diff --git a/android/android.c.v b/android/android.c.v
index 0f702e2..e7850a2 100644
--- a/android/android.c.v
+++ b/android/android.c.v
@@ -11,7 +11,7 @@ pub fn env() &jni.Env {
 }
 */
 
-pub fn activity() ?&os.NativeActivity {
+pub fn activity() !&os.NativeActivity {
 	actvty := &os.NativeActivity(C.sapp_android_get_native_activity())
 	if isnil(actvty) {
 		return error(@MOD + '.' + @FN + ': could not get reference to Android native activity')
diff --git a/android/keyboard/keyboard.v b/android/keyboard/keyboard.v
index 67daede..475d0f8 100644
--- a/android/keyboard/keyboard.v
+++ b/android/keyboard/keyboard.v
@@ -191,9 +191,9 @@ pub fn is_visible() bool {
 
 		// Release references to objects
 		jni.delete_local_ref(env, view_visible_rect)
-		jni.delete_local_ref(env, &jni.JavaObject(voidptr(&rect_class)))
+		jni.delete_local_ref(env, jni.JavaObject(rect_class))
 		jni.delete_local_ref(env, display_dimension)
-		jni.delete_local_ref(env, &jni.JavaObject(voidptr(&view_class)))
+		jni.delete_local_ref(env, jni.JavaObject(view_class))
 
 		// hack := display_height - status_bar_height != view_visible_height // ??? Original code had this
 		// but it doesn't work on devices with where the primary keys are software keys places in a bar in the bottom.
diff --git a/examples/android/keyboard/keyboard.v b/examples/android/keyboard/keyboard.v
index ad734f2..aabbdb3 100644
--- a/examples/android/keyboard/keyboard.v
+++ b/examples/android/keyboard/keyboard.v
@@ -39,7 +39,7 @@ fn on_soft_keyboard_input(env &jni.Env, thiz jni.JavaObject, app_ptr i64, jstr j
 	buffer := jni.j2v_string(env, jstr)
 	println(@MOD + '.' + @FN + ': "${buffer}" (${start},${before},${count})')
 
-	mut char_code := byte(0)
+	mut char_code := u8(0)
 	mut char_literal := ''
 
 	mut pos := start + before
@@ -49,7 +49,7 @@ fn on_soft_keyboard_input(env &jni.Env, thiz jni.JavaObject, app_ptr i64, jstr j
 		// Backspace
 		println(@MOD + '.' + @FN + ': ${start} > ${buffer.len}')
 	} else {
-		char_code = byte(buffer[pos])
+		char_code = u8(buffer[pos])
 		char_literal = char_code.ascii_str()
 	}
 
@@ -173,7 +173,7 @@ fn event(ev &gg.Event, mut app App) {
 
 fn main() {
 	mut app := &App{
-		gg: 0
+		gg: unsafe { nil }
 	}
 
 	app.gg = gg.new_context(
diff --git a/examples/android/toast/toast.v b/examples/android/toast/toast.v
index 5e29e4a..c8a9864 100644
--- a/examples/android/toast/toast.v
+++ b/examples/android/toast/toast.v
@@ -76,30 +76,8 @@ fn draw_triangle() {
 fn init(mut app App) {
 	desc := sapp.create_desc()
 	gfx.setup(&desc)
-	sgl_desc := sgl.Desc{
-		max_vertices: 50 * 65536
-	}
+	sgl_desc := sgl.Desc{}
 	sgl.setup(&sgl_desc)
-
-	// 3d pipeline
-	mut pipdesc := gfx.PipelineDesc{}
-	unsafe { vmemset(&pipdesc, 0, int(sizeof(pipdesc))) }
-
-	color_state := gfx.ColorState{
-		blend: gfx.BlendState{
-			enabled: true
-			src_factor_rgb: .src_alpha
-			dst_factor_rgb: .one_minus_src_alpha
-		}
-	}
-	pipdesc.colors[0] = color_state
-
-	pipdesc.depth = gfx.DepthState{
-		write_enabled: true
-		compare: .less_equal
-	}
-	pipdesc.cull_mode = .back
-	app.pip_3d = sgl.make_pipeline(&pipdesc)
 }
 
 fn cleanup(mut app App) {
@@ -130,7 +108,7 @@ fn event(ev &gg.Event, mut app App) {
 fn main() {
 	// App init
 	mut app := &App{
-		gg: 0
+		gg: unsafe { nil }
 	}
 
 	app.gg = gg.new_context(
diff --git a/jni.c.v b/jni.c.v
index bf18e0a..874140c 100644
--- a/jni.c.v
+++ b/jni.c.v
@@ -12,98 +12,110 @@ pub enum Version {
 	v10  = 0x000a0000 // C.JNI_VERSION_10
 }
 
