/**
* Copyright 2014 JogAmp Community. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification, are
* permitted provided that the following conditions are met:
*
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* conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice, this list
* of conditions and the following disclaimer in the documentation and/or other materials
* provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY JogAmp Community ``AS IS'' AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL JogAmp Community OR
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package com.jogamp.opengl.util.stereo;
import com.jogamp.nativewindow.util.DimensionImmutable;
import com.jogamp.nativewindow.util.RectangleImmutable;
import com.jogamp.opengl.GL;
import com.jogamp.opengl.math.FovHVHalves;
/**
* Stereoscopic device rendering interface.
* <p>
* The following pseudo-code describes how to implement a renderer
* using a {@link StereoDeviceRenderer}.
* See {@link StereoClientRenderer} which implements the following:
* <ul>
* <li>device.{@link #beginFrame(GL)}</li>
* <li>For both eyes:<ul>
* <li>device.{@link #updateViewerPose(int)}</li>
* <li>if device.{@link #ppAvailable()}: Set the render target, e.g. FBO</li>
* <li>Set the viewport using {@link Eye#getViewport()}</li>
* <li>{@link StereoGLEventListener#reshapeForEye(com.jogamp.opengl.GLAutoDrawable, int, int, int, int, EyeParameter, ViewerPose) upstream.reshapeEye(..)}</li>
* <li>{@link StereoGLEventListener#display(com.jogamp.opengl.GLAutoDrawable, int) upstream.display(..)}.</li>
* </ul></li>
* <li>Reset the viewport</li>
* <li>If device.{@link #ppAvailable()}:<ul>
* <li>device.{@link #ppBegin(GL)}</li>
* <li>Use render target, e.g. FBO's texture</li>
* <li>device.{@link #ppBothEyes(GL)} or device.{@link #ppOneEye(GL, int)} for both eyes</li>
* <li>device.{@link #ppEnd(GL)}</li>
* </ul></li>
* <li>device.{@link #endFrame(GL)}</li>
* </ul>
* </p>
* <a name="asymFOVRendering"><h5>Correct {@link FovHVHalves Asymmetric FOV} Rendering</h5></a>
* <p>
* The {@link StereoClientRenderer} shall render both images for each eye correctly <i>Off-axis</i>
* utilizing an asymmetric camera frustum, i.e. by using {@link StereoDevice StereoDevice}'s {@link StereoDevice#getDefaultFOV() default} {@link FovHVHalves}.<br>
*
* Some references:
* <ul>
* <li><a href="https://en.wikipedia.org/wiki/Binocular_vision">Wiki: Binocular Vision</a></li>
* <li><a href="http://paulbourke.net/stereographics/stereorender/">Paul Burke: Stereo Graphics - Stereo Renderer</a></li>
* <li><a href="https://en.wikipedia.org/wiki/Distortion_%28optics%29">Wiki: Distortion (Optics)</a></li>
* </ul>
* </p>
*/
public interface StereoDeviceRenderer {
/**
* Distortion Bit: Barrel distortion compensating lens pincushion distortion
*/
public static final int DISTORTION_BARREL = 1 << 0;
/**
* Distortion Bit: Chromatic distortion compensating lens chromatic aberration.
*/
public static final int DISTORTION_CHROMATIC = 1 << 1;
/**
* Distortion Bit: Vignette distortion compensating lens chromatic aberration.
*/
public static final int DISTORTION_VIGNETTE = 1 << 2;
/**
* Distortion Bit: Timewarp distortion technique to predict
* {@link ViewerPose} movement to reduce latency.
* <p>
* FIXME: Explanation needs refinement!
* </p>
*/
public static final int DISTORTION_TIMEWARP = 1 << 3;
/** Returns the {@link StereoDevice} of this {@link StereoDeviceRenderer} instance. */
public StereoDevice getDevice();
/**
* Interface describing one eye of the stereoscopic device,
* see {@link StereoDeviceRenderer#getEye(int)}.
*/
public static interface Eye {
/**
* Returns the viewport for this eye.
