1 3ebbd193 2017-06-19 rsc #include	<stdio.h>
  2 3ebbd193 2017-06-19 rsc #include	<math.h>
  3 3ebbd193 2017-06-19 rsc #include	"pic.h"
  4 3ebbd193 2017-06-19 rsc #include	"y.tab.h"
  5 3ebbd193 2017-06-19 rsc 
  6 3ebbd193 2017-06-19 rsc void arc_extreme(double, double, double, double, double, double);
  7 3ebbd193 2017-06-19 rsc int quadrant(double x, double y);
  8 3ebbd193 2017-06-19 rsc 
  9 3ebbd193 2017-06-19 rsc obj *arcgen(int type)	/* handles circular and (eventually) elliptical arcs */
 10 3ebbd193 2017-06-19 rsc {
 11 3ebbd193 2017-06-19 rsc 	static double prevw = HT10;
 12 3ebbd193 2017-06-19 rsc 	static double prevh = HT5;
 13 3ebbd193 2017-06-19 rsc 	static double prevrad = HT2;
 14 3ebbd193 2017-06-19 rsc 	static int dtox[2][4] ={ { 1, -1, -1, 1}, {1, 1, -1, -1} };
 15 3ebbd193 2017-06-19 rsc 	static int dtoy[2][4] ={ {1, 1, -1, -1}, {-1, 1, 1, -1} };
 16 3ebbd193 2017-06-19 rsc 	static int dctrx[2][4] ={ {0, -1, 0, 1}, {0, 1, 0, -1} };
 17 3ebbd193 2017-06-19 rsc 	static int dctry[2][4] ={ {1, 0, -1, 0}, {-1, 0, 1, 0} };
 18 3ebbd193 2017-06-19 rsc 	static int nexthv[2][4] ={ {U_DIR, L_DIR, D_DIR, R_DIR}, {D_DIR, R_DIR, U_DIR, L_DIR} };
 19 3ebbd193 2017-06-19 rsc 	double dx2, dy2, ht, phi, r, d;
 20 3ebbd193 2017-06-19 rsc 	int i, head, to, at, cw, invis, ddtype, battr;
 21 3ebbd193 2017-06-19 rsc 	obj *p, *ppos;
 22 3ebbd193 2017-06-19 rsc 	double fromx, fromy, tox, toy, fillval = 0;
 23 3ebbd193 2017-06-19 rsc 	Attr *ap;
 24 3ebbd193 2017-06-19 rsc 
 25 3ebbd193 2017-06-19 rsc 	tox=toy=0.0; /* Botch? (gcc) */
 26 3ebbd193 2017-06-19 rsc 
 27 3ebbd193 2017-06-19 rsc 	prevrad = getfval("arcrad");
 28 3ebbd193 2017-06-19 rsc 	prevh = getfval("arrowht");
 29 3ebbd193 2017-06-19 rsc 	prevw = getfval("arrowwid");
 30 3ebbd193 2017-06-19 rsc 	fromx = curx;
 31 3ebbd193 2017-06-19 rsc 	fromy = cury;
 32 3ebbd193 2017-06-19 rsc 	head = to = at = cw = invis = ddtype = battr = 0;
 33 3ebbd193 2017-06-19 rsc 	for (i = 0; i < nattr; i++) {
 34 3ebbd193 2017-06-19 rsc 		ap = &attr[i];
 35 3ebbd193 2017-06-19 rsc 		switch (ap->a_type) {
 36 3ebbd193 2017-06-19 rsc 		case TEXTATTR:
 37 3ebbd193 2017-06-19 rsc 			savetext(ap->a_sub, ap->a_val.p);
 38 3ebbd193 2017-06-19 rsc 			break;
 39 3ebbd193 2017-06-19 rsc 		case HEAD:
 40 3ebbd193 2017-06-19 rsc 			head += ap->a_val.i;
 41 3ebbd193 2017-06-19 rsc 			break;
 42 3ebbd193 2017-06-19 rsc 		case INVIS:
