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/*
* Copyright 2013 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#pragma once
#include <jni.h>
#include <vector>
#include <string>
#include <android/log.h>
#include <android_native_app_glue.h>
#define LOGI(...) ((void)__android_log_print(ANDROID_LOG_INFO, ndk_helper::JNIHelper::GetInstance()->GetAppName(), __VA_ARGS__))
#define LOGW(...) ((void)__android_log_print(ANDROID_LOG_WARN, ndk_helper::JNIHelper::GetInstance()->GetAppName(), __VA_ARGS__))
#define LOGE(...) ((void)__android_log_print(ANDROID_LOG_ERROR, ndk_helper::JNIHelper::GetInstance()->GetAppName(), __VA_ARGS__))
namespace ndk_helper
{
/******************************************************************
* Helper functions for JNI calls
* This class wraps JNI calls and provides handy interface calling commonly used features
* in Java SDK.
* Such as
* - loading graphics files (e.g. PNG, JPG)
* - character code conversion
* - retrieving system properties which only supported in Java SDK
*
* NOTE: To use this class, add NDKHelper.java as a corresponding helpers in Java code
*/
class JNIHelper
{
private:
std::string app_name_;
ANativeActivity* activity_;
jobject jni_helper_java_ref_;
jclass jni_helper_java_class_;
//mutex for synchronization
//This class uses singleton pattern and can be invoked from multiple threads,
//each methods locks the mutex for a thread safety
mutable pthread_mutex_t mutex_;
jstring GetExternalFilesDirJString( JNIEnv *env );
jclass RetrieveClass( JNIEnv *jni,
const char* class_name );
JNIHelper();
~JNIHelper();
JNIHelper( const JNIHelper& rhs );
JNIHelper& operator=( const JNIHelper& rhs );
public:
/*
* To load your own Java classes, JNIHelper requires to be initialized with a ANativeActivity handle.
* This methods need to be called before any call to the helper class.
* Static member of the class
*
* arguments:
* in: activity, pointer to ANativeActivity. Used internally to set up JNI environment
* in: helper_class_name, pointer to Java side helper class name. (e.g. "com/sample/helper/NDKHelper" in samples )
*/
static void Init( ANativeActivity* activity,
const char* helper_class_name );
/*
* Retrieve the singleton object of the helper.
* Static member of the class
* Methods in the class are designed as thread safe.
*/
static JNIHelper* GetInstance();
/*
* Read a file from a strorage.
* First, the method tries to read the file from an external storage.
* If it fails to read, it falls back to use assset manager and try to read the file from APK asset.
*
* arguments:
* in: file_name, file name to read
* out: buffer_ref, pointer to a vector buffer to read a file.
* when the call succeeded, the buffer includes contents of specified file
* when the call failed, contents of the buffer remains same
* return:
* true when file read succeeded
* false when it failed to read the file
*/
bool ReadFile( const char* file_name,
std::vector<uint8_t>* buffer_ref );
/*
* Load and create OpenGL texture from given file name.
* The method invokes BitmapFactory in Java so it can read jpeg/png formatted files
*
* The methods creates mip-map and set texture parameters like this,
* glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_NEAREST );
* glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR );
* glGenerateMipmap( GL_TEXTURE_2D );
*
* arguments:
* in: file_name, file name to read, PNG&JPG is supported
* return:
* OpenGL texture name when the call succeeded
* When it failed to load the texture, it returns -1
*/
uint32_t LoadTexture( const char* file_name );
/*
* Convert string from character code other than UTF-8
*
* arguments:
* in: str, pointer to a string which is encoded other than UTF-8
* in: encoding, pointer to a character encoding string.
* The encoding string can be any valid java.nio.charset.Charset name
* e.g. "UTF-16", "Shift_JIS"
* return: converted input string as an UTF-8 std::string
*/
std::string ConvertString( const char* str,
const char* encode );
/*
* Retrieve external file directory through JNI call
*
* return: std::string containing external file diretory
*/
std::string GetExternalFilesDir();
/*
* Audio helper
* Retrieves native audio buffer size which is required to achieve low latency audio
*
* return: Native audio buffer size which is a hint to achieve low latency audio
* If the API is not supported (API level < 17), it returns 0
*/
int32_t GetNativeAudioBufferSize();
/*
* Audio helper
* Retrieves native audio sample rate which is required to achieve low latency audio
*
* return: Native audio sample rate which is a hint to achieve low latency audio
*/
int32_t GetNativeAudioSampleRate();
/*
* Retrieves application bundle name
*
* return: pointer to an app name string
*
*/
const char* GetAppName()
{
return app_name_.c_str();
}
};
} //namespace ndkHelper
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