/* $Id$
 * Copyright (C) 2001 The Apache Software Foundation. All rights reserved.
 * For details on use and redistribution please refer to the
 * LICENSE file included with these sources.
 */

package org.apache.fop.pdf;

//Java... 
import java.util.Vector;

//FOP
import org.apache.fop.datatypes.ColorSpace;

/**
 * class representing a PDF Smooth Shading object.
 * 
 * PDF Functions represent parameterized mathematical formulas and sampled representations with
 * arbitrary resolution. Functions are used in two areas: device-dependent
 * rasterization information for halftoning and transfer
 * functions, and color specification for smooth shading (a PDF 1.3 feature).
 * 
 * All PDF Functions have a shadingType (0,2,3, or 4), a Domain, and a Range.
 */
public class PDFShading extends PDFObject {
	//Guts common to all function types
	/** The name of the Shading e.g. "Shading1" */
	protected String shadingName = null;
	
	/**
	 * Required: The Type of shading (1,2,3,4,5,6,7)
	 */
	protected int shadingType = 3; //Default
	
	/**
	 * A ColorSpace representing the colorspace. "DeviceRGB" is an example.
	 */
	//protected StringBuffer colorSpace = null;
   protected ColorSpace colorSpace=null;
	/**
	 * The background color. Since shading is opaque,
	 * this is very rarely used.
	 */
	protected Vector background = null;
	/**
	 * Optional: A Vector specifying the clipping rectangle
	 */
	protected Vector bBox = null;

	/**
	 * Optional: A flag whether or not to filter the shading function
	 * to prevent aliasing artifacts. Default is false.
	 */
	protected boolean antiAlias = false;
	
	/**
	 * Optional for Type 1: Array of four numbers, xmin, xmax, ymin, ymax. Default is [0 1 0 1]
	 * Optional for Type 2: An array of two numbers between which the blend varies between start and end points. Default is 0, 1.
	 * Optional for Type 3: An array of two numbers between which the blend varies between start and end points. Default is 0, 1.
	 */
	
	protected Vector domain = null;
   
   /** Optional for Type 1: A transformation matrix */
   protected Vector matrix = null;
   
   /**
    * Required for Type 1, 2, and 3: 
    * The object of the color mapping function (usually type 2 or 3).
    * Optional for Type 4,5,6, and 7: When it's nearly the same thing.
    */
   protected PDFFunction function = null;
	
	/** Required for Type 2: An Array of four numbers specifying the starting and ending coordinate pairs 
	 * Required for Type 3: An Array of six numbers [x0,y0,r0,x1,y1,r1] specifying the centers and radii of
	 * the starting and ending circles.
	 */
	protected Vector coords = null;
	
	/**
	 * Required for Type 2+3: An Array of two boolean values specifying whether to extend the
	 * start and end colors past the start and end points,
	 * respectively. Default is false, false.
	 */
	protected Vector extend = null;
	
	/**
	 * Required for Type 4,5,6, and 7: Specifies the number of bits used to represent each vertex coordinate.
	 * Allowed to be 1,2,4,8,12,16,24, or 32.
	 */
	protected int bitsPerCoordinate = 0;

	/**
	 * Required for Type 4,5,6, and 7: Specifies the number of bits used to represent the edge flag for each vertex.
	 * Allowed to be 2,4,or 8, while the Edge flag itself is allowed to be 0,1 or 2.
	 */
	protected int bitsPerFlag = 0;

	/**
	 * Required for Type 4,5,6, and 7: Array of Doubles which specifies how to decode coordinate and color component values.
	 * Each type has a differing number of decode array members, so check the spec.
	 * Page 303 in PDF Spec 1.3
	 */
	protected Vector decode = null;

	/**
	 * Required for Type 4,5,6, and 7: Specifies the number of bits used to represent each color coordinate.
	 * Allowed to be 1,2,4,8,12, or 16
	 */
	protected int bitsPerComponent = 0;

	/**
	 * Required for Type 5:The number of vertices in each "row" of the lattice; it must be greater than or equal to 2.
	 */
	protected int verticesPerRow = 0;
	
