/*******************************************************************************
* Copyright 2011 See AUTHORS file.
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
* an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
* specific language governing permissions and limitations under the License.
******************************************************************************/
package com.badlogic.gdx.graphics.glutils;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.IntBuffer;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import com.badlogic.gdx.Application;
import com.badlogic.gdx.Gdx;
import com.badlogic.gdx.Application.ApplicationType;
import com.badlogic.gdx.graphics.GL20;
import com.badlogic.gdx.graphics.Pixmap;
import com.badlogic.gdx.graphics.Texture;
import com.badlogic.gdx.graphics.Texture.TextureFilter;
import com.badlogic.gdx.graphics.Texture.TextureWrap;
import com.badlogic.gdx.utils.BufferUtils;
import com.badlogic.gdx.utils.Disposable;
import com.badlogic.gdx.utils.GdxRuntimeException;
/**
* <p>
* Encapsulates OpenGL ES 2.0 frame buffer objects. This is a simple helper class which should cover most FBO uses. It
* will automatically create a texture for the color attachment and a renderbuffer for the depth buffer. You can get a
* hold of the texture by {@link FrameBuffer#getColorBufferTexture()}. This class will only work with OpenGL ES 2.0.
* </p>
*
* <p>
* FrameBuffers are managed. In case of an OpenGL context loss, which only happens on Android when a user switches to
* another application or receives an incoming call, the framebuffer will be automatically recreated.
* </p>
*
* <p>
* A FrameBuffer must be disposed if it is no longer needed
* </p>
*
* @author mzechner
*/
public class FrameBuffer implements Disposable {
/** the frame buffers **/
private final static Map<Application, List<FrameBuffer>> buffers = new HashMap<Application, List<FrameBuffer>>();
/** the color buffer texture **/
protected Texture colorTexture;
/** the default framebuffer handle, a.k.a screen. */
private static int defaultFramebufferHandle;
/** true if we have polled for the default handle already. */
private static boolean defaultFramebufferHandleInitialized = false;
/** the framebuffer handle **/
private int framebufferHandle;
/** the depthbuffer render object handle **/
private int depthbufferHandle;
/** width **/
protected final int width;
/** height **/
protected final int height;
/** depth **/
protected final boolean hasDepth;
/** format **/
protected final Pixmap.Format format;
/**
* Creates a new FrameBuffer having the given dimensions and potentially a depth buffer attached.
*
* @param format
* the format of the color buffer
* @param width
* the width of the framebuffer in pixels
* @param height
* the height of the framebuffer in pixels
* @param hasDepth
* whether to attach a depth buffer
* @throws GdxRuntimeException
* in case the FraeBuffer could not be created
*/
public FrameBuffer(Pixmap.Format format, int width, int height, boolean hasDepth) {
this.width = width;
this.height = height;
this.format = format;
this.hasDepth = hasDepth;
build();
addManagedFrameBuffer(Gdx.app, this);
}
/**
* Override this method in a derived class to set up the backing texture as you like.
*/
protected void setupTexture() {
colorTexture = new Texture(width, height, format);
colorTexture.setFilter(TextureFilter.Linear, TextureFilter.Linear);
colorTexture.setWrap(TextureWrap.ClampToEdge, TextureWrap.ClampToEdge);
}
private void build() {
if (!Gdx.graphics.isGL20Available())
throw new GdxRuntimeException("GL2 is required.");
GL20 gl = Gdx.graphics.getGL20();
// iOS uses a different framebuffer handle! (not necessarily 0)
if (!defaultFramebufferHandleInitialized) {
defaultFramebufferHandleInitialized = true;
if (Gdx.app.getType() == ApplicationType.iOS) {
IntBuffer intbuf = ByteBuffer.allocateDirect(16 * Integer.SIZE / 8).order(ByteOrder.nativeOrder())
.asIntBuffer();
gl.glGetIntegerv(GL20.GL_FRAMEBUFFER_BINDING, intbuf);
defaultFramebufferHandle = intbuf.get();
} else {
defaultFramebufferHandle = 0;
}
}
setupTexture();
IntBuffer handle = BufferUtils.newIntBuffer(1);
gl.glGenFramebuffers(1, handle);
framebufferHandle = handle.get(0);
if (hasDepth) {
handle.clear();
