一、前言二、准备工作OpenGL ES 声明Activity 三、GLSurfaceView和NativeRenderGLSurfaceViewRender 四、NDK和JNINativeRenderJNIC++开发环境搭建安装NDK配置CMakeLists.txtJNI
一、前言
本篇包括：
准备工作GLSurfaceView和NativeRenderNDK和JNI
Demo Github:
二、准备工作
整个项目目录如下：
1. app 业务上层，简单的界面逻辑2. basic 一些通用的工具类3. demos 一些demos存放的地方4. libmedianative native opengl es代码
注意：一般搭建环境，只需要app和native即可，或直接都放在app里
OpenGL ES 声明
<uses-feature android:glEsVersion="0x00030001" android:required="true" />
更详细可参考官方：/guide/topics/graphics/opengl#java
final ConfigurationInfo configurationInfo = activityManager.getDeviceConfigurationInfo();final boolean supportsEs3 = configurationInfo.reqGlEsVersion >= 0x30000
代码层面可根据不同的机型做如上判断
Activity
public class MainActivity extends AppCompatActivity {@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);getWindow().addFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);setContentView(new DefaultGLSurfaceView(this));}}
1. 沉浸式Flag设置2. new DefaultGLSurfaceView
三、GLSurfaceView和NativeRender
GLSurfaceView
public class DefaultGLSurfaceView extends GLSurfaceView {BaseWrapRender baseWrapRender;public DefaultGLSurfaceView(Context context) {this(context,null);}public DefaultGLSurfaceView(Context context, AttributeSet attrs) {super(context, attrs);init();}private void init() {setEGLContextClientVersion(3);baseWrapRender = new BaseWrapRender(new NativeRenderV2(IAssignType.LearnOpenGL.ASSIGN_LEARN_OPENGL_SHADER_UNIFORM_SHADER));setRenderer(baseWrapRender);//RENDERMODE_CONTINUOUSLY 1s 60帧// setRenderMode(GLSurfaceView.RENDERMODE_WHEN_DIRTY);setRenderMode(GLSurfaceView.RENDERMODE_CONTINUOUSLY);}@Overridepublic void surfaceDestroyed(SurfaceHolder holder) {super.surfaceDestroyed(holder);baseWrapRender.onSurfaceDestroyed();}}
注：在源码里详细说明了GLSurfaceView的简单功能和用法An implementation of SurfaceView that uses the dedicated surface for displaying OpenGL rendering.A GLSurfaceView provides the following features:1. Manages a surface, which is a special piece of memory that can be composited into the Android view system.2. Manages an EGL display, which enables OpenGL to render into a surface.3. Accepts a user-provided Renderer object that does the actual rendering.4. Renders on a dedicated thread to decouple rendering performance from the UI thread.5. Supports both on-demand and continuous rendering.6. Optionally wraps, traces, and/or error-checks the renderer's OpenGL calls.
这里就不细说GLSurfaceView，感兴趣的可看源码，主要做了如下几件事情
1. setEGLContextClientVersion(3); 设置version 3 EGL Context2. 设置render -> BaseWrapRender3. 设置render Mode。RENDERMODE_CONTINUOUSLY为连续请求(经测试1s60帧)RENDERMODE_WHEN_DIRTY surface create / 手动调用requestRender触发
Render
public class NativeRenderV2 implements IRender {NativeRenderJni nativeRenderJni;private int assignType = IAssignType.LearnOpenGL.ASSIGN_LEARN_OPENGL_TRIANGLE_SIMPLE;public NativeRenderV2(int assignType) {this.assignType = assignType;}@Overridepublic void init() {AssetManager assetManager = AppContext.basicContext.getAssets();nativeRenderJni = new NativeRenderJni();nativeRenderJni.initV2(assetManager, assignType);}@Overridepublic void onSurfaceCreated() {nativeRenderJni.onSurfaceCreated();}@Overridepublic void onSurfaceChanged(int width, int height) {nativeRenderJni.onSurfaceChanged(width,height);}@Overridepublic void onDrawFrame() {nativeRenderJni.onDrawFrame();}@Overridepublic void onSurfaceDestroyed() {}}
1. BaseWrapRender是实现IRender接口的NativeRender的一层包装2. IRender定义了调用到Native层面的接口。自己也可直接在GLSurfaceView里设置setRender(new NativeRender())这样实现3. 该Render最终都调用到NativeRenderJni类
四、NDK和JNI
NativeRenderJNI
public class NativeRenderJni {public native void init(AssetManager assetManager, int assignType, String vertexShaderAssetName, String fragmentShaderAssetName);public native void initV2(AssetManager assetManager, int assignType);public native void onSurfaceCreated();public native void onSurfaceChanged(int width, int height);public native void onDrawFrame();public native void onDestroy();}
1. AssetManager用于读取放在asset里的glsl shader2. assignType用于区分使用哪类demo
