FileDocCategorySizeDatePackage
GradientColorMap.javaAPI DocphoneME MR2 API (J2ME)6608Wed May 02 18:00:36 BST 2007com.sun.pisces

GradientColorMap

public class GradientColorMap extends Object

Fields Summary
public static final int
CYCLE_NONE
public static final int
CYCLE_REPEAT
public static final int
CYCLE_REFLECT
public int
cycleMethod
private static final int
LG_RAMP_SIZE
private static final int
RAMP_SIZE
public int[]
fractions
public int[]
rgba
public int[]
colors
Constructors Summary
public GradientColorMap(int[] fractions, int[] rgba, int cycleMethod)


//     private static void printArray(int[] arr, String name) {
//         System.out.print(name + " = {");
//         System.out.print(arr[0]);
//         for (int i = 1; i < arr.length; i++) {
//             System.out.print(", " + arr[i]);
//         }
//         System.out.println("}");
//     }

           
        this.cycleMethod = cycleMethod;

//         System.out.println("GCM ctor:");
//         printArray(fractions, "fractions before");
//         printArray(rgba, "rgba before");
    
        int numStops = fractions.length;
        if (fractions[0] != 0) {
            int[] nfractions = new int[numStops + 1];
            int[] nrgba = new int[numStops + 1];
            System.arraycopy(fractions, 0, nfractions, 1, numStops);
            System.arraycopy(rgba, 0, nrgba, 1, numStops);
            nfractions[0] = 0;
            nrgba[0] = rgba[0];
            fractions = nfractions;
            rgba = nrgba;
            ++numStops;
        }

        if (fractions[numStops - 1] != 0x10000) {
            int[] nfractions = new int[numStops + 1];
            int[] nrgba = new int[numStops + 1];
            System.arraycopy(fractions, 0, nfractions, 0, numStops);
            System.arraycopy(rgba, 0, nrgba, 0, numStops);
            nfractions[numStops] = 0x10000;
            nrgba[numStops] = rgba[numStops - 1];
            fractions = nfractions;
            rgba = nrgba;
        }

//         printArray(fractions, "fractions after");
//         printArray(rgba, "rgba after");

        this.fractions = new int[fractions.length];
        System.arraycopy(fractions, 0, this.fractions, 0, fractions.length);
        this.rgba = new int[rgba.length];
        System.arraycopy(rgba, 0, this.rgba, 0, rgba.length);

        createRamp(fractions, rgba);
Methods Summary
private voidaccumColor(int frac, int[] fractions, int[] r, int[] g, int[] b, int[] a, int[] red, int[] green, int[] blue, int[] alpha)

        int numStops = fractions.length;
        int stop = -1;
        for (int i = 0; i < numStops; i++) {
            if (fractions[i] > frac) {
                stop = i;
                break;
            }
        }

        frac -= fractions[stop - 1];
        int delta = fractions[stop] - fractions[stop - 1];

        red[0] += r[stop - 1] + (frac*(r[stop] - r[stop - 1]))/delta;
        green[0] += g[stop - 1] + (frac*(g[stop] - g[stop - 1]))/delta;
        blue[0] += b[stop - 1] + (frac*(b[stop] - b[stop - 1]))/delta;
        alpha[0] += a[stop - 1] + (frac*(a[stop] - a[stop - 1]))/delta;
private voidcreateRamp(int[] fractions, int[] rgba)

        this.colors = new int[RAMP_SIZE];

        int[] alpha = new int[1];
        int[] red = new int[1];
        int[] green = new int[1];
        int[] blue = new int[1];

        int numStops = fractions.length;
        int[] a = new int[numStops];
        int[] r = new int[numStops];
        int[] g = new int[numStops];
        int[] b = new int[numStops];

        for (int i = 0; i < numStops; i++) {
            a[i] = (rgba[i] >> 24) & 0xff;
            r[i] = (rgba[i] >> 16) & 0xff;
            g[i] = (rgba[i] >>  8) & 0xff;
            b[i] =  rgba[i]        & 0xff;
        }

        for (int i = 0; i < RAMP_SIZE; i++) {
            red[0] = green[0] = blue[0] = alpha[0] = 0;
            colors[i] = getColorAA(i << (16 - LG_RAMP_SIZE), fractions,
                                   r, g, b, a,
                                   red, green, blue, alpha);
        }
public intgetColor(int frac)

        frac = pad(frac);
        frac >>= 16 - LG_RAMP_SIZE;
        return colors[frac];
private intgetColorAA(int frac, int[] fractions, int[] r, int[] g, int[] b, int[] a, int[] red, int[] green, int[] blue, int[] alpha)

        int delta = 256;
        int step = 1;
        int total = 0;
        for (int i = -delta; i <= delta; i += step) {
            int f = pad(frac + i);
            accumColor(f, fractions, r, g, b, a, red, green, blue, alpha);
            ++total;
        }

        alpha[0] /= total;
        red[0] /= total;
        green[0] /= total;
        blue[0] /= total;

        return (alpha[0] << 24) | (red[0] << 16) | (green[0] << 8) | blue[0];
private intpad(int frac)

        switch (cycleMethod) {
        case CYCLE_NONE:
            if (frac < 0) {
                return 0;
            } else if (frac > 0xffff) {
                return 0xffff;
            } else {
                return frac;
            }

        case CYCLE_REPEAT:
            return frac & 0xffff;

        case CYCLE_REFLECT:
            if (frac < 0) {
                frac = -frac;
            }
            frac = frac & 0x1ffff;
            if (frac > 0xffff) {
                frac = 0x1ffff - frac;
            }
            return frac;
            
        default:
            throw new RuntimeException("Unknown cycle method: " + cycleMethod);
        }