Fix a few major nivision Java wrapper issues.

- sliceByteBuffer() was not setting native order on the duplicated buffer.
  This caused all array-copyin functions to generate bad values.
- Correctly handle unsigned byte and unsigned short values.  These could
  read/write to bad locations previously.
- Implement custom version of imaqReadFile() to always pass in NULL for
  the colorTable.  Eventually a more-complete version should be written.

Also this works around a crash in imaqGetErrorText() by not calling it from
throwJavaException().  It's not clear why imaqGetErrorText() is crashing at
present (my best guess is there's still something fishy with multiple C++
lib versions getting loaded somehow), as this used to work.  Instead,
the exception now just gives the error code without the error message,
which is not user friendly but at least doesn't crash.  This will be fixed
in a future commit by creating our own version of imaqGetErrorText() based
on the information available in the header file.

Change-Id: I4d099e62ee41f8e2a50089806561be191cb5d9d7

wpilibj/wpilibJavaJNI/nivision/gen_java.py

@@ -9,15 +9,18 @@ except ImportError:
 
 from nivision_parse import *
 
+# base, cast-out-pre, cast-out-post, cast-in-pre, cast-in-post
 java_accessor_map = {
-        "B": "",
-        "C": "Char",
-        "S": "Short",
-        "I": "Int",
-        "J": "Long",
-        "F": "Float",
-        "D": "Double",
-        "Z": "Boolean",
+        "B": ("", "", "", "", ""),
+        "C": ("Char", "", "", "", ""),
+        "S": ("Short", "", "", "", ""),
+        "I": ("Int", "", "", "", ""),
+        "J": ("Long", "", "", "", ""),
+        "F": ("Float", "", "", "", ""),
+        "D": ("Double", "", "", "", ""),
+        "Z": ("Boolean", "", "", "", ""),
+        "X": ("", "(short)(", " & 0xff)", "(byte)(", " & 0xff)"),
+        "Y": ("Short", "(int)(", " & 0xffff)", "(short)(", " & 0xffff)"),
         }
 
 java_size_map = {
@@ -63,9 +66,9 @@ java_types_map = {
         ("int", None): JavaType("int", "int", "jint", "I"),
         ("char", None): JavaType("byte", "byte", "jbyte", "B"),
         ("wchar_t", None): JavaType("char", "char", "jchar", "C"),
-        ("unsigned char", None): JavaType("short", "short", "jshort", "S"),
+        ("unsigned char", None): JavaType("short", "short", "jshort", "X"),
         ("short", None): JavaType("short", "short", "jshort", "S"),
-        ("unsigned short", None): JavaType("int", "int", "jint", "I"),
+        ("unsigned short", None): JavaType("int", "int", "jint", "Y"),
         ("unsigned", None): JavaType("int", "int", "jint", "I"),
         ("unsigned int", None): JavaType("int", "int", "jint", "I"),
         ("uInt32", None): JavaType("int", "int", "jint", "I"),
@@ -431,8 +434,8 @@ structEmit.toArg = "{fname}.getAddress()"
 
 # java type
 jtypeEmit = JavaEmitData()
-jtypeEmit.addBackingRead("{fname} = {backing}.get{jaccessor}({foffset});")
-jtypeEmit.addBackingWrite("{backing}.put{jaccessor}({foffset}, {fname});")
+jtypeEmit.addBackingRead("{fname} = {jaccessor_cast_out_pre}{backing}.get{jaccessor}({foffset}){jaccessor_cast_out_post};")
+jtypeEmit.addBackingWrite("{backing}.put{jaccessor}({foffset}, {jaccessor_cast_in_pre}{fname}{jaccessor_cast_in_post});")
 