	/**
	 * Constructor for type function based shading
	 * 
	 * @param theNumber The object number of this PDF object
	 * @param theShadingName The name of the shading pattern. Can be anything
	 * without spaces. "Shading1" or "Sh1" are good examples.
	 * @param theShadingType The type of shading object, which should be 1 for function
	 * based shading.
	 * @param theColorSpace The colorspace is 'DeviceRGB' or something similar.
	 * @param theBackground An array of color components appropriate to the
	 * colorspace key specifying a single color value.
	 * This key is used by the f operator buy ignored by the sh operator.
	 * @param theBBox Vector of double's representing a rectangle
	 * in the coordinate space that is current at the
	 * time of shading is imaged. Temporary clipping
	 * boundary.
	 * @param theAntiAlias Whether or not to anti-alias.
	 * @param theDomain Optional vector of Doubles specifying the domain.
	 * @param theMatrix Vector of Doubles specifying the matrix.
	 * If it's a pattern, then the matrix maps it to pattern space.
	 * If it's a shading, then it maps it to current user space.
	 * It's optional, the default is the identity matrix
	 * @param theFunction The PDF Function that maps an (x,y) location to a color
	 */
	public PDFShading(int theNumber, String theShadingName, int theShadingType, ColorSpace theColorSpace,
		Vector theBackground, Vector theBBox, boolean theAntiAlias,
		Vector theDomain, Vector theMatrix, PDFFunction theFunction)
	{
		super(theNumber);
		this.shadingName = theShadingName;
		this.shadingType = theShadingType; //1
		this.colorSpace=theColorSpace;
		this.background= theBackground;
		this.bBox = theBBox;
		this.antiAlias = theAntiAlias;
		
		this.domain = theDomain;
		this.matrix = theMatrix;
		this.function = theFunction;
	
	}

		/**
		 * Constructor for Type 2 and 3
		 * 
		 * @param theNumber The object number of this PDF object.
		 * @param theShadingName The name of the shading pattern. Can be anything
		 * without spaces. "Shading1" or "Sh1" are good examples.
		 * @param theShadingType 2 or 3 for axial or radial shading
		 * @param theColorSpace "DeviceRGB" or similar.
		 * @param theBackground theBackground An array of color components appropriate to the
		 * colorspace key specifying a single color value.
		 * This key is used by the f operator buy ignored by the sh operator.
		 * @param theBBox Vector of double's representing a rectangle
		 * in the coordinate space that is current at the
		 * time of shading is imaged. Temporary clipping
		 * boundary.
		 * @param theAntiAlias Default is false
		 * @param theCoords Vector of four (type 2) or 6 (type 3) Double
		 * @param theDomain Vector of Doubles specifying the domain
		 * @param theFunction the Stitching (PDFfunction type 3) function, even if it's stitching a single function
		 * @param theExtend Vector of Booleans of whether to extend teh start and end colors past the start and end points
		 * The default is [false, false]
		 */
	public PDFShading(int theNumber, String theShadingName,
		int theShadingType, ColorSpace theColorSpace,
		Vector theBackground, Vector theBBox, boolean theAntiAlias,
		Vector theCoords, Vector theDomain, PDFFunction theFunction,
		Vector theExtend)
	{
		super(theNumber);
		this.shadingName = theShadingName;
		this.shadingType=theShadingType; //2 or 3
		this.colorSpace=theColorSpace;
		this.background= theBackground;
		this.bBox = theBBox;
		this.antiAlias = theAntiAlias;

		this.coords = theCoords;
		this.domain = theDomain;
		this.function = theFunction;
		this.extend=theExtend;
	
	}
	
	/**
	 * Constructor for Type 4,6, or 7
	 * 
	 * @param theNumber The object number of this PDF object.
	 * @param theShadingType 4, 6, or 7 depending on whether it's
	 * Free-form gouraud-shaded triangle meshes, coons patch meshes, 
	 * or tensor product patch meshes, respectively.
	 * @param theShadingName The name of the shading pattern. Can be anything
	 * without spaces. "Shading1" or "Sh1" are good examples.
	 * @param theColorSpace "DeviceRGB" or similar.
	 * @param theBackground theBackground An array of color components appropriate to the
	 * colorspace key specifying a single color value.
	 * This key is used by the f operator buy ignored by the sh operator.
	 * @param theBBox Vector of double's representing a rectangle
	 * in the coordinate space that is current at the
	 * time of shading is imaged. Temporary clipping
	 * boundary.
	 * @param theAntiAlias Default is false
	 * @param theBitsPerCoordinate 1,2,4,8,12,16,24 or 32.
	 * @param theBitsPerComponent 1,2,4,8,12, and 16
	 * @param theBitsPerFlag 2,4,8.
	 * @param theDecode Vector of Doubles see PDF 1.3 spec pages 303 to 312.
	 * @param theFunction the PDFFunction
	 */
	public PDFShading(int theNumber, String theShadingName, int theShadingType, ColorSpace theColorSpace,
		Vector theBackground, Vector theBBox, boolean theAntiAlias,
		int theBitsPerCoordinate, int theBitsPerComponent,
		int theBitsPerFlag, Vector theDecode, PDFFunction theFunction)
	{
		super(theNumber);
		
		this.shadingType = theShadingType;//4,6 or 7
		this.colorSpace = theColorSpace;
		this.background= theBackground;
		this.bBox = theBBox;
		this.antiAlias = theAntiAlias;
		
		this.bitsPerCoordinate = theBitsPerCoordinate;
		this.bitsPerComponent = theBitsPerComponent;
		this.bitsPerFlag = theBitsPerFlag;
		this.decode = theDecode;
		this.function =theFunction;
	}

