/*

   Copyright 2001,2003  The Apache Software Foundation 

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.

 */
package org.apache.batik.svggen.font.table;

import java.io.ByteArrayInputStream;

/**
 * @version $Id: GlyfCompositeComp.java,v 1.4 2004/08/18 07:15:20 vhardy Exp $
 * @author <a href="mailto:david@steadystate.co.uk">David Schweinsberg</a>
 */
public class GlyfCompositeComp {

    public static final short ARG_1_AND_2_ARE_WORDS = 0x0001;
    public static final short ARGS_ARE_XY_VALUES = 0x0002;
    public static final short ROUND_XY_TO_GRID = 0x0004;
    public static final short WE_HAVE_A_SCALE = 0x0008;
    public static final short MORE_COMPONENTS = 0x0020;
    public static final short WE_HAVE_AN_X_AND_Y_SCALE = 0x0040;
    public static final short WE_HAVE_A_TWO_BY_TWO = 0x0080;
    public static final short WE_HAVE_INSTRUCTIONS = 0x0100;
    public static final short USE_MY_METRICS = 0x0200;

    private final int firstIndex;
    private final int firstContour;
    private final short argument1;
    private final short argument2;
    private final short flags;
    private final short glyphIndex;
    private double xscale = 1.0;
    private double yscale = 1.0;
    private double scale01 = 0.0;
    private double scale10 = 0.0;
    private int xtranslate = 0;
    private int ytranslate = 0;
    private int point1 = 0;
    private int point2 = 0;

    protected GlyfCompositeComp(int firstIndex, int firstContour, ByteArrayInputStream bais) {
        this.firstIndex = firstIndex;
        this.firstContour = firstContour;
        flags = (short)(bais.read()<<8 | bais.read());
        glyphIndex = (short)(bais.read()<<8 | bais.read());

        // Get the arguments as just their raw values
        if ((flags & ARG_1_AND_2_ARE_WORDS) != 0) {
            argument1 = (short)(bais.read()<<8 | bais.read());
            argument2 = (short)(bais.read()<<8 | bais.read());
        } else {
            argument1 = (short) bais.read();
            argument2 = (short) bais.read();
        }

        // Assign the arguments according to the flags
        if ((flags & ARGS_ARE_XY_VALUES) != 0) {
            xtranslate = argument1;
            ytranslate = argument2;
        } else {
            point1 = argument1;
            point2 = argument2;
        }

        // Get the scale values (if any)
        if ((flags & WE_HAVE_A_SCALE) != 0) {
            int i = (short)(bais.read()<<8 | bais.read());
            xscale = yscale = (double) i / (double) 0x4000;
        } else if ((flags & WE_HAVE_AN_X_AND_Y_SCALE) != 0) {
            short i = (short)(bais.read()<<8 | bais.read());
            xscale = (double) i / (double) 0x4000;
            i = (short)(bais.read()<<8 | bais.read());
            yscale = (double) i / (double) 0x4000;
        } else if ((flags & WE_HAVE_A_TWO_BY_TWO) != 0) {
            int i = (short)(bais.read()<<8 | bais.read());
            xscale = (double) i / (double) 0x4000;
            i = (short)(bais.read()<<8 | bais.read());
            scale01 = (double) i / (double) 0x4000;
            i = (short)(bais.read()<<8 | bais.read());
            scale10 = (double) i / (double) 0x4000;
            i = (short)(bais.read()<<8 | bais.read());
            yscale = (double) i / (double) 0x4000;
        }
    }

    public int getFirstIndex() {
        return firstIndex;
    }

    public int getFirstContour() {
        return firstContour;
    }

    public short getArgument1() {
        return argument1;
    }

    public short getArgument2() {
        return argument2;
    }

    public short getFlags() {
        return flags;
    }

    public short getGlyphIndex() {
        return glyphIndex;
    }

    public double getScale01() {
        return scale01;
    }

    public double getScale10() {
        return scale10;
    }

    public double getXScale() {
        return xscale;
    }

    public double getYScale() {
        return yscale;
    }

    public int getXTranslate() {
        return xtranslate;
    }

    public int getYTranslate() {
        return ytranslate;
    }

    /**
     * Transforms an x-coordinate of a point for this component.
     * @param x The x-coordinate of the point to transform
     * @param y The y-coordinate of the point to transform
     * @return The transformed x-coordinate
     */
    public int scaleX(int x, int y) {
        return Math.round((float)(x * xscale + y * scale10));
    }

    /**
     * Transforms a y-coordinate of a point for this component.
     * @param x The x-coordinate of the point to transform
     * @param y The y-coordinate of the point to transform
     * @return The transformed y-coordinate
     */
    public int scaleY(int x, int y) {
        return Math.round((float)(x * scale01 + y * yscale));
    }
}