/*******************************************************************************
* 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 com.badlogic.gdx.Gdx;
import com.badlogic.gdx.graphics.Cubemap;
import com.badlogic.gdx.graphics.GL20;
import com.badlogic.gdx.graphics.Pixmap;
import com.badlogic.gdx.graphics.Texture.TextureFilter;
import com.badlogic.gdx.graphics.Texture.TextureWrap;
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 cubemap for the color attachment and a renderbuffer for the depth buffer. You can get a hold of the
* cubemap by {@link FrameBufferCubemap#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>
*
* <p>
* Typical use: <br />
* FrameBufferCubemap frameBuffer = new FrameBufferCubemap(Format.RGBA8888, fSize, fSize, true); <br />
* frameBuffer.begin(); <br />
* while( frameBuffer.nextSide() ) { <br />
* frameBuffer.getSide().getUp(camera.up); <br />
* frameBuffer.getSide().getDirection(camera.direction);<br />
* camera.update(); <br />
*
* Gdx.gl.glClearColor(0, 0, 0, 1); <br />
* Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT | GL20.GL_DEPTH_BUFFER_BIT); <br />
* modelBatch.begin(camera); <br />
* modelBatch.render(renderableProviders); <br />
* modelBatch.end(); <br />
* } <br />
* frameBuffer.end(); <br />
* Cubemap cubemap = frameBuffer.getColorBufferCubemap();
* </p>
*
* @author realitix */
public class FrameBufferCubemap extends GLFrameBuffer<Cubemap> {
/** the zero-based index of the active side **/
private int currentSide;
/** Creates a new FrameBuffer having the given dimensions and potentially a depth buffer attached.
*
* @param format
* @param width
* @param height
* @param hasDepth */
public FrameBufferCubemap (Pixmap.Format format, int width, int height, boolean hasDepth) {
this(format, width, height, hasDepth, false);
}
/** Creates a new FrameBuffer having the given dimensions and potentially a depth and a stencil buffer attached.
*
* @param format the format of the color buffer; according to the OpenGL ES 2.0 spec, only RGB565, RGBA4444 and RGB5_A1 are
* color-renderable
* @param width the width of the cubemap in pixels
* @param height the height of the cubemap in pixels
* @param hasDepth whether to attach a depth buffer
* @param hasStencil whether to attach a stencil buffer
* @throws com.badlogic.gdx.utils.GdxRuntimeException in case the FrameBuffer could not be created */
public FrameBufferCubemap (Pixmap.Format format, int width, int height, boolean hasDepth, boolean hasStencil) {
super(format, width, height, hasDepth, hasStencil);
}
@Override
protected Cubemap createColorTexture () {
int glFormat = Pixmap.Format.toGlFormat(format);
int glType = Pixmap.Format.toGlType(format);
GLOnlyTextureData data = new GLOnlyTextureData(width, height, 0, glFormat, glFormat, glType);
Cubemap result = new Cubemap(data, data, data, data, data, data);
result.setFilter(TextureFilter.Linear, TextureFilter.Linear);
result.setWrap(TextureWrap.ClampToEdge, TextureWrap.ClampToEdge);
return result;
}
@Override
protected void disposeColorTexture (Cubemap colorTexture) {
colorTexture.dispose();
}
@Override
protected void attachFrameBufferColorTexture() {
GL20 gl = Gdx.gl20;
int glHandle = colorTexture.getTextureObjectHandle();
Cubemap.CubemapSide[] sides = Cubemap.CubemapSide.values();
for (Cubemap.CubemapSide side : sides) {
gl.glFramebufferTexture2D(GL20.GL_FRAMEBUFFER, GL20.GL_COLOR_ATTACHMENT0, side.glEnum,
glHandle, 0);
}
}
/** Makes the frame buffer current so everything gets drawn to it, must be followed by call to either {@link #nextSide()} or
* {@link #bindSide(com.badlogic.gdx.graphics.Cubemap.CubemapSide)} to activate the side to render onto. */
@Override
public void bind () {
currentSide = -1;
super.bind();
}
/** Bind the next side of cubemap and return false if no more side. Should be called in between a call to {@link #begin()} and
* #end to cycle to each side of the cubemap to render on. */
public boolean nextSide () {
if (currentSide > 5) {
throw new GdxRuntimeException("No remaining sides.");
} else if (currentSide == 5) {
return false;
}
currentSide++;
bindSide(getSide());
return true;
}
/** Bind the side, making it active to render on. Should be called in between a call to {@link #begin()} and {@link #end()}.
* @param side The side to bind */
protected void bindSide (final Cubemap.CubemapSide side) {
Gdx.gl20.glFramebufferTexture2D(GL20.GL_FRAMEBUFFER, GL20.GL_COLOR_ATTACHMENT0, side.glEnum,
colorTexture.getTextureObjectHandle(), 0);
}
/** Get the currently bound side. */
public Cubemap.CubemapSide getSide () {
return currentSide < 0 ? null : Cubemap.CubemapSide.values()[currentSide];
}
}