-type JavaVM = C.JavaVM
-type Env = C.JNIEnv
+pub type JavaVM = C.JavaVM
+pub type Env = C.JNIEnv
 
 // type JavaByte = C.jbyte
-type JavaObject = C.jobject
-type JavaString = C.jstring
-type JavaClass = C.jclass
+pub type JavaObject = voidptr // C.jobject
+pub type JavaString = voidptr // C.jstring
+pub type JavaClass = voidptr // C.jclass
 
 // type JavaSize = C.jsize
-type JavaMethodID = C.jmethodID
-type JavaFieldID = C.jfieldID
-type JavaThrowable = C.jthrowable
+pub type JavaMethodID = C.jmethodID
+pub type JavaFieldID = C.jfieldID
+pub type JavaThrowable = voidptr // C.jthrowable = C.jobject = void*
 
 //
-type JavaArray = C.jarray
-type JavaByteArray = C.jbyteArray
-type JavaCharArray = C.jcharArray
-type JavaShortArray = C.jshortArray
-type JavaIntArray = C.jintArray
-type JavaLongArray = C.jlongArray
-type JavaFloatArray = C.jfloatArray
-type JavaDoubleArray = C.jdoubleArray
-type JavaObjectArray = C.jobjectArray
+pub type JavaArray = voidptr // C.jarray
+pub type JavaByteArray = voidptr // C.jbyteArray
+pub type JavaCharArray = voidptr // C.jcharArray
+pub type JavaShortArray = voidptr // C.jshortArray
+pub type JavaIntArray = voidptr // C.jintArray
+pub type JavaLongArray = voidptr // C.jlongArray
+pub type JavaFloatArray = voidptr // C.jfloatArray
+pub type JavaDoubleArray = voidptr // C.jdoubleArray
+pub type JavaObjectArray = voidptr // C.jobjectArray
 
 pub type JavaValue = C.jvalue
 
-// jni.h
-@[typedef]
-struct C.jstring {}
+// For more info on the C types see https://docs.oracle.com/javase/8/docs/technotes/guides/jni/spec/types.html
 
-@[typedef]
-struct C.JNIEnv {}
+pub type C.jboolean = u8
 
-@[typedef]
-struct C.JavaVM {}
+pub type C.jbyte = i8
 
-@[typedef]
-struct C.jobject {}
+pub type C.jchar = u16
 
-@[typedef]
-struct C.jclass {}
+pub type C.jshort = i16
 
-@[typedef]
-struct C.jmethodID {}
+pub type C.jint = i32
 
-@[typedef]
-struct C.jfieldID {}
+pub type C.jlong = i64
 
-@[typedef]
-struct C.jthrowable {}
+pub type C.jfloat = f32
+
+pub type C.jdouble = f64
+
+pub type C.jsize = i32 // C.jint
+
+// jni.h
 
 @[typedef]
-struct C.jweak {}
+pub struct C.JNIEnv {}
 
-//
 @[typedef]
-struct C.JNINativeMethod {
-	name      &char
-	signature &char
-	fn_ptr    voidptr
-}
+pub struct C.JavaVM {}
+
+pub type C.jobject = voidptr
+
+pub type C.jclass = voidptr // C.jobject = void*
+
+pub type C.jstring = voidptr
 
 // Arrays
-@[typedef]
-struct C.jarray {}
+pub type C.jarray = voidptr
 
-@[typedef]
-struct C.jbyteArray {}
+pub type C.jobjectArray = voidptr // C.jarray = C.jobject = void*
 
-@[typedef]
-struct C.jcharArray {}
+pub type C.jbooleanArray = voidptr // C.jarray = C.jobject = void*
 
-@[typedef]
-struct C.jshortArray {}
+pub type C.jbyteArray = voidptr // C.jarray = C.jobject = void*
 