 43 3ebbd193 2017-06-19 rsc 			invis = INVIS;
 44 3ebbd193 2017-06-19 rsc 			break;
 45 3ebbd193 2017-06-19 rsc 		case HEIGHT:	/* length of arrowhead */
 46 3ebbd193 2017-06-19 rsc 			prevh = ap->a_val.f;
 47 3ebbd193 2017-06-19 rsc 			break;
 48 3ebbd193 2017-06-19 rsc 		case WIDTH:	/* width of arrowhead */
 49 3ebbd193 2017-06-19 rsc 			prevw = ap->a_val.f;
 50 3ebbd193 2017-06-19 rsc 			break;
 51 3ebbd193 2017-06-19 rsc 		case RADIUS:
 52 3ebbd193 2017-06-19 rsc 			prevrad = ap->a_val.f;
 53 3ebbd193 2017-06-19 rsc 			break;
 54 3ebbd193 2017-06-19 rsc 		case DIAMETER:
 55 3ebbd193 2017-06-19 rsc 			prevrad = ap->a_val.f / 2;
 56 3ebbd193 2017-06-19 rsc 			break;
 57 3ebbd193 2017-06-19 rsc 		case CW:
 58 3ebbd193 2017-06-19 rsc 			cw = 1;
 59 3ebbd193 2017-06-19 rsc 			break;
 60 3ebbd193 2017-06-19 rsc 		case FROM:	/* start point of arc */
 61 3ebbd193 2017-06-19 rsc 			ppos = ap->a_val.o;
 62 3ebbd193 2017-06-19 rsc 			fromx = ppos->o_x;
 63 3ebbd193 2017-06-19 rsc 			fromy = ppos->o_y;
 64 3ebbd193 2017-06-19 rsc 			break;
 65 3ebbd193 2017-06-19 rsc 		case TO:	/* end point of arc */
 66 3ebbd193 2017-06-19 rsc 			ppos = ap->a_val.o;
 67 3ebbd193 2017-06-19 rsc 			tox = ppos->o_x;
 68 3ebbd193 2017-06-19 rsc 			toy = ppos->o_y;
 69 3ebbd193 2017-06-19 rsc 			to++;
 70 3ebbd193 2017-06-19 rsc 			break;
 71 3ebbd193 2017-06-19 rsc 		case AT:	/* center of arc */
 72 3ebbd193 2017-06-19 rsc 			ppos = ap->a_val.o;
 73 3ebbd193 2017-06-19 rsc 			curx = ppos->o_x;
 74 3ebbd193 2017-06-19 rsc 			cury = ppos->o_y;
 75 3ebbd193 2017-06-19 rsc 			at = 1;
 76 3ebbd193 2017-06-19 rsc 			break;
 77 3ebbd193 2017-06-19 rsc 		case UP:
 78 3ebbd193 2017-06-19 rsc 			hvmode = U_DIR;
 79 3ebbd193 2017-06-19 rsc 			break;
 80 3ebbd193 2017-06-19 rsc 		case DOWN:
 81 3ebbd193 2017-06-19 rsc 			hvmode = D_DIR;
 82 3ebbd193 2017-06-19 rsc 			break;
 83 3ebbd193 2017-06-19 rsc 		case RIGHT:
 84 3ebbd193 2017-06-19 rsc 			hvmode = R_DIR;
 85 3ebbd193 2017-06-19 rsc 			break;
 86 3ebbd193 2017-06-19 rsc 		case LEFT:
 87 3ebbd193 2017-06-19 rsc 			hvmode = L_DIR;
 88 3ebbd193 2017-06-19 rsc 			break;
 89 3ebbd193 2017-06-19 rsc 		case FILL:
 90 3ebbd193 2017-06-19 rsc 			battr |= FILLBIT;
 91 3ebbd193 2017-06-19 rsc 			if (ap->a_sub == DEFAULT)
 92 3ebbd193 2017-06-19 rsc 				fillval = getfval("fillval");
 93 3ebbd193 2017-06-19 rsc 			else
 94 3ebbd193 2017-06-19 rsc 				fillval = ap->a_val.f;
