processing.opengl.LinePath Maven / Gradle / Ivy
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/* -*- mode: java; c-basic-offset: 2; indent-tabs-mode: nil -*- */
/*
* Copyright 2006 Sun Microsystems, Inc. All Rights Reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code 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. Sun designates this
* particular file as subject to the "Classpath" exception as provided
* by Sun in the LICENSE file that accompanied this code.
*
* This code 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 in the LICENSE file that
* accompanied this code).
*
* 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 USA or visit www.sun.com if you need additional information or
* have any questions.
*/
package processing.opengl;
import processing.core.PMatrix2D;
/**
* The {@code LinePath} class allows to represent polygonal paths,
* potentially composed by several disjoint polygonal segments.
* It can be iterated by the {@link PathIterator} class including all
* of its segment types and winding rules
*
*/
public class LinePath {
/**
* The winding rule constant for specifying an even-odd rule
* for determining the interior of a path.
* The even-odd rule specifies that a point lies inside the
* path if a ray drawn in any direction from that point to
* infinity is crossed by path segments an odd number of times.
*/
public static final int WIND_EVEN_ODD = 0;
/**
* The winding rule constant for specifying a non-zero rule
* for determining the interior of a path.
* The non-zero rule specifies that a point lies inside the
* path if a ray drawn in any direction from that point to
* infinity is crossed by path segments a different number
* of times in the counter-clockwise direction than the
* clockwise direction.
*/
public static final int WIND_NON_ZERO = 1;
/**
* Starts segment at a given position.
*/
public static final byte SEG_MOVETO = 0;
/**
* Extends segment by adding a line to a given position.
*/
public static final byte SEG_LINETO = 1;
/**
* Closes segment at current position.
*/
public static final byte SEG_CLOSE = 2;
/**
* Joins path segments by extending their outside edges until they meet.
*/
public final static int JOIN_MITER = 0;
/**
* Joins path segments by rounding off the corner at a radius of half the line
* width.
*/
public final static int JOIN_ROUND = 1;
/**
* Joins path segments by connecting the outer corners of their wide outlines
* with a straight segment.
*/
public final static int JOIN_BEVEL = 2;
/**
* Ends unclosed subpaths and dash segments with no added decoration.
*/
public final static int CAP_BUTT = 0;
/**
* Ends unclosed subpaths and dash segments with a round decoration that has a
* radius equal to half of the width of the pen.
*/
public final static int CAP_ROUND = 1;
/**
* Ends unclosed subpaths and dash segments with a square projection that
* extends beyond the end of the segment to a distance equal to half of the
* line width.
*/
public final static int CAP_SQUARE = 2;
private static PMatrix2D identity = new PMatrix2D();
private static float defaultMiterlimit = 10.0f;
static final int INIT_SIZE = 20;
static final int EXPAND_MAX = 500;
protected byte[] pointTypes;
protected float[] floatCoords;
protected int[] pointColors;
protected int numTypes;
protected int numCoords;
protected int windingRule;
/**
* Constructs a new empty single precision {@code LinePath} object with a
* default winding rule of {@link #WIND_NON_ZERO}.
*/
public LinePath() {
this(WIND_NON_ZERO, INIT_SIZE);
}
/**
* Constructs a new empty single precision {@code LinePath} object with the
* specified winding rule to control operations that require the interior of
* the path to be defined.
*
* @param rule
* the winding rule
* @see #WIND_EVEN_ODD
* @see #WIND_NON_ZERO
*/
public LinePath(int rule) {
this(rule, INIT_SIZE);
}
/**
* Constructs a new {@code LinePath} object from the given specified initial
* values. This method is only intended for internal use and should not be
* made public if the other constructors for this class are ever exposed.
*
* @param rule
* the winding rule
* @param initialCapacity
* the size to make the initial array to store the path segment types
*/
public LinePath(int rule, int initialCapacity) {
setWindingRule(rule);
this.pointTypes = new byte[initialCapacity];
floatCoords = new float[initialCapacity * 2];
pointColors = new int[initialCapacity];
}
void needRoom(boolean needMove, int newPoints) {
if (needMove && numTypes == 0) {
throw new RuntimeException("missing initial moveto "
+ "in path definition");
}
int size = pointTypes.length;
if (numTypes >= size) {
int grow = size;
if (grow > EXPAND_MAX) {
grow = EXPAND_MAX;
}
pointTypes = copyOf(pointTypes, size + grow);
}
size = floatCoords.length;
if (numCoords + newPoints * 2 > size) {
int grow = size;
if (grow > EXPAND_MAX * 2) {
grow = EXPAND_MAX * 2;
}
if (grow < newPoints * 2) {
grow = newPoints * 2;
}
floatCoords = copyOf(floatCoords, size + grow);
}
size = pointColors.length;
if (numCoords/2 + newPoints > size) {
int grow = size;
if (grow > EXPAND_MAX) {
grow = EXPAND_MAX;
}
if (grow < newPoints) {
grow = newPoints;
}
pointColors = copyOf(pointColors, size + grow);
}
}
/**
* Adds a point to the path by moving to the specified coordinates specified
* in float precision.
