osg for android (一) 简单几何物体的加载与显示

1. 首先需要一个OSG for android的环境

(1)NDK 现在Eclipse 对NDK已经相当友好了，已经不需要另外cygwin的参与，具体可以参考

Android NDK开发篇(一)：新版NDK环境搭建(免Cygwin，超级快)

(2).OSG for android的编译，参考 osg for android学习之一：windows下编译(亲测通过) 建议编译OpenGL ES2版本.

2.然后加载OSG自带的Example：osgAndroidExampleGLES2

(1)点击菜单键加载文件路径，输入/sdcard/osg/cow.osg(必须先往sdcard创建文件夹osg并把cow.osg放到该文件夹里边)



(2)接着经典的牛出现了:)




3.自带的example太多的代码，这样的代码无论对于NDK的初学者或OSG很不直观，所以本人重写了一个HelloWolrd for

osg的例子。例子很简单，就是简单加载一个四边形并附上颜色。

(1)java代码

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package com.example.helloosg; import javax.microedition.khronos.egl.EGLConfig; import javax.microedition.khronos.opengles.GL10; import android.opengl.GLSurfaceView.Renderer; public class NDKRenderer implements Renderer{ NDKRenderer(){ } @Override public void onSurfaceCreated(GL10 gl, EGLConfig config) { // TODO Auto-generated method stub gl.glEnable(GL10.GL_DEPTH_TEST); } @Override public void onSurfaceChanged(GL10 gl, int width, int height) { // TODO Auto-generated method stub osgNativeLib.init(width, height); } @Override public void onDrawFrame(GL10 gl) { // TODO Auto-generated method stub osgNativeLib.step(); } }

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package com.example.helloosg; public class osgNativeLib { static { System.loadLibrary("osgNativeLib"); } /** * @param width the current view width * @param height the current view height */ public static native void init(int width, int height); public static native void step(); }

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package com.example.helloosg; import android.app.Activity; import android.opengl.GLSurfaceView; import android.os.Bundle; import android.view.Menu; import android.view.MenuItem; import android.widget.TextView; public class MainActivity extends Activity { private GLSurfaceView mGLSurfaceView; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); mGLSurfaceView = new GLSurfaceView(this); mGLSurfaceView.setEGLContextClientVersion(2); NDKRenderer renderer = new NDKRenderer(); this.mGLSurfaceView.setRenderer(renderer); this.setContentView(mGLSurfaceView); } @Override public boolean onCreateOptionsMenu(Menu menu) { // Inflate the menu; this adds items to the action bar if it is present. getMenuInflater().inflate(R.menu.main, menu); return true; } @Override protected void onResume() { // TODO Auto-generated method stub super.onResume(); mGLSurfaceView.onResume(); } @Override protected void onPause() { // TODO Auto-generated method stub super.onPause(); mGLSurfaceView.onPause(); } @Override public boolean onOptionsItemSelected(MenuItem item) { // Handle action bar item clicks here. The action bar will // automatically handle clicks on the Home/Up button, so long // as you specify a parent activity in AndroidManifest.xml. int id = item.getItemId(); if (id == R.id.action_settings) { return true; } return super.onOptionsItemSelected(item); } }