 95 3ebbd193 2017-06-19 rsc 			break;
 96 3ebbd193 2017-06-19 rsc 		}
 97 3ebbd193 2017-06-19 rsc 	}
 98 3ebbd193 2017-06-19 rsc 	if (!at && !to) {	/* the defaults are mostly OK */
 99 3ebbd193 2017-06-19 rsc 		curx = fromx + prevrad * dctrx[cw][hvmode];
100 3ebbd193 2017-06-19 rsc 		cury = fromy + prevrad * dctry[cw][hvmode];
101 3ebbd193 2017-06-19 rsc 		tox = fromx + prevrad * dtox[cw][hvmode];
102 3ebbd193 2017-06-19 rsc 		toy = fromy + prevrad * dtoy[cw][hvmode];
103 3ebbd193 2017-06-19 rsc 		hvmode = nexthv[cw][hvmode];
104 3ebbd193 2017-06-19 rsc 	}
105 3ebbd193 2017-06-19 rsc 	else if (!at) {
106 3ebbd193 2017-06-19 rsc 		dx2 = (tox - fromx) / 2;
107 3ebbd193 2017-06-19 rsc 		dy2 = (toy - fromy) / 2;
108 3ebbd193 2017-06-19 rsc 		phi = atan2(dy2, dx2) + (cw ? -PI/2 : PI/2);
109 3ebbd193 2017-06-19 rsc 		if (prevrad <= 0.0)
110 3ebbd193 2017-06-19 rsc 			prevrad = dx2*dx2+dy2*dy2;
111 3ebbd193 2017-06-19 rsc 		for (r=prevrad; (d = r*r - (dx2*dx2+dy2*dy2)) <= 0.0; r *= 2)
112 3ebbd193 2017-06-19 rsc 			;	/* this kludge gets around too-small radii */
113 3ebbd193 2017-06-19 rsc 		prevrad = r;
114 3ebbd193 2017-06-19 rsc 		ht = sqrt(d);
115 3ebbd193 2017-06-19 rsc 		curx = fromx + dx2 + ht * cos(phi);
116 3ebbd193 2017-06-19 rsc 		cury = fromy + dy2 + ht * sin(phi);
117 3ebbd193 2017-06-19 rsc 		dprintf("dx2,dy2=%g,%g, phi=%g, r,ht=%g,%g\n",
118 3ebbd193 2017-06-19 rsc 			dx2, dy2, phi, r, ht);
119 3ebbd193 2017-06-19 rsc 	}
120 3ebbd193 2017-06-19 rsc 	else if (at && !to) {	/* do we have all the cases??? */
121 3ebbd193 2017-06-19 rsc 		tox = fromx + prevrad * dtox[cw][hvmode];
122 3ebbd193 2017-06-19 rsc 		toy = fromy + prevrad * dtoy[cw][hvmode];
123 3ebbd193 2017-06-19 rsc 		hvmode = nexthv[cw][hvmode];
124 3ebbd193 2017-06-19 rsc 	}
125 3ebbd193 2017-06-19 rsc 	if (cw) {	/* interchange roles of from-to and heads */
126 3ebbd193 2017-06-19 rsc 		double temp;
127 3ebbd193 2017-06-19 rsc 		temp = fromx; fromx = tox; tox = temp;
128 3ebbd193 2017-06-19 rsc 		temp = fromy; fromy = toy; toy = temp;
129 3ebbd193 2017-06-19 rsc 		if (head == HEAD1)
130 3ebbd193 2017-06-19 rsc 			head = HEAD2;
131 3ebbd193 2017-06-19 rsc 		else if (head == HEAD2)
132 3ebbd193 2017-06-19 rsc 			head = HEAD1;
133 3ebbd193 2017-06-19 rsc 	}
134 3ebbd193 2017-06-19 rsc 	p = makenode(type, 7);
135 3ebbd193 2017-06-19 rsc 	arc_extreme(fromx, fromy, tox, toy, curx, cury);
