I am trying to learn FBOs so I can render to a texture. It sort of works, but there is a lot of color bleeding between the background and the texture. If anyone can give me a hint or a solution I would appreciate it. Here is the code.
The only 2 methods that have FBO code are initGL and render.
package lesson;
/*
* This Code Was Created By Jeff Molofee 2000
* A HUGE Thanks To Fredric Echols For Cleaning Up
* And Optimizing The Base Code, Making It More Flexible!
* If You've Found This Code Useful, Please Let Me Know.
* Visit My Site At nehe.gamedev.net
*/
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.IntBuffer;
import javax.imageio.ImageIO;
import org.lwjgl.opengl.Display;
import org.lwjgl.opengl.DisplayMode;
import org.lwjgl.opengl.EXTFramebufferObject;
import org.lwjgl.opengl.GL11;
import org.lwjgl.util.glu.GLU;
import org.lwjgl.input.Keyboard;
/**
* @author Mark Bernard
* date: 16-Nov-2003
*
* Port of NeHe's Lesson 6 to LWJGL
* Title: Texture Mapping
* Uses version 0.8alpha of LWJGL http://www.lwjgl.org/
*
* Be sure that the LWJGL libraries are in your classpath
*
* Ported directly from the C++ version
*
* 2004-05-08: Updated to version 0.9alpha of LWJGL.
* Changed from all static to all instance objects.
* 2004-09-21: Updated to version 0.92alpha of LWJGL.
* 2004-12-17: Updated to version 0.94alpha of LWJGL and to use
* DevIL for image loading.
*/
public class Lesson06 {
private boolean done = false;
private boolean fullscreen = false;
private final String windowTitle = "NeHe's OpenGL Lesson 6 for LWJGL (Texture Mapping)";
private boolean f1 = false;
private DisplayMode displayMode;
private float xrot; // X Rotation ( NEW )
private float yrot; // Y Rotation ( NEW )
private float zrot; // Z Rotation ( NEW )
private int texture; // Storage For One Texture ( NEW )
private int frameBufferId;
public static void main(String args[]) {
boolean fullscreen = false;
if(args.length>0) {
if(args[0].equalsIgnoreCase("fullscreen")) {
fullscreen = true;
}
}
Lesson06 l6 = new Lesson06();
l6.run(fullscreen);
}
public void run(boolean fullscreen) {
this.fullscreen = fullscreen;
try {
init();
while (!done) {
mainloop();
render();
Display.update();
}
cleanup();
}
catch (Exception e) {
e.printStackTrace();
System.exit(0);
}
}
private void mainloop() {
if(Keyboard.isKeyDown(Keyboard.KEY_ESCAPE)) { // Exit if Escape is pressed
done = true;
}
if(Display.isCloseRequested()) { // Exit if window is closed
done = true;
}
if(Keyboard.isKeyDown(Keyboard.KEY_F1) && !f1) { // Is F1 Being Pressed?
f1 = true; // Tell Program F1 Is Being Held
switchMode(); // Toggle Fullscreen / Windowed Mode
}
if(!Keyboard.isKeyDown(Keyboard.KEY_F1)) { // Is F1 Being Pressed?
