effects: Minor fixes for big-endian systems

mojoshader_effects.c

@@ -254,20 +254,40 @@ static uint32 readui32(const uint8 **_ptr, uint32 *_len)
     return retval;
 } // readui32
 
+static uint16 readui16(const uint8 **_ptr, uint32 *_len)
+{
+    uint16 retval = 0;
+    if (*_len < sizeof (retval))
+        *_len = 0;
+    else
+    {
+        const uint16 *ptr = (const uint16 *) *_ptr;
+        retval = SWAP16(*ptr);
+        *_ptr += sizeof (retval);
+        *_len -= sizeof (retval);
+    } // else
+    return retval;
+} // readui16
+
 static char *readstring(const uint8 *base,
                         const uint32 offset,
                         MOJOSHADER_malloc m,
                         void *d)
 {
     // !!! FIXME: sanity checks!
     // !!! FIXME: verify this doesn't go past EOF looking for a null.
-    const char *str = ((const char *) base) + offset;
-    const uint32 len = *((const uint32 *) str);
-    char *strptr = NULL;
+    uint8 *pair = (uint8 *) (base + offset);
+    const uint32 *lenptr = (const uint32 *) pair;
+    char *strptr = (char *) (pair + sizeof(uint32));
+
+    const uint32 len = SWAP32(*lenptr);
+    char *result = NULL;
+
     if (len == 0) return NULL; /* No length? No string. */
-    strptr = (char *) m(len, d);
-    memcpy(strptr, str + 4, len);
-    return strptr;
+
+    result = (char *) m(len, d);
+    memcpy(result, strptr, len);
+    return result;
 } // readstring
 
 static int findparameter(const MOJOSHADER_effectParam *params,
@@ -955,8 +975,9 @@ MOJOSHADER_effect *MOJOSHADER_compileEffect(const unsigned char *buf,
 
     /* Read in header magic, seek to initial offset */
     const uint8 *base = NULL;
-    uint32 header = readui32(&ptr, &len);
-    if (header == 0xBCF00BCF)
+    uint16 version = readui16(&ptr, &len);
+    uint16 header = readui16(&ptr, &len);
+    if ((header == 0xBCF0) && (version == 0x0BCF))
     {
         /* The Effect compiler provided with XNA4 adds some extra mess at the
          * beginning of the file. It's useless though, so just skip it.
@@ -965,9 +986,10 @@ MOJOSHADER_effect *MOJOSHADER_compileEffect(const unsigned char *buf,
         const uint32 skip = readui32(&ptr, &len) - 8;
         ptr += skip;
         len += skip;
-        header = readui32(&ptr, &len);
+        header = readui16(&ptr, &len);
+        version = readui16(&ptr, &len);
     } // if
-    if (header != 0xFEFF0901)
+    if ((header != 0xFEFF) && (version != 0x0901))
     {
         MOJOSHADER_deleteEffect(retval);
         return &MOJOSHADER_not_an_effect_effect;