// Copyright 2001-2006, FreeHEP.
   package org.freehep.graphicsio.swf;
   
   import java.awt.Color;
   import java.awt.geom.AffineTransform;
   import java.awt.geom.Rectangle2D;
   import java.io.IOException;
   import java.io.InputStream;
   
  import org.freehep.util.io.ActionHeader;
  import org.freehep.util.io.TagHeader;
  import org.freehep.util.io.TaggedInputStream;
  
  /**
   * This class extends the TaggedInputStream with several methods to read SWF
   * primitives from the stream and to read TagHeaders. It also handles the
   * management of the SWFDictionary.
   * 
   * @author Mark Donszelmann
   * @author Charles Loomis
   * @version $Id: SWFInputStream.java 9979 2006-11-27 22:51:07Z duns $
   */
  public class SWFInputStream extends TaggedInputStream implements SWFConstants {
  
      private SWFDictionary dictionary;
  
      private byte[] jpegTable;
  
      public SWFInputStream(InputStream is) throws IOException {
  
          this(is, DEFAULT_VERSION);
      }
  
      public SWFInputStream(InputStream is, int version) throws IOException {
  
          this(is, new SWFTagSet(version), new SWFActionSet(version));
      }
  
      public SWFInputStream(InputStream is, SWFSpriteTagSet tagSet,
              SWFActionSet actionSet) throws IOException {
  
          // SWF is little-endian
          super(is, tagSet, actionSet, true);
  
          dictionary = new SWFDictionary();
      }
  
      /**
       * Read a fixed point value (16.16).
       */
      public float readFixed() throws IOException {
  
          byteAlign();
          int frac = readUnsignedByte();
          frac |= readUnsignedByte() << 8;
          int whole = readUnsignedByte();
          whole |= readUnsignedByte() << 8;
          return ((float) whole) + ((float) frac) / ((float) 0x10000);
      }
  
      /**
       * Read a fixed point value (8.8).
       */
      public float readFixed8() throws IOException {
  
          byteAlign();
          int frac = readUnsignedByte();
          int whole = readUnsignedByte();
          return ((float) whole) + ((float) frac) / ((float) 0x100);
      }
  
      /**
       * Read a rectangle from the stream.
       */
      public Rectangle2D readRect() throws IOException {
  
          byteAlign();
          int nbits = (int) readUBits(5);
          int xmin = (int) readSBits(nbits);
          int xmax = (int) readSBits(nbits);
          int ymin = (int) readSBits(nbits);
          int ymax = (int) readSBits(nbits);
          return new Rectangle2D.Double(xmin / TWIPS, ymin / TWIPS, (xmax - xmin)
                  / TWIPS, (ymax - ymin) / TWIPS);
      }
  
      /**
       * Read an RGB value from the stream.
       */
      public Color readColor(boolean alpha) throws IOException {
          int r = readUnsignedByte();
          int g = readUnsignedByte();
          int b = readUnsignedByte();
          int a = (alpha) ? readUnsignedByte() : 255;
          return new Color(r, g, b, a);
      }
  
      /**
       * Read a matrix from the stream.
      */
     public AffineTransform readMatrix() throws IOException {
 
         byteAlign();
 
         // Set default values.
         float sx = 1.f;
         float sy = 1.f;
         float kx = 0.f;
         float ky = 0.f;
         float tx = 0.f;
         float ty = 0.f;
 
         // Get the scale bits.
         if (readBitFlag()) {
             int nbits = (int) readUBits(5);
             sx = readFBits(nbits);
             sy = readFBits(nbits);
         }
 
         // Rotate or skew values.
         if (readBitFlag()) {
             int nbits = (int) readUBits(5);
             kx = readFBits(nbits);
             ky = readFBits(nbits);
         }
 
         // Translation values.
         int nbits = (int) readUBits(5);
         tx = (float) readSBits(nbits) / TWIPS;
         ty = (float) readSBits(nbits) / TWIPS;
 
         return new AffineTransform(sx, ky, kx, sy, tx, ty);
     }
 
     /**
      * Read a string from the stream.
      */
     public String readString() throws IOException {
         if (getVersion() >= 6) {
             String s = readUTF();
             readByte();
             return s;
         } else {
             return readAsciiZString();
         }
     }
 
     public int readLanguageCode() throws IOException {
         return readUnsignedByte();
     }
 
     protected TagHeader readTagHeader() throws IOException {
         // Read the tag.
         byteAlign();
         int temp = read();
         // End of stream
         if (temp == -1)
             return null;
 
         temp |= readUnsignedByte() << 8;
         int tagID = temp >> 6;
         long length = temp & FIELD_MASK[5];
         if (length == 0x3f)
             length = readUnsignedInt();
         return new TagHeader(tagID, length);
     }
 
     protected ActionHeader readActionHeader() throws IOException {
 
         int actionCode = readUnsignedByte();
         if (actionCode == 0)
             return null;
 
         int length = 0;
         if ((actionCode & 0x80) > 0) {
             length = readUnsignedShort();
         }
 
         return new ActionHeader(actionCode, length);
     }
 
     private SWFHeader header;
 
     public SWFHeader readHeader() throws IOException {
         if (header == null) {
             header = new SWFHeader(this);
             int version = header.getVersion();
             tagSet = new SWFTagSet(version);
             actionSet = new SWFActionSet(version);
         }
         return header;
     }
 
     public SWFDictionary getDictionary() {
         return dictionary;
     }
 
     public void setJPEGTable(byte[] table) {
         jpegTable = table;
     }
 
     public byte[] getJPEGTable() {
         return jpegTable;
     }
 
     public int getVersion() {
         return ((SWFSpriteTagSet) tagSet).getVersion();
     }
 }