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root/radiance/ray/src/rt/devcomm.c
Revision: 1.7
Committed: Wed Nov 1 17:33:03 1989 UTC (34 years, 6 months ago) by greg
Content type: text/plain
Branch: MAIN
Changes since 1.6: +25 -20 lines
Log Message:
modified interface to independent drivers

File Contents

# Content
1 /* Copyright (c) 1988 Regents of the University of California */
2
3 #ifndef lint
4 static char SCCSid[] = "$SunId$ LBL";
5 #endif
6
7 /*
8 * devcomm.c - communication routines for separate drivers.
9 *
10 * 10/5/88
11 */
12
13 #include <stdio.h>
14
15 #include <signal.h>
16
17 #include "color.h"
18
19 #include "driver.h"
20
21 #ifndef DEVPATH
22 #define DEVPATH getenv("PATH") /* device search path */
23 #endif
24
25 #ifndef BSD
26 #define vfork fork
27 #endif
28
29 #ifndef WFLUSH
30 #define WFLUSH 30 /* flush after this many rays */
31 #endif
32
33 extern char *getpath(), *getenv();
34
35 int onsigio();
36
37 int comm_close(), comm_clear(), comm_paintr(), comm_errout(),
38 comm_getcur(), comm_comout(), comm_comin();
39
40 struct driver comm_driver, comm_default = {
41 comm_close, comm_clear, comm_paintr, comm_getcur,
42 comm_comout, comm_comin,
43 MAXRES, MAXRES, 0
44 };
45
46 FILE *devin, *devout;
47
48 int devchild;
49
50
51 struct driver *
52 comm_init(dname, id) /* set up and execute driver */
53 char *dname, *id;
54 {
55 char *devname;
56 int p1[2], p2[2];
57 char pin[16], pout[16];
58 /* find driver program */
59 if ((devname = getpath(dname, DEVPATH, 1)) == NULL) {
60 stderr_v(dname);
61 stderr_v(": not found\n");
62 return(NULL);
63 }
64 /* open communication pipes */
65 if (pipe(p1) == -1 || pipe(p2) == -1)
66 goto syserr;
67 if ((devchild = vfork()) == 0) { /* fork driver process */
68 close(p1[1]);
69 close(p2[0]);
70 sprintf(pin, "%d", p1[0]);
71 sprintf(pout, "%d", p2[1]);
72 execl(devname, dname, pin, pout, id, 0);
73 perror(devname);
74 _exit(127);
75 }
76 if (devchild == -1)
77 goto syserr;
78 close(p1[0]);
79 close(p2[1]);
80 if ((devout = fdopen(p1[1], "w")) == NULL)
81 goto syserr;
82 if ((devin = fdopen(p2[0], "r")) == NULL)
83 goto syserr;
84 bcopy(&comm_default, &comm_driver, sizeof(comm_driver));
85 /* verify & get resolution */
86 putw(COM_SENDM, devout);
87 fflush(devout);
88 if (getw(devin) != COM_RECVM)
89 return(NULL);
90 comm_driver.xsiz = getw(devin);
91 comm_driver.ysiz = getw(devin);
92 /* input handling */
93 signal(SIGIO, onsigio);
94 /* set error vectors */
95 cmdvec = comm_comout;
96 if (wrnvec != NULL)
97 wrnvec = comm_comout;
98 return(&comm_driver);
99 syserr:
100 perror(dname);
101 return(NULL);
102 }
103
104
105 static
106 comm_close() /* done with driver */
107 {
108 int pid;
109
110 cmdvec = NULL; /* reset error vectors */
111 if (wrnvec != NULL)
112 wrnvec = stderr_v;
113 signal(SIGIO, SIG_DFL);
114 fclose(devout);
115 fclose(devin);
116 while ((pid = wait(0)) != -1 && pid != devchild)
117 ;
118 }
119
120
121 static
122 comm_clear(xres, yres) /* clear screen */
123 int xres, yres;
124 {
125 putc(COM_CLEAR, devout);
126 fwrite(&xres, sizeof(xres), 1, devout);
127 fwrite(&yres, sizeof(yres), 1, devout);
128 fflush(devout);
129 }
130
131
132 static
133 comm_paintr(col, xmin, ymin, xmax, ymax) /* paint a rectangle */
134 COLOR col;
135 int xmin, ymin, xmax, ymax;
136 {
137 extern long nrays; /* number of rays traced */
138 static long lastflush = 0; /* ray count at last flush */
139
140 putc(COM_PAINTR, devout);
141 fwrite(col, sizeof(COLOR), 1, devout);
142 fwrite(&xmin, sizeof(xmin), 1, devout);
143 fwrite(&ymin, sizeof(ymin), 1, devout);
144 fwrite(&xmax, sizeof(xmax), 1, devout);
145 fwrite(&ymax, sizeof(ymax), 1, devout);
146 if (nrays - lastflush >= WFLUSH) {
147 fflush(devout);
148 lastflush = nrays;
149 }
150 }
151
152
153 static int
154 comm_getcur(xp, yp) /* get and return cursor position */
155 int *xp, *yp;
156 {
157 int c;
158
159 putc(COM_GETCUR, devout);
160 fflush(devout);
161 if (getc(devin) != COM_GETCUR)
162 reply_error("getcur");
163 c = getc(devin);
164 fread(xp, sizeof(*xp), 1, devin);
165 fread(yp, sizeof(*yp), 1, devin);
166 return(c);
167 }
168
169
170 static
171 comm_comout(str) /* print string to command line */
172 char *str;
173 {
174 putc(COM_COMOUT, devout);
175 myputs(str, devout);
176 fflush(devout);
177 }
178
179
180 static
181 comm_comin(buf) /* read string from command line */
182 char *buf;
183 {
184 putc(COM_COMIN, devout);
185 fflush(devout);
186 if (getc(devin) != COM_COMIN)
187 reply_error("comin");
188 mygets(buf, devin);
189 if (comm_driver.inpready > 0)
190 comm_driver.inpready--;
191 }
192
193
194 static
195 comm_errout(str) /* display an error message */
196 char *str;
197 {
198 comm_comout(str);
199 stderr_v(str); /* send to standard error also */
200 }
201
202
203 static
204 mygets(s, fp) /* get string from file (with nul) */
205 register char *s;
206 register FILE *fp;
207 {
208 register int c;
209
210 while ((c = getc(fp)) != EOF)
211 if ((*s++ = c) == '\0')
212 return;
213 *s = '\0';
214 }
215
216
217 static
218 myputs(s, fp) /* put string to file (with nul) */
219 register char *s;
220 register FILE *fp;
221 {
222 do
223 putc(*s, fp);
224 while (*s++);
225 }
226
227
228 static
229 reply_error(routine) /* what should we do here? */
230 char *routine;
231 {
232 stderr_v(routine);
233 stderr_v(": driver reply error\n");
234 quit(1);
235 }
236
237
238 static
239 onsigio() /* input ready */
240 {
241 comm_driver.inpready++;
242 }