136 3ebbd193 2017-06-19 rsc 	p->o_val[0] = fromx;
137 3ebbd193 2017-06-19 rsc 	p->o_val[1] = fromy;
138 3ebbd193 2017-06-19 rsc 	p->o_val[2] = tox;
139 3ebbd193 2017-06-19 rsc 	p->o_val[3] = toy;
140 3ebbd193 2017-06-19 rsc 	if (cw) {
141 3ebbd193 2017-06-19 rsc 		curx = fromx;
142 3ebbd193 2017-06-19 rsc 		cury = fromy;
143 3ebbd193 2017-06-19 rsc 	} else {
144 3ebbd193 2017-06-19 rsc 		curx = tox;
145 3ebbd193 2017-06-19 rsc 		cury = toy;
146 3ebbd193 2017-06-19 rsc 	}
147 3ebbd193 2017-06-19 rsc 	p->o_val[4] = prevw;
148 3ebbd193 2017-06-19 rsc 	p->o_val[5] = prevh;
149 3ebbd193 2017-06-19 rsc 	p->o_val[6] = prevrad;
150 3ebbd193 2017-06-19 rsc 	p->o_attr = head | (cw ? CW_ARC : 0) | invis | ddtype | battr;
151 3ebbd193 2017-06-19 rsc 	p->o_fillval = fillval;
152 3ebbd193 2017-06-19 rsc 	if (head)
153 3ebbd193 2017-06-19 rsc 		p->o_nhead = getfval("arrowhead");
154 3ebbd193 2017-06-19 rsc 	dprintf("arc rad %g at %g %g from %g %g to %g %g head %g %g\n",
155 3ebbd193 2017-06-19 rsc 		prevrad, p->o_x, p->o_y,
156 3ebbd193 2017-06-19 rsc 		p->o_val[0], p->o_val[1], p->o_val[2], p->o_val[3], p->o_val[4], p->o_val[5]);
157 3ebbd193 2017-06-19 rsc 	return(p);
158 3ebbd193 2017-06-19 rsc }
159 3ebbd193 2017-06-19 rsc 
160 3ebbd193 2017-06-19 rsc /***************************************************************************
161 3ebbd193 2017-06-19 rsc    bounding box of a circular arc             Eric Grosse  24 May 84
162 3ebbd193 2017-06-19 rsc 
163 3ebbd193 2017-06-19 rsc Conceptually, this routine generates a list consisting of the start,
164 3ebbd193 2017-06-19 rsc end, and whichever north, east, south, and west points lie on the arc.
165 3ebbd193 2017-06-19 rsc The bounding box is then the range of this list.
166 3ebbd193 2017-06-19 rsc     list = {start,end}
167 3ebbd193 2017-06-19 rsc     j = quadrant(start)
168 3ebbd193 2017-06-19 rsc     k = quadrant(end)
169 3ebbd193 2017-06-19 rsc     if( j==k && long way 'round )  append north,west,south,east
170 3ebbd193 2017-06-19 rsc     else
171 3ebbd193 2017-06-19 rsc       while( j != k )
172 3ebbd193 2017-06-19 rsc          append center+radius*[j-th of north,west,south,east unit vectors]
173 3ebbd193 2017-06-19 rsc          j += 1  (mod 4)
174 3ebbd193 2017-06-19 rsc     return( bounding box of list )
175 3ebbd193 2017-06-19 rsc The following code implements this, with simple optimizations.