（2）JNI代码

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/ * Created on: 2014-10-19 * Author: VCC */ #include "OsgMainApp.h" OsgMainApp::OsgMainApp() { } void OsgMainApp::initOsgWindow(int x, int y, int width, int height) { __android_log_write(ANDROID_LOG_ERROR, "OSGANDROID", "Init geometry"); _viewer = new osgViewer::Viewer(); _viewer->setUpViewerAsEmbeddedInWindow(x, y, width, height); _viewer->setThreadingModel(osgViewer::ViewerBase::SingleThreaded); _root = new osg::Group(); _viewer->realize(); _viewer->addEventHandler(new osgViewer::StatsHandler); _viewer->addEventHandler( new osgGA::StateSetManipulator( _viewer->getCamera()->getOrCreateStateSet())); _viewer->addEventHandler(new osgViewer::ThreadingHandler); _viewer->addEventHandler(new osgViewer::LODScaleHandler); _manipulator = new osgGA::KeySwitchMatrixManipulator; _manipulator->addMatrixManipulator('1', "Trackball", new osgGA::TrackballManipulator()); _viewer->setCameraManipulator(_manipulator.get()); _viewer->getViewerStats()->collectStats("scene", true); loadModels(); } void OsgMainApp::draw() { _viewer->frame(); } void OsgMainApp::loadModels() { osg::ref_ptr<osg::Node> loadedModel = osgDB::readNodeFile( "/sdcard/osg/cow.osg"); loadedModel->setName("cow"); if (loadedModel != NULL) { __android_log_print(ANDROID_LOG_ERROR, "OSGANDROID", "Not NULL"); } osg::Shader * vshader = new osg::Shader(osg::Shader::VERTEX, gVertexShader); osg::Shader * fshader = new osg::Shader(osg::Shader::FRAGMENT, gFragmentShader); osg::Program * prog = new osg::Program; prog->addShader(vshader); prog->addShader(fshader); osg::ref_ptr<osg::Node> node = createNode(); //loadedModel->getOrCreateStateSet()->setAttribute(prog); node->getOrCreateStateSet()->setAttribute(prog); //_root->addChild(loadedModel); _root->addChild(node); osgViewer::Viewer::Windows windows; _viewer->getWindows(windows); for (osgViewer::Viewer::Windows::iterator itr = windows.begin(); itr != windows.end(); ++itr) { (*itr)->getState()->setUseModelViewAndProjectionUniforms(true); (*itr)->getState()->setUseVertexAttributeAliasing(true); } _viewer->setSceneData(NULL); _viewer->setSceneData(_root.get()); _manipulator->getNode(); _viewer->home(); _viewer->getDatabasePager()->clear(); _viewer->getDatabasePager()->registerPagedLODs(_root.get()); _viewer->getDatabasePager()->setUpThreads(3, 1); _viewer->getDatabasePager()->setTargetMaximumNumberOfPageLOD(2); _viewer->getDatabasePager()->setUnrefImageDataAfterApplyPolicy(true, true); } //创建一个四边形节点 osg::ref_ptr<osg::Node> OsgMainApp::createNode() { //创建一个叶节点对象 osg::ref_ptr<osg::Geode> geode = new osg::Geode(); //创建一个几何体对象 osg::ref_ptr<osg::Geometry> geom = new osg::Geometry(); //添加顶点数据 注意顶点的添加顺序是逆时针 osg::ref_ptr<osg::Vec3Array> v = new osg::Vec3Array(); //添加数据 v->push_back(osg::Vec3(0, 0, 0)); v->push_back(osg::Vec3(1, 0, 0)); v->push_back(osg::Vec3(1, 0, 1)); v->push_back(osg::Vec3(0, 0, 1)); //设置顶点数据 geom->setVertexArray(v.get()); //创建纹理订点数据 osg::ref_ptr<osg::Vec2Array> vt = new osg::Vec2Array(); //添加纹理坐标 vt->push_back(osg::Vec2(0, 0)); vt->push_back(osg::Vec2(1, 0)); vt->push_back(osg::Vec2(1, 1)); vt->push_back(osg::Vec2(0, 1)); //设置纹理坐标 geom->setTexCoordArray(0, vt.get()); //创建颜色数组 osg::ref_ptr<osg::Vec4Array> vc = new osg::Vec4Array(); //添加数据 vc->push_back(osg::Vec4(1, 0, 0, 1)); vc->push_back(osg::Vec4(0, 1, 0, 1)); vc->push_back(osg::Vec4(0, 0, 1, 1)); vc->push_back(osg::Vec4(1, 1, 0, 1)); //设置颜色数组 geom->setColorArray(vc.get()); //设置颜色的绑定方式为单个顶点 geom->setColorBinding(osg::Geometry::BIND_PER_VERTEX); //创建法线数组 osg::ref_ptr<osg::Vec3Array> nc = new osg::Vec3Array(); //添加法线 nc->push_back(osg::Vec3(0, -1, 0)); //设置法线 geom->setNormalArray(nc.get()); //设置法绑定为全部顶点 geom->setNormalBinding(osg::Geometry::BIND_OVERALL); //添加图元 geom->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::QUADS, 0, 4)); //添加到叶子节点 geode->addDrawable(geom.get()); return geode.get(); }

