android–GLSurfaceView onDrawFrame清除行为

概述我使用GLSurfaceView遇到了不同的行为.AFAIK是程序的责任,清除每帧的缓冲区(颜色和深度).这意味着如果我不清除缓冲区,我会得到最后一帧的内容(或者之前用于双缓冲的内容).似乎无论在某些设备上是什么,缓冲区都被清除了.我在Addison Wesley OpenglES2.0编程指南中对一些具有不同结果的测试设备进行了“Hello Triangl

我使用GLSurfaceVIEw遇到了不同的行为.
AFAIK是程序的责任,清除每帧的缓冲区(颜色和深度).这意味着如果我不清除缓冲区,我会得到最后一帧的内容(或者之前用于双缓冲的内容).

似乎无论在某些设备上是什么,缓冲区都被清除了.我在Addison Wesley OpenglES2.0编程指南中对一些具有不同结果的测试设备进行了“Hello Triangle”程序的以下修改：

> Acer Iconia A500(4.0.3)：未清除(预期行为)
> Sony XPERIA Go(4.0.4)：已清除
> galaxy S3(4.1.1)：清除
> LG Optimus 4x HD(4.0.3)：未清除
>三星galaxy Tab 20.1(4.0.4)：未清除
>摩托罗拉Xoom(3.2)：未清除
> galaxy S2(4.1.2 – rooted)：清除

有没有办法强制在每个绘制回调中获得一个未更改的缓冲区？

清除屏幕的设备的结果如下所示：

测试活动如下所示：

package com.example.glcleartest;import java.nio.Buffer;import java.nio.ByteBuffer;import java.nio.ByteOrder;import java.nio.floatBuffer;import javax.microedition.khronos.egl.EGLConfig;import javax.microedition.khronos.opengles.GL10;import androID.opengl.GLES20;import androID.opengl.GLSurfaceVIEw;import androID.opengl.GLSurfaceVIEw.Renderer;import androID.os.Bundle;import androID.app.Activity;import androID.util.Log;public class MainActivity extends Activity {protected static final int NUM_VERTICES = 3;@OverrIDeprotected voID onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentVIEw(R.layout.activity_main);    GLSurfaceVIEw glvIEw = (GLSurfaceVIEw) findVIEwByID(R.ID.glvIEw);    glvIEw.setEGLConfigChooser(false);    glvIEw.setEGLContextClIEntVersion(2);    glvIEw.setRenderer(new Renderer() {        private int programObject;        private floatBuffer vertexBuffer;        @OverrIDe        public voID onSurfaceCreated(GL10 gl,EGLConfig config) {        }        @OverrIDe        public voID onSurfaceChanged(GL10 gl,int wIDth,int height) {            GLES20.glVIEwport(0,wIDth,height);            init();        }        @OverrIDe        public voID onDrawFrame(GL10 gl) {            float x = 0.1f*(float) Math.sin(System.currentTimeMillis()/1000.0);            float[] vVertices = new float[]{x,0.5f,0.0f,x-0.5f,-0.5f,x+0.5f,0.0f};            vertexBuffer.rewind();            vertexBuffer.put(vVertices);            vertexBuffer.rewind();            // Use the program object            GLES20.gluseProgram(programObject);            int handle = GLES20.glGetUniformlocation(programObject,"ucolor");            float r = (float) (0.5f+Math.sin(System.currentTimeMillis()/1000.0));            float g = (float) (0.5f+Math.sin(System.currentTimeMillis()/300.0));            GLES20.gluniform4f(handle,r,g,1);            // Load the vertex data            GLES20.glVertexAttribPointer(0,3,GLES20.GL_float,false,vertexBuffer);            GLES20.glEnabLevertexAttribarray(0);            GLES20.glDrawArrays(GLES20.GL_TRIANGLES,3);                     }        private voID error(String s) {            Log.e("GLTEST",s);        }        private int loadShader(int shaderType,String source) {            if (shaderType != GLES20.GL_FRAGMENT_SHADER && shaderType != GLES20.GL_VERTEX_SHADER) {                throw new RuntimeException("Illegal shader type");            }            int shader = GLES20.glCreateShader(shaderType);            if (shader != 0) {                GLES20.glShaderSource(shader,source);                GLES20.glCompileShader(shader);                int[] compiled = new int[1];                GLES20.glGetShaderiv(shader,GLES20.GL_COMPILE_STATUS,compiled,0);                if (compiled[0] == 0) {                    error("@R_301_5717@ not compile shader :");                    error(GLES20.glGetShaderInfolog(shader));                    GLES20.glDeleteShader(shader);                    shader = 0;                    throw new RuntimeException("Shader Syntax / compilation error");                }            }            return shader;        }        private voID init() {            String vShaderStr = "attribute vec4 vposition; \n" +                                     "voID main() \n" + "{ \n" +                                     " gl_position = vposition; \n" +                                     "} \n";            String fShaderStr = "precision mediump float; \n" +                                        "uniform vec4 ucolor;" +                                        "voID main() \n" +                                         "{ \n" +                                         " gl_Fragcolor = ucolor; \n" +                                         "} \n";            ByteBuffer vbb = ByteBuffer.allocateDirect(NUM_VERTICES*3*4);            vbb.order(ByteOrder.nativeOrder());            vertexBuffer = vbb.asfloatBuffer();            int vertexShader;            int fragmentShader;            // Load the vertex/fragment shaders            vertexShader = loadShader(GLES20.GL_VERTEX_SHADER,vShaderStr);            fragmentShader = loadShader(GLES20.GL_FRAGMENT_SHADER,fShaderStr);            // Create the program object            programObject = GLES20.glCreateProgram();            if (programObject == 0)                return;            GLES20.glAttachShader(programObject,vertexShader);            GLES20.glAttachShader(programObject,fragmentShader);            // Bind vposition to attribute 0            GLES20.glBindAttribLocation(programObject,"vposition");            // link the program            GLES20.gllinkProgram(programObject);            int[] linkStatus = new int[1];            GLES20.glGetProgramiv(programObject,GLES20.GL_link_STATUS,linkStatus,0);            if (linkStatus[0] != GLES20.GL_TRUE) {                error("@R_301_5717@ not link program: ");                error(GLES20.glGetProgramInfolog(programObject));                GLES20.glDeleteProgram(programObject);                programObject = 0;            }        }    });}}

最佳答案如果要在交换后保留后备缓冲内容,则必须将交换表面的EGL_SWAP_BEHAVIOR属性设置为EGL_BUFFER_PRESERVED,如EGL API所记录的那样.尽管在大多数平台上都会意识到,这将是一个相当大的性能影响.在大多数情况下,重新绘制框架要好得多.

有点历史：见http://www.khronos.org/registry/egl/specs/EGLTechNote0001.html 总结

以上是内存溢出为你收集整理的android – GLSurfaceView onDrawFrame清除行为全部内容，希望文章能够帮你解决android – GLSurfaceView onDrawFrame清除行为所遇到的程序开发问题。

如果觉得内存溢出网站内容还不错，欢迎将内存溢出网站推荐给程序员好友。