在LWJGL中呈現給一個FBO

Question

我正嘗試在LWJGL中使用Java呈現一些FBO的基本四邊形，但實際上並不是呈現，我不知道爲什麼。

import static org.lwjgl.opengl.GL11.*; 
import static org.lwjgl.util.glu.GLU.*; 

import java.nio.ByteBuffer; 
import java.nio.ByteOrder; 
import java.nio.FloatBuffer; 
import java.nio.IntBuffer; 

import org.lwjgl.BufferUtils; 
import org.lwjgl.LWJGLException; 
import org.lwjgl.Sys; 
import org.lwjgl.input.Keyboard; 
import org.lwjgl.input.Mouse; 
import org.lwjgl.opengl.Display; 
import org.lwjgl.opengl.DisplayMode; 
import org.lwjgl.opengl.EXTFramebufferObject; 
import org.lwjgl.opengl.GLContext; 
import org.newdawn.slick.Color; 

import elec0.utils.Camera; 
import elec0.utils.Vector2f; 
import elec0.utils.Vector3f; 

public class lwjglFBO 
{ 
    private Camera camera = new Camera(); 
    private boolean running = true, wireframe = false; 
    private long lastFPS; 
    private int fps; 

// boolean FBOEnabled = GLContext.getCapabilities().GL_EXT_framebuffer_object; 
    private int iFBOBuffer; 

    public void start() 
    { 
     initGL(); 
     init(); 

     lastFPS = getTime(); 

     while(!Display.isCloseRequested()) 
     { 
      updateFPS(); 
      pollInput(); 


      render(); 

      Display.update(); 
      Display.sync(60); // limit FPS to 60 
     } 
     Display.destroy(); 
     System.exit(0); 
    } 

    private void render() 
    { 
     glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); 
     glMatrixMode(GL_MODELVIEW); 
     glLoadIdentity(); 

     /*gluLookAt(0, 0, 5, // Set up the LookAt 
       0, 0, 0, 
       0, 1, 0);*/ 

     camera.render(); 

     drawGrid(); // Render this fill, it's lines 
     int verts = 0; 
     EXTFramebufferObject.glBindFramebufferEXT(EXTFramebufferObject.GL_FRAMEBUFFER_EXT, iFBOBuffer); 
     glPushAttrib(GL_VIEWPORT_BIT); 
     glViewport(0, 0, 800, 600); 
     glClear(GL_COLOR_BUFFER_BIT); 


     for(int z = 0; z < 20; ++z) 
     { 
      for(int y = 0; y < 20; ++y) 
      { 
       for(int x = 0; x < 20; ++x) 
       { 
        glPushMatrix(); 
        glTranslatef(x, y, z); 
        drawBox(); 
//     verts+=24; 
        glPopMatrix(); 
       } 
      } 
     } 
//  System.out.println(verts); 

     EXTFramebufferObject.glBindFramebufferEXT(EXTFramebufferObject.GL_FRAMEBUFFER_EXT, 0); 
     glPopAttrib(); 
     // Render 
     if(wireframe) 
      glPolygonMode(GL_FRONT_AND_BACK, GL_LINE); 
     else 
      glPolygonMode(GL_FRONT_AND_BACK, GL_FILL); 


