/**
* CircleTool
* Copyright 2007 by Michael Christen
* First released 22.05.2007 at http://yacy.net
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program in the file lgpl21.txt
* If not, see <http://www.gnu.org/licenses/>.
*/
package org.loklak.graphics;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
public class CircleTool {
private static List<int[]> circles = new ArrayList<>();
public static void clearcache() {
circles.clear();
}
private static int[] getCircleCoords(final short radius) {
if (radius - 1 < circles.size()) return circles.get(radius - 1);
// read some lines from known circles
Set<Integer> crds = new HashSet<>();
Integer co;
for (short i = (short) Math.max(0, circles.size() - 1); i < circles.size(); i++) {
int[] circle = circles.get(i);
for (int c: circle) crds.add(c);
}
// compute more lines in new circles
short x, y;
List<Integer> crc;
short r1;
int rc = radius < 200 ? (radius < 100 ? 100 : radius + 9) : radius;
for (short r = (short) circles.size(); r < rc; r++) {
r1 = (short) (r + 1);
crc = new ArrayList<>();
for (short a = 0; a < 2 * r1; a++) {
double h = RasterPlotter.PI4 * a / r1;
double cosh = Math.cos(h);
double sinh = Math.sin(h);
x = (short) (r1 * cosh);
y = (short) (r1 * sinh);
co = x << 16 | y;
if (!(crds.contains(co))) {
crc.add(co);
crds.add(co);
}
x = (short) ((r + 0.5) * cosh);
y = (short) ((r + 0.5) * sinh);
co = x << 16 | y;
if (!(crds.contains(co))) {
crc.add(co);
crds.add(co);
}
}
// put coordinates into array
//System.out.print("Radius " + r + " => " + crc.size() + " points: ");
int[] newCircle = new int[crc.size() - 1];
int coords;
for (short i = 0; i < crc.size() - 1; i++) {
coords = crc.get(i);
newCircle[i] = coords;
}
circles.add(newCircle);
}
crc = null;
crds = null;
// finally return wanted slice
return circles.get(radius - 1);
}
public static void circle(final RasterPlotter matrix, final int xc, final int yc, final int radius, final int intensity) {
if (radius == 0) {
//matrix.plot(xc, yc, 100);
} else {
final int[] c = getCircleCoords((short) radius);
short x, y;
short limit = (short) c.length;
int co;
for (short i = 0; i < limit; i++) {
co = c[i];
x = (short) (0xffff & (co >> 16));
y = (short) (0xffff & co);
matrix.plot(xc + x , yc - y - 1, intensity); // quadrant 1
matrix.plot(xc - x + 1, yc - y - 1, intensity); // quadrant 2
matrix.plot(xc + x , yc + y , intensity); // quadrant 4
matrix.plot(xc - x + 1, yc + y , intensity); // quadrant 3
}
}
}
public static void circle(final RasterPlotter matrix, final int xc, final int yc, final int radius, int fromArc, int toArc) {
// draws only a part of a circle
// arc is given in degree
while (fromArc > 360) fromArc -=360;
while (fromArc < 0 ) fromArc +=360;
while ( toArc > 360) toArc -=360;
while ( toArc < 0 ) toArc +=360;
if (radius == 0) {
//matrix.plot(xc, yc, 100);
} else {
int[] c = getCircleCoords((short) radius);
if (c == null) c = getCircleCoords((short) radius);
final short q = (short) c.length;
final short q2 = (short) (q * 2);
final short q3 = (short) (q * 3);
final short q4 = (short) (q * 4);
final short[] c4x = new short[q4];
final short[] c4y = new short[q4];
short a0, a1, a2, a3, b0, b1;
int co;
for (short i = 0; i < q; i++) {
b0 = i;
b1 = (short) (q - 1 - i);
co = c[b0];
a0 = (short) (0xffff & (co >> 16));
a1 = (short) (0xffff & co);
co = c[b1];
a2 = (short) (0xffff & (co >> 16));
a3 = (short) (0xffff & co);
c4x[i ] = a0 ; // quadrant 1
c4y[i ] = (short) (-a1 - 1); // quadrant 1
c4x[i + q ] = (short) ( 1 - a2); // quadrant 2
c4y[i + q ] = (short) (-a3 - 1); // quadrant 2
c4x[i + q2] = (short) ( 1 - a0); // quadrant 3
c4y[i + q2] = a1 ; // quadrant 3
c4x[i + q3] = a2 ; // quadrant 4
c4y[i + q3] = a3 ; // quadrant 4
}
if (fromArc == toArc) {
int i = q4 * fromArc / 360;
matrix.plot(xc + c4x[i], yc + c4y[i], 100);
} else if (fromArc > toArc) {
// draw two parts
int from = q4 * fromArc / 360;
int to = q4 * toArc / 360;
for (int i = from; i < q4; i++) {
matrix.plot(xc + c4x[i], yc + c4y[i], 100);
}
for (int i = 0; i < to; i++) {
matrix.plot(xc + c4x[i], yc + c4y[i], 100);
}
} else {
// can be drawn in one part
int from = q4 * fromArc / 360;
int to = q4 * toArc / 360;
for (int i = from; i < to; i++) {
matrix.plot(xc + c4x[i], yc + c4y[i], 100);
}
}
}
}
}