Merged gcj-eclipse branch to trunk.

From-SVN: r120621
author: Tom Tromey <tromey@gcc.gnu.org> 2007-01-09 19:58:05 +0000
committer: Tom Tromey <tromey@gcc.gnu.org> 2007-01-09 19:58:05 +0000
commit: 97b8365cafc3a344a22d3980b8ed885f5c6d8357 (patch)
tree: 996a5f57d4a68c53473382e45cb22f574cb3e4db /libjava/classpath/java/awt/image/RescaleOp.java
parent: c648dedbde727ca3f883bb5fd773aa4af70d3369 (diff)
download: gcc-97b8365cafc3a344a22d3980b8ed885f5c6d8357.zip
gcc-97b8365cafc3a344a22d3980b8ed885f5c6d8357.tar.gz
gcc-97b8365cafc3a344a22d3980b8ed885f5c6d8357.tar.bz2
1 files changed, 230 insertions, 63 deletions
diff --git a/libjava/classpath/java/awt/image/RescaleOp.java b/libjava/classpath/java/awt/image/RescaleOp.java
index d5b2969..d56b12cb9 100644
--- a/libjava/classpath/java/awt/image/RescaleOp.java
+++ b/libjava/classpath/java/awt/image/RescaleOp.java
@@ -1,4 +1,4 @@
-/* Copyright (C) 2004  Free Software Foundation
+/* Copyright (C) 2004, 2006  Free Software Foundation
 
 This file is part of GNU Classpath.
 
@@ -43,7 +43,23 @@ import java.awt.geom.Rectangle2D;
 import java.util.Arrays;
 
 /**
+ * RescaleOp is a filter that changes each pixel by a scaling factor and offset.
+ * 
+ * For filtering Rasters, either one scaling factor and offset can be specified,
+ * which will be applied to all bands; or a scaling factor and offset can be
+ * specified for each band.
+ * 
+ * For BufferedImages, the scaling may apply to both color and alpha components.
+ * If only one scaling factor is provided, or if the number of factors provided
+ * equals the number of color components, the scaling is performed on all color
+ * components.  Otherwise, the scaling is performed on all components including
+ * alpha.  Alpha premultiplication is ignored.
+ * 
+ * After filtering, if color conversion is necessary, the conversion happens,
+ * taking alpha premultiplication into account.
+ * 
  * @author Jerry Quinn (jlquinn@optonline.net)
+ * @author Francis Kung (fkung@redhat.com)
  */
 public class RescaleOp implements BufferedImageOp, RasterOp
 {
@@ -51,15 +67,43 @@ public class RescaleOp implements BufferedImageOp, RasterOp
   private float[] offsets;
   private RenderingHints hints = null;
   
+  /**
+   * Create a new RescaleOp object using the given scale factors and offsets.
+   * 
+   * The length of the arrays must be equal to the number of bands (or number of
+   * data or color components) of the raster/image that this Op will be used on,
+   * otherwise an IllegalArgumentException will be thrown when calling the
+   * filter method.
+   *  
+   * @param scaleFactors an array of scale factors.
+   * @param offsets an array of offsets.
+   * @param hints any rendering hints to use (can be null).
+   * @throws NullPointerException if the scaleFactors or offsets array is null.
+   */
   public RescaleOp(float[] scaleFactors,
 		   float[] offsets,
 		   RenderingHints hints)
   {
-    this.scale = scaleFactors;
-    this.offsets = offsets;
+    int length = Math.min(scaleFactors.length, offsets.length);
+    
+    scale = new float[length];
+    System.arraycopy(scaleFactors, 0, this.scale, 0, length);
+    
+    this.offsets = new float[length];
+    System.arraycopy(offsets, 0, this.offsets, 0, length);
+    
     this.hints = hints;
   }
   
+  /**
+   * Create a new RescaleOp object using the given scale factor and offset.
+   * 
+   * The same scale factor and offset will be used on all bands/components.
+   *  
+   * @param scaleFactor the scale factor to use.
+   * @param offset the offset to use.
+   * @param hints any rendering hints to use (can be null).
+   */
   public RescaleOp(float scaleFactor,
 		   float offset,
 		   RenderingHints hints)
@@ -69,22 +113,47 @@ public class RescaleOp implements BufferedImageOp, RasterOp
     this.hints = hints;
   }
 
