Diff: _bitio.cpp

Revision:

0:805cffac956b

Child:

1:02bfb013660c

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/_bitio.cpp	Thu Aug 26 12:48:50 2010 +0000
@@ -0,0 +1,76 @@
+#include "mbed.h"
+#include "string"
+#include "_bitio.h"
+
+
+/*
+#define TRUE     1
+#define FALSE    0
+*/
+#define rightbits(n, x) ((x) & ((1U << (n)) - 1U))  
+/*
+typedef unsigned int  Uint;
+typedef unsigned char Uchar;
+*/
+FILE *infp, *outfp;
+int  getcount, putcount;
+Uint bitbuf;
+
+void init_bit_o(void)
+{
+    putcount = 8; bitbuf = 0;
+}
+
+void init_bit_i(void)
+{
+    getcount = 0; bitbuf = 0;
+}
+
+
+Uint getbit(void)
+{
+    int flag;
+    if (--getcount >= 0)  return (bitbuf >> getcount) & 1U;
+    getcount = 7; 
+    if((flag = fgetc(infp))==EOF)return OVERRUN;
+    else bitbuf = flag;
+    return (bitbuf >> 7) & 1U;
+}
+
+Uint getbits(int n)
+{
+    Uint x = 0;
+    if (n < 1 || 25 < n)  return 0;
+    while (n > getcount) {
+        n -= getcount;
+        x |= rightbits(getcount, bitbuf) << n;
+        bitbuf = fgetc(infp); getcount = 8;
+    }
+    getcount -= n;
+    return x | rightbits(n, bitbuf >> getcount);
+}
+
+
+void putbit(Uint bit)
+{
+    putcount--;
+    if (bit != 0)  bitbuf |= (1 << putcount);
+    if (putcount == 0) {
+        if (fputc(bitbuf, outfp) == EOF)  error("can't write\r\n");
+        bitbuf = 0; putcount = 8;
+    }
+}
+
+
+void putbits(int n, Uint x)
+{
+    if (n < 1 || 25 < n)  return;
+    while (n >= putcount) {
+        n -= putcount;
+        bitbuf |= rightbits(putcount, x >> n);
+        if (fputc(bitbuf, outfp) == EOF)  error("cant write\r\n");
+        bitbuf = 0U; putcount = 8;
+    }
+    putcount -= n;
+    bitbuf |= rightbits(n, x) << putcount;
+}