f1 = false;
}
}
private void switchMode() {
fullscreen = !fullscreen;
try {
Display.setFullscreen(fullscreen);
}
catch(Exception e) {
e.printStackTrace();
}
}
private boolean render() {
GL11.glBindTexture(GL11.GL_TEXTURE_2D, 0);
EXTFramebufferObject.glBindFramebufferEXT( EXTFramebufferObject.GL_FRAMEBUFFER_EXT, frameBufferId);
GL11.glPushAttrib(GL11.GL_PIXEL_MODE_BIT);
GL11.glViewport( 0, 0, 256, 256);
GL11.glClearColor(0, 0, 0, 0);
GL11.glClear(GL11.GL_COLOR_BUFFER_BIT | GL11.GL_DEPTH_BUFFER_BIT); // Clear The Screen And The Depth Buffer
GL11.glColor3d(1.0, 1.0, 1.0);
GL11.glBegin(GL11.GL_QUADS);
GL11.glVertex2i(0, 0);
GL11.glVertex2i(256, 0);
GL11.glVertex2i(256, 256);
GL11.glVertex2i(0, 256);
GL11.glEnd();
EXTFramebufferObject.glBindFramebufferEXT( EXTFramebufferObject.GL_FRAMEBUFFER_EXT, 0);
GL11.glBindTexture(GL11.GL_TEXTURE_2D, texture); // Select Our Texture
EXTFramebufferObject.glGenerateMipmapEXT(GL11.GL_TEXTURE_2D);
GL11.glBindTexture(GL11.GL_TEXTURE_2D, 0);
GL11.glPopAttrib();
GL11.glClearColor(0, 1, 1, 1);
GL11.glClear(GL11.GL_COLOR_BUFFER_BIT); // Clear The Screen And The Depth Buffer
GL11.glLoadIdentity(); // Reset The Current Modelview Matrix
GL11.glTranslatef(0.0f, 0.0f, -5.0f); // Move Into The Screen 5 Units
GL11.glRotatef(xrot, 1.0f, 0.0f, 0.0f); // Rotate On The X Axis
GL11.glRotatef(yrot, 0.0f, 1.0f, 0.0f); // Rotate On The Y Axis
GL11.glRotatef(zrot, 0.0f, 0.0f, 1.0f); // Rotate On The Z Axis
GL11.glBindTexture(GL11.GL_TEXTURE_2D, texture); // Select Our Texture
GL11.glBegin(GL11.GL_QUADS);
// Front Face
GL11.glTexCoord2f(0.0f, 0.0f);
GL11.glVertex3f(-1.0f, -1.0f, 1.0f); // Bottom Left Of The Texture and Quad
GL11.glTexCoord2f(1.0f, 0.0f);
GL11.glVertex3f(1.0f, -1.0f, 1.0f); // Bottom Right Of The Texture and Quad
GL11.glTexCoord2f(1.0f, 1.0f);
GL11.glVertex3f(1.0f, 1.0f, 1.0f); // Top Right Of The Texture and Quad
GL11.glTexCoord2f(0.0f, 1.0f);
GL11.glVertex3f(-1.0f, 1.0f, 1.0f); // Top Left Of The Texture and Quad
// Back Face
GL11.glTexCoord2f(1.0f, 0.0f);
GL11.glVertex3f(-1.0f, -1.0f, -1.0f); // Bottom Right Of The Texture and Quad
GL11.glTexCoord2f(1.0f, 1.0f);
GL11.glVertex3f(-1.0f, 1.0f, -1.0f); // Top Right Of The Texture and Quad
GL11.glTexCoord2f(0.0f, 1.0f);
GL11.glVertex3f(1.0f, 1.0f, -1.0f); // Top Left Of The Texture and Quad
GL11.glTexCoord2f(0.0f, 0.0f);
GL11.glVertex3f(1.0f, -1.0f, -1.0f); // Bottom Left Of The Texture and Quad
// Top Face
GL11.glTexCoord2f(0.0f, 1.0f);
GL11.glVertex3f(-1.0f, 1.0f, -1.0f); // Top Left Of The Texture and Quad
GL11.glTexCoord2f(0.0f, 0.0f);
GL11.glVertex3f(-1.0f, 1.0f, 1.0f); // Bottom Left Of The Texture and Quad
GL11.glTexCoord2f(1.0f, 0.0f);
GL11.glVertex3f(1.0f, 1.0f, 1.0f); // Bottom Right Of The Texture and Quad
GL11.glTexCoord2f(1.0f, 1.0f);
GL11.glVertex3f(1.0f, 1.0f, -1.0f); // Top Right Of The Texture and Quad
// Bottom Face
GL11.glTexCoord2f(1.0f, 1.0f);
GL11.glVertex3f(-1.0f, -1.0f, -1.0f); // Top Right Of The Texture and Quad
GL11.glTexCoord2f(0.0f, 1.0f);
GL11.glVertex3f(1.0f, -1.0f, -1.0f); // Top Left Of The Texture and Quad
GL11.glTexCoord2f(0.0f, 0.0f);
