我正在尝试使用Java向LWJGL中的FBO渲染一些基本四边形，但它实际上并不是渲染，我不知道为什么。
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();
}
}
答案 0 :(得分：0)
我花了一些时间来查看你的代码，我可能只是错过了一些东西，但是我找不到你拍摄fbo纹理并在屏幕上渲染它的地方。
我看到你画了网格的地方以及你画了所有立方体的地方但是我没有看到任何被绑定到任何立方体的东西。