summaryrefslogtreecommitdiffstatshomepage
path: root/trunk/src/lib/formats/imageutl.c
diff options
context:
space:
mode:
Diffstat (limited to 'trunk/src/lib/formats/imageutl.c')
-rw-r--r--trunk/src/lib/formats/imageutl.c223
1 files changed, 223 insertions, 0 deletions
diff --git a/trunk/src/lib/formats/imageutl.c b/trunk/src/lib/formats/imageutl.c
new file mode 100644
index 00000000000..b662792ba95
--- /dev/null
+++ b/trunk/src/lib/formats/imageutl.c
@@ -0,0 +1,223 @@
+/***************************************************************************
+
+ imageutl.h
+
+ Image related utilities
+
+****************************************************************************
+
+ Copyright Aaron Giles
+ All rights reserved.
+
+ Redistribution and use in source and binary forms, with or without
+ modification, are permitted provided that the following conditions are
+ met:
+
+ * Redistributions of source code must retain the above copyright
+ notice, this list of conditions and the following disclaimer.
+ * Redistributions in binary form must reproduce the above copyright
+ notice, this list of conditions and the following disclaimer in
+ the documentation and/or other materials provided with the
+ distribution.
+ * Neither the name 'MAME' nor the names of its contributors may be
+ used to endorse or promote products derived from this software
+ without specific prior written permission.
+
+ THIS SOFTWARE IS PROVIDED BY AARON GILES ''AS IS'' AND ANY EXPRESS OR
+ IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ DISCLAIMED. IN NO EVENT SHALL AARON GILES BE LIABLE FOR ANY DIRECT,
+ INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ POSSIBILITY OF SUCH DAMAGE.
+
+***************************************************************************/
+
+#include <ctype.h>
+#include "imageutl.h"
+
+int compute_log2(int val)
+{
+ int count = 0;
+
+ while(val > 1)
+ {
+ if (val & 1)
+ return -1;
+ val /= 2;
+ count++;
+ }
+ return (val == 0) ? -1 : count;
+}
+
+/*
+ Compute CCITT CRC-16 using the correct bit order for floppy disks.
+ CRC code courtesy of Tim Mann.
+*/
+
+/* Accelerator table to compute the CRC eight bits at a time */
+static const unsigned short ccitt_crc16_table[256] =
+{
+ 0x0000, 0x1021, 0x2042, 0x3063, 0x4084, 0x50A5, 0x60C6, 0x70E7,
+ 0x8108, 0x9129, 0xA14A, 0xB16B, 0xC18C, 0xD1AD, 0xE1CE, 0xF1EF,
+ 0x1231, 0x0210, 0x3273, 0x2252, 0x52B5, 0x4294, 0x72F7, 0x62D6,
+ 0x9339, 0x8318, 0xB37B, 0xA35A, 0xD3BD, 0xC39C, 0xF3FF, 0xE3DE,
+ 0x2462, 0x3443, 0x0420, 0x1401, 0x64E6, 0x74C7, 0x44A4, 0x5485,
+ 0xA56A, 0xB54B, 0x8528, 0x9509, 0xE5EE, 0xF5CF, 0xC5AC, 0xD58D,
+ 0x3653, 0x2672, 0x1611, 0x0630, 0x76D7, 0x66F6, 0x5695, 0x46B4,
+ 0xB75B, 0xA77A, 0x9719, 0x8738, 0xF7DF, 0xE7FE, 0xD79D, 0xC7BC,
+ 0x48C4, 0x58E5, 0x6886, 0x78A7, 0x0840, 0x1861, 0x2802, 0x3823,
+ 0xC9CC, 0xD9ED, 0xE98E, 0xF9AF, 0x8948, 0x9969, 0xA90A, 0xB92B,
+ 0x5AF5, 0x4AD4, 0x7AB7, 0x6A96, 0x1A71, 0x0A50, 0x3A33, 0x2A12,
+ 0xDBFD, 0xCBDC, 0xFBBF, 0xEB9E, 0x9B79, 0x8B58, 0xBB3B, 0xAB1A,
+ 0x6CA6, 0x7C87, 0x4CE4, 0x5CC5, 0x2C22, 0x3C03, 0x0C60, 0x1C41,
+ 0xEDAE, 0xFD8F, 0xCDEC, 0xDDCD, 0xAD2A, 0xBD0B, 0x8D68, 0x9D49,
+ 0x7E97, 0x6EB6, 0x5ED5, 0x4EF4, 0x3E13, 0x2E32, 0x1E51, 0x0E70,
+ 0xFF9F, 0xEFBE, 0xDFDD, 0xCFFC, 0xBF1B, 0xAF3A, 0x9F59, 0x8F78,
+ 0x9188, 0x81A9, 0xB1CA, 0xA1EB, 0xD10C, 0xC12D, 0xF14E, 0xE16F,
+ 0x1080, 0x00A1, 0x30C2, 0x20E3, 0x5004, 0x4025, 0x7046, 0x6067,
+ 0x83B9, 0x9398, 0xA3FB, 0xB3DA, 0xC33D, 0xD31C, 0xE37F, 0xF35E,
+ 0x02B1, 0x1290, 0x22F3, 0x32D2, 0x4235, 0x5214, 0x6277, 0x7256,
+ 0xB5EA, 0xA5CB, 0x95A8, 0x8589, 0xF56E, 0xE54F, 0xD52C, 0xC50D,
+ 0x34E2, 0x24C3, 0x14A0, 0x0481, 0x7466, 0x6447, 0x5424, 0x4405,
+ 0xA7DB, 0xB7FA, 0x8799, 0x97B8, 0xE75F, 0xF77E, 0xC71D, 0xD73C,
+ 0x26D3, 0x36F2, 0x0691, 0x16B0, 0x6657, 0x7676, 0x4615, 0x5634,