*/
public RectangleImmutable getViewport();
/**
* Returns the {@link EyeParameter} of this eye.
*/
public EyeParameter getEyeParameter();
}
/**
* Returns the {@link Eye} instance for the denoted <code>eyeNum</code>.
*/
public Eye getEye(final int eyeNum);
/**
* Updates the {@link ViewerPose} and returns it.
*/
public ViewerPose updateViewerPose();
/**
* Returns the last {@link ViewerPose}.
*/
public ViewerPose getLastViewerPose();
/**
* Returns used distortion compensation bits, e.g. {@link #DISTORTION_BARREL},
* in case the stereoscopic display requires such, i.e. in case lenses are utilized.
* <p>
* Distortion requires {@link #ppAvailable() post-processing}.
* </p>
*/
public int getDistortionBits();
/**
* Method returns <code>true</code> if using <i>side-by-side</i> (SBS)
* stereoscopic images, otherwise <code>false</code>.
* <p>
* SBS requires that both eye's images are presented
* <i>side-by-side</i> in the final framebuffer.
* </p>
* <p>
* Either the renderer presents the images <i>side-by-side</i> according to the {@link Eye#getViewport() eye's viewport},
* or {@link #ppAvailable() post-processing} is utilized to merge {@link #getTextureCount() textures}
* to a <i>side-by-side</i> configuration.
* </p>
*/
public boolean usesSideBySideStereo();
/**
* Returns the surface size for each eye's a single image in pixel units.
*/
public DimensionImmutable[] getEyeSurfaceSize();
/**
* Returns the total surface size required for the complete images in pixel units.
* <p>
* If {@link #usesSideBySideStereo()} the total size spans over both {@link #getEyeSurfaceSize()}, side-by-side.
* </p>
* <p>
* Otherwise the size is equal to {@link #getEyeSurfaceSize()}.
* </p>
*/
public DimensionImmutable getTotalSurfaceSize();
/**
* Returns the used texture-image count for post-processing, see {@link #ppAvailable()}.
* <p>
* In case the renderer does not support multiple textures for post-processing,
* or no post-processing at all, method returns zero despite the request
* from {@link StereoDevice#createRenderer(int, int, float[], com.jogamp.opengl.math.FovHVHalves[], float)}.
* </p>
*/
public int getTextureCount();
/** Returns the desired texture-image unit for post-processing, see {@link #ppAvailable()}. */
public int getTextureUnit();
/** Initialize OpenGL related resources */
public void init(final GL gl);
/** Release all OpenGL related resources */
public void dispose(final GL gl);
/** Notifying that a new frame is about to start. */
public void beginFrame(final GL gl);
/** Notifying that the frame has been rendered completely. */
public void endFrame(final GL gl);
/**
* Returns <code>true</code> if stereoscopic post-processing is required and available,
* otherwise <code>false</code>.
* <p>
* Stereoscopic post-processing is available if:
* <ul>
* <li>one of the <i>distortion</i> bits are set, see {@link #getDistortionBits()}</li>
* </ul>
* </p>
* <p>
* If stereoscopic post-processing is used
* the following post-processing methods must be called to before {@link #endFrame()}:
* <ul>
* <li>{@link #ppBegin(GL)}</li>
* <li>{@link #ppOneEye(GL, int)} for both eyes</li>
* <li>{@link #ppEnd(GL)}</li>
* </ul>
* </p>
*/
public boolean ppAvailable();
/**
* Begin stereoscopic post-processing, see {@link #ppAvailable()}.
* <p>
* {@link #updateViewerPose(int)} for both eyes must be called upfront
* when rendering upstream {@link StereoGLEventListener}.
* </p>
*
* @param gl
*/
public void ppBegin(final GL gl);
/**
* Performs stereoscopic post-processing for one eye, see {@link #ppAvailable()}.
* @param gl
* @param eyeNum
*/
public void ppOneEye(final GL gl, final int eyeNum);
/**
* End stereoscopic post-processing, see {@link #ppAvailable()}.
* @param gl
*/
public void ppEnd(final GL gl);
}