Opengl ES 1.x NDK实例开发之七:旋转的纹理立方体

开发框架介绍请参见：Opengl
ES NDK实例开发之一:搭建开发框架

本章在第六章(Opengl ES 1.x NDK实例开发之六:纹理贴图)的基础上绘制一个旋转的纹理立方体，原理和纹理贴图一样，需要注意的是定好正方体的顶点数组。

【实例讲解】

本实例添加了一个显示fps的小功能，在java层实现，原理是统计一分钟内屏幕刷新的次数



【实例源码】

[GLJNIActivity.java]

/*
* Copyright (C) 2007 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.
*
* author: mnorst@foxmail.com
*/

package com.android.gljni;

import java.text.DecimalFormat;

import com.android.gljni.GLJNIView;

import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.ViewGroup.LayoutParams;
import android.widget.TextView;

public class GLJNIActivity extends Activity {
GLJNIView mView;
TextView mTextView;

@Override
protected void onCreate(Bundle icicle) {
super.onCreate(icicle);
mView = new GLJNIView(getApplication());
setContentView(mView);

mView.setHandler(new Handler(){
@Override
public void handleMessage(Message msg) {
super.handleMessage(msg);

// 显示fps
mTextView.setText("fps:"+msg.what);
}
}
);

mTextView = new TextView(this);
mTextView.setText("fps:0");
addContentView(mTextView, new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));
}

@Override
protected void onPause() {
super.onPause();
mView.onPause();
}

@Override
protected void onResume() {
super.onResume();
mView.onResume();
}
}

[GLJNIView.java]

/*
* Copyright (C) 2007 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.
*
* author: mnorst@foxmail.com
*/

package com.android.gljni;

import java.io.IOException;
import java.io.InputStream;

import javax.microedition.khronos.egl.EGLConfig;
import javax.microedition.khronos.opengles.GL10;

import com.android.gljni.GLJNILib;
import com.android.gljnidemo07.R;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.opengl.GLSurfaceView;
import android.opengl.GLUtils;
import android.os.Handler;
import android.util.Log;

/**
* A simple GLSurfaceView sub-class that demonstrate how to perform
* OpenGL ES 1.x rendering into a GL Surface.
*/
public class GLJNIView extends GLSurfaceView {

private static final String LOG_TAG = GLJNIView.class.getSimpleName();

private Renderer renderer;

public GLJNIView(Context context) {
super(context);

// setEGLConfigChooser会对fps产生影响
setEGLConfigChooser(8, 8, 8, 8, 16, 0);

renderer = new Renderer(context);
setRenderer(renderer);
}

public void setHandler( Handler handler){
renderer.setHandler(handler);
}

private static class Renderer implements GLSurfaceView.Renderer {
//用于纹理映射的绑定，并把绑定后的ID传递给C++代码，供其调用
private int[] mTexture = new int[2];
//用于加载Bitmap的context
private Context mContext;

// 统计fps
private Handler mHandler;
private long mStartMili;
private long mEndMili;
private int mFps = 0;

public Renderer(Context ctx) {
mContext = ctx;
mStartMili =System.currentTimeMillis();
}

public void setHandler( Handler handler){
mHandler = handler;
}

public void onDrawFrame(GL10 gl) {

GLJNILib.step();

// 以一分钟绘制的帧数来统计fps
mEndMili = System.currentTimeMillis();
if( mEndMili - mStartMili > 1000 ){
mHandler.sendEmptyMessageDelayed(mFps, 100);
mStartMili = mEndMili;
mFps = 0;
}
mFps++;
}

public void onSurfaceChanged(GL10 gl, int width, int height) {
GLJNILib.resize(width, height);
}

public void onSurfaceCreated(GL10 gl, EGLConfig config) {
//用来绑定Bitmap纹理
genTexture(gl, mContext);
//调用本地setTexture方法，把纹理绑定的ID传递给C++代码，以供其调用
GLJNILib.setTexture(mTexture);
GLJNILib.init();
}

/**
* 加载Bitmap的方法，
* 用来从res中加载Bitmap资源
* */
private Bitmap loadBitmap(Context context, int resourceId) {
InputStream is = context.getResources().openRawResource(resourceId);
Bitmap bitmap = null;
try {

