cones |
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* |
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* 2/12/86 |
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*/ |
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|
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#include "standard.h" |
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|
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#include "object.h" |
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|
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#include "otypes.h" |
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|
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#include "cone.h" |
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|
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/* |
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* In general, a cone may be any one of a cone, a cylinder, a ring, |
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* a cup (inverted cone), or a tube (inverted cylinder). |
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* Most cones are specified with a starting point and radius and |
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* an ending point and radius. In the cases of a cylinder or tube, |
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* only one radius is needed. In the case of a ring, a normal direction |
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* is specified instead of a second endpoint. |
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* |
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* mtype (cone|cup) name |
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* 0 |
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* 0 |
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* 8 P0x P0y P0z P1x P1y P1z R0 R1 |
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* |
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* mtype (cylinder|tube) name |
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* 0 |
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* 0 |
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* 7 P0x P0y P0z P1x P1y P1z R |
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* |
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* mtype ring name |
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* 0 |
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* 0 |
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* 8 Px Py Pz Nx Ny Nz R0 R1 |
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*/ |
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|
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|
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CONE * |
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getcone(o, getxf) /* get cone structure */ |
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register OBJREC *o; |
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int getxf; |
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{ |
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double fabs(), sqrt(); |
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register CONE *co; |
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|
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if ((co = (CONE *)o->os) == NULL) { |
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|
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co = (CONE *)malloc(sizeof(CONE)); |
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if (co == NULL) |
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error(SYSTEM, "out of memory in makecone"); |
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|
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co->ca = o->oargs.farg; |
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/* get radii */ |
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if (o->otype == OBJ_CYLINDER || o->otype == OBJ_TUBE) { |
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if (o->oargs.nfargs != 7) |
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goto argcerr; |
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if (co->ca[6] <= FTINY) |
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goto raderr; |
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co->r0 = co->r1 = 6; |
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} else { |
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if (o->oargs.nfargs != 8) |
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goto argcerr; |
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if (co->ca[6] < 0.0 || co->ca[7] < 0.0) |
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goto raderr; |
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if (fabs(co->ca[7] - co->ca[6]) <= FTINY) |
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goto raderr; |
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co->r0 = 6; |
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co->r1 = 7; |
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} |
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/* get axis orientation */ |
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co->p0 = 0; |
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if (o->otype == OBJ_RING) { |
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if (co->ca[6] > co->ca[7]) { /* make r0 smaller */ |
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co->r0 = 7; |
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co->r1 = 6; |
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} |
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co->p1 = 0; |
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VCOPY(co->ad, o->oargs.farg+3); |
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} else { |
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co->p1 = 3; |
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co->ad[0] = co->ca[3] - co->ca[0]; |
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co->ad[1] = co->ca[4] - co->ca[1]; |
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co->ad[2] = co->ca[5] - co->ca[2]; |
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} |
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co->al = normalize(co->ad); |
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if (co->al == 0.0) |
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objerror(o, USER, "zero orientation"); |
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/* compute axis and side lengths */ |
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if (o->otype == OBJ_RING) { |
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co->al = 0.0; |
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co->sl = co->ca[co->r1] - co->ca[co->r0]; |
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} else if (o->otype == OBJ_CONE || o->otype == OBJ_CUP) { |
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co->sl = co->ca[7] - co->ca[6]; |
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co->sl = sqrt(co->sl*co->sl + co->al*co->al); |
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} else { /* OBJ_CYLINDER || OBJ_TUBE */ |
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co->sl = co->al; |
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} |
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co->tm = NULL; |
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o->os = (char *)co; |
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} |
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if (getxf && co->tm == NULL) |
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conexform(co); |
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return(co); |
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|
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argcerr: |
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objerror(o, USER, "bad # arguments"); |
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raderr: |
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objerror(o, USER, "illegal radii"); |
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} |
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|
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|
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freecone(o) /* free memory associated with cone */ |
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OBJREC *o; |
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{ |
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register CONE *co = (CONE *)o->os; |
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|
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if (co->tm != NULL) |
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free((char *)co->tm); |
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free(o->os); |
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o->os = NULL; |
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} |
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|
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|
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conexform(co) /* get cone transformation matrix */ |
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register CONE *co; |
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{ |
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double sqrt(), fabs(); |
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double m4[4][4]; |
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register double d; |
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register int i; |
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|
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co->tm = (double (*)[4])malloc(sizeof(m4)); |
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if (co->tm == NULL) |
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error(SYSTEM, "out of memory in conexform"); |
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|
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/* translate to origin */ |
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setident4(co->tm); |
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if (co->r0 == co->r1) |
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d = 0.0; |
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else |
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d = co->ca[co->r0] / (co->ca[co->r1] - co->ca[co->r0]); |
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for (i = 0; i < 3; i++) |
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co->tm[3][i] = d*(co->ca[co->p1+i] - co->ca[co->p0+i]) |
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- co->ca[co->p0+i]; |
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|
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/* rotate to positive z-axis */ |
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setident4(m4); |
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d = co->ad[1]*co->ad[1] + co->ad[2]*co->ad[2]; |
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if (d <= FTINY*FTINY) { |
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m4[0][0] = 0.0; |
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m4[0][2] = co->ad[0]; |
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m4[2][0] = -co->ad[0]; |
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m4[2][2] = 0.0; |
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} else { |
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d = sqrt(d); |
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m4[0][0] = d; |
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m4[1][0] = -co->ad[0]*co->ad[1]/d; |
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m4[2][0] = -co->ad[0]*co->ad[2]/d; |
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m4[1][1] = co->ad[2]/d; |
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m4[2][1] = -co->ad[1]/d; |
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m4[0][2] = co->ad[0]; |
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m4[1][2] = co->ad[1]; |
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m4[2][2] = co->ad[2]; |
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} |
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multmat4(co->tm, co->tm, m4); |
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|
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/* scale z-axis */ |
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setident4(m4); |
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if (co->p0 != co->p1 && co->r0 != co->r1) { |
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d = fabs(co->ca[co->r1] - co->ca[co->r0]); |
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m4[2][2] = d/co->al; |
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} |
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multmat4(co->tm, co->tm, m4); |
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} |