 # string - array of characters
 strSizedEmit = JavaEmitData()
@@ -561,7 +564,7 @@ class JavaStructEmitHelper:
         struct_sz = None
         buftype = "ByteBuffer"
         array_size = jtype.array_size or ""
-        jaccessor = None
+        jaccessor = (None, None, None, None, None)
 
         writeBufs = []
         backingRead = []
@@ -612,7 +615,7 @@ for (int i=0, off={foffset}; i<%s; i++, off += {struct_sz})
                 elif jtype.jni_sig[1] == 'B':
                     typeemit = byteArrayEmit
                 elif jtype.jni_sig[1] in java_accessor_map:
-                    buftype = "%sBuffer" % java_accessor_map[jtype.jni_sig[1]]
+                    buftype = "%sBuffer" % java_accessor_map[jtype.jni_sig[1]][0]
                     struct_sz = java_size_map[jtype.jni_sig[1]]
                     typeemit = jtypeArrayEmit
                 else:
@@ -660,7 +663,11 @@ for (int i=0, off={foffset}; i<%s; i++, off += {struct_sz})
                      struct_sz=struct_sz,
                      array_size=array_size,
                      buftype=buftype,
-                     jaccessor=jaccessor,
+                     jaccessor=jaccessor[0],
+                     jaccessor_cast_out_pre=jaccessor[1],
+                     jaccessor_cast_out_post=jaccessor[2],
+                     jaccessor_cast_in_pre=jaccessor[3],
+                     jaccessor_cast_in_post=jaccessor[4],
                      backing=backing)
         jconstruct = [x.format(**fargs) for x in construct]
         jwritebufs = [x.format(**fargs) for x in writeBufs]
@@ -922,7 +929,7 @@ public class {classname} {{
     }}
 
     public static ByteBuffer sliceByteBuffer(ByteBuffer bb, int offset, int size) {{
-        ByteBuffer new_bb = bb.duplicate();
+        ByteBuffer new_bb = bb.duplicate().order(ByteOrder.nativeOrder());
         new_bb.position(offset);
         new_bb.limit(size);
         return new_bb;
@@ -1129,10 +1136,12 @@ public class {classname} {{
 static void throwJavaException(JNIEnv *env) {{
     jclass je = env->FindClass("{packagepath}/VisionException");
     int err = imaqGetLastError();
-    char* err_text = imaqGetErrorText(err);
-    char* full_err_msg = (char*)malloc(30+strlen(err_text));
-    sprintf(full_err_msg, "imaqError: %d: %s", err, err_text);
-    imaqDispose(err_text);
+    //char* err_text = imaqGetErrorText(err);
+    //char* full_err_msg = (char*)malloc(30+strlen(err_text));
+    //sprintf(full_err_msg, "imaqError: %d: %s", err, err_text);
+    //imaqDispose(err_text);
+    char* full_err_msg = (char*)malloc(30);
+    sprintf(full_err_msg, "imaqError: %d", err);
     env->ThrowNew(je, full_err_msg);
     free(full_err_msg);
 }}
@@ -1491,6 +1500,29 @@ JNIEXPORT jint JNICALL Java_{package}_{classname}__1IMAQdxGetImageData(JNIEnv* e
     return (jint)actualBufferNumber;
 }}""".format(package=self.package.replace(".", "_"),
              classname=self.classname), file=self.outc)
+        elif name == "imaqReadFile":
+            print("""
+    public static void imaqReadFile(Image image, String fileName) {{
+        ByteBuffer fileName_buf;
+        byte[] fileName_bytes;
+        try {{
+            fileName_bytes = fileName.getBytes("UTF-8");
+        }} catch (UnsupportedEncodingException e) {{
+            fileName_bytes = new byte[0];
+        }}
+        fileName_buf = ByteBuffer.allocateDirect(fileName_bytes.length+1);
+        putBytes(fileName_buf, fileName_bytes, 0, fileName_bytes.length).put(fileName_bytes.length, (byte)0);
+        _imaqReadFile(image.getAddress(), getByteBufferAddress(fileName_buf), 0, 0);
+    }}
+    private static native void _imaqReadFile(long image, long fileName, long colorTable, long numColors);""".format(), file=self.out)
+            print("""
+JNIEXPORT void JNICALL Java_{package}_{classname}__1imaqReadFile(JNIEnv* env, jclass , jlong image, jlong fileName, jlong colorTable, jlong numColors)
+{{
+    int rv = imaqReadFile((Image*)image, (const char*)fileName, (RGBValue*)colorTable, (int*)numColors);
+    if (rv == 0) throwJavaException(env);
+}}""".format(package=self.package.replace(".", "_"),
+             classname=self.classname), file=self.outc)
+            return
         if self.config_getboolean(name, "exclude", fallback=False):
             return