// 利用BitmapFactory生成Bitmap
bitmap = BitmapFactory.decodeStream(is);
} finally {
try {

// 关闭流
is.close();
is = null;
} catch (IOException e) {
e.printStackTrace();
}

}
return bitmap;

}

/**
* 绑定Bitmap纹理
* */

private void genTexture(GL10 gl, Context context) {
//生成纹理
gl.glGenTextures(2, mTexture, 0);
//加载Bitmap
Bitmap bitmap = loadBitmap(context, R.drawable.logo);
if (bitmap != null) {
//如果bitmap加载成功，则生成此bitmap的纹理映射
gl.glBindTexture(GL10.GL_TEXTURE_2D, mTexture[0]);
//设置纹理映射的属性
gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_MIN_FILTER,
GL10.GL_NEAREST);
gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_MAG_FILTER,
GL10.GL_NEAREST);
//生成纹理映射
GLUtils.texImage2D(GL10.GL_TEXTURE_2D, 0, bitmap, 0);
//释放bitmap资源
bitmap.recycle();
}

}
}

}

[GLJNILib.java]

/*
* Copyright (C) 2007 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.
*
* author: mnorst@foxmail.com
*/

package com.android.gljni;

//Wrapper for native library
public class GLJNILib {

static {
System.loadLibrary("gljni");
}

/**
* @param width the current view width
* @param height the current view height
*/
public static native void resize(int width, int height);

/**
* render
*/
public static native void step();

/**
* init
*/
public static native void init();

/**
* set the texture
* @param texture	texture id
*/
public static native void setTexture(int[] texture);
}

[[gl_code.cpp]

/*
* Copyright (C) 2007 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.
*
* author: 	mnorst@foxmail.com
* created:	2014/10/27
* purpose:	旋转的纹理立方体
*/

// OpenGL ES 1.x code

#include <jni.h>
#include <android/log.h>

#include <GLES/gl.h>
#include <GLES/glext.h>

#include <stdio.h>
#include <stdlib.h>
#include <math.h>

/************************************************************************/
/*                             定义                                     */
/************************************************************************/

#define  LOG_TAG    "libgljni"
#define  LOGI(...)  __android_log_print(ANDROID_LOG_INFO,LOG_TAG,__VA_ARGS__)
#define  LOGE(...)  __android_log_print(ANDROID_LOG_ERROR,LOG_TAG,__VA_ARGS__)

//初始化纹理数组
GLuint *gTexture = 0;

// 定义π
const GLfloat PI = 3.1415f;

// 定义顶点坐标
#define pos 1.0f

// 定义顶点坐标
// 一个正方体有8个顶点,6个面
#define one 1.0f
static GLfloat gVertices[] = {
one, one, -one,
-one, one, -one,
one, one, one,

-one, one, one,
one, -one,one,
-one, -one, one,

one, -one, -one,
-one, -one, -one,
one, one,one,

-one, one, one,
one, -one, one,
-one, -one, one,

one, -one,-one,
-one, -one, -one,
one, one, -one,

-one, one, -one,
-one, one,one,
-one, one, -one,

-one, -one, one,
-one, -one, -one,
one, one,-one,

one, one, one,
one, -one, -one,
one, -one, one
};

// 定义纹理坐标
// 纹理坐标原点会因不同系统环境而有所不同。
// 比如在iOS以及Android上，纹理坐标原点（0, 0）是在左上角
// 而在OS X上，纹理坐标的原点是在左下角
static GLfloat gTexCoords[] = {
0, one,
one, one,
0, 0,
one, 0,

0, one,
one, one,
0, 0,
one, 0,

0, one,
one, one,
0, 0,
one, 0,

0, one,
one, one,
0, 0,
one, 0,

0, one,
one, one,
0, 0,
one, 0,

0, one,
one, one,
0, 0,
one, 0,

};

// 旋转角度
static GLfloat gAngle = 0.0f;
/************************************************************************/
/*                             C++代码                                  */
/************************************************************************/

static void printGLString(const char *name, GLenum s) {
const char *v = (const char *) glGetString(s);
LOGI("GL %s = %s\n", name, v);
}

static void checkGlError(const char* op) {
for (GLint error = glGetError(); error; error = glGetError()) {
LOGI("after %s() glError (0x%x)\n", op, error);
}
}

bool init() {
printGLString("Version", GL_VERSION);
printGLString("Vendor", GL_VENDOR);
printGLString("Renderer", GL_RENDERER);
printGLString("Extensions", GL_EXTENSIONS);