-@[typedef]
-struct C.jintArray {}
+pub type C.jcharArray = voidptr // C.jarray = C.jobject = void*
+
+pub type C.jshortArray = voidptr // C.jarray = C.jobject = void*
+
+pub type C.jintArray = voidptr // C.jarray = C.jobject = void*
+
+pub type C.jlongArray = voidptr // C.jarray = C.jobject = void*
+
+pub type C.jfloatArray = voidptr // C.jarray = C.jobject = void*
+
+pub type C.jdoubleArray = voidptr // C.jarray = C.jobject = void*
+
+// Misc
+pub type C.jthrowable = voidptr // C.jobject = void*
+pub type C.jweak = voidptr // C.jobject = void*
 
 @[typedef]
-struct C.jlongArray {}
+pub struct C.jmethodID {}
 
 @[typedef]
-struct C.jfloatArray {}
+pub struct C.jfieldID {}
 
 @[typedef]
-struct C.jdoubleArray {}
+pub struct C.jthrowable {}
 
+//
 @[typedef]
-struct C.jobjectArray {}
+pub struct C.JNINativeMethod {
+	name      &char
+	signature &char
+	fn_ptr    voidptr
+}
 
 @[typedef]
-union C.jvalue {
+pub union C.jvalue {
 	z C.jboolean
 	b C.jbyte
 	c C.jchar
@@ -167,7 +179,7 @@ pub fn find_class(env &Env, name string) JavaClass {
 	}
 	n := name.replace('.', '/')
 	$if debug {
-		mut cls := C.jclass(0) //{}
+		mut cls := JavaClass(unsafe { nil }) // C.jclass(0)
 		$if android {
 			cls = C.gFindClass(n.str)
 		} $else {
@@ -176,7 +188,7 @@ pub fn find_class(env &Env, name string) JavaClass {
 		if exception_check(env) {
 			exception_describe(env)
 			if !isnil(cls) {
-				o := &JavaObject(voidptr(&cls)) // o := C.ClassToObject(cls)
+				o := JavaObject(cls) // o := C.ClassToObject(cls)
 				// o := C.ClassToObject(cls)
 				delete_local_ref(env, o)
 			}
@@ -338,7 +350,7 @@ pub fn get_method_id(env &Env, clazz JavaClass, name string, sig string) JavaMet
 		if exception_check(env) {
 			exception_describe(env)
 			if !isnil(mid) {
-				o := &JavaObject(voidptr(&mid)) // o := C.MethodIDToObject(mid)
+				o := JavaObject(mid) // o := C.MethodIDToObject(mid)
 				delete_local_ref(env, o)
 			}
 			panic(@MOD + '.' + @FN +
@@ -691,8 +703,8 @@ pub fn set_object_field(env &Env, obj JavaObject, field_id JavaFieldID, val Java
 
 pub fn set_string_field(env &Env, obj JavaObject, field_id JavaFieldID, val string) {
 	jstr := jstring(env, val)
-	jobj := &JavaObject(voidptr(&jstr))
-	set_object_field(env, obj, field_id, jobj)
+	// jobj := &JavaObject(voidptr(&jstr))
+	set_object_field(env, obj, field_id, jstr)
 }
 
 fn C.SetBooleanField(env &C.JNIEnv, obj C.jobject, fieldID C.jfieldID, val C.jboolean)
@@ -743,7 +755,7 @@ pub fn get_static_method_id(env &Env, clazz JavaClass, name string, sig string)
 		if exception_check(env) {
 			exception_describe(env)
 			if !isnil(mid) {
-				o := &JavaObject(voidptr(&mid)) // o := C.MethodIDToObject(mid)
+				o := JavaObject(mid) // TODO? o := C.MethodIDToObject(mid)
 				delete_local_ref(env, o)
 			}
 			// clsn := get_class_name(env, clazz)
@@ -1168,4 +1180,12 @@ fn C.GetDirectBufferCapacity(env &C.JNIEnv, buf C.jobject) C.jlong
 