gl.glGenRenderbuffers(1, handle);
depthbufferHandle = handle.get(0);
}
gl.glBindTexture(GL20.GL_TEXTURE_2D, colorTexture.getTextureObjectHandle());
if (hasDepth) {
gl.glBindRenderbuffer(GL20.GL_RENDERBUFFER, depthbufferHandle);
gl.glRenderbufferStorage(GL20.GL_RENDERBUFFER, GL20.GL_DEPTH_COMPONENT16, colorTexture.getWidth(),
colorTexture.getHeight());
}
gl.glBindFramebuffer(GL20.GL_FRAMEBUFFER, framebufferHandle);
gl.glFramebufferTexture2D(GL20.GL_FRAMEBUFFER, GL20.GL_COLOR_ATTACHMENT0, GL20.GL_TEXTURE_2D,
colorTexture.getTextureObjectHandle(), 0);
if (hasDepth) {
gl.glFramebufferRenderbuffer(GL20.GL_FRAMEBUFFER, GL20.GL_DEPTH_ATTACHMENT, GL20.GL_RENDERBUFFER,
depthbufferHandle);
}
int result = gl.glCheckFramebufferStatus(GL20.GL_FRAMEBUFFER);
gl.glBindRenderbuffer(GL20.GL_RENDERBUFFER, 0);
gl.glBindTexture(GL20.GL_TEXTURE_2D, 0);
gl.glBindFramebuffer(GL20.GL_FRAMEBUFFER, defaultFramebufferHandle);
if (result != GL20.GL_FRAMEBUFFER_COMPLETE) {
colorTexture.dispose();
if (hasDepth) {
handle.clear();
handle.put(depthbufferHandle);
handle.flip();
gl.glDeleteRenderbuffers(1, handle);
}
colorTexture.dispose();
handle.clear();
handle.put(framebufferHandle);
handle.flip();
gl.glDeleteFramebuffers(1, handle);
if (result == GL20.GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT)
throw new IllegalStateException("frame buffer couldn't be constructed: incomplete attachment");
if (result == GL20.GL_FRAMEBUFFER_INCOMPLETE_DIMENSIONS)
throw new IllegalStateException("frame buffer couldn't be constructed: incomplete dimensions");
if (result == GL20.GL_FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT)
throw new IllegalStateException("frame buffer couldn't be constructed: missing attachment");
}
}
/** Releases all resources associated with the FrameBuffer. */
public void dispose() {
GL20 gl = Gdx.graphics.getGL20();
IntBuffer handle = BufferUtils.newIntBuffer(1);
colorTexture.dispose();
if (hasDepth) {
handle.put(depthbufferHandle);
handle.flip();
gl.glDeleteRenderbuffers(1, handle);
}
handle.clear();
handle.put(framebufferHandle);
handle.flip();
gl.glDeleteFramebuffers(1, handle);
if (buffers.get(Gdx.app) != null)
buffers.get(Gdx.app).remove(this);
}
/** Makes the frame buffer current so everything gets drawn to it. */
public void begin() {
Gdx.graphics.getGL20().glViewport(0, 0, colorTexture.getWidth(), colorTexture.getHeight());
Gdx.graphics.getGL20().glBindFramebuffer(GL20.GL_FRAMEBUFFER, framebufferHandle);
}
/** Unbinds the framebuffer, all drawing will be performed to the normal framebuffer from here on. */
public void end() {
Gdx.graphics.getGL20().glViewport(0, 0, Gdx.graphics.getWidth(), Gdx.graphics.getHeight());
Gdx.graphics.getGL20().glBindFramebuffer(GL20.GL_FRAMEBUFFER, defaultFramebufferHandle);
}
private void addManagedFrameBuffer(Application app, FrameBuffer frameBuffer) {
List<FrameBuffer> managedResources = buffers.get(app);
if (managedResources == null)
managedResources = new ArrayList<FrameBuffer>();
managedResources.add(frameBuffer);
buffers.put(app, managedResources);
}
/**
* Invalidates all frame buffers. This can be used when the OpenGL context is lost to rebuild all managed frame
* buffers. This assumes that the texture attached to this buffer has already been rebuild! Use with care.
*/
public static void invalidateAllFrameBuffers(Application app) {
if (Gdx.graphics.getGL20() == null)
return;
List<FrameBuffer> bufferList = buffers.get(app);
if (bufferList == null)
return;
for (int i = 0; i < bufferList.size(); i++) {
bufferList.get(i).build();
}
}
public static void clearAllFrameBuffers(Application app) {
buffers.remove(app);
}
public static String getManagedStatus() {
StringBuilder builder = new StringBuilder();
int i = 0;
builder.append("Managed buffers/app: { ");
for (Application app : buffers.keySet()) {
builder.append(buffers.get(app).size());
builder.append(" ");
}
builder.append("}");
return builder.toString();
}
/** @return the color buffer texture */
public Texture getColorBufferTexture() {
return colorTexture;
}
/** @return the height of the framebuffer in pixels */
public int getHeight() {
return colorTexture.getHeight();
}
/** @return the width of the framebuffer in pixels */
public int getWidth() {
return colorTexture.getWidth();
}
}