*
* This method provides a single precision variant of the double precision
* {@code moveTo()} method on the base {@code LinePath} class.
*
* @param x
* the specified X coordinate
* @param y
* the specified Y coordinate
* @see LinePath#moveTo
*/
public final void moveTo(float x, float y, int c) {
if (numTypes > 0 && pointTypes[numTypes - 1] == SEG_MOVETO) {
floatCoords[numCoords - 2] = x;
floatCoords[numCoords - 1] = y;
pointColors[numCoords/2-1] = c;
} else {
needRoom(false, 1);
pointTypes[numTypes++] = SEG_MOVETO;
floatCoords[numCoords++] = x;
floatCoords[numCoords++] = y;
pointColors[numCoords/2-1] = c;
}
}
/**
* Adds a point to the path by drawing a straight line from the current
* coordinates to the new specified coordinates specified in float precision.
*
* This method provides a single precision variant of the double precision
* {@code lineTo()} method on the base {@code LinePath} class.
*
* @param x
* the specified X coordinate
* @param y
* the specified Y coordinate
* @see LinePath#lineTo
*/
public final void lineTo(float x, float y, int c) {
needRoom(true, 1);
pointTypes[numTypes++] = SEG_LINETO;
floatCoords[numCoords++] = x;
floatCoords[numCoords++] = y;
pointColors[numCoords/2-1] = c;
}
/**
* The iterator for this class is not multi-threaded safe, which means that
* the {@code LinePath} class does not guarantee that modifications to the
* geometry of this {@code LinePath} object do not affect any iterations of that
* geometry that are already in process.
*/
public PathIterator getPathIterator() {
return new PathIterator(this);
}
/**
* Closes the current subpath by drawing a straight line back to the
* coordinates of the last {@code moveTo}. If the path is already closed then
* this method has no effect.
*/
public final void closePath() {
if (numTypes == 0 || pointTypes[numTypes - 1] != SEG_CLOSE) {
needRoom(false, 0);
pointTypes[numTypes++] = SEG_CLOSE;
}
}
/**
* Returns the fill style winding rule.
*
* @return an integer representing the current winding rule.
* @see #WIND_EVEN_ODD
* @see #WIND_NON_ZERO
* @see #setWindingRule
*/
public final int getWindingRule() {
return windingRule;
}
/**
* Sets the winding rule for this path to the specified value.
*
* @param rule
* an integer representing the specified winding rule
* @exception IllegalArgumentException
* if {@code rule} is not either {@link #WIND_EVEN_ODD} or
* {@link #WIND_NON_ZERO}
* @see #getWindingRule
*/
public final void setWindingRule(int rule) {
if (rule != WIND_EVEN_ODD && rule != WIND_NON_ZERO) {
throw new IllegalArgumentException("winding rule must be "
+ "WIND_EVEN_ODD or " + "WIND_NON_ZERO");
}
windingRule = rule;
}
/**
* Resets the path to empty. The append position is set back to the beginning
* of the path and all coordinates and point types are forgotten.
