Revision 17:c72c092fcdf7, committed 2014-12-01

Comitter:

alecguertin

Date:

Mon Dec 01 00:41:04 2014 +0000

Parent:

16:f1beef7beeb9

Child:

18:eab7b0e89398

Commit message:

added instruction parsing loop -- untested

Changed in this revision

--- a/main.c	Sun Nov 30 21:52:58 2014 +0000
+++ b/main.c	Mon Dec 01 00:41:04 2014 +0000
@@ -40,11 +40,18 @@
 /* Local File System */
 LocalFileSystem local("local");
 
+/* Boolean for drawing/moving. */
+int draw;
+
 /**
  * @brief Entry point. Main loop.
  */
 int main()
 {
+    FILE *ps_file;
+    int instbuflen = 250;
+    char instbuf[instbuflen];
+    
     //
     // Basic setup information
     start_button.mode(PullUp);
@@ -76,7 +83,7 @@
         pi.locate(0,0);
         pi.printf("P: %f", pos);
         */
-    } while (pos != -1 && pos < 0.2);
+    } while (pos != -1 && pos <= 0.3);
     pi.stop();
     wait(1);
     if (pos != -1) {
@@ -181,17 +188,60 @@
     //
     // Main program loop.
     // robot_loop();
-    
+    size_t bytes_read = 0;
+    int err, x, y, last_x, last_y;
+    int offset = 0;
+    char *cur, *next;
     ps_file = fopen("/local/test.ps", "r");
-    while () {
-        memset(instbuf, 0, instbuflen);
-        fread(instbuf, sizeof(char), instbuflen, ps_file);
+    /* PS parsing loop. */
+    while (1) {
+        memset(instbuf+offset, 0, instbuflen-offset);
+        bytes_read = fread(instbuf+offset, sizeof(char), instbuflen-1-offset, ps_file);
+        if (bytes_read == 0) {
+            break;
+        }
+        cur = instbuf;
+        while (cur[0] != '\0') {
+            err = retrieve_inst(instbuf, &x, &y, &draw);
+            move(x, y, draw);
+            last_x = x;
+            last_y = y;
+            next = strchr(cur, '\n');
+            if (next == NULL) {
+                break;
+            }
+            cur = next+1;
+        }
+        offset = instbuf+instbuflen-cur;
+        memcpy(instbuf, cur, offset);
     }
     //
     // We should never reach this point!
     return 0;
 }
 
+int retrieve_inst(char *buf, int *x, int *y, int *draw)
+{
+    int matches;
+    char *srch;
+    matches = sscanf(buf, "%d %d", x, y);
+    if (matches != 2) {
+        return 0;
+    }
+    srch = strchr(buf, ' ');
+    srch++;
+    srch = strchr(buf, ' ');
+    srch++;
+    if (srch[0] == 'm') {
+        *draw = 0;
+    } else if (srch[0] == 'd') {
+        *draw = 1;
+    } else {
+        return 0;
+    }
+    return 1;
+}
+
 int forward(int amt)
 {
     Timer t;

--- a/main.h	Sun Nov 30 21:52:58 2014 +0000
+++ b/main.h	Mon Dec 01 00:41:04 2014 +0000
@@ -20,6 +20,18 @@
 #define DRIVE_RATE  1/50
 
 /**
+ * @brief get values of next PostScript instruction.
+ *
+ * @param       buf     Buffer with PS instructions.
+ * @param       x       Pointer to storage for x coordinate.
+ * @param       y       Pointer to storage for y coordinate.
+ * @param       draw    Pointer to storage for draw/move boolean.
+ * 
+ * @return              Success or failure code.
+ */
+int retrieve_inst(char *buf, int *x, int *y, int *draw);
+
+/**
  * @brief Driver forward.
  *
  * @param[in]   amt     Amount to drive forward. In centimeters.