    } 

    private void drawBox() 
    { 
     /* draws the sides of a unit cube (0,0,0)-(1,1,1) */ 
      glBegin(GL_POLYGON);/* f1: front */ 
      glNormal3f(-1.0f,0.0f,0.0f); 
      glVertex3f(0.0f,0.0f,0.0f); 
      glVertex3f(0.0f,0.0f,1.0f); 
      glVertex3f(1.0f,0.0f,1.0f); 
      glVertex3f(1.0f,0.0f,0.0f); 
      glEnd(); 
      glBegin(GL_POLYGON);/* f2: bottom */ 
      glNormal3f(0.0f,0.0f,-1.0f); 
      glVertex3f(0.0f,0.0f,0.0f); 
      glVertex3f(1.0f,0.0f,0.0f); 
      glVertex3f(1.0f,1.0f,0.0f); 
      glVertex3f(0.0f,1.0f,0.0f); 
      glEnd(); 
      glBegin(GL_POLYGON);/* f3:back */ 
      glNormal3f(1.0f,0.0f,0.0f); 
      glVertex3f(1.0f,1.0f,0.0f); 
      glVertex3f(1.0f,1.0f,1.0f); 
      glVertex3f(0.0f,1.0f,1.0f); 
      glVertex3f(0.0f,1.0f,0.0f); 
      glEnd(); 
      glBegin(GL_POLYGON);/* f4: top */ 
      glNormal3f(0.0f,0.0f,1.0f); 
      glVertex3f(1.0f,1.0f,1.0f); 
      glVertex3f(1.0f,0.0f,1.0f); 
      glVertex3f(0.0f,0.0f,1.0f); 
      glVertex3f(0.0f,1.0f,1.0f); 
      glEnd(); 
      glBegin(GL_POLYGON);/* f5: left */ 
      glNormal3f(0.0f,1.0f,0.0f); 
      glVertex3f(0.0f,0.0f,0.0f); 
      glVertex3f(0.0f,1.0f,0.0f); 
      glVertex3f(0.0f,1.0f,1.0f); 
      glVertex3f(0.0f,0.0f,1.0f); 
      glEnd(); 
      glBegin(GL_POLYGON);/* f6: right */ 
      glNormal3f(0.0f,-1.0f,0.0f); 
      glVertex3f(1.0f,0.0f,0.0f); 
      glVertex3f(1.0f,0.0f,1.0f); 
      glVertex3f(1.0f,1.0f,1.0f); 
      glVertex3f(1.0f,1.0f,0.0f); 
      glEnd(); 

    } 

    private void init() 
    { 

     Mouse.setGrabbed(true); 
     camera.initCamera(); 
     camera.farPlane = 1000; 
     camera.initPerspective(); 

    } 

    private void initGL() 
    { 
     try { 
      Display.setDisplayMode(new DisplayMode(800, 600)); 
      Display.create(); 
      Display.setVSyncEnabled(true); 
     } catch (LWJGLException e) { 
      e.printStackTrace(); 
      System.exit(0); 
     } 

     glViewport(0, 0, Display.getWidth(), Display.getHeight()); 

     glEnable(GL_TEXTURE_2D); // Enable Texture Mapping 
     glShadeModel(GL_SMOOTH); // Enable Smooth Shading 
     glClearColor(0.0f, 0.0f, 0.0f, 1.0f); // Black Background 
     glClearDepth(1.0); // Depth Buffer Setup 
     glEnable(GL_DEPTH_TEST); // Enables Depth Testing 
     glDepthFunc(GL_LEQUAL); // The Type Of Depth Testing To Do 

     glMatrixMode(GL_MODELVIEW); 
     glLoadIdentity(); 


     IntBuffer buffer = ByteBuffer.allocateDirect(1*4).order(ByteOrder.nativeOrder()).asIntBuffer(); // allocate a 1 int byte buffer 
     EXTFramebufferObject.glGenFramebuffersEXT(buffer); // generate 
     iFBOBuffer = buffer.get(); 

//  glEnable(GL_FOG); 
//   FloatBuffer fogColor = BufferUtils.createFloatBuffer(4); 
//   fogColor.put(0f).put(0f).put(0f).put(1f).flip(); 
//   
//   int fogMode = GL_LINEAR; 
//   glFogi(GL_FOG_MODE, fogMode); 
//   glFog(GL_FOG_COLOR, fogColor); 
//   glFogf(GL_FOG_DENSITY, 0.35f); 
//   glHint(GL_FOG_HINT, GL_DONT_CARE); 
//   glFogf(GL_FOG_START, 100.0f); 
//   glFogf(GL_FOG_END, 500.0f); 

     // Alpha blending 
     glEnable(GL_BLEND); 
     glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA); 

     glMatrixMode(GL_MODELVIEW); // Select The Modelview Matrix 
     glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST); 