+  /**
+   * Returns the scaling factors.  This method accepts an optional array, which
+   * will be used to store the factors if not null (this avoids allocating a 
+   * new array).  If this array is too small to hold all the scaling factors,
+   * the array will be filled and the remaining factors discarded.
+   * 
+   * @param scaleFactors array to store the scaling factors in (can be null).
+   * @return an array of scaling factors.
+   */
   public final float[] getScaleFactors(float[] scaleFactors)
   {
     if (scaleFactors == null)
       scaleFactors = new float[scale.length];
-    System.arraycopy(scale, 0, scaleFactors, 0, scale.length);
+    System.arraycopy(scale, 0, scaleFactors, 0, Math.min(scale.length,
+                                                         scaleFactors.length));
     return scaleFactors;
   }
 
+  /**
+   * Returns the offsets.  This method accepts an optional array, which
+   * will be used to store the offsets if not null (this avoids allocating a 
+   * new array).  If this array is too small to hold all the offsets, the array 
+   * will be filled and the remaining factors discarded.
+   * 
+   * @param offsets array to store the offsets in (can be null).
+   * @return an array of offsets.
+   */
   public final float[] getOffsets(float[] offsets)
   {
     if (offsets == null)
       offsets = new float[this.offsets.length];
-    System.arraycopy(this.offsets, 0, offsets, 0, this.offsets.length);
+    System.arraycopy(this.offsets, 0, offsets, 0, Math.min(this.offsets.length,
+                                                           offsets.length));
     return offsets;
   }
 
+  /**
+   * Returns the number of scaling factors / offsets.
+   * 
+   * @return the number of scaling factors / offsets.
+   */
   public final int getNumFactors()
   {
     return scale.length;
@@ -98,36 +167,74 @@ public class RescaleOp implements BufferedImageOp, RasterOp
     return hints;
   }
 
-  /* (non-Javadoc)
-   * @see java.awt.image.BufferedImageOp#filter(java.awt.image.BufferedImage, java.awt.image.BufferedImage)
+  /**
+   * Converts the source image using the scale factors and offsets specified in 
+   * the constructor.  The resulting image is stored in the destination image if 
+   * one is provided; otherwise a new BufferedImage is created and returned. 
+   * 
+   * The source image cannot use an IndexColorModel, and the destination image
+   * (if one is provided) must have the same size.
+   * 
+   * If the final value of a sample is beyond the range of the color model, it
+   * will be clipped to the appropriate maximum / minimum.
+   *
+   * @param src The source image.
+   * @param dst The destination image.
+   * @throws IllegalArgumentException if the rasters and/or color spaces are
+   *            incompatible.
+   * @return The rescaled image.
    */
   public final BufferedImage filter(BufferedImage src, BufferedImage dst)
   {
-    // TODO Make sure premultiplied alpha is handled correctly.
-    // TODO See that color conversion is handled.
-    // TODO figure out how to use rendering hints.
-    if (scale.length != offsets.length)
-      throw new IllegalArgumentException();
+    // Initial checks
+    if (scale.length != 1
+        && scale.length != src.getColorModel().getNumComponents()
+        && (scale.length != src.getColorModel().getNumColorComponents()))
+      throw new IllegalArgumentException("Source image has wrong number of "
+                                         + "bands for these scaling factors.");
 
-    ColorModel scm = src.getColorModel();
-    if (dst == null) dst = createCompatibleDestImage(src, null);
+    if (dst == null)
+      dst = createCompatibleDestImage(src, null);
+    else if (src.getHeight() != dst.getHeight()
+             || src.getWidth() != dst.getWidth())
+      throw new IllegalArgumentException("Source and destination images are "
+                                         + "different sizes.");
 
