1 #include	<math.h>
2 #include	<stdio.h>
3 #include	"pic.h"
4 #include	"y.tab.h"
5 
6 obj*
7 linegen(int type)
8 {
9 	static double prevdx = HT;
10 	static double prevdy = 0;
11 	static double prevw = HT10;
12 	static double prevh = HT5;
13 	int i, j, some, head, ddtype, invis, chop;
14 	double ddval, chop1, chop2, x0, y0, x1, y1;
15 	double theta;
16 	double defx, defy;
17 	obj *p, *ppos;
18 	static int xtab[] = { 1, 0, -1, 0 };	/* R=0, U=1, L=2, D=3 */
19 	static int ytab[] = { 0, 1, 0, -1 };
20 	double dx[500], dy[500];
21 	int ndxy;
22 	double nx, ny;
23 	Attr *ap;
24 
25 	nx = curx;
26 	ny = cury;
27 	defx = getfval("linewid");
28 	defy = getfval("lineht");
29 	prevh = getfval("arrowht");
30 	prevw = getfval("arrowwid");
31 	dx[0] = dy[0] = ndxy = some = head = invis = 0;
32 	chop = chop1 = chop2 = 0;
33 	ddtype = ddval = 0;
34 	for (i = 0; i < nattr; i++) {
35 		ap = &attr[i];
36 		switch (ap->a_type) {
37 		case TEXTATTR:
38 			savetext(ap->a_sub, ap->a_val.p);
39 			break;
40 		case HEAD:
41 			head += ap->a_val.i;
42 			break;
43 		case INVIS:
44 			invis = INVIS;
45 			break;
46 		case CHOP:
47 			if (chop++ == 0)
48 				chop1 = chop2 = ap->a_val.f;
49 			else
50 				chop2 = ap->a_val.f;
51 			break;
52 		case DOT:
53 		case DASH:
54 			ddtype = ap->a_type==DOT ? DOTBIT : DASHBIT;
55 			if (ap->a_sub == DEFAULT)
56 				ddval = getfval("dashwid");
57 			else
58 				ddval = ap->a_val.f;
59 			break;
60 		case SAME:
61 			dx[ndxy] = prevdx;
62 			dy[ndxy] = prevdy;
63 			some++;
64 			break;
65 		case LEFT:
66 			dx[ndxy] -= (ap->a_sub==DEFAULT) ? defx : ap->a_val.f;
67 			some++;
68 			hvmode = L_DIR;
69 			break;
70 		case RIGHT:
71 			dx[ndxy] += (ap->a_sub==DEFAULT) ? defx : ap->a_val.f;
72 			some++;
73 			hvmode = R_DIR;
74 			break;
75 		case UP:
76 			dy[ndxy] += (ap->a_sub==DEFAULT) ? defy : ap->a_val.f;
77 			some++;
78 			hvmode = U_DIR;
79 			break;
80 		case DOWN:
81 			dy[ndxy] -= (ap->a_sub==DEFAULT) ? defy : ap->a_val.f;
82 			some++;
83 			hvmode = D_DIR;
84 			break;
85 		case HEIGHT:	/* length of arrowhead */
86 			prevh = ap->a_val.f;
87 			break;
88 		case WIDTH:	/* width of arrowhead */
89 			prevw = ap->a_val.f;
90 			break;
91 		case TO:
92 			if (some) {
93 				nx += dx[ndxy];
94 				ny += dy[ndxy];
95 				ndxy++;
96 				dx[ndxy] = dy[ndxy] = some = 0;
97 			}
98 			ppos = attr[i].a_val.o;
99 			dx[ndxy] = ppos->o_x - nx;
100 			dy[ndxy] = ppos->o_y - ny;
101 			some++;
102 			break;
103 		case BY:
104 			if (some) {
105 				nx += dx[ndxy];
106 				ny += dy[ndxy];
107 				ndxy++;
108 				dx[ndxy] = dy[ndxy] = some = 0;
109 			}
110 			ppos = ap->a_val.o;
111 			dx[ndxy] = ppos->o_x;
112 			dy[ndxy] = ppos->o_y;
113 			some++;
114 			break;
