Bugzilla #37305:

Better approach to higher resolution on-the-fly images generated by Batik.
Submitted by: Thomas Deweese <deweese.at.apache.org>

Changes to the patch:
Added a transcoding hint to be able to set this value.
Default device resolution set to 300dpi.

git-svn-id: https://svn.apache.org/repos/asf/xmlgraphics/fop/trunk@332304 13f79535-47bb-0310-9956-ffa450edef68

2 files changed, 50 insertions, 4 deletions

diff --git a/src/java/org/apache/fop/svg/PDFDocumentGraphics2D.java b/src/java/org/apache/fop/svg/PDFDocumentGraphics2D.java
index 85e5f667f..43d0cdf3c 100644
--- a/src/java/org/apache/fop/svg/PDFDocumentGraphics2D.java
+++ b/src/java/org/apache/fop/svg/PDFDocumentGraphics2D.java
@@ -67,11 +67,22 @@ public class PDFDocumentGraphics2D extends PDFGraphics2D
     private float svgWidth;
     private float svgHeight;
 
-    /** Initial clipping area, used to restore to original setting when a new page is started. */
+    /** Default device resolution (300dpi is a resonable quality for most purposes) */
+    public static final int DEFAULT_NATIVE_DPI = 300;
+  
+    /**
+     * The device resolution may be different from the normal target resolution. See
+     * http://issues.apache.org/bugzilla/show_bug.cgi?id=37305
+     */
+    private float deviceDPI = DEFAULT_NATIVE_DPI;
+
+    /** Initial clipping area, used to restore to original setting
+     * when a new page is started. */
     protected Shape initialClip;
+
     /**
-     * Initial transformation matrix, used to restore to original setting when a new page is 
-     * started.
+     * Initial transformation matrix, used to restore to original
+     * setting when a new page is started.
      */
     protected AffineTransform initialTransform;
 
@@ -183,6 +194,22 @@ public class PDFDocumentGraphics2D extends PDFGraphics2D
     }
 
     /**
+     * Set the device resolution for rendering.  Will take effect at the
+     * start of the next page.
+     * @param deviceDPI the device resolution (in dpi)
+     */
+    public void setDeviceDPI(float deviceDPI) {
+        this.deviceDPI = deviceDPI;
+    }
+
+    /**
+     * @return the device resolution (in dpi) for rendering.
+     */
+    public float getDeviceDPI() {
+        return deviceDPI;
+    }
+
+    /**
      * Get the font info for this pdf document.
      * @return the font information
      */
@@ -316,6 +343,14 @@ public class PDFDocumentGraphics2D extends PDFGraphics2D
             currentStream.write("" + PDFNumber.doubleOut(scaleX) + " 0 0 "
                                 + PDFNumber.doubleOut(scaleY) + " 0 0 cm\n");
         }
+        if (deviceDPI != DEFAULT_NATIVE_DPI) {
+            double s = DEFAULT_NATIVE_DPI / deviceDPI;
+            at.scale(s, s);
+            currentStream.write("" + PDFNumber.doubleOut(s) + " 0 0 "
+                                + PDFNumber.doubleOut(s) + " 0 0 cm\n");
+            
+            scale(1 / s, 1 / s);
+        }
         // Remember the transform we installed.
         graphicsState.setTransform(at);
 
diff --git a/src/java/org/apache/fop/svg/PDFTranscoder.java b/src/java/org/apache/fop/svg/PDFTranscoder.java
index d19f75bcf..a07b1c9f5 100644
--- a/src/java/org/apache/fop/svg/PDFTranscoder.java
+++ b/src/java/org/apache/fop/svg/PDFTranscoder.java
@@ -32,7 +32,9 @@ import org.apache.batik.bridge.UserAgent;
 import org.apache.batik.ext.awt.RenderingHintsKeyExt;
 import org.apache.batik.transcoder.TranscoderException;
 import org.apache.batik.transcoder.TranscoderOutput;
+import org.apache.batik.transcoder.TranscodingHints;
 import org.apache.batik.transcoder.image.ImageTranscoder;
+import org.apache.batik.transcoder.keys.FloatKey;
 import org.w3c.dom.Document;
 import org.w3c.dom.svg.SVGLength;
 
@@ -66,7 +68,13 @@ import org.w3c.dom.svg.SVGLength;
 public class PDFTranscoder extends AbstractFOPTranscoder
         implements Configurable {
 
-    private   Configuration         cfg      = null;
+    /**
+     * The key is used to specify the resolution for on-the-fly images generated
+     * due to complex effects like gradients and filters. 
+     */
+    public static final TranscodingHints.Key KEY_DEVICE_RESOLUTION = new FloatKey();
+
+    private Configuration cfg = null;
     
     /** Graphics2D instance that is used to paint to */
     protected PDFDocumentGraphics2D graphics = null;
@@ -143,6 +151,9 @@ public class PDFTranscoder extends AbstractFOPTranscoder
         //int h = (int)(height + 0.5);
 
         try {
+            if (hints.containsKey(KEY_DEVICE_RESOLUTION)) {
+                graphics.setDeviceDPI(((Float)hints.get(KEY_DEVICE_RESOLUTION)).floatValue());
+            }
             graphics.setupDocument(output.getOutputStream(), w, h);
             graphics.setSVGDimension(width, height);