C++开发环境搭建
安装NDK
project Structure选择对应的NDK；如果没有，则去SDK Manager里下载对应的NDK
配置
buildTypes {debug {minifyEnabled falseproguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'externalNativeBuild {cmake {arguments '-DANDROID_PLATFORM=android-21', '-DANDROID_TOOLCHAIN=clang','-DANDROID_ARM_NEON=TRUE', '-DANDROID_STL=c++_static'cFlags '-O3', '-DGL_GLEXT_PROTOTYPES', '-DEGL_EGLEXT_PROTOTYPES', '-fsigned-char', '-Wformat','-mfpu=neon', '-mfloat-abi=softfp -frtti' // full optimization, char data type is signed// 编译优化，设置函式是否能被 inline 的伪指令长度cppFlags '-O3', '-fexceptions', '-fsigned-char',"-frtti -std=c++11", '-Wformat'}}}release {minifyEnabled falseproguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'externalNativeBuild {cmake {arguments '-DANDROID_PLATFORM=android-21', '-DANDROID_TOOLCHAIN=clang','-DANDROID_ARM_NEON=TRUE', '-DANDROID_STL=c++_static'cFlags '-O3', '-DGL_GLEXT_PROTOTYPES', '-DEGL_EGLEXT_PROTOTYPES', '-fsigned-char', '-Wformat','-mfpu=neon', '-mfloat-abi=softfp -frtti'// full optimization, char data type is signed// 编译优化，设置函式是否能被 inline 的伪指令长度cppFlags '-O3', '-fexceptions', '-fsigned-char',"-frtti -std=c++11", '-Wformat'}}}}externalNativeBuild {cmake {path "CMakeLists.txt"version "3.10.2"}}compileOptions {sourceCompatibility = JavaVersion.VERSION_1_8targetCompatibility = JavaVersion.VERSION_1_8}
1. externalNativeBuild配置
CMakeLists.txt
// 版本说明 和build.gradle对应上。具体不同版本号差异可自行查询相关资料cmake_minimum_required(VERSION 3.10.2)//设置code目录变量：PATH_TO_CODE_CORE set(PATH_TO_CODE_CORE ${CMAKE_SOURCE_DIR}/src/main/cpp)//文件操作命令设置全局变量file(GLOB FILES_JNI_LAYER "${PATH_TO_JNI_LAYER}/*.cpp")//将给定目录添加到编译器用来搜索包含文件的目录中。相对路径被解释为相对于当前源目录。include_directories(${PATH_TO_CODE_CORE}/include/)include_directories(${PATH_TO_CODE_CORE}/common/)include_directories(${PATH_TO_CODE_CORE}/jni/)include_directories(${PATH_TO_CODE_CORE}/)//相关库可参考：///ndk/guides/stable_apis#opengl_es_10_/*******log库 日志记录**********///<android/log.h> 包含用于记录到 logcat 的 API。find_library(log-lib log)/**Android 原生应用 APIAPI 包括：资源Choreographer配置输入Looper原生 Activity原生硬件缓冲区原生窗口内存网络传感器存储SurfaceTexture库：libandroid**/find_library(android-lib android)//zlib 压缩//您可以通过添加 <zlib.h> 并链接到 libz 来使用find_library(z-lib z)/***EGLEGL 通过 <EGL/egl.h> 和 <EGL/eglext.h> 头文件提供原生平台接口，用于分配和管理 OpenGL ES 上下文和 Surface。EGL 可让您通过原生代码执行以下操作：列出支持的 EGL 配置。分配和释放 OpenGL ES Surface。创建和销毁 OpenGL ES 上下文。切换或翻转 Surface。**/find_library(EGL-lib EGL)//open gl es 头文件find_library(GLESv3-lib GLESv3)//设置platform-libs变量set(platform-libs${log-lib}${android-lib}${EGL-lib}${GLESv3-lib}${z-lib})//add_library 根据源码文件生成目标库。注意这里需要添加所需要的C++代码。这里只放入了NativeRenderJNI对应的NativeRenderJNI.cppadd_library(openglnative SHARED${FILES_JNI_LAYER}${FILES_LIB_CORE_CODE}${PATH_TO_CODE_CORE}/jni/NativeRenderJNI.cpp)//link libraries => medianative.sotarget_link_libraries(openglnative${platform-libs})
CmakeLists.txt里cmake使用语法具体可参考如下记录：/sunquan9301/AndroidLearning/blob/master/OpenGL/learnnote/Cmake%20Develop%20Guide
此时我们把所有相关的cpp代码编译成了名为openglnative库，因此在App启动的时候需要loadLibrary =>
try {System.loadLibrary("openglnative");} catch (Throwable ignore) {Log.e(TAG, "loadLibrary Load native library failed : " + ignore.getMessage());}
这里我们编译好了相关的C++ native开发环境也引入了相关的库，此时NativeRenderJNI.java和NativeRenderJNI.cpp相对应，在NativeRenderJNI.cpp我们通过JNI建立与NativeRenderJNI.java对应的函数。
JNI
JNI相关资料可自行查阅，android通过JNI链接上层java开发和下层C++开发。JNI有2种链接函数方式静态链接和动态链接。
1. 静态链接根据函数签名方式在编译时注册，可直接在代码里通过提示创建。2. 动态链接在JNI_OnLoad方法里通过registerNativeMethods方式注册
最终在NativeRenderJNI.cpp里呈现如下(部分函数)，输出log验证正确性。
JNIEXPORT void JNICALLJava_com_scott_nativecode_NativeRenderJni_onSurfaceCreated(JNIEnv *env, jobject thiz) {__android_log_print(ANDROID_LOG_DEBUG, "NativeRenderJni", "onSurfaceCreated");}JNIEXPORT void JNICALLJava_com_scott_nativecode_NativeRenderJni_onSurfaceChanged(JNIEnv *env, jobject thiz, jint width,jint height) {}JNIEXPORT void JNICALLJava_com_scott_nativecode_NativeRenderJni_onDrawFrame(JNIEnv *env, jobject thiz) {}
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