115 		case THEN:	/* turn off any previous accumulation */
116 			if (some) {
117 				nx += dx[ndxy];
118 				ny += dy[ndxy];
119 				ndxy++;
120 				dx[ndxy] = dy[ndxy] = some = 0;
121 			}
122 			break;
123 		case FROM:
124 		case AT:
125 			ppos = ap->a_val.o;
126 			nx = curx = ppos->o_x;
127 			ny = cury = ppos->o_y;
128 			break;
129 		}
130 	}
131 	if (some) {
132 		nx += dx[ndxy];
133 		ny += dy[ndxy];
134 		ndxy++;
135 		defx = dx[ndxy-1];
136 		defy = dy[ndxy-1];
137 	} else {
138 		defx *= xtab[hvmode];
139 		defy *= ytab[hvmode];
140 		dx[ndxy] = defx;
141 		dy[ndxy] = defy;
142 		ndxy++;
143 		nx += defx;
144 		ny += defy;
145 	}
146 	prevdx = defx;
147 	prevdy = defy;
148 	if (chop) {
149 		if (chop == 1 && chop1 == 0)	/* just said "chop", so use default */
150 			chop1 = chop2 = getfval("circlerad");
151 		theta = atan2(dy[0], dx[0]);
152 		x0 = chop1 * cos(theta);
153 		y0 = chop1 * sin(theta);
154 		curx += x0;
155 		cury += y0;
156 		dx[0] -= x0;
157 		dy[0] -= y0;
158 
159 		theta = atan2(dy[ndxy-1], dx[ndxy-1]);
160 		x1 = chop2 * cos(theta);
161 		y1 = chop2 * sin(theta);
162 		nx -= x1;
163 		ny -= y1;
164 		dx[ndxy-1] -= x1;
165 		dy[ndxy-1] -= y1;
166 		dprintf("chopping %g %g %g %g; cur=%g,%g end=%g,%g\n",
167 			x0, y0, x1, y1, curx, cury, nx, ny);
168 	}
169 	p = makenode(type, 5 + 2 * ndxy);
170 	curx = p->o_val[0] = nx;
171 	cury = p->o_val[1] = ny;
172 	if (head || type == ARROW) {
173 		p->o_nhead = getfval("arrowhead");
174 		p->o_val[2] = prevw;
175 		p->o_val[3] = prevh;
176 		if (head == 0)
177 			head = HEAD2;	/* default arrow head */
178 	}
179 	p->o_attr = head | invis | ddtype;
180 	p->o_val[4] = ndxy;
181 	nx = p->o_x;
182 	ny = p->o_y;
183 	for (i = 0, j = 5; i < ndxy; i++, j += 2) {
184 		p->o_val[j] = dx[i];
185 		p->o_val[j+1] = dy[i];
186 		if (type == LINE || type == ARROW)
187 			extreme(nx += dx[i], ny += dy[i]);
188 		else if (type == SPLINE && i < ndxy-1) {
189 			/* to compute approx extreme of spline at p,
190 			/* compute midway between p-1 and p+1,
191 			/* then go 3/4 from there to p */
192 			double ex, ey, xi, yi, xi1, yi1;
193 			xi = nx + dx[i]; yi = ny + dy[i];	/* p */
194 			xi1 = xi + dx[i+1]; yi1 = yi + dy[i+1];	/* p+1 */
195 			ex = (nx+xi1)/2; ey = (ny+yi1)/2;	/* midway */
196 			ex += 0.75*(xi-ex); ey += 0.75*(yi-ey);
197 			extreme(ex, ey);
198 			nx = xi; ny = yi;
199 		}
200 
201 	}
202 	p->o_ddval = ddval;
203 	if (dbg) {
204 		printf("S or L from %g %g to %g %g with %d elements:\n", p->o_x, p->o_y, curx, cury, ndxy);
205 		for (i = 0, j = 5; i < ndxy; i++, j += 2)
206 			printf("%g %g\n", p->o_val[j], p->o_val[j+1]);
207 	}
208 	extreme(p->o_x, p->o_y);
209 	extreme(curx, cury);
210 	return(p);
211 }