/* * Copyright (c) 2003 Sun Microsystems, Inc. All Rights Reserved. * Copyright (c) 2010 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: * * - Redistribution of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * - Redistribution 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. * * Neither the name of Sun Microsystems, Inc. or the names of * contributors may be used to endorse or promote products derived from * this software without specific prior written permission. * * This software is provided "AS IS," without a warranty of any kind. ALL * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, * INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A * PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN * MICROSYSTEMS, INC. ("SUN") AND ITS LICENSORS SHALL NOT BE LIABLE FOR * ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR * DISTRIBUTING THIS SOFTWARE OR ITS DERIVATIVES. IN NO EVENT WILL SUN OR * ITS LICENSORS BE LIABLE FOR ANY LOST REVENUE, PROFIT OR DATA, OR FOR * DIRECT, INDIRECT, SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE * DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY, * ARISING OUT OF THE USE OF OR INABILITY TO USE THIS SOFTWARE, EVEN IF * SUN HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. * * You acknowledge that this software is not designed or intended for use * in the design, construction, operation or maintenance of any nuclear * facility. * * Sun gratefully acknowledges that this software was originally authored * and developed by Kenneth Bradley Russell and Christopher John Kline. */ package com.jogamp.nativewindow; import java.util.List; import com.jogamp.common.util.PropertyAccess; import jogamp.nativewindow.Debug; /** <P> The default implementation of the {@link CapabilitiesChooser} interface, which provides consistent visual selection behavior across platforms. The precise algorithm is deliberately left loosely specified. Some properties are: </P> <LI> Attempts to match as closely as possible the given Capabilities, but will select one with fewer capabilities (i.e., lower color depth) if necessary. <LI> If there is no exact match, prefers a more-capable visual to a less-capable one. <LI> If there is more than one exact match, chooses an arbitrary one. <LI> If a valid windowSystemRecommendedChoice parameter is supplied, chooses that instead of using the cross-platform code. </UL> */ public class DefaultCapabilitiesChooser implements CapabilitiesChooser { private static final boolean DEBUG; static { Debug.initSingleton(); DEBUG = PropertyAccess.isPropertyDefined("nativewindow.debug.CapabilitiesChooser", true); } private final static int NO_SCORE = -9999999; private final static int COLOR_MISMATCH_PENALTY_SCALE = 36; @Override public int chooseCapabilities(final CapabilitiesImmutable desired, final List<? extends CapabilitiesImmutable> available, final int windowSystemRecommendedChoice) { if (DEBUG) { System.err.println("Desired: " + desired); for (int i = 0; i < available.size(); i++) { System.err.println("Available " + i + ": " + available.get(i)); } System.err.println("Window system's recommended choice: " + windowSystemRecommendedChoice); } final int availnum = available.size(); if (windowSystemRecommendedChoice >= 0 && windowSystemRecommendedChoice < availnum && null != available.get(windowSystemRecommendedChoice)) { if (DEBUG) { System.err.println("Choosing window system's recommended choice of " + windowSystemRecommendedChoice); System.err.println(available.get(windowSystemRecommendedChoice)); } return windowSystemRecommendedChoice; } // Create score array final int[] scores = new int[availnum]; for (int i = 0; i < availnum; i++) { scores[i] = NO_SCORE; } // Compute score for each for (int i = 0; i < availnum; i++) { final CapabilitiesImmutable cur = available.get(i); if (cur == null) { continue; } if (desired.isOnscreen() && !cur.isOnscreen()) { continue; // requested onscreen, but n/a } int score = 0; // Compute difference in color depth score += (COLOR_MISMATCH_PENALTY_SCALE * ((cur.getRedBits() + cur.getGreenBits() + cur.getBlueBits() + cur.getAlphaBits()) - (desired.getRedBits() + desired.getGreenBits() + desired.getBlueBits() + desired.getAlphaBits()))); scores[i] = score; } if (DEBUG) { System.err.print("Scores: ["); for (int i = 0; i < availnum; i++) { if (i > 0) { System.err.print(","); } System.err.print(" " + scores[i]); } System.err.println(" ]"); } // Ready to select. Choose score closest to 0. int scoreClosestToZero = NO_SCORE; int chosenIndex = -1; for (int i = 0; i < availnum; i++) { final int score = scores[i]; if (score == NO_SCORE) { continue; } // Don't substitute a positive score for a smaller negative score if ((scoreClosestToZero == NO_SCORE) || (Math.abs(score) < Math.abs(scoreClosestToZero) && ((sign(scoreClosestToZero) < 0) || (sign(score) > 0)))) { scoreClosestToZero = score; chosenIndex = i; } } if (chosenIndex < 0) { throw new NativeWindowException("Unable to select one of the provided Capabilities"); } if (DEBUG) { System.err.println("Chosen index: " + chosenIndex); System.err.println("Chosen capabilities:"); System.err.println(available.get(chosenIndex)); } return chosenIndex; } private static int sign(final int score) { if (score < 0) { return -1; } return 1; } }