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/* * OsgMainApp.h * * Created on: 2014-10-19 * Author: VCC */ #ifndef OSGMAINAPP_H_ #define OSGMAINAPP_H_ //android log #include <android/log.h> #include <iostream> #include <cstdlib> #include <math.h> #include <string> //osg #include <osg/GL> #include <osg/GLExtensions> #include <osg/Depth> #include <osg/Program> #include <osg/Shader> #include <osg/Node> #include <osg/Notify> #include <osg/ShapeDrawable> #include <osgText/Text> //osgDB #include <osgDB/DatabasePager> #include <osgDB/Registry> #include <osgDB/ReadFile> #include <osgDB/WriteFile> //osg_viewer #include <osgViewer/Viewer> #include <osgViewer/Renderer> #include <osgViewer/ViewerEventHandlers> //osgGA #include <osgGA/GUIEventAdapter> #include <osgGA/MultiTouchTrackballManipulator> #include <osgGA/TrackballManipulator> #include <osgGA/FlightManipulator> #include <osgGA/DriveManipulator> #include <osgGA/KeySwitchMatrixManipulator> #include <osgGA/StateSetManipulator> #include <osgGA/AnimationPathManipulator> #include <osgGA/TerrainManipulator> #include <osgGA/SphericalManipulator> //Static plugins Macro USE_OSGPLUGIN(ive) USE_OSGPLUGIN(osg) USE_OSGPLUGIN(osg2) USE_OSGPLUGIN(terrain) USE_OSGPLUGIN(rgb) USE_OSGPLUGIN(OpenFlight) USE_OSGPLUGIN(dds) //Static DOTOSG USE_DOTOSGWRAPPER_LIBRARY(osg) USE_DOTOSGWRAPPER_LIBRARY(osgFX) USE_DOTOSGWRAPPER_LIBRARY(osgParticle) USE_DOTOSGWRAPPER_LIBRARY(osgTerrain) USE_DOTOSGWRAPPER_LIBRARY(osgText) USE_DOTOSGWRAPPER_LIBRARY(osgViewer) USE_DOTOSGWRAPPER_LIBRARY(osgVolume) //Static serializer USE_SERIALIZER_WRAPPER_LIBRARY(osg) USE_SERIALIZER_WRAPPER_LIBRARY(osgAnimation) USE_SERIALIZER_WRAPPER_LIBRARY(osgFX) USE_SERIALIZER_WRAPPER_LIBRARY(osgManipulator) USE_SERIALIZER_WRAPPER_LIBRARY(osgParticle) USE_SERIALIZER_WRAPPER_LIBRARY(osgTerrain) USE_SERIALIZER_WRAPPER_LIBRARY(osgText) USE_SERIALIZER_WRAPPER_LIBRARY(osgVolume) #define LOG_TAG "osgNativeLib" #define LOGI(...) __android_log_print(ANDROID_LOG_INFO, LOG_TAG, __VA_ARGS__) #define LOGE(...) __android_log_print(ANDROID_LOG_ERROR, LOG_TAG, __VA_ARGS__) static const char gVertexShader[] = "void main() { \n" " gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex; \n" "} \n"; static const char gFragmentShader[] = "void main() { \n" " gl_FragColor =vec4(0.4,0.4,0.8,1.0); \n" "} \n"; class OsgMainApp { private: osg::ref_ptr<osgViewer::Viewer> _viewer; osg::ref_ptr<osg::Group> _root; osg::ref_ptr<osgGA::KeySwitchMatrixManipulator> _manipulator; public: OsgMainApp(); void initOsgWindow(int x,int y,int width,int height); void draw(); private: osg::ref_ptr<osg::Node> createNode(); void loadModels(); }; #endif /* OSGMAINAPP_H_ */