+ 0xD94C, 0xC96D, 0xF90E, 0xE92F, 0x99C8, 0x89E9, 0xB98A, 0xA9AB,
+ 0x5844, 0x4865, 0x7806, 0x6827, 0x18C0, 0x08E1, 0x3882, 0x28A3,
+ 0xCB7D, 0xDB5C, 0xEB3F, 0xFB1E, 0x8BF9, 0x9BD8, 0xABBB, 0xBB9A,
+ 0x4A75, 0x5A54, 0x6A37, 0x7A16, 0x0AF1, 0x1AD0, 0x2AB3, 0x3A92,
+ 0xFD2E, 0xED0F, 0xDD6C, 0xCD4D, 0xBDAA, 0xAD8B, 0x9DE8, 0x8DC9,
+ 0x7C26, 0x6C07, 0x5C64, 0x4C45, 0x3CA2, 0x2C83, 0x1CE0, 0x0CC1,
+ 0xEF1F, 0xFF3E, 0xCF5D, 0xDF7C, 0xAF9B, 0xBFBA, 0x8FD9, 0x9FF8,
+ 0x6E17, 0x7E36, 0x4E55, 0x5E74, 0x2E93, 0x3EB2, 0x0ED1, 0x1EF0
+};
+
+unsigned short ccitt_crc16(unsigned short crc, const unsigned char *buffer, size_t buffer_len)
+{
+ size_t i;
+ for (i = 0; i < buffer_len; i++)
+ crc = (crc << 8) ^ ccitt_crc16_table[(crc >> 8) ^ buffer[i]];
+ return crc;
+}
+
+unsigned short ccitt_crc16_one( unsigned short crc, const unsigned char data )
+{
+ return (crc << 8) ^ ccitt_crc16_table[(crc >> 8) ^ data];
+}
+
+
+/*-------------------------------------------------
+ is_delim - returns whether c is a comma or \0
+-------------------------------------------------*/
+
+static int is_delim(char c)
+{
+ return (c == '\0') || (c == ',');
+}
+
+
+
+/*-------------------------------------------------
+ image_internal_find_extension - find an extension in
+ an extension list
+-------------------------------------------------*/
+
+static int image_internal_find_extension(const char *extension_list, const char *target_extension)
+{
+ /* this version allows target_extension to be delimited with a comma */
+ int pos = 0;
+ int i;
+
+ while(extension_list[pos] != '\0')
+ {
+ /* compare a file extension */
+ i = 0;
+ while(!is_delim(extension_list[pos + i])
+ && !is_delim(target_extension[i])
+ && (tolower(extension_list[pos + i]) == tolower(target_extension[i])))
+ {
+ i++;
+ }
+
+ /* check to see if it was found */
+ if (is_delim(extension_list[pos + i]) && is_delim(target_extension[i]))
+ return TRUE;
+
+ /* move to next position in the buffer */
+ pos += i;
+ while(!is_delim(extension_list[pos]))
+ pos++;
+ while(extension_list[pos] == ',')
+ pos++;
+ }
+
+ /* not found */
+ return FALSE;
+}
+
+
+
+/*-------------------------------------------------
+ image_find_extension - find an extension in an extension
+ list
+-------------------------------------------------*/
+
+int image_find_extension(const char *extension_list, const char *target_extension)
+{
+ /* the internal function allows something that we do not */
+ if (strchr(target_extension, ','))
+ return FALSE;
+
+ /* special case to allow ext to be in the form '.EXT' */
+ if (*target_extension == '.')
+ target_extension++;
+
+ /* do the actual work */
+ return image_internal_find_extension(extension_list, target_extension);
+}
+
+
+
+/*-------------------------------------------------
+ image_specify_extension - merge a comma-delimited
+ list of file extensions onto an existing list
+-------------------------------------------------*/
+
+void image_specify_extension(char *buffer, size_t buffer_len, const char *extension)
+{
+ int extension_pos = 0;
+ int len;
+ int found;
+
+ /* determine the length of the buffer */
+ len = strlen(buffer);
+
+ /* be aware that extension can be NULL */
+ if (extension != NULL)
+ {
+ while(extension[extension_pos] != '\0')
+ {
+ /* try to find the file extension */
+ found = image_internal_find_extension(buffer, &extension[extension_pos]);
+
+ /* append a delimiter if we have to */
+ if (!found && (len > 0))
+ len += snprintf(&buffer[len], buffer_len - len, ",");
+
+ /* move to the next extension, appending the extension if not found */
+ while(!is_delim(extension[extension_pos]))
+ {
+ if (!found)
+ len += snprintf(&buffer[len], buffer_len - len, "%c", extension[extension_pos]);
+ extension_pos++;
+ }
+ while(extension[extension_pos] == ',')
+ extension_pos++;
+ }
+ }
+}
+