-    WritableRaster wsrc = src.getRaster();
-    WritableRaster wdst = dst.getRaster();
-    
-    // Share constant across colors except alpha
-    if (scale.length == 1 || scale.length == scm.getNumColorComponents())
+    // Prepare for possible colorspace conversion
+    BufferedImage dst2 = dst;
+    if (dst.getColorModel().getColorSpace().getType() != src.getColorModel().getColorSpace().getType())
+      dst2 = createCompatibleDestImage(src, src.getColorModel());
+
+    // Figure out how many bands to scale
+    int numBands = scale.length;
+    if (scale.length == 1)
+      numBands = src.getColorModel().getNumColorComponents();
+    boolean[] bands = new boolean[numBands];
+    // this assumes the alpha, if present, is the last band
+    Arrays.fill(bands, true);
+
+    // Perform rescaling
+    filter(src.getRaster(), dst2.getRaster(), bands);
+
+    // Copy alpha band if needed (ie if it exists and wasn't scaled)
+    // NOTE: This assumes the alpha component is the last band!
+    if (src.getColorModel().hasAlpha()
+        && numBands == src.getColorModel().getNumColorComponents())
       {
-	// Construct a raster that doesn't include an alpha band.
-	int[] subbands = new int[scm.getNumColorComponents()];
-	for (int i=0; i < subbands.length; i++) subbands[i] = i;
-	wsrc = 
-	  wsrc.createWritableChild(wsrc.minX, wsrc.minY, wsrc.width, wsrc.height,
-				   wsrc.minX, wsrc.minY, subbands);
+
+        dst2.getRaster().setSamples(0, 0, src.getWidth(), src.getHeight(),
+                                    numBands,
+                                    src.getRaster().getSamples(0, 0,
+                                                               src.getWidth(),
+                                                               src.getHeight(),
+                                                               numBands,
+                                                               (int[]) null));
       }
-    // else all color bands
 
-    filter(wsrc, wdst);
+    // Perform colorspace conversion if needed
+    if (dst != dst2)
+      new ColorConvertOp(hints).filter(dst2, dst);
+
     return dst;
   }
 
@@ -136,50 +243,106 @@ public class RescaleOp implements BufferedImageOp, RasterOp
    */
   public final WritableRaster filter(Raster src, WritableRaster dest)
   {
-    if (dest == null) dest = src.createCompatibleWritableRaster();
-
     // Required sanity checks
-    if (src.numBands != dest.numBands || scale.length != offsets.length)
-      throw new IllegalArgumentException();
     if (scale.length != 1 && scale.length != src.numBands)
-      throw new IllegalArgumentException();
+      throw new IllegalArgumentException("Number of rasters is incompatible "
+                                             + "with the number of scaling "
+                                             + "factors provided.");
 
-    // Create scaling arrays if needed
-    float[] lscale = scale;
-    float[] loff = offsets;
-    if (scale.length == 1)
-      {
-	lscale = new float[src.numBands];
-	Arrays.fill(lscale, scale[0]);
-	loff = new float[src.numBands];
-	Arrays.fill(loff, offsets[0]);
-      }
+    if (dest == null)
+      dest = src.createCompatibleWritableRaster();
+    else if (src.getHeight() != dest.getHeight()
+             || src.getWidth() != dest.getWidth())
+      throw new IllegalArgumentException("Source and destination rasters are "
+                                         + "different sizes.");
+    else if (src.numBands != dest.numBands)
+      throw new IllegalArgumentException("Source and destination rasters "
+                                         + "are incompatible.");
+
+    // Filter all bands
+    boolean[] bands = new boolean[src.getNumBands()];
+    Arrays.fill(bands, true);
+    return filter(src, dest, bands);
+  }
+  
+  /**
+   * Perform raster-based filtering on a selected number of bands.
+   * 
+   * The length of the bands array should equal the number of bands; a true
+   * element indicates filtering should happen on the corresponding band, while
+   * a false element will skip the band.
+   * 
+   * The rasters are assumed to be compatible and non-null.
+   * 
+   * @param src the source raster.
+   * @param dest the destination raster.
+   * @param bands an array indicating which bands to filter.
+   * @throws NullPointerException if any parameter is null.
+   * @throws ArrayIndexOutOfBoundsException if the bands array is too small.
+   * @return the destination raster.
+   */
+  private WritableRaster filter(Raster src, WritableRaster dest, boolean[] bands)
+  {
+    int[] values = new int[src.getHeight() * src.getWidth()];
+    float scaleFactor, offset;
+    
+    // Find max sample value, to be used for clipping later
+    int[] maxValue = src.getSampleModel().getSampleSize();
+    for (int i = 0; i < maxValue.length; i++)
+      maxValue[i] = (int)Math.pow(2, maxValue[i]) - 1;
+    
+    // TODO: can this be optimized further?
+    // Filter all samples of all requested bands
+    for (int band = 0; band < bands.length; band++)
+      if (bands[band])
+        {
+          values = src.getSamples(src.getMinX(), src.getMinY(), src.getWidth(),
+                                  src.getHeight(), band, values);
 
