[JNI] Cách truyền Struct từ JAVA parameter xuống C++

[haian]

đây là hàm trên JAVA:

public native void drawPage(Canvas canvas, int page);

hàm dưới C++

static SkCanvas* getCanvas(JNIEnv* env, jobject jcanvas) {
	return (SkCanvas*) env->GetIntField(jcanvas, fields.nativeCanvas);
}

/*
 * Method:    drawPage
 * Signature: (Landroid/graphics/Canvas;I)V
 */
static void drawPage(JNIEnv *env, jobject clazz, jobject jcanvas, jint page) {
	PDFDoc *doc = getDoc(env, clazz);

	if (!doc || !doc->isOk())
		return;

	SkCanvas *canvas = getCanvas(env, jcanvas);

	AndroidOutputDev out(canvas, doc->getXRef());
	double hDPI = gethDPI(env, clazz);
	double vDPI = getvDPI(env, clazz);
	int rotate = getRotate(env, clazz);
	int useMediaBox = getUseMediaBox(env, clazz);
	int crop = getCrop(env, clazz);

	LOGV("page: %d", page);

	doc->displayPage(&out, (int)page, hDPI, vDPI, rotate, useMediaBox, crop,
			0, NULL, NULL, NULL, NULL);
}

mình hỏi là SkCanvas nó tưong đưong với import android.graphics.Canvas à ???