GL11.glVertex3f(1.0f, -1.0f, 1.0f); // Bottom Left Of The Texture and Quad
GL11.glTexCoord2f(1.0f, 0.0f);
GL11.glVertex3f(-1.0f, -1.0f, 1.0f); // Bottom Right Of The Texture and Quad
// Right face
GL11.glTexCoord2f(1.0f, 0.0f);
GL11.glVertex3f(1.0f, -1.0f, -1.0f); // Bottom Right Of The Texture and Quad
GL11.glTexCoord2f(1.0f, 1.0f);
GL11.glVertex3f(1.0f, 1.0f, -1.0f); // Top Right Of The Texture and Quad
GL11.glTexCoord2f(0.0f, 1.0f);
GL11.glVertex3f(1.0f, 1.0f, 1.0f); // Top Left Of The Texture and Quad
GL11.glTexCoord2f(0.0f, 0.0f);
GL11.glVertex3f(1.0f, -1.0f, 1.0f); // Bottom Left Of The Texture and Quad
// Left Face
GL11.glTexCoord2f(0.0f, 0.0f);
GL11.glVertex3f(-1.0f, -1.0f, -1.0f); // Bottom Left Of The Texture and Quad
GL11.glTexCoord2f(1.0f, 0.0f);
GL11.glVertex3f(-1.0f, -1.0f, 1.0f); // Bottom Right Of The Texture and Quad
GL11.glTexCoord2f(1.0f, 1.0f);
GL11.glVertex3f(-1.0f, 1.0f, 1.0f); // Top Right Of The Texture and Quad
GL11.glTexCoord2f(0.0f, 1.0f);
GL11.glVertex3f(-1.0f, 1.0f, -1.0f); // Top Left Of The Texture and Quad
GL11.glEnd();
xrot += 0.3f; // X Axis Rotation
yrot += 0.2f; // Y Axis Rotation
zrot += 0.4f; // Z Axis Rotation
return true;
}
private void createWindow() throws Exception {
Display.setFullscreen(fullscreen);
DisplayMode d[] = Display.getAvailableDisplayModes();
for (int i = 0; i < d.length; i++) {
if (d[i].getWidth() == 640
&& d[i].getHeight() == 480
&& d[i].getBitsPerPixel() == 32) {
displayMode = d[i];
break;
}
}
Display.setDisplayMode(displayMode);
Display.setTitle(windowTitle);
Display.create();
}
private void init() throws Exception {
createWindow();
loadTextures();
initGL();
}
private void loadTextures() throws IOException {
texture = loadTexture("data/NeHe.bmp");
}
private void initGL() {
GL11.glEnable(GL11.GL_TEXTURE_2D); // Enable Texture Mapping
GL11.glShadeModel(GL11.GL_SMOOTH); // Enable Smooth Shading
GL11.glClearColor(0.0f, 0.0f, 0.0f, 0.0f); // Black Background
GL11.glClearDepth(1.0f); // Depth Buffer Setup
GL11.glEnable(GL11.GL_DEPTH_TEST); // Enables Depth Testing
GL11.glDepthFunc(GL11.GL_LEQUAL); // The Type Of Depth Testing To Do
GL11.glMatrixMode(GL11.GL_PROJECTION); // Select The Projection Matrix
GL11.glLoadIdentity(); // Reset The Projection Matrix
// Calculate The Aspect Ratio Of The Window
GLU.gluPerspective(45.0f, (float) displayMode.getWidth() / (float) displayMode.getHeight(), 0.1f, 100.0f);
GL11.glMatrixMode(GL11.GL_MODELVIEW); // Select The Modelview Matrix
// Really Nice Perspective Calculations
GL11.glHint(GL11.GL_PERSPECTIVE_CORRECTION_HINT, GL11.GL_NICEST);
IntBuffer fboId = ByteBuffer.allocateDirect(4).asIntBuffer();
EXTFramebufferObject.glGenFramebuffersEXT(fboId);
frameBufferId = fboId.get();
EXTFramebufferObject.glBindFramebufferEXT(EXTFramebufferObject.GL_FRAMEBUFFER_EXT, frameBufferId);
EXTFramebufferObject.glFramebufferTexture2DEXT(EXTFramebufferObject.GL_FRAMEBUFFER_EXT, EXTFramebufferObject.GL_COLOR_ATTACHMENT0_EXT, GL11.GL_TEXTURE_2D, texture, 0);
int framebuffer = EXTFramebufferObject.glCheckFramebufferStatusEXT( EXTFramebufferObject.GL_FRAMEBUFFER_EXT );
