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
+  }
 }