//===========================================================================//=-------------------------------------------------------------------------=//= Module history:                                                         =//= - February 24 2006 - Gina Chiquillo: Original base version              =//= - April 4 2006 - Oscar Chavarro: Quality check - comments added         =//= - May 26 2006 - David Diaz/Oscar Chavarro: documentation added          =//===========================================================================package vsdk.toolkit.media;import java.util.ArrayList;import vsdk.toolkit.common.ColorRgb;/**This class represents a color palette, as an indexed set of colors.*/public class RGBColorPalette extends MediaEntity {    /// Check the general attribute description in superclass Entity.    public static final long serialVersionUID = 20060502L;    protected ArrayList<ColorRgb> colors;    /**    Builds a default color pallete: the 256 tones gray scale    */    public RGBColorPalette()    {        colors = new ArrayList<ColorRgb>();        init(256);    }    /**    Initialize this color palette's data to a gray scale color palette with a     number of levels specified by the input parameter.    @param size Initial size of gray scale for current color palette's     initialization    */    public void init(int size)    {        colors = new ArrayList<ColorRgb>();        int i;        ColorRgb c;        for ( i = 0; i < size; i++ ) {            c = new ColorRgb(0, 0, 0);            colors.add(c);        }        buildGrayLevelsTable();    }    /**    Returns the size of current palette    @return The size of current palette    */    public int size()    {        return colors.size();    }    /**    Given current RGBColorPalette assigned in memory, and withoun changing its    size, this method change the palette's values to make it correspond to    a gray scale.  The first values in the are near black, and the last values     in the table are near white.    */    public void buildGrayLevelsTable()    {        int pos = 0;        double val = 0;        int i;        for ( i = 0; i < colors.size(); i++ ) {            ColorRgb c = colors.get(i);            c.r = c.g = c.b = val;            val += 1.0/((double)(colors.size()-1));            pos++;                }    }    /**    Returns the exact color in the given index color table position. Note that    this is a direct table manipulation method, as opposed to the `evalNearest`    and `evalLinear` methods, which are the recomended ones to use for most    applications.    @param i The index of the color to return    @return The color in the index parameter position    */    public ColorRgb getColorAt(int i)    {        if ( i < 0 || i >= colors.size() ) return null;        return colors.get(i);    }    public void setColorAt(int i, ColorRgb c)    {        if ( i < 0 || i >= colors.size() ) return;        colors.set(i, c);    }    public void setColorAt(int i, double r, double g, double b)    {        if ( i < 0 || i >= colors.size() ) return;        colors.set(i, new ColorRgb(r, g, b));    }    public void addColor(ColorRgb c)    {        colors.add(c);    }    public void addColor(double r, double g, double b)    {        colors.add(new ColorRgb(r, g, b));    }    /**    The parameter `t` must be between 0 and 1    */    public ColorRgb evalNearest(double t)    {        if ( t < 0.0 ) t = 0.0;        if ( t > 1.0 ) t = 1.0;        int N = colors.size();        int i = (int)(t*((double)N));        if ( i < 0 ) i = 0;        if ( i >= N ) i = N-1;        return colors.get(i);    }    /**    The parameter `t` must be between 0 and 1.    */    public ColorRgb evalLinear(double t)    {        if ( t < 0.0 ) t = 0.0;        if ( t > 1.0 ) t = 1.0;        int N = colors.size()-1;        int inf = (int)(t*((double)N));        int sup = inf+1;        double delta = 1/((double)N);        double r = t - inf*delta;        double p = r / delta;        if ( inf < 0 ) inf = 0;        if ( inf > N ) inf = N;        if ( sup < 0 ) sup = 0;        if ( sup > N ) sup = N;        ColorRgb a = colors.get(inf);        ColorRgb b = colors.get(sup);        ColorRgb c = new ColorRgb(            a.r + (b.r-a.r)*p,            a.g + (b.g-a.g)*p,            a.b + (b.b-a.b)*p    );        return c;    }    public int selectNearestIndexToRgb(ColorRgb c)    {        double minDistance = Double.MAX_VALUE;        int i;        double currentDistance;        int index = 0;        for ( i = 0; i < colors.size(); i++ ) {            currentDistance = colors.get(i).distance(c);            if ( currentDistance < minDistance ) {                minDistance = currentDistance;                index = i;            }        }        return index;    }}//===========================================================================//= EOF                                                                     =//===========================================================================