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root/radiance/ray/src/rt/devcomm.c
Revision: 2.2
Committed: Thu Mar 19 09:34:02 1992 UTC (32 years, 1 month ago) by greg
Content type: text/plain
Branch: MAIN
Changes since 2.1: +2 -4 lines
Log Message:
added vfork.h include

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 "standard.h"
14
15 #include "color.h"
16
17 #include "driver.h"
18
19 #include "vfork.h"
20
21 #ifndef DEVPATH
22 #define DEVPATH getenv("PATH") /* device search path */
23 #endif
24
25 #ifndef DELAY
26 #define DELAY 20 /* seconds to wait for response */
27 #endif
28
29 static int comm_close(), comm_clear(), comm_paintr(), comm_errout(),
30 comm_getcur(), comm_comout(), comm_comin(), comm_flush();
31
32 struct driver comm_driver = {
33 comm_close, comm_clear, comm_paintr, comm_getcur,
34 comm_comout, comm_comin, comm_flush
35 };
36
37 FILE *devin, *devout;
38
39 int devchild;
40
41
42 struct driver *
43 comm_init(dname, id) /* set up and execute driver */
44 char *dname, *id;
45 {
46 char *devname;
47 int p1[2], p2[2];
48 char pin[16], pout[16];
49 /* find driver program */
50 if ((devname = getpath(dname, DEVPATH, X_OK)) == NULL) {
51 stderr_v(dname);
52 stderr_v(": not found\n");
53 return(NULL);
54 }
55 /* open communication pipes */
56 if (pipe(p1) == -1 || pipe(p2) == -1)
57 goto syserr;
58 if ((devchild = vfork()) == 0) { /* fork driver process */
59 close(p1[1]);
60 close(p2[0]);
61 sprintf(pin, "%d", p1[0]);
62 sprintf(pout, "%d", p2[1]);
63 execl(devname, dname, pin, pout, id, 0);
64 perror(devname);
65 _exit(127);
66 }
67 if (devchild == -1)
68 goto syserr;
69 close(p1[0]);
70 close(p2[1]);
71 if ((devout = fdopen(p1[1], "w")) == NULL)
72 goto syserr;
73 if ((devin = fdopen(p2[0], "r")) == NULL)
74 goto syserr;
75 /* verify initialization */
76 putw(COM_SENDM, devout);
77 fflush(devout);
78 if (getw(devin) != COM_RECVM)
79 return(NULL);
80 /* get driver parameters */
81 getstate();
82 /* set error vectors */
83 cmdvec = comm_comout;
84 if (wrnvec != NULL)
85 wrnvec = comm_comout;
86 return(&comm_driver);
87 syserr:
88 perror(dname);
89 return(NULL);
90 }
91
92
93 static
94 comm_close() /* done with driver */
95 {
96 int pid;
97
98 cmdvec = NULL; /* reset error vectors */
99 if (wrnvec != NULL)
100 wrnvec = stderr_v;
101 fclose(devout);
102 fclose(devin);
103 while ((pid = wait(0)) != -1 && pid != devchild)
104 ;
105 }
106
107
108 static
109 comm_clear(xres, yres) /* clear screen */
110 int xres, yres;
111 {
112 putc(COM_CLEAR, devout);
113 putw(xres, devout);
114 putw(yres, devout);
115 fflush(devout);
116 }
117
118
119 static
120 comm_paintr(col, xmin, ymin, xmax, ymax) /* paint a rectangle */
121 COLOR col;
122 int xmin, ymin, xmax, ymax;
123 {
124 putc(COM_PAINTR, devout);
125 fwrite((char *)col, sizeof(COLOR), 1, devout);
126 putw(xmin, devout);
127 putw(ymin, devout);
128 putw(xmax, devout);
129 putw(ymax, devout);
130 }
131
132
133 static
134 comm_flush() /* flush output to driver */
135 {
136 putc(COM_FLUSH, devout);
137 fflush(devout);
138 if (getc(devin) != COM_FLUSH)
139 reply_error("flush");
140 getstate();
141 }
142
143
144 static int
145 comm_getcur(xp, yp) /* get and return cursor position */
146 int *xp, *yp;
147 {
148 int c;
149
150 putc(COM_GETCUR, devout);
151 fflush(devout);
152 if (getc(devin) != COM_GETCUR)
153 reply_error("getcur");
154 c = getc(devin);
155 *xp = getw(devin);
156 *yp = getw(devin);
157 return(c);
158 }
159
160
161 static
162 comm_comout(str) /* print string to command line */
163 char *str;
164 {
165 putc(COM_COMOUT, devout);
166 myputs(str, devout);
167 if (str[strlen(str)-1] == '\n')
168 fflush(devout);
169 }
170
171
172 static
173 comm_comin(buf, prompt) /* read string from command line */
174 char *buf;
175 char *prompt;
176 {
177 putc(COM_COMIN, devout);
178 if (prompt == NULL)
179 putc(0, devout);
180 else {
181 putc(1, devout);
182 myputs(prompt, devout);
183 }
184 fflush(devout);
185 if (getc(devin) != COM_COMIN)
186 reply_error("comin");
187 mygets(buf, devin);
188 getstate();
189 }
190
191
192 static
193 comm_errout(str) /* display an error message */
194 char *str;
195 {
196 comm_comout(str);
197 stderr_v(str); /* send to standard error also */
198 }
199
200
201 static
202 mygets(s, fp) /* get string from file (with nul) */
203 register char *s;
204 register FILE *fp;
205 {
206 register int c;
207
208 while ((c = getc(fp)) != EOF)
209 if ((*s++ = c) == '\0')
210 return;
211 *s = '\0';
212 }
213
214
215 static
216 myputs(s, fp) /* put string to file (with nul) */
217 register char *s;
218 register FILE *fp;
219 {
220 do
221 putc(*s, fp);
222 while (*s++);
223 }
224
225
226 static
227 reply_error(routine) /* what should we do here? */
228 char *routine;
229 {
230 stderr_v(routine);
231 stderr_v(": driver reply error\n");
232 quit(1);
233 }
234
235
236 static
237 getstate() /* get driver state variables */
238 {
239 fread((char *)&comm_driver.pixaspect,
240 sizeof(comm_driver.pixaspect), 1, devin);
241 comm_driver.xsiz = getw(devin);
242 comm_driver.ysiz = getw(devin);
243 comm_driver.inpready = getw(devin);
244 }