	/**
	 * Constructor for type 5
	 * 
	 * @param theShadingType 5 for lattice-Form Gouraud shaded-triangle mesh
	 * @param theShadingName The name of the shading pattern. Can be anything
	 * without spaces. "Shading1" or "Sh1" are good examples.
	 * @param theColorSpace "DeviceRGB" or similar.
	 * @param theBackground theBackground An array of color components appropriate to the
	 * colorspace key specifying a single color value.
	 * This key is used by the f operator buy ignored by the sh operator.
	 * @param theBBox Vector of double's representing a rectangle
	 * in the coordinate space that is current at the
	 * time of shading is imaged. Temporary clipping
	 * boundary.
	 * @param theAntiAlias Default is false
	 * @param theBitsPerCoordinate 1,2,4,8,12,16, 24, or 32
	 * @param theBitsPerComponent 1,2,4,8,12,24,32
	 * @param theDecode Vector of Doubles. See page 305 in PDF 1.3 spec.
	 * @param theVerticesPerRow number of vertices in each "row" of the lattice.
	 * @param theFunction The PDFFunction that's mapped on to this shape
	 * @param theNumber the object number of this PDF object.
	 */
	public PDFShading(int theNumber, String theShadingName, int theShadingType, ColorSpace theColorSpace,
		Vector theBackground, Vector theBBox, boolean theAntiAlias,
		int theBitsPerCoordinate, int theBitsPerComponent,
		Vector theDecode, int theVerticesPerRow, PDFFunction theFunction)
	{
		super(theNumber);
		this.shadingName = theShadingName;
		this.shadingType = theShadingType;//5
		this.colorSpace=theColorSpace;
		this.background= theBackground;
		this.bBox = theBBox;
		this.antiAlias = theAntiAlias;
		
		this.bitsPerCoordinate = theBitsPerCoordinate;
		this.bitsPerComponent = theBitsPerComponent;
		this.decode = theDecode;
		this.verticesPerRow = theVerticesPerRow;
		this.function = theFunction;
	
	}
	
	public String getName() {
		return (this.shadingName);
   }
   
	 /**
	  * represent as PDF. Whatever the shadingType is, the correct
	  * representation spits out. The sets of required and optional
	  * attributes are different for each type, but if a required
	  * attribute's object was constructed as null, then no error
	  * is raised. Instead, the malformed PDF that was requested
	  * by the construction is dutifully output.
	  * This policy should be reviewed.
	  * 
	  * @return the PDF string.
	  */ 
	public byte[] toPDF() {
		int vectorSize;
		int tempInt;
		StringBuffer p = new StringBuffer();
		p.append(this.number + " " + this.generation 
			+ " obj\n<< \n/ShadingType "+this.shadingType+" \n");
		if(this.colorSpace != null)
		{
			p.append("/ColorSpace /"
				+this.colorSpace.getColorSpacePDFString()+" \n");
		}
		
		if(this.background != null)
		{
			p.append("/Background [ ");
			vectorSize = this.background.size();
			for(tempInt=0; tempInt < vectorSize; tempInt++)
			{
				p.append(PDFNumber.doubleOut(
				(Double)this.background.elementAt(tempInt)) +" ");
			}
			p.append("] \n");
		}
		
		if(this.bBox != null)
		{//I've never seen an example, so I guess this is right.
			p.append("/BBox [ ");
			vectorSize = this.bBox.size();
			for(tempInt=0; tempInt < vectorSize; tempInt++)
			{
				p.append(PDFNumber.doubleOut(
				(Double)this.bBox.elementAt(tempInt)) +" ");
			}
			p.append("] \n");
		}
		
		if(this.antiAlias)
		{
			p.append("/AntiAlias "+this.antiAlias+" \n");
		}
		
		//Here's where we differentiate based on what type it is.
		if(this.shadingType == 1)
		{//function based shading
			if(this.domain != null)
			{
				p.append("/Domain [ ");
				vectorSize = this.domain.size();
				for(tempInt=0; tempInt < vectorSize; tempInt++)
				{
					p.append(PDFNumber.doubleOut(
					(Double)this.domain.elementAt(tempInt)) +" ");
				}
				p.append("] \n");
			}
			else
			{
				p.append("/Domain [ 0 1 ] \n");
			}
			
