Android2.1模擬器運行OpenGL示例出錯問題

　　昨天看了看《Android應用開發揭祕》一書中的OpenGL章節，在2.0上運行沒有任何問題。改用2.1的模擬器運行卻出現問題，根據Logcat顯示程序崩潰的原因是void glVertexPointer(size,  type,  stride,  pointer)這個方法。

 

　　分析原因：書上源碼以及API Demos中緩衝區定義的不同方式

 

書中源碼中的Render：

package com.yarin.android.Examples_12_01; import java.nio.IntBuffer; import javax.microedition.khronos.egl.EGLConfig; import javax.microedition.khronos.opengles.GL10; import android.opengl.GLSurfaceView.Renderer; public class GLRender implements Renderer { int one = 0x10000; private IntBuffer triggerBuffer = IntBuffer.wrap(new int[]{ 0,one,0, -one,-one,0, one,-one,0,}); private IntBuffer quaterBuffer = IntBuffer.wrap(new int[]{ one,one,0, -one,one,0, one,-one,0, -one,-one,0}); @Override public void onDrawFrame(GL10 gl) { gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT); gl.glLoadIdentity(); gl.glTranslatef(-1.5f, 0.0f, -6.0f); gl.glEnableClientState(GL10.GL_VERTEX_ARRAY); gl.glVertexPointer(3, GL10.GL_FIXED, 0, triggerBuffer); gl.glDrawArrays(GL10.GL_TRIANGLES, 0, 3); gl.glLoadIdentity(); gl.glTranslatef(1.5f, 0.0f, -6.0f); gl.glVertexPointer(3, GL10.GL_FIXED, 0, quaterBuffer); gl.glDrawArrays(GL10.GL_TRIANGLE_STRIP, 0, 4); gl.glDisableClientState(GL10.GL_VERTEX_ARRAY); } @Override public void onSurfaceChanged(GL10 gl, int width, int height) { float ratio = (float) width / height; gl.glViewport(0, 0, width, height); gl.glMatrixMode(GL10.GL_PROJECTION); gl.glLoadIdentity(); gl.glFrustumf(-ratio, ratio, -1, 1, 1, 10); gl.glMatrixMode(GL10.GL_MODELVIEW); gl.glLoadIdentity(); } @Override public void onSurfaceCreated(GL10 gl, EGLConfig config) { gl.glShadeModel(GL10.GL_SMOOTH); gl.glClearColor(0, 0, 0, 0); gl.glClearDepthf(1.0f); gl.glEnable(GL10.GL_DEPTH_TEST); gl.glDepthFunc(GL10.GL_LEQUAL); gl.glHint(GL10.GL_PERSPECTIVE_CORRECTION_HINT, GL10.GL_FASTEST); } }

 

API Demos中的Cube：

/* * 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. */ package com.lbz.pack; import java.nio.ByteBuffer; import java.nio.ByteOrder; import java.nio.IntBuffer; import javax.microedition.khronos.opengles.GL10; /** * A vertex shaded cube. */ class Cube { public Cube() { int one = 0x10000; int vertices[] = { -one, -one, -one, one, -one, -one, one, one, -one, -one, one, -one, -one, -one, one, one, -one, one, one, one, one, -one, one, one, }; int colors[] = { 0, 0, 0, one, one, 0, 0, one, one, one, 0, one, 0, one, 0, one, 0, 0, one, one, one, 0, one, one, one, one, one, one, 0, one, one, one, }; byte indices[] = { 0, 4, 5, 0, 5, 1, 1, 5, 6, 1, 6, 2, 2, 6, 7, 2, 7, 3, 3, 7, 4, 3, 4, 0, 4, 7, 6, 4, 6, 5, 3, 0, 1, 3, 1, 2 }; ByteBuffer vbb = ByteBuffer.allocateDirect(vertices.length*4); vbb.order(ByteOrder.nativeOrder()); mVertexBuffer = vbb.asIntBuffer(); mVertexBuffer.put(vertices); mVertexBuffer.position(0); ByteBuffer cbb = ByteBuffer.allocateDirect(colors.length*4); cbb.order(ByteOrder.nativeOrder()); mColorBuffer = cbb.asIntBuffer(); mColorBuffer.put(colors); mColorBuffer.position(0); mIndexBuffer = ByteBuffer.allocateDirect(indices.length); mIndexBuffer.put(indices); mIndexBuffer.position(0); } public void draw(GL10 gl) { gl.glFrontFace(GL10.GL_CW); gl.glVertexPointer(3, GL10.GL_FIXED, 0, mVertexBuffer); gl.glColorPointer(4, GL10.GL_FIXED, 0, mColorBuffer); gl.glDrawElements(GL10.GL_TRIANGLES, 36, GL10.GL_UNSIGNED_BYTE, mIndexBuffer); } private IntBuffer mVertexBuffer; private IntBuffer mColorBuffer; private ByteBuffer mIndexBuffer; }

從這兩段代碼中可以看到定義頂點等Buffer的時候兩者的不同之處，在開發中最好使用API Demos中的方法，這樣就不會出現在2.1中不能運行通過的問題。

　　對於數據結構方面的東西沒有深究，如果有人知道是爲什麼期待您的解答哦……