X-Git-Url: http://git.tdb.fi/?a=blobdiff_plain;f=cochran.c;h=360f2eb7c9d836a1f77688821f6ad33872442b51;hb=2cada118eb515e369ba23b85c8f3fb8c4d100aaa;hp=907dc765aa03cd9944252cd559457acffa09424c;hpb=b1a747f537d1df8b9ea9f4caf55e568dd4c3a733;p=ext%2Fsubsurface.git

diff --git a/cochran.c b/cochran.c
index 907dc76..360f2eb 100644
--- a/cochran.c
+++ b/cochran.c
@@ -1,4 +1,5 @@
 #include <stdio.h>
+#include <string.h>
 #include <unistd.h>
 #include <sys/types.h>
 #include <sys/stat.h>
@@ -7,6 +8,8 @@
 #include "dive.h"
 #include "file.h"
 
+#define DON
+
 /*
  * The Cochran file format is designed to be annoying to read. It's roughly:
  *
@@ -76,24 +79,88 @@ static int figure_out_modulus(const unsigned char *decode, const unsigned char *
 	return best;
 }
 
-static void cochran_debug_write(int dive, const unsigned char *data, unsigned size)
+#define hexchar(n) ("0123456789abcdef"[(n)&15])
+
+static int show_line(unsigned offset, const unsigned char *data, unsigned size, int show_empty)
 {
-	char buffer[60];
-	int fd;
-
-	snprintf(buffer, sizeof(buffer), "cochran.%d.out", dive);
-	fd = open(buffer, O_CREAT | O_TRUNC | O_WRONLY, 0666);
-	if (fd >= 0) {
-		write(fd, data, size);
-		close(fd);
+	unsigned char bits;
+	int i, off;
+	char buffer[120];
+
+	if (size > 16)
+		size = 16;
+
+	bits = 0;
+	memset(buffer, ' ', sizeof(buffer));
+	off = sprintf(buffer, "%06x ", offset);
+	for (i = 0; i < size; i++) {
+		char *hex = buffer + off + 3*i;
+		char *asc = buffer + off + 50 + i;
+		unsigned char byte = data[i];
+
+		hex[0] = hexchar(byte>>4);
+		hex[1] = hexchar(byte);
+		bits |= byte;
+		if (byte < 32 || byte > 126)
+			byte = '.';
+		asc[0] = byte;
+		asc[1] = 0;
+	}
+
+	if (bits) {
+		puts(buffer);
+		return 1;
 	}
+	if (show_empty)
+		puts("...");
+	return 0;
 }
 
-static void parse_cochran_dive(int dive, const unsigned char *decode, unsigned mod,
+static void cochran_debug_write(const char *filename, const unsigned char *data, unsigned size)
+{
+	int i, show = 1;
+
+	for (i = 0; i < size; i += 16)
+		show = show_line(i, data + i, size - i, show);
+}
+
+static void parse_cochran_header(const char *filename,
+		const unsigned char *decode, unsigned mod,
 		const unsigned char *in, unsigned size)
 {
 	char *buf = malloc(size);
 
+	/* Do the "null decode" using a one-byte decode array of '\0' */
+	partial_decode(0    , 0x0b14, "", 0, 1, in, size, buf);
+
+	/*
+	 * The header scrambling is different form the dive
+	 * scrambling. Oh yay!
+	 */
+	partial_decode(0x010e, 0x0b14, decode, 0, mod, in, size, buf);
+	partial_decode(0x0b14, 0x1b14, decode, 0, mod, in, size, buf);
+	partial_decode(0x1b14, 0x2b14, decode, 0, mod, in, size, buf);
+	partial_decode(0x2b14, 0x3b14, decode, 0, mod, in, size, buf);
+	partial_decode(0x3b14, 0x5414, decode, 0, mod, in, size, buf);
+	partial_decode(0x5414,   size, decode, 0, mod, in, size, buf);
+
+	printf("\n%s, header\n\n", filename);
+	cochran_debug_write(filename, buf, size);
+
+	free(buf);
+}
+
+static void parse_cochran_dive(const char *filename, int dive,
+		const unsigned char *decode, unsigned mod,
+		const unsigned char *in, unsigned size)
+{
+	char *buf = malloc(size);
+#ifdef DON
+	unsigned int offset = 0x4a14;
+#else
+	unsigned int offset = 0x4b14;
+#endif
+
 	/*
 	 * The scrambling has odd boundaries. I think the boundaries
 	 * match some data structure size, but I don't know. They were
@@ -115,9 +182,11 @@ static void parse_cochran_dive(int dive, const unsigned char *decode, unsigned m
 	 * scrambled, but there seems to be size differences in the data,
 	 * so this just descrambles part of it:
 	 */
-	partial_decode(0x48ff, size, decode, 0, mod, in, size, buf);
+	partial_decode(0x48ff, offset, decode, 0, mod, in, size, buf);
+	partial_decode(offset,   size, decode, 0, mod, in, size, buf);
 
-	cochran_debug_write(dive, buf, size);
+	printf("\n%s, dive %d\n\n", filename, dive);
+	cochran_debug_write(filename, buf, size);
 
 	free(buf);
 }
@@ -139,6 +208,8 @@ int try_to_open_cochran(const char *filename, struct memblock *mem, GError **err
 
 	mod = figure_out_modulus(decode, mem->buffer + dive1, dive2 - dive1);
 
+	parse_cochran_header(filename, decode, mod, mem->buffer + 0x40000, dive1 - 0x40000);
+
 	for (i = 0; i < 65534; i++) {
 		dive1 = offsets[i];
 		dive2 = offsets[i+1];
@@ -146,8 +217,8 @@ int try_to_open_cochran(const char *filename, struct memblock *mem, GError **err
 			break;
 		if (dive2 > mem->size)
 			break;
-		parse_cochran_dive(i, decode, mod, mem->buffer + dive1, dive2 - dive1);
+		parse_cochran_dive(filename, i+1, decode, mod, mem->buffer + dive1, dive2 - dive1);
 	}
 
-	return 1;
+	exit(0);
 }