// 启用阴影平滑
glShadeModel(GL_SMOOTH);

// 黑色背景
glClearColor(0.0f, 0.0f, 0.0f, 0.0f);

// 设置深度缓存
glClearDepthf(1.0f);

// 启用深度测试
glEnable(GL_DEPTH_TEST);

// 所作深度测试的类型
glDepthFunc(GL_LEQUAL);

// 对透视进行修正
glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);

return true;
}

static void _gluPerspective(GLfloat fovy, GLfloat aspect, GLfloat zNear, GLfloat zFar)
{
GLfloat top = zNear * ((GLfloat) tan(fovy * PI / 360.0));
GLfloat bottom = -top;
GLfloat left = bottom * aspect;
GLfloat right = top * aspect;
glFrustumf(left, right, bottom, top, zNear, zFar);
}

void resize(int width, int height)
{
// 防止被零除
if (height==0)
{
height=1;
}

// 重置当前的视口
glViewport(0, 0, width, height);
// 选择投影矩阵
glMatrixMode(GL_PROJECTION);
// 重置投影矩阵
glLoadIdentity();

// 设置视口的大小
_gluPerspective(45.0f,(GLfloat)width/(GLfloat)height,0.1f,100.0f);

// 选择模型观察矩阵
glMatrixMode(GL_MODELVIEW);

// 重置模型观察矩阵
glLoadIdentity();
}

void renderFrame() {
// 清除屏幕和深度缓存
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
// 重置当前的模型观察矩阵
glLoadIdentity();

glTranslatef(0,0,-10.0f);
glRotatef(gAngle, 0, 1.0F, 0);
glRotatef(gAngle, 0, 0, 1.0F);

// 启用顶点数组
glEnableClientState(GL_VERTEX_ARRAY);
//glEnableClientState(GL_COLOR_ARRAY);
glEnableClientState(GL_TEXTURE_COORD_ARRAY);

// 启用纹理映射
glEnable(GL_TEXTURE_2D);

// 选择纹理
glBindTexture(GL_TEXTURE_2D, gTexture[0]);

// 绘制正方体的六个面
glVertexPointer(3,GL_FLOAT,0,gVertices);
glTexCoordPointer(2, GL_FLOAT, 0, gTexCoords);

for (int i = 0; i < 6; i++) {
glDrawArrays(GL_TRIANGLE_STRIP, i * 4, 4);
}

// 关闭顶点数组
glDisableClientState(GL_VERTEX_ARRAY);
glDisableClientState(GL_TEXTURE_COORD_ARRAY);
//glDisableClientState(GL_OLOR_ARRAY);

gAngle += 5.f;
}

/************************************************************************/
/*                          JNI代码                                     */
/************************************************************************/

extern "C" {
JNIEXPORT void JNICALL Java_com_android_gljni_GLJNILib_resize(JNIEnv * env, jobject obj,  jint width, jint height);
JNIEXPORT void JNICALL Java_com_android_gljni_GLJNILib_step(JNIEnv * env, jobject obj);
JNIEXPORT void JNICALL Java_com_android_gljni_GLJNILib_init(JNIEnv * env, jobject obj);
JNIEXPORT void JNICALL Java_com_android_gljni_GLJNILib_setTexture(JNIEnv * env, jclass obj, jintArray tex);
};

JNIEXPORT void JNICALL Java_com_android_gljni_GLJNILib_resize(JNIEnv * env, jobject obj,  jint width, jint height)
{
resize(width, height);
}

JNIEXPORT void JNICALL Java_com_android_gljni_GLJNILib_step(JNIEnv * env, jobject obj)
{
renderFrame();
}

JNIEXPORT void JNICALL Java_com_android_gljni_GLJNILib_init(JNIEnv * env, jobject obj)
{
init();
}

JNIEXPORT void JNICALL Java_com_android_gljni_GLJNILib_setTexture(JNIEnv * env, jclass obj, jintArray tex)
{
gTexture = (GLuint *)env->GetIntArrayElements(tex,0);
}

源码工程：http://download.csdn.net/detail/mnorst/8123375