package org.newdawn.slick.opengl.pbuffer;
import java.nio.IntBuffer;
import org.lwjgl.BufferUtils;
import org.lwjgl.opengl.EXTFramebufferObject;
import org.lwjgl.opengl.GL11;
import org.lwjgl.opengl.GLContext;
import org.newdawn.slick.Graphics;
import org.newdawn.slick.Image;
import org.newdawn.slick.SlickException;
import org.newdawn.slick.opengl.SlickCallable;
import org.newdawn.slick.opengl.Texture;
import org.newdawn.slick.opengl.InternalTextureLoader;
import org.newdawn.slick.util.Log;
/**
* A graphics implementation that renders to an FBO
*
* @author kevin
*/
public class FBOGraphics extends Graphics {
/** The image we're we're sort of rendering to */
private Image image;
/** The ID of the FBO in use */
private int FBO;
/** True if this context is valid */
private boolean valid = true;
/**
* Create a new graphics context around an FBO
*
* @param image The image we're rendering to
* @throws SlickException Indicates a failure to use pbuffers
*/
public FBOGraphics(Image image) throws SlickException {
super(image.getTexture().getTextureWidth(), image.getTexture().getTextureHeight());
this.image = image;
Log.debug("Creating FBO "+image.getWidth()+"x"+image.getHeight());
boolean FBOEnabled = GLContext.getCapabilities().GL_EXT_framebuffer_object;
if (!FBOEnabled) {
throw new SlickException("Your OpenGL card does not support PBuffers and hence can't handle the dynamic images required for this application.");
}
init();
}
/**
* Check the FBO for completeness as shown in the LWJGL tutorial
*
* @throws SlickException Indicates an incomplete FBO
*/
private void completeCheck() throws SlickException {
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 SlickException( "FrameBuffer: " + FBO
+ ", has caused a GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT_EXT exception" );
case EXTFramebufferObject.GL_FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT_EXT:
throw new SlickException( "FrameBuffer: " + FBO
+ ", has caused a GL_FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT_EXT exception" );
case EXTFramebufferObject.GL_FRAMEBUFFER_INCOMPLETE_DIMENSIONS_EXT:
throw new SlickException( "FrameBuffer: " + FBO
+ ", has caused a GL_FRAMEBUFFER_INCOMPLETE_DIMENSIONS_EXT exception" );
case EXTFramebufferObject.GL_FRAMEBUFFER_INCOMPLETE_DRAW_BUFFER_EXT:
throw new SlickException( "FrameBuffer: " + FBO
+ ", has caused a GL_FRAMEBUFFER_INCOMPLETE_DRAW_BUFFER_EXT exception" );
case EXTFramebufferObject.GL_FRAMEBUFFER_INCOMPLETE_FORMATS_EXT:
throw new SlickException( "FrameBuffer: " + FBO
+ ", has caused a GL_FRAMEBUFFER_INCOMPLETE_FORMATS_EXT exception" );
case EXTFramebufferObject.GL_FRAMEBUFFER_INCOMPLETE_READ_BUFFER_EXT:
throw new SlickException( "FrameBuffer: " + FBO
+ ", has caused a GL_FRAMEBUFFER_INCOMPLETE_READ_BUFFER_EXT exception" );
default:
throw new SlickException( "Unexpected reply from glCheckFramebufferStatusEXT: " + framebuffer);
}
}
/**
* Initialise the FBO that will be used to render to
*
* @throws SlickException
*/
private void init() throws SlickException {
IntBuffer buffer = BufferUtils.createIntBuffer(1);
EXTFramebufferObject.glGenFramebuffersEXT(buffer);
FBO = buffer.get();
// for some reason FBOs won't work on textures unless you've absolutely just
// created them.
try {
Texture tex = InternalTextureLoader.get().createTexture(image.getWidth(), image.getHeight());
EXTFramebufferObject.glBindFramebufferEXT(EXTFramebufferObject.GL_FRAMEBUFFER_EXT, FBO);
EXTFramebufferObject.glFramebufferTexture2DEXT(EXTFramebufferObject.GL_FRAMEBUFFER_EXT,
EXTFramebufferObject.GL_COLOR_ATTACHMENT0_EXT,
GL11.GL_TEXTURE_2D, tex.getTextureID(), 0);
completeCheck();
unbind();
// Clear our destination area before using it
clear();
flush();
// keep hold of the original content
drawImage(image, 0, 0);
image.setTexture(tex);
} catch (Exception e) {
throw new SlickException("Failed to create new texture for FBO");
}
}
/**
* Bind to the FBO created
*/
private void bind() {
EXTFramebufferObject.glBindFramebufferEXT(EXTFramebufferObject.GL_FRAMEBUFFER_EXT, FBO);
}
/**
* Unbind from the FBO created
*/
private void unbind() {
EXTFramebufferObject.glBindFramebufferEXT(EXTFramebufferObject.GL_FRAMEBUFFER_EXT, 0);
}
/**
* @see org.newdawn.slick.Graphics#disable()
*/
protected void disable() {
GL.flush();
unbind();
GL11.glPopClientAttrib();
GL11.glPopAttrib();
GL11.glMatrixMode(GL11.GL_MODELVIEW);
GL11.glPopMatrix();
GL11.glMatrixMode(GL11.GL_PROJECTION);
GL11.glPopMatrix();
GL11.glMatrixMode(GL11.GL_MODELVIEW);
SlickCallable.leaveSafeBlock();
}
/**
* @see org.newdawn.slick.Graphics#enable()
*/
protected void enable() {
if (!valid) {
throw new RuntimeException("Attempt to use a destroy()ed offscreen graphics context.");
}
SlickCallable.enterSafeBlock();
GL11.glPushAttrib(GL11.GL_ALL_ATTRIB_BITS);
GL11.glPushClientAttrib(GL11.GL_ALL_CLIENT_ATTRIB_BITS);
GL11.glMatrixMode(GL11.GL_PROJECTION);
GL11.glPushMatrix();
GL11.glMatrixMode(GL11.GL_MODELVIEW);
GL11.glPushMatrix();
bind();
initGL();
}
/**
* Initialise the GL context
*/
protected void initGL() {
GL11.glEnable(GL11.GL_TEXTURE_2D);
GL11.glShadeModel(GL11.GL_SMOOTH);
GL11.glDisable(GL11.GL_DEPTH_TEST);
GL11.glDisable(GL11.GL_LIGHTING);
GL11.glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
GL11.glClearDepth(1);
GL11.glEnable(GL11.GL_BLEND);
GL11.glBlendFunc(GL11.GL_SRC_ALPHA, GL11.GL_ONE_MINUS_SRC_ALPHA);
GL11.glViewport(0,0,screenWidth,screenHeight);
GL11.glMatrixMode(GL11.GL_MODELVIEW);
GL11.glLoadIdentity();
enterOrtho();
}
/**
* Enter the orthographic mode
*/
protected void enterOrtho() {
GL11.glMatrixMode(GL11.GL_PROJECTION);
GL11.glLoadIdentity();
GL11.glOrtho(0, screenWidth, 0, screenHeight, 1, -1);
GL11.glMatrixMode(GL11.GL_MODELVIEW);
}
/**
* @see org.newdawn.slick.Graphics#destroy()
*/
public void destroy() {
super.destroy();
IntBuffer buffer = BufferUtils.createIntBuffer(1);
buffer.put(FBO);
buffer.flip();
EXTFramebufferObject.glDeleteFramebuffersEXT(buffer);
valid = false;
}
}