-    // TODO The efficiency here can be improved for various data storage
-    // patterns, aka SampleModels.
-    float[] pixel = new float[src.numBands];
-    for (int y = src.minY; y < src.height + src.minY; y++)
-      for (int x = src.minX; x < src.width + src.minX; x++)
-	{
-	  src.getPixel(x, y, pixel);
-	  for (int b = 0; b < src.numBands; b++)
-	    pixel[b] = pixel[b] * lscale[b] + loff[b];
-	  dest.setPixel(x, y, pixel);
-	}
+          if (scale.length == 1)
+            {
+              scaleFactor = scale[0];
+              offset = offsets[0];
+            }
+          else
+            {
+              scaleFactor = scale[band];
+              offset = offsets[band];
+            }
+
+          for (int i = 0; i < values.length; i++)
+            {
+              values[i] = (int) (values[i] * scaleFactor + offset);
+
+              // Clip if needed
+              if (values[i] < 0)
+                values[i] = 0;
+              if (values[i] > maxValue[band])
+                values[i] = maxValue[band];
+            }
+
+          dest.setSamples(dest.getMinX(), dest.getMinY(), dest.getWidth(),
+                          dest.getHeight(), band, values);
+        }
+    
     return dest;
   }
 
-  /* (non-Javadoc)
-   * @see java.awt.image.BufferedImageOp#createCompatibleDestImage(java.awt.image.BufferedImage, java.awt.image.ColorModel)
+  /*
+   * (non-Javadoc)
+   * 
+   * @see java.awt.image.BufferedImageOp#createCompatibleDestImage(java.awt.image.BufferedImage,
+   *      java.awt.image.ColorModel)
    */
   public BufferedImage createCompatibleDestImage(BufferedImage src,
 						 ColorModel dstCM)
   {
-    if (dstCM == null) dstCM = src.getColorModel();
-    WritableRaster wr = src.getRaster().createCompatibleWritableRaster();
-    BufferedImage image
-      = new BufferedImage(dstCM, wr, src.isPremultiplied, null);
-    return image;
+    if (dstCM == null)
+      return new BufferedImage(src.getWidth(), src.getHeight(), src.getType());
+    
+    return new BufferedImage(dstCM,
+                             src.getRaster().createCompatibleWritableRaster(),
+                             src.isAlphaPremultiplied(), null);
   }
 
   /* (non-Javadoc)
@@ -209,9 +372,13 @@ public class RescaleOp implements BufferedImageOp, RasterOp
   /* (non-Javadoc)
    * @see java.awt.image.BufferedImageOp#getPoint2D(java.awt.geom.Point2D, java.awt.geom.Point2D)
    */
-  public final Point2D getPoint2D(Point2D src, Point2D dst) {
-    if (dst == null) dst = (Point2D) src.clone();
-    else dst.setLocation(src);
+  public final Point2D getPoint2D(Point2D src, Point2D dst)
+  {
+    if (dst == null)
+      dst = (Point2D) src.clone();
+    else
+      dst.setLocation(src);
+    
     return dst;
   }
author	Tom Tromey <tromey@gcc.gnu.org>	2007-01-09 19:58:05 +0000
committer	Tom Tromey <tromey@gcc.gnu.org>	2007-01-09 19:58:05 +0000
commit	97b8365cafc3a344a22d3980b8ed885f5c6d8357 (patch)
tree	996a5f57d4a68c53473382e45cb22f574cb3e4db /libjava/classpath/java/awt/image/RescaleOp.java
parent	c648dedbde727ca3f883bb5fd773aa4af70d3369 (diff)
download	gcc-97b8365cafc3a344a22d3980b8ed885f5c6d8357.zip gcc-97b8365cafc3a344a22d3980b8ed885f5c6d8357.tar.gz gcc-97b8365cafc3a344a22d3980b8ed885f5c6d8357.tar.bz2