Fixed Issue 173: Adjust gamma, brightness and contrast

Added com.sun.opengl.util.Gamma supporting adjusting of gamma,
brightness, and contrast. API and implementation derived from code in
the LWJGL project. Added demos.gamma.TestGamma demo illustrating how
to use the APIs. Tested on Linux, Mac OS X and Windows. No Solaris
support at this time, although future Solaris releases, being based on
the Xorg server, will probably have support for the required
XF86VidMode extension.


git-svn-id: file:///usr/local/projects/SUN/JOGL/git-svn/svn-server-sync/jogl/trunk@557 232f8b59-042b-4e1e-8c03-345bb8c30851

1 files changed, 157 insertions, 1 deletions

diff --git a/src/classes/com/sun/opengl/impl/GLDrawableFactoryImpl.java b/src/classes/com/sun/opengl/impl/GLDrawableFactoryImpl.java
index d47003e45..45a875361 100644
--- a/src/classes/com/sun/opengl/impl/GLDrawableFactoryImpl.java
+++ b/src/classes/com/sun/opengl/impl/GLDrawableFactoryImpl.java
@@ -42,8 +42,9 @@ package com.sun.opengl.impl;
 import java.awt.Component;
 import java.awt.GraphicsConfiguration;
 import java.awt.GraphicsDevice;
-import com.sun.gluegen.runtime.*;
+import java.nio.*;
 import javax.media.opengl.*;
+import com.sun.gluegen.runtime.*;
 
 /** Extends GLDrawableFactory with a few methods for handling
     typically software-accelerated offscreen rendering (Device
@@ -73,4 +74,159 @@ public abstract class GLDrawableFactoryImpl extends GLDrawableFactory implements
   public static GLDrawableFactoryImpl getFactoryImpl() {
     return (GLDrawableFactoryImpl) getFactory();
   }
+
+  //----------------------------------------------------------------------
+  // Gamma adjustment support
+  // Thanks to the LWJGL team for illustrating how to make these
+  // adjustments on various OSs.
+
+  /*
+   * Portions Copyright (c) 2002-2004 LWJGL Project
+   * All rights reserved.
+   *
+   * Redistribution and use in source and binary forms, with or without
+   * modification, are permitted provided that the following conditions are
+   * met:
+   *
+   * * Redistributions of source code must retain the above copyright
+   *   notice, this list of conditions and the following disclaimer.
+   *
+   * * 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.
+   *
+   * * Neither the name of 'LWJGL' nor the names of
+   *   its contributors may be used to endorse or promote products derived
+   *   from this software without specific prior written permission.
+   *
+   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+   * "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 THE COPYRIGHT OWNER OR
+   * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+   * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+   * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+   * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+   * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+   * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+   * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+   */
+
+  /**
+   * Sets the gamma, brightness, and contrast of the current main
+   * display. Returns true if the settings were changed, false if
+   * not. If this method returns true, the display settings will
+   * automatically be reset upon JVM exit (assuming the JVM does not
+   * crash); if the user wishes to change the display settings back to
+   * normal ahead of time, use resetDisplayGamma(). Throws
+   * IllegalArgumentException if any of the parameters were
+   * out-of-bounds.
+   * 
+   * @param gamma The gamma value, typically > 1.0 (default value is
+   *   1.0)
+   * @param brightness The brightness value between -1.0 and 1.0,
+   *   inclusive (default value is 0)
+   * @param contrast The contrast, greater than 0.0 (default value is 1)
+   * @throws IllegalArgumentException if any of the parameters were
+   *   out-of-bounds
+   */
+  public boolean setDisplayGamma(float gamma, float brightness, float contrast) throws IllegalArgumentException {
+    if ((brightness < -1.0f) || (brightness > 1.0f)) {
+      throw new IllegalArgumentException("Brightness must be between -1.0 and 1.0");
+    }
+    if (contrast < 0) {
+      throw new IllegalArgumentException("Contrast must be greater than 0.0");
+    }
+    // FIXME: ensure gamma is > 1.0? Are smaller / negative values legal?
+    int rampLength = getGammaRampLength();
+    if (rampLength == 0) {
+      return false;
+    }
+    float[] gammaRamp = new float[rampLength];
+    for (int i = 0; i < rampLength; i++) {
+      float intensity = (float) i / (float) (rampLength - 1);
+      // apply gamma
+      float rampEntry = (float) java.lang.Math.pow(intensity, gamma);
+      // apply brightness
+      rampEntry += brightness;
+      // apply contrast
+      rampEntry = (rampEntry - 0.5f) * contrast + 0.5f;
+      // Clamp entry to [0, 1]
+      if (rampEntry > 1.0f)
+        rampEntry = 1.0f;
+      else if (rampEntry < 0.0f)
+        rampEntry = 0.0f;
+      gammaRamp[i] = rampEntry;
+    }
+    registerGammaShutdownHook();
+    return setGammaRamp(gammaRamp);
+  }
+
+  public synchronized void resetDisplayGamma() {
+    if (gammaShutdownHook == null) {
+      throw new IllegalArgumentException("Should not call this unless setDisplayGamma called first");
+    }
+    resetGammaRamp(originalGammaRamp);
+    unregisterGammeShutdownHook();
+  }
+
+  //------------------------------------------------------
+  // Gamma-related methods to be implemented by subclasses
+  //
+
+  /** Returns the length of the computed gamma ramp for this OS and
+      hardware. Returns 0 if gamma changes are not supported. */
+  protected int getGammaRampLength() {
+    return 0;
+  }
+
+  /** Sets the gamma ramp for the main screen. Returns false if gamma
+      ramp changes were not supported. */
+  protected boolean setGammaRamp(float[] ramp) {
+    return false;
+  }
+
+  /** Gets the current gamma ramp. This is basically an opaque value
+      used only on some platforms to reset the gamma ramp to its
+      original settings. */
+  protected Buffer getGammaRamp() {
+    return null;
+  }
+
+  /** Resets the gamma ramp, potentially using the specified Buffer as
+      data to restore the original values. */
+  protected void resetGammaRamp(Buffer originalGammaRamp) {
+  }
+
+  // Shutdown hook mechanism for resetting gamma
+  private boolean gammaShutdownHookRegistered;
+  private Thread  gammaShutdownHook;
+  private Buffer  originalGammaRamp;
+  private synchronized void registerGammaShutdownHook() {
+    if (gammaShutdownHookRegistered)
+      return;
+    if (gammaShutdownHook == null) {
+      gammaShutdownHook = new Thread(new Runnable() {
+          public void run() {
+            synchronized (GLDrawableFactoryImpl.this) {
+              resetGammaRamp(originalGammaRamp);
+            }
+          }
+        });
+      originalGammaRamp = getGammaRamp();
+    }
+    Runtime.getRuntime().addShutdownHook(gammaShutdownHook);
+    gammaShutdownHookRegistered = true;
+  }
+
+  private synchronized void unregisterGammeShutdownHook() {
+    if (!gammaShutdownHookRegistered)
+      return;
+    if (gammaShutdownHook == null) {
+      throw new InternalError("Error in gamma shutdown hook logic");
+    }
+    Runtime.getRuntime().removeShutdownHook(gammaShutdownHook);
+    gammaShutdownHookRegistered = false;
+    // Leave the original gamma ramp data alone
+  }
 }