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#include <jni.h> #include <string.h> #include <osg/Node> #include <iostream> #include "OsgMainApp.h" OsgMainApp mainApp; extern "C"{ JNIEXPORT void JNICALL Java_com_example_helloosg_osgNativeLib_init(JNIEnv* env, jobject obj, jint width, jint height); JNIEXPORT void JNICALL Java_com_example_helloosg_osgNativeLib_step(JNIEnv* env, jobject obj); } JNIEXPORT void JNICALL Java_com_example_helloosg_osgNativeLib_init(JNIEnv* env, jobject obj, jint width, jint height) { mainApp.initOsgWindow(0, 0, width, height); } JNIEXPORT void JNICALL Java_com_example_helloosg_osgNativeLib_step(JNIEnv* env, jobject obj){ mainApp.draw(); }

(3).mk文件

android.mk

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LOCAL_PATH := $(call my-dir) include $(CLEAR_VARS) LOCAL_MODULE := osgNativeLib ### Main Install dir OSG_ANDROID_DIR := C:/Develop/osggles2 LIBDIR := $(OSG_ANDROID_DIR)/obj/local/armeabi ifeq ($(TARGET_ARCH_ABI),armeabi-v7a) LOCAL_ARM_NEON := true LIBDIR := $(OSG_ANDROID_DIR)/obj/local/armeabi-v7a endif ### Add all source file names to be included in lib separated by a whitespace LOCAL_C_INCLUDES:= $(OSG_ANDROID_DIR)/include LOCAL_CFLAGS := -fno-short-enums LOCAL_CPPFLAGS := -DOSG_LIBRARY_STATIC LOCAL_LDLIBS := -lGLESv2 -lz -llog LOCAL_SRC_FILES := osgNativeLib.cpp OsgMainApp.cpp LOCAL_LDFLAGS := -L $(LIBDIR) \ -losgdb_dds \ -losgdb_openflight \ -losgdb_tga \ -losgdb_rgb \ -losgdb_osgterrain \ -losgdb_osg \ -losgdb_ive \ -losgdb_deprecated_osgviewer \ -losgdb_deprecated_osgvolume \ -losgdb_deprecated_osgtext \ -losgdb_deprecated_osgterrain \ -losgdb_deprecated_osgsim \ -losgdb_deprecated_osgshadow \ -losgdb_deprecated_osgparticle \ -losgdb_deprecated_osgfx \ -losgdb_deprecated_osganimation \ -losgdb_deprecated_osg \ -losgdb_serializers_osgvolume \ -losgdb_serializers_osgtext \ -losgdb_serializers_osgterrain \ -losgdb_serializers_osgsim \ -losgdb_serializers_osgshadow \ -losgdb_serializers_osgparticle \ -losgdb_serializers_osgmanipulator \ -losgdb_serializers_osgfx \ -losgdb_serializers_osganimation \ -losgdb_serializers_osg \ -losgViewer \ -losgVolume \ -losgTerrain \ -losgText \ -losgShadow \ -losgSim \ -losgParticle \ -losgManipulator \ -losgGA \ -losgFX \ -losgDB \ -losgAnimation \ -losgUtil \ -losg \ -lOpenThreads \ -lgnustl_static include $(BUILD_SHARED_LIBRARY)

application.mk

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#ANDROID APPLICATION MAKEFILE APP_BUILD_SCRIPT := $(call my-dir)/Android.mk #APP_PROJECT_PATH := $(call my-dir) APP_OPTIM := release APP_PLATFORM := android-8 APP_STL := gnustl_static APP_CPPFLAGS := -fexceptions -frtti APP_ABI := armeabi armeabi-v7a APP_MODULES := osgNativeLib

运行结果



注：由于代码是基于OpenGL ES2，简单加载了一个四边形，并在片元着色器将四边形的颜色赋为浅蓝色，其实也可以通过

OSG将四边形的颜色或者纹理赋到四边形上，具体下篇将说明