    } 

    private long lastF; 


    private void pollInput() 
    { 
     int x = Mouse.getX(); 
     int y = Display.getHeight() - Mouse.getY(); 
     float speed = .1f; 
     int iKeypressSpeed = 50; 
     int iDelta = getDelta(); 
     speed *= iDelta; 

     if(Keyboard.isKeyDown(Keyboard.KEY_LSHIFT)) 
      speed *= 4; 

     if(Keyboard.isKeyDown(Keyboard.KEY_W)) 
     { 
      camera.MoveForwards(speed); 
     } 
     if(Keyboard.isKeyDown(Keyboard.KEY_S)) 
     { 
      camera.MoveForwards(-speed); 
     } 
     if(Keyboard.isKeyDown(Keyboard.KEY_A)) 
     { 
      camera.MoveRight(-speed); 
     } 
     if(Keyboard.isKeyDown(Keyboard.KEY_D)) 
     { 
      camera.MoveRight(speed); 
     } 
     if(Keyboard.isKeyDown(Keyboard.KEY_SPACE)) 
     { 
      camera.moveUp(speed); 
     } 

     if(Keyboard.isKeyDown(Keyboard.KEY_ESCAPE)) 
     { 
      Display.destroy(); 
      System.exit(0); 
     } 
     if(Keyboard.isKeyDown(Keyboard.KEY_P)) 
     { 
      if(getTime() - lastF > iKeypressSpeed) 
       wireframe = !wireframe; 
      lastF = getTime(); 
     } 
     if(Keyboard.isKeyDown(Keyboard.KEY_N)) 
     { 
      if(getTime() - lastF > iKeypressSpeed) 
      lastF = getTime(); 
     } 
     if(Keyboard.isKeyDown(Keyboard.KEY_C)) 
     { 
      if(getTime() - lastF > iKeypressSpeed) 
      lastF = getTime(); 
     } 

     checkMouseMove(x, y); 
    } 

    Vector2f previous = new Vector2f(), mousePos = new Vector2f(); 
    private float MOUSE_SENSITIVITY = 4.0f; 

    private void checkMouseMove(float x, float y) 
    { 
     float DeltX, DeltY; 
     int centX = Display.getWidth()/2, centY = Display.getHeight()/2; 

     DeltX = (float)(centX - x)/MOUSE_SENSITIVITY; 
     DeltY = (float)(centY - y)/MOUSE_SENSITIVITY; 

     camera.Rotate(DeltY, DeltX, 0); 

     Mouse.setCursorPosition(centX, centY); 
    } 

    public long getTime() 
    { 
     return (Sys.getTime() * 1000)/Sys.getTimerResolution(); 
    } 

    public void updateFPS() 
    { 
     if (getTime() - lastFPS > 1000) { 
      Display.setTitle("FPS: " + fps); 
      fps = 0; //reset the FPS counter 
      lastFPS += 1000; //add one second 
     } 
     fps++; 
    } 

    long lastFrame; 
    public int getDelta() 
    { 
     long time = getTime(); 

     int delta = (int) (time - lastFrame); 

     lastFrame = time; 
     return delta; 
    } 

    private void drawGrid() 
    {  
     glPushMatrix(); 

     glDisable(GL_TEXTURE_2D); 

     glColor3f(0.25f, 0.25f, 0.25f); 

     float gridSize = 30; 
     int mX = 64, mZ = 64; 

     glTranslatef(-(mX+gridSize)/2, -5, -(mZ+gridSize)/2); 


     for(int x = 0; x < mX; ++x) 
     { 
      for(int z = 0; z < mZ; ++z) 
      { 
       glBegin(GL_LINE_LOOP); 
        glVertex3f(x, 0, z); 
        glVertex3f(x+gridSize, 0, z); 
        glVertex3f(x+gridSize, 0, z+gridSize); 
        glVertex3f(x, 0, z+gridSize); 
       glEnd(); 
      } 
     } 

     glEnable(GL_TEXTURE_2D); 
     glPopMatrix(); 
    } 

    public static void main(String[] args) 
    { 
     lwjglFBO city = new lwjglFBO(); 
     city.start(); 

    } 
} 

Answer 1

我花了一些時間通過您的代碼看，我可能只是錯過了一些東西，但我找不到任何地方，你把你的FBO的質感和呈現在屏幕上。

我看到你繪製了網格的位置，並且繪製了所有立方體的位置，但是我沒有看到任何綁定到任何立方體的東西。