switch ( framebuffer ) {
case EXTFramebufferObject.GL_FRAMEBUFFER_COMPLETE_EXT:
break;
case EXTFramebufferObject.GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT_EXT:
throw new RuntimeException( "FrameBuffer: " + frameBufferId
+ ", has caused a GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT_EXT exception" );
case EXTFramebufferObject.GL_FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT_EXT:
throw new RuntimeException( "FrameBuffer: " + frameBufferId
+ ", has caused a GL_FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT_EXT exception" );
case EXTFramebufferObject.GL_FRAMEBUFFER_INCOMPLETE_DIMENSIONS_EXT:
throw new RuntimeException( "FrameBuffer: " + frameBufferId
+ ", has caused a GL_FRAMEBUFFER_INCOMPLETE_DIMENSIONS_EXT exception" );
case EXTFramebufferObject.GL_FRAMEBUFFER_INCOMPLETE_DRAW_BUFFER_EXT:
throw new RuntimeException( "FrameBuffer: " + frameBufferId
+ ", has caused a GL_FRAMEBUFFER_INCOMPLETE_DRAW_BUFFER_EXT exception" );
case EXTFramebufferObject.GL_FRAMEBUFFER_INCOMPLETE_FORMATS_EXT:
throw new RuntimeException( "FrameBuffer: " + frameBufferId
+ ", has caused a GL_FRAMEBUFFER_INCOMPLETE_FORMATS_EXT exception" );
case EXTFramebufferObject.GL_FRAMEBUFFER_INCOMPLETE_READ_BUFFER_EXT:
throw new RuntimeException( "FrameBuffer: " + frameBufferId
+ ", has caused a GL_FRAMEBUFFER_INCOMPLETE_READ_BUFFER_EXT exception" );
default:
throw new RuntimeException( "Unexpected reply from glCheckFramebufferStatusEXT: " + framebuffer );
}
EXTFramebufferObject.glBindFramebufferEXT(EXTFramebufferObject.GL_FRAMEBUFFER_EXT, 0);
}
private void cleanup() {
Display.destroy();
}
/**
* Texture loading using DevIL
* Example created by Mark Bernard
*/
private int loadTexture(String path) throws IOException {
BufferedImage image = ImageIO.read(getClass().getResourceAsStream("data/NeHe.bmp"));
byte data[] = (byte[])image.getRaster().getDataElements(0, 0, image.getWidth(), image.getHeight(), null);
ByteBuffer scratch = ByteBuffer.allocateDirect(image.getWidth() * image.getHeight() * 3).order(ByteOrder.nativeOrder());
scratch.put(data);
scratch.rewind();
// Create A IntBuffer For Image Address In Memory
IntBuffer buf = ByteBuffer.allocateDirect(4).order(ByteOrder.nativeOrder()).asIntBuffer();
GL11.glGenTextures(buf); // Create Texture In OpenGL
GL11.glBindTexture(GL11.GL_TEXTURE_2D, buf.get(0));
// Typical Texture Generation Using Data From The Image
// Linear Filtering
GL11.glTexParameteri(GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_MIN_FILTER, GL11.GL_LINEAR);
// Linear Filtering
GL11.glTexParameteri(GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_MAG_FILTER, GL11.GL_LINEAR);
// Generate The Texture
GL11.glTexImage2D(GL11.GL_TEXTURE_2D, 0, GL11.GL_RGB, image.getWidth(),
image.getHeight(), 0, GL11.GL_RGB, GL11.GL_UNSIGNED_BYTE, scratch);
return buf.get(0); // Return Image Address In Memory
}
}
I attached an FBO example to another post here (http://lwjgl.org/forum/index.php/topic,2745.msg15369.html#msg15369) a while ago
Great, thanks. I'll take a look.
I tried a search before but there were so many results I couldn't find it.