176 3ebbd193 2017-06-19 rsc ***********************************************************************/
177 3ebbd193 2017-06-19 rsc 
178 3ebbd193 2017-06-19 rsc 
179 3ebbd193 2017-06-19 rsc void arc_extreme(double x0, double y0, double x1, double y1, double xc, double yc)
180 3ebbd193 2017-06-19 rsc 			  /* start, end, center */
181 3ebbd193 2017-06-19 rsc {
182 3ebbd193 2017-06-19 rsc 	/* assumes center isn't too far out */
183 3ebbd193 2017-06-19 rsc 	double r, xmin, ymin, xmax, ymax;
184 3ebbd193 2017-06-19 rsc 	int j, k;
185 3ebbd193 2017-06-19 rsc 	x0 -= xc; y0 -= yc;	/* move to center */
186 3ebbd193 2017-06-19 rsc 	x1 -= xc; y1 -= yc;
187 3ebbd193 2017-06-19 rsc 	xmin = (x0<x1)?x0:x1; ymin = (y0<y1)?y0:y1;
188 3ebbd193 2017-06-19 rsc 	xmax = (x0>x1)?x0:x1; ymax = (y0>y1)?y0:y1;
189 3ebbd193 2017-06-19 rsc 	r = sqrt(x0*x0 + y0*y0);
190 3ebbd193 2017-06-19 rsc 	if (r > 0.0) {
191 3ebbd193 2017-06-19 rsc 		j = quadrant(x0,y0);
192 3ebbd193 2017-06-19 rsc 		k = quadrant(x1,y1);
193 3ebbd193 2017-06-19 rsc 		if (j == k && y1*x0 < x1*y0) {
194 3ebbd193 2017-06-19 rsc 			/* viewed as complex numbers, if Im(z1/z0)<0, arc is big */
195 3ebbd193 2017-06-19 rsc 			if( xmin > -r) xmin = -r; if( ymin > -r) ymin = -r;
196 3ebbd193 2017-06-19 rsc 			if( xmax <  r) xmax =  r; if( ymax <  r) ymax =  r;
197 3ebbd193 2017-06-19 rsc 		} else {
198 3ebbd193 2017-06-19 rsc 			while (j != k) {
199 3ebbd193 2017-06-19 rsc 				switch (j) {
200 3ebbd193 2017-06-19 rsc 					case 1: if( ymax <  r) ymax =  r; break; /* north */
201 3ebbd193 2017-06-19 rsc 					case 2: if( xmin > -r) xmin = -r; break; /* west */
202 3ebbd193 2017-06-19 rsc 					case 3: if( ymin > -r) ymin = -r; break; /* south */
203 3ebbd193 2017-06-19 rsc 					case 4: if( xmax <  r) xmax =  r; break; /* east */
204 3ebbd193 2017-06-19 rsc 				}
205 3ebbd193 2017-06-19 rsc 				j = j%4 + 1;
206 3ebbd193 2017-06-19 rsc 			}
207 3ebbd193 2017-06-19 rsc 		}
208 3ebbd193 2017-06-19 rsc 	}
209 3ebbd193 2017-06-19 rsc 	xmin += xc; ymin += yc;
210 3ebbd193 2017-06-19 rsc 	xmax += xc; ymax += yc;
211 3ebbd193 2017-06-19 rsc 	extreme(xmin, ymin);
212 3ebbd193 2017-06-19 rsc 	extreme(xmax, ymax);
213 3ebbd193 2017-06-19 rsc }
214 3ebbd193 2017-06-19 rsc 
215 3ebbd193 2017-06-19 rsc int
216 3ebbd193 2017-06-19 rsc quadrant(double x, double y)
217 3ebbd193 2017-06-19 rsc {
218 3ebbd193 2017-06-19 rsc 	if (     x>=0.0 && y> 0.0) return(1);
219 3ebbd193 2017-06-19 rsc 	else if( x< 0.0 && y>=0.0) return(2);
220 3ebbd193 2017-06-19 rsc 	else if( x<=0.0 && y< 0.0) return(3);
221 3ebbd193 2017-06-19 rsc 	else if( x> 0.0 && y<=0.0) return(4);
222 3ebbd193 2017-06-19 rsc 	else			   return 0;	/* shut up lint */
223 3ebbd193 2017-06-19 rsc }