 // New JNI 1.6 Features
 
-fn C.GetObjectRefType(env &C.JNIEnv, obj C.jobject) C.jobjectRefType
+// JObjectRefType is C.jobjectRefType
+pub enum JObjectRefType {
+	invald      = C.JNIInvalidRefType // = 0,
+	local       = C.JNILocalRefType // = 1,
+	global      = C.JNIGlobalRefType // = 2,
+	weak_global = C.JNIWeakGlobalRefType // = 3
+}
+
+fn C.GetObjectRefType(env &C.JNIEnv, obj C.jobject) JObjectRefType
diff --git a/jni.v b/jni.v
index b56526e..1db05e6 100644
--- a/jni.v
+++ b/jni.v
@@ -292,8 +292,8 @@ pub fn call_object_method(env &Env, obj JavaObject, signature string, args ...Ty
 
 fn get_class_static_method_id(env &Env, fqn_sig string) (JavaClass, JavaMethodID) {
 	clazz, fn_name, fn_sig := v2j_signature(fqn_sig)
-	// mut jclazz := JavaClass{}
-	mut jclazz := C.jclass(0)
+
+	mut jclazz := JavaClass(unsafe { nil })
 	// Find the Java class
 	$if android {
 		jclazz = find_class(default_env(), clazz)
@@ -340,7 +340,8 @@ pub fn (jo JavaObject) call(env &Env, typ MethodType, signature string, args ...
 @[inline]
 pub fn (jc JavaClass) get_name(env &Env) string {
 	unsafe {
-		o := &JavaObject(voidptr(&jc))
+		// o := &JavaObject(voidptr(&jc))
+		o := JavaObject(jc)
 		return o.class_name(env)
 	}
 }
diff --git a/types.v b/types.v
index de5f8e2..088c9e3 100644
--- a/types.v
+++ b/types.v
@@ -180,7 +180,8 @@ pub fn v2j_value(env &Env, vt Type) JavaValue {
 		}
 		string {
 			jstr := jstring(env, vt)
-			jobj := &JavaObject(voidptr(&jstr))
+			// jobj := &JavaObject(voidptr(&jstr))
+			jobj := JavaObject(jstr)
 			JavaValue{
 				l: jobj
 			}
@@ -231,7 +232,7 @@ pub fn j2v_byte(jbyte C.jbyte) u8 {
 
 @[inline]
 pub fn j2v_boolean(jbool C.jboolean) bool {
-	return jbool == C.jboolean(C.JNI_TRUE)
+	return jbool == C.JNI_TRUE // C.jboolean(C.JNI_TRUE)
 }
 
 @[inline]
@@ -267,49 +268,49 @@ pub fn j2v_double(jdouble C.jdouble) f64 {
 @[inline]
 pub fn jboolean(val bool) C.jboolean {
 	if val {
-		return C.jboolean(C.JNI_TRUE)
+		return u8(C.JNI_TRUE) // C.jboolean(C.JNI_TRUE)
 	}
-	return C.jboolean(C.JNI_FALSE)
+	return u8(C.JNI_FALSE) // C.jboolean(C.JNI_FALSE)
 }
 
 @[inline]
 pub fn jbyte(val u8) C.jbyte {
-	return C.jbyte(val)
+	return val // C.jbyte(val)
 }
 
 @[inline]
 pub fn jfloat(val f32) C.jfloat {
-	return C.jfloat(val)
+	return val // C.jfloat(val)
 }
 
 @[inline]
 pub fn jdouble(val f64) C.jdouble {
-	return C.jdouble(val)
+	return val // C.jdouble(val)
 }
 
 @[inline]
 pub fn jint(val int) C.jint {
-	return C.jint(val)
+	return i32(val) // C.jint(val)
 }
 
 @[inline]
 pub fn jsize(val int) C.jsize {
-	return C.jsize(val)
+	return i32(val) // C.jsize(val) = C.jint = i32
 }
 
 @[inline]
 pub fn jshort(val i16) C.jshort {
-	return C.jshort(val)
+	return val // C.jshort(val)
 }
 
 @[inline]
 pub fn jlong(val i64) C.jlong {
-	return C.jlong(val)
+	return val // C.jlong(val)
 }
 
 @[inline]
 pub fn jchar(val rune) C.jchar {
-	return C.jchar(val)
+	return u16(val) // C.jchar(val)
 }
 
 @[inline]
diff --git a/util.c.v b/util.c.v
index a2fdb12..56b9d7b 100644
--- a/util.c.v
+++ b/util.c.v
@@ -15,7 +15,7 @@ pub fn set_java_vm(vm &JavaVM) {
 }
 
 pub fn env_detach() (&Env, bool) {
-	env := &C.JNIEnv(0)
+	env := &C.JNIEnv(unsafe { nil })
 	need_detach := C.gEnvNeedDetach(&env)
 
 	if isnil(env) {