diff options
Diffstat (limited to 'src/net/java/games/jogl/DefaultGLCapabilitiesChooser.java')
| -rw-r--r-- | src/net/java/games/jogl/DefaultGLCapabilitiesChooser.java | 216 |
1 files changed, 216 insertions, 0 deletions
diff --git a/src/net/java/games/jogl/DefaultGLCapabilitiesChooser.java b/src/net/java/games/jogl/DefaultGLCapabilitiesChooser.java new file mode 100644 index 000000000..de7f500b5 --- /dev/null +++ b/src/net/java/games/jogl/DefaultGLCapabilitiesChooser.java @@ -0,0 +1,216 @@ +/* + * Copyright (c) 2003 Sun Microsystems, Inc. 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 + * MIDROSYSTEMS, 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 net.java.games.jogl; + +/** <P> The default implementation of the {@link + GLCapabilitiesChooser} interface, which provides consistent visual + selection behavior across platforms. The precise algorithm is + deliberately left loosely specified. Some properties are: </P> + + <UL> + + <LI> As long as there is at least one available non-null + GLCapabilities which matches the "stereo" option, will return a + valid index. + + <LI> Attempts to match as closely as possible the given + GLCapabilities, but will select one with fewer capabilities (i.e., + lower color depth) if necessary. + + <LI> Prefers hardware-accelerated visuals to + non-hardware-accelerated. + + <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> May select the opposite of a double- or single-buffered + visual (based on the user's request) in dire situations. + + <LI> Color depth (including alpha) mismatches are weighted higher + than depth buffer mismatches, which are in turn weighted higher + than accumulation buffer (including alpha) and stencil buffer + depth mismatches. + + </UL> +*/ + +public class DefaultGLCapabilitiesChooser implements GLCapabilitiesChooser { + private static final boolean DEBUG = false; + + public int chooseCapabilities(GLCapabilities desired, GLCapabilities[] available) { + if (DEBUG) { + for (int i = 0; i < available.length; i++) { + System.err.println("Available " + i + ": " + available[i]); + } + } + + // Create score array + int[] scores = new int[available.length]; + int NO_SCORE = -9999999; + int DOUBLE_BUFFER_MISMATCH_PENALTY = 1000; + int STENCIL_MISMATCH_PENALTY = 500; + // Pseudo attempt to keep equal rank penalties scale-equivalent + // (e.g., stencil mismatch is 3 * accum because there are 3 accum + // components) + int COLOR_MISMATCH_PENALTY_SCALE = 36; + int DEPTH_MISMATCH_PENALTY_SCALE = 6; + int ACCUM_MISMATCH_PENALTY_SCALE = 1; + int STENCIL_MISMATCH_PENALTY_SCALE = 3; + for (int i = 0; i < scores.length; i++) { + scores[i] = NO_SCORE; + } + // Compute score for each + for (int i = 0; i < scores.length; i++) { + GLCapabilities cur = available[i]; + if (cur == null) { + continue; + } + if (desired.getStereo() != cur.getStereo()) { + continue; + } + int score = 0; + // Compute difference in color depth + // (Note that this decides the direction of all other penalties) + score += (COLOR_MISMATCH_PENALTY_SCALE * + ((cur.getRedBits() + cur.getGreenBits() + cur.getBlueBits() + cur.getAlphaBits()) - + (desired.getRedBits() + desired.getGreenBits() + desired.getBlueBits() + desired.getAlphaBits()))); + // Compute difference in depth buffer depth + score += (DEPTH_MISMATCH_PENALTY_SCALE * sign(score) * + Math.abs(cur.getDepthBits() - desired.getDepthBits())); + // Compute difference in accumulation buffer depth + score += (ACCUM_MISMATCH_PENALTY_SCALE * sign(score) * + Math.abs((cur.getAccumRedBits() + cur.getAccumGreenBits() + cur.getAccumBlueBits() + cur.getAccumAlphaBits()) - + (desired.getAccumRedBits() + desired.getAccumGreenBits() + desired.getAccumBlueBits() + desired.getAccumAlphaBits()))); + // Compute difference in stencil bits + score += STENCIL_MISMATCH_PENALTY_SCALE * sign(score) * (cur.getStencilBits() - desired.getStencilBits()); + if (cur.getDoubleBuffered() != desired.getDoubleBuffered()) { + score += sign(score) * DOUBLE_BUFFER_MISMATCH_PENALTY; + } + if ((desired.getStencilBits() > 0) && (cur.getStencilBits() == 0)) { + score += sign(score) * STENCIL_MISMATCH_PENALTY; + } + scores[i] = score; + } + // Now prefer hardware-accelerated visuals by pushing scores of + // non-hardware-accelerated visuals out + boolean gotHW = false; + int maxAbsoluteHWScore = 0; + for (int i = 0; i < scores.length; i++) { + int score = scores[i]; + if (score == NO_SCORE) { + continue; + } + GLCapabilities cur = available[i]; + if (cur.getHardwareAccelerated()) { + int absScore = Math.abs(score); + if (!gotHW || + (absScore > maxAbsoluteHWScore)) { + gotHW = true; + maxAbsoluteHWScore = absScore; + } + } + } + if (gotHW) { + for (int i = 0; i < scores.length; i++) { + int score = scores[i]; + if (score == NO_SCORE) { + continue; + } + GLCapabilities cur = available[i]; + if (!cur.getHardwareAccelerated()) { + if (score <= 0) { + score -= maxAbsoluteHWScore; + } else if (score > 0) { + score += maxAbsoluteHWScore; + } + scores[i] = score; + } + } + } + + if (DEBUG) { + System.err.print("Scores: ["); + for (int i = 0; i < available.length; 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 < scores.length; i++) { + 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 GLException("Unable to select one of the provided GLCapabilities"); + } + if (DEBUG) { + System.err.println("Chosen index: " + chosenIndex); + System.err.println("Chosen capabilities:"); + System.err.println(available[chosenIndex]); + } + + return chosenIndex; + } + + private static int sign(int score) { + if (score < 0) { + return -1; + } + return 1; + } +} |