/*
*
* Copyright 1990-2007 Sun Microsystems, Inc. All Rights Reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License version
* 2 only, as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License version 2 for more details (a copy is
* included at /legal/license.txt).
*
* You should have received a copy of the GNU General Public License
* version 2 along with this work; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA
*
* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa
* Clara, CA 95054 or visit www.sun.com if you need additional
* information or have any questions.
*/
package com.sun.pisces;
public class GradientColorMap {
public static final int CYCLE_NONE = 0;
public static final int CYCLE_REPEAT = 1;
public static final int CYCLE_REFLECT = 2;
public int cycleMethod;
private static final int LG_RAMP_SIZE = 8;
private static final int RAMP_SIZE = 1 << LG_RAMP_SIZE;
public int[] fractions = null;
public int[] rgba = null;
public int[] colors = null;
// 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("}");
// }
public GradientColorMap(int[] fractions, int[] rgba, int cycleMethod) {
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);
}
private int pad(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);
}
}
private void accumColor(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 int getColorAA(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 void createRamp(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 int getColor(int frac) {
frac = pad(frac);
frac >>= 16 - LG_RAMP_SIZE;
return colors[frac];
}
}
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