			if(this.matrix != null)
			{
				p.append("/Matrix [ ");
				vectorSize = this.matrix.size();
				for(tempInt=0; tempInt < vectorSize; tempInt++)
				{
					p.append(PDFNumber.doubleOut(
					(Double)this.matrix.elementAt(tempInt)) +" ");
				}
				p.append("] \n");
			}

			if(this.function != null)
			{
				p.append("/Function ");
				p.append(this.function.referencePDF()+" \n");
			}
		}
		else if((this.shadingType == 2)
		|| (this.shadingType == 3))
		{//2 is axial shading (linear gradient)
		//3 is radial shading (circular gradient)	
			if(this.coords != null)
			{
				p.append("/Coords [ ");
				vectorSize = this.coords.size();
				for(tempInt=0; tempInt < vectorSize; tempInt++)
				{
					p.append(PDFNumber.doubleOut(
					(Double)this.coords.elementAt(tempInt)) +" ");
				}
				p.append("] \n");
			}
			
			//DOMAIN
			if(this.domain != null)
			{
				p.append("/Domain [ ");
				vectorSize = this.domain.size();
				for(tempInt=0; tempInt < vectorSize; tempInt++)
				{
					p.append(PDFNumber.doubleOut(
					(Double)this.domain.elementAt(tempInt)) +" ");
				}
				p.append("] \n");
			}
			else
			{
				p.append("/Domain [ 0 1 ] \n");
			}
			
			if(this.extend != null)
			{
				p.append("/Extend [ ");
				vectorSize = this.extend.size();
				for(tempInt=0; tempInt < vectorSize; tempInt++)
				{
					p.append(((Boolean)this.extend.elementAt(tempInt)) +" ");
				}
				
				p.append("] \n");
			}
			else
			{
				p.append("/Extend [ true true ] \n");
			}


			if(this.function != null)
			{
				p.append("/Function ");
				p.append(this.function.referencePDF()+" \n");
			}
			
			
		}
		
		else if ((this.shadingType == 4) ||
					(this.shadingType == 6) ||
					(this.shadingType == 7))
		{//4:Free-form Gouraud-shaded triangle meshes
		// 6:coons patch meshes
		// 7://tensor product patch meshes (which no one ever uses)
			if(this.bitsPerCoordinate > 0)
			{
				p.append("/BitsPerCoordinate "+this.bitsPerCoordinate+" \n");
			}
			else
			{
				p.append("/BitsPerCoordinate 1 \n");
			}
			
			if(this.bitsPerComponent > 0)
			{
				p.append("/BitsPerComponent "+this.bitsPerComponent+" \n");
			}
			else
			{
				p.append("/BitsPerComponent 1 \n");
			}
			
			if(this.bitsPerFlag > 0)
			{
				p.append("/BitsPerFlag "+this.bitsPerFlag+" \n");
			}
			else
			{
				p.append("/BitsPerFlag 2 \n");
			}

			if(this.decode != null)
			{
				p.append("/Decode [ ");
				vectorSize = this.decode.size();
				for(tempInt=0; tempInt < vectorSize; tempInt++)
				{
					p.append(((Boolean)this.decode.elementAt(tempInt)) +" ");
				}
				
				p.append("] \n");
			}
		
			if(this.function != null)
			{
				p.append("/Function ");
				p.append(this.function.referencePDF()+" \n");
			}
			
		}

		else if (this.shadingType == 5)
		{ //Lattice Free form gouraud-shaded triangle mesh
		 
			if(this.bitsPerCoordinate > 0)
			{
				p.append("/BitsPerCoordinate "+this.bitsPerCoordinate+" \n");
			}
			else
			{
				p.append("/BitsPerCoordinate 1 \n");
			}
			
			if(this.bitsPerComponent > 0)
			{
				p.append("/BitsPerComponent "+this.bitsPerComponent+" \n");
			}
			else
			{
				p.append("/BitsPerComponent 1 \n");
			}			

			if(this.decode != null)
			{
				p.append("/Decode [ ");
				vectorSize = this.decode.size();
				for(tempInt=0; tempInt < vectorSize; tempInt++)
				{
					p.append(((Boolean)this.decode.elementAt(tempInt)) +" ");
				}
				
				p.append("] \n");
			}
		
			if(this.function != null)
			{
				p.append("/Function ");
				p.append(this.function.referencePDF()+" \n");
			}
			
			if(this.verticesPerRow > 0)
			{
				p.append("/VerticesPerRow "+this.verticesPerRow+" \n");
			}
			else
			{
				p.append("/VerticesPerRow 2 \n");
			}
			
		}

		p.append(">> \nendobj\n");
	
		return(p.toString().getBytes());
	}
}