如何在不同的线程上访问 android 应用程序的资产？ （爪哇）

Question

This is a reformulation of my question here: How to access files form the Renderer class Opengles (android, java) ,but nobody answered, so I decided to ask in a different way.

I am building an Opengl es app for android and I want to access some local files. My main game loop is situated in the Renderer class which is an implementation of GLSurfaceView.Renderer and will be used to set the view in the MainActivity. The only way I know of getting kind of local files* is to do Activity.getAssets().open("file.something"); but then I need the MainActivity. The problem is, if I understood my researches correctly, the Renderer class is automaticaly run on a seperate thread than MainActivity, which results in MainActivity.getAssets().open(); to return nothing. Please help me find a workaround or just use threads, if thats the solution.

*I know that they are not called local files, but they still serve the purpose of beeing files that you don't access with an absolute path qnd that's what I want.

Edit #1:

Here's where I call getAssets.open():

import android.app.Activity;
import android.content.Context;
import android.opengl.GLES20;
import android.widget.Toast;
import com.GyooStudios.Glu.MainActivity;
import com.GyooStudios.Glu.ShaderProgram;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.util.Scanner;


public abstract class ShaderProgram {
  
  private int programID;
  private int vertexShaderID;
  private int fragmentShaderID;
  
  public boolean hasFoundFile = true;
  public boolean isCompiled = true;
  public boolean canReadFile = true;
  
  public String exceptionError = "null";
  
  public ShaderProgram (MainActivity main, String vertexFile, String fragmentFile){
    vertexShaderID = loadShader(main, vertexFile, GLES20.GL_VERTEX_SHADER);
    fragmentShaderID = loadShader(main, fragmentFile, GLES20.GL_FRAGMENT_SHADER);
    
    programID = GLES20.glCreateProgram();
    GLES20.glAttachShader(programID, vertexShaderID);
    GLES20.glAttachShader(programID, fragmentShaderID);
    GLES20.glLinkProgram(programID);
    GLES20.glValidateProgram(programID);
  }
  
  public void start(){
    GLES20.glUseProgram(programID);
  }
  
  public void stop(){
    GLES20.glUseProgram(0);
  }
  
  protected abstract void bindAttributes();
  
  protected void bindAttribute(int attribute, String variableName){
    GLES20.glBindAttribLocation(programID, attribute, variableName);
  }
  
  private int loadShader(MainActivity main,String fileName, int type){
    int shaderID = 0;
    try{
      InputStream file = main.getAssets().open(fileName);
      Scanner scan = new Scanner(file);
      String code = new String();
      while(scan.hasNext()){
        code = new String(code + scan.nextLine() + "/n");
      }
      
      shaderID = GLES20.glCreateShader(type);
      GLES20.glShaderSource(shaderID, code);
      GLES20.glCompileShader(shaderID);
      int[] compileStatus = new int[1];
      GLES20.glGetShaderiv(shaderID,GLES20.GL_COMPILE_STATUS,compileStatus,0);
      if(compileStatus[0] == 0){
        Toast.makeText(main.getApplicationContext(),GLES20.glGetShaderInfoLog(shaderID),Toast.LENGTH_LONG);
        GLES20.glDeleteShader(shaderID);
        isCompiled = false;
      }
    }catch(FileNotFoundException e){
      hasFoundFile = false;
    }catch(IOException e){
      canReadFile = false;
    }catch(Exception e){
      isCompiled = false;
      exceptionError = "something went wrong";
      exceptionError = e.toString();
    }
    
    return shaderID;
    
  }
}

ShaderProgram is Implemented in this class:

import com.GyooStudios.Glu.MainActivity;


public class StaticShader extends ShaderProgram{
  
  private static final String VERTEX_FILE = "quad.vertex";
  private static final String FRAGMENT_FILE = "quad.fragment";
  
  public StaticShader(MainActivity main){
    super(main,VERTEX_FILE, FRAGMENT_FILE);
    //bindAttributes();
  }
  
  @Override
  protected void bindAttributes(){
    super.bindAttribute(0,"position");
  }
  
}

StaticShader is used in the constructor of another class which is created in Renederer. Renderer is beeing used here, in MainActivity:

import android.Manifest;
import android.app.Activity;
import android.opengl.GLSurfaceView;
import android.os.Bundle;
import android.widget.Toast;
import com.GyooStudios.Glu.StaticShader;
import com.GyooStudios.Glu.renderer;
import java.io.InputStream;
import java.util.Scanner;

public class MainActivity extends Activity {
    
    private renderer surface;
    private GLSurfaceView surfaceView;
    private int STORAGE_PERMISSION_CODE = 1;
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        //Keep in mind that renderer implements GLSurfaceView.Renderer
        //And yes, renderer class is with a lower case r, it's my mistake.
        super.onCreate(savedInstanceState);
        surfaceView = new GLSurfaceView(this);
        surfaceView.setEGLContextClientVersion(2);
        surface = new renderer(this);
        surfaceView.setRenderer(surface);
        setContentView(surfaceView);
    }
    
    protected void onPause(){
        super.onPause();
        surfaceView.onPause();
    }
    
    protected void onResume(){
        super.onResume();
        surfaceView.onResume();
    }

}

Edit #2: I tried passing only the AssetManager returned by Activity.getAssets(); and also the Context. The AssetManager lets the apps run, but it gives me an Exception and I couldn't figure which one. When I tired to get the exception using Toast.makeText(passedOnContext,exception.toString(),Toast.LENGTH_LONG); it crashed the app. (And yes I use Toasts to get debug messages, it's limitation of my IDE, it doesn't provide a terminal in apps developpement)

Answer 1

Turns out that wasn't the problem at all: See here to get the new problem: GLES20.glShaderSource does nothing