GLTextureOutputRenderer.java

package com.marshalchen.common.uimodule.imageprocessing.input;

import java.util.ArrayList;
import java.util.List;

import com.marshalchen.common.uimodule.imageprocessing.GLRenderer;
import com.marshalchen.common.uimodule.imageprocessing.output.GLTextureInputRenderer;
import android.opengl.GLES20;

/**
 * A output producing extension of GLRenderer.  
 * This class produces its output in the form of a texture and then sends that texture to
 * all of the filters or endpoints that have been added as targets to this renderer.
 * @author Chris Batt
 */
public abstract class GLTextureOutputRenderer extends GLRenderer {
	protected int[] frameBuffer;
	protected int[] texture_out;
	protected int[] depthRenderBuffer;
	
	private List<GLTextureInputRenderer> targets;
	private Object listLock = new Object();
	
	private boolean dirty;
	
	/**
	 * Creates a GLTextureOutputRenderer which initially has an empty list of targets.
	 */
	public GLTextureOutputRenderer() {
		super();
		targets = new ArrayList<GLTextureInputRenderer>();
	}
	
	/**
	 * Adds the given target to the list of targets that this renderer sends its output to.
	 * @param target
	 * The target which should be added to the list of targets that this renderer sends its output to.
	 */
	public synchronized void addTarget(GLTextureInputRenderer target) {
		synchronized(listLock) {
			targets.add(target);
		}
	}
	
	/* (non-Javadoc)
	 * @see com.marshalchen.common.uimodule.imageprocessing.GLRenderer#destroy()
	 */
	@Override
	public void destroy() {
		super.destroy();
		if(frameBuffer != null) {
			GLES20.glDeleteFramebuffers(1, frameBuffer, 0);
			frameBuffer = null;
		}
		if(texture_out != null) {
			GLES20.glDeleteTextures(1, texture_out, 0);
			texture_out = null;
		}
		if(depthRenderBuffer != null) {
			GLES20.glDeleteRenderbuffers(1, depthRenderBuffer, 0);
			depthRenderBuffer = null;
		}
	}
	
	@Override
	protected void drawFrame() {
		if(frameBuffer == null) {
			if(getWidth() != 0 && getHeight() != 0) {
				initFBO();
			} else {
				return;
			}
		}

		boolean newData = false;
		if(dirty) {
			newData = true;
			
			GLES20.glBindFramebuffer(GLES20.GL_FRAMEBUFFER, frameBuffer[0]);
			
			super.drawFrame();
			
			GLES20.glBindFramebuffer(GLES20.GL_FRAMEBUFFER, 0);
		}
		
		synchronized(listLock) {
			for(GLTextureInputRenderer target : targets) {
				target.newTextureReady(texture_out[0], this, newData);
			}
		}
	}
	
	/**
	 * Returns the object used to lock the target list.  Iterating over or changing the target list
	 * should be done in a synchronized block that is locked using the object return.
	 * @return lock
	 * the object which is used to lock the target list
	 */
	public Object getLockObject() {
		return listLock;
	}
	
	/**
	 * Returns a list of all the targets that this renderer should send its output to.  Iterating over or changing this
	 * list should be done in a synchronized block, locked using the object returned from getLockObject().
	 * @return targets 
	 */
	public List<GLTextureInputRenderer> getTargets() {
		return targets;
	}
	
	@Override
	protected void handleSizeChange() {
		initFBO();
	}
	
	private void initFBO() {
		if(frameBuffer != null) {
			GLES20.glDeleteFramebuffers(1, frameBuffer, 0);
			frameBuffer = null;
		}
		if(texture_out != null) {
			GLES20.glDeleteTextures(1, texture_out, 0);
			texture_out = null;
		}
		if(depthRenderBuffer != null) {
			GLES20.glDeleteRenderbuffers(1, depthRenderBuffer, 0);
			depthRenderBuffer = null;
		}
		frameBuffer = new int[1];
		texture_out = new int[1];
		depthRenderBuffer = new int[1];
		GLES20.glGenFramebuffers(1, frameBuffer, 0);
		GLES20.glGenRenderbuffers(1, depthRenderBuffer, 0);
		GLES20.glGenTextures(1, texture_out, 0);
		
		GLES20.glBindFramebuffer(GLES20.GL_FRAMEBUFFER, frameBuffer[0]);
		
		GLES20.glActiveTexture(GLES20.GL_TEXTURE0);
		GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, texture_out[0]);
		GLES20.glTexImage2D(GLES20.GL_TEXTURE_2D, 0, GLES20.GL_RGBA, getWidth(), getHeight(), 0, GLES20.GL_RGBA, GLES20.GL_UNSIGNED_BYTE, null);
		GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_WRAP_S, GLES20.GL_CLAMP_TO_EDGE);
		GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_WRAP_T, GLES20.GL_CLAMP_TO_EDGE);
		GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MAG_FILTER, GLES20.GL_LINEAR);
		GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MIN_FILTER, GLES20.GL_LINEAR);
		GLES20.glFramebufferTexture2D(GLES20.GL_FRAMEBUFFER, GLES20.GL_COLOR_ATTACHMENT0, GLES20.GL_TEXTURE_2D, texture_out[0], 0);
		
		GLES20.glBindRenderbuffer(GLES20.GL_RENDERBUFFER, depthRenderBuffer[0]);
		GLES20.glRenderbufferStorage(GLES20.GL_RENDERBUFFER, GLES20.GL_DEPTH_COMPONENT16, getWidth(), getHeight());
		GLES20.glFramebufferRenderbuffer(GLES20.GL_FRAMEBUFFER, GLES20.GL_DEPTH_ATTACHMENT, GLES20.GL_RENDERBUFFER, depthRenderBuffer[0]);
		
		int status = GLES20.glCheckFramebufferStatus(GLES20.GL_FRAMEBUFFER);
		if (status != GLES20.GL_FRAMEBUFFER_COMPLETE) {
			throw new RuntimeException(this+": Failed to set up render buffer with status "+status+" and error "+GLES20.glGetError());
		}
	}
	
	/**
	 * Removes the given target from the list of targets that this renderer sends its output to.
	 * @param target
	 * The target which should be removed from the list of targets that this renderer sends its output to.
	 */
	public void removeTarget(GLTextureInputRenderer target) {
		synchronized(listLock) {
			targets.remove(target);
		}
	}
	
	public void markAsDirty() {
		dirty = true;
	}
}