*/
public final void reset() {
numTypes = numCoords = 0;
}
static public class PathIterator {
float floatCoords[];
int typeIdx;
int pointIdx;
int colorIdx;
LinePath path;
static final int curvecoords[] = { 2, 2, 0 };
PathIterator(LinePath p2df) {
this.path = p2df;
this.floatCoords = p2df.floatCoords;
pointIdx = 0;
colorIdx = 0;
}
public int currentSegment(float[] coords) {
int type = path.pointTypes[typeIdx];
int numCoords = curvecoords[type];
if (numCoords > 0) {
System.arraycopy(floatCoords, pointIdx, coords, 0, numCoords);
int color = path.pointColors[colorIdx];
coords[numCoords + 0] = (color >> 24) & 0xFF;
coords[numCoords + 1] = (color >> 16) & 0xFF;
coords[numCoords + 2] = (color >> 8) & 0xFF;
coords[numCoords + 3] = (color >> 0) & 0xFF;
}
return type;
}
public int currentSegment(double[] coords) {
int type = path.pointTypes[typeIdx];
int numCoords = curvecoords[type];
if (numCoords > 0) {
for (int i = 0; i < numCoords; i++) {
coords[i] = floatCoords[pointIdx + i];
}
int color = path.pointColors[colorIdx];
coords[numCoords + 0] = (color >> 24) & 0xFF;
coords[numCoords + 1] = (color >> 16) & 0xFF;
coords[numCoords + 2] = (color >> 8) & 0xFF;
coords[numCoords + 3] = (color >> 0) & 0xFF;
}
return type;
}
public int getWindingRule() {
return path.getWindingRule();
}
public boolean isDone() {
return (typeIdx >= path.numTypes);
}
public void next() {
int type = path.pointTypes[typeIdx++];
if (0 < curvecoords[type]) {
pointIdx += curvecoords[type];
colorIdx++;
}
}
}
/////////////////////////////////////////////////////////////////////////////
//
// Stroked path methods
static public LinePath createStrokedPath(LinePath src, float weight,
int caps, int join) {
return createStrokedPath(src, weight, caps, join, defaultMiterlimit, null);
}
static public LinePath createStrokedPath(LinePath src, float weight,
int caps, int join, float miterlimit) {
return createStrokedPath(src, weight, caps, join, miterlimit, null);
}
/**
* Constructs a solid LinePath with the specified attributes.
*
* @param src
* the original path to be stroked
* @param weight
* the weight of the stroked path
* @param caps
* the decoration of the ends of the segments in the path
* @param join
* the decoration applied where path segments meet
* @param miterlimit
* @param transform
*
*/
static public LinePath createStrokedPath(LinePath src, float weight,
int caps, int join,
float miterlimit, PMatrix2D transform) {
final LinePath dest = new LinePath();
strokeTo(src, weight, caps, join, miterlimit, transform, new LineStroker() {
@Override
public void moveTo(int x0, int y0, int c0) {
dest.moveTo(S15_16ToFloat(x0), S15_16ToFloat(y0), c0);
}
@Override
public void lineJoin() {
}
@Override
public void lineTo(int x1, int y1, int c1) {
dest.lineTo(S15_16ToFloat(x1), S15_16ToFloat(y1), c1);
}
@Override
public void close() {
dest.closePath();
}
@Override
public void end() {
}
});
return dest;
}
private static void strokeTo(LinePath src, float width, int caps, int join,
float miterlimit, PMatrix2D transform,
LineStroker lsink) {
lsink = new LineStroker(lsink, FloatToS15_16(width), caps, join,
FloatToS15_16(miterlimit),
transform == null ? identity : transform);
PathIterator pi = src.getPathIterator();
pathTo(pi, lsink);
}
private static void pathTo(PathIterator pi, LineStroker lsink) {
float coords[] = new float[6];
while (!pi.isDone()) {
int color;
switch (pi.currentSegment(coords)) {
case SEG_MOVETO:
color = ((int)coords[2]<<24) |
((int)coords[3]<<16) |
((int)coords[4]<< 8) |
(int)coords[5];
lsink.moveTo(FloatToS15_16(coords[0]), FloatToS15_16(coords[1]), color);
break;
case SEG_LINETO:
color = ((int)coords[2]<<24) |
((int)coords[3]<<16) |
((int)coords[4]<< 8) |
(int)coords[5];
lsink.lineJoin();
lsink.lineTo(FloatToS15_16(coords[0]), FloatToS15_16(coords[1]), color);
break;
case SEG_CLOSE:
lsink.lineJoin();
lsink.close();
break;
default:
throw new InternalError("unknown flattened segment type");
}
pi.next();
}
lsink.end();
}
/////////////////////////////////////////////////////////////////////////////
//
// Utility methods
public static float[] copyOf(float[] source, int length) {
float[] target = new float[length];
for (int i = 0; i < target.length; i++) {
if (i > source.length - 1)
target[i] = 0f;
else
target[i] = source[i];
}
return target;
}
public static byte[] copyOf(byte[] source, int length) {
byte[] target = new byte[length];
for (int i = 0; i < target.length; i++) {
if (i > source.length - 1)
target[i] = 0;
else
target[i] = source[i];
}
return target;
}
public static int[] copyOf(int[] source, int length) {
int[] target = new int[length];
for (int i = 0; i < target.length; i++) {
if (i > source.length - 1)
target[i] = 0;
else
target[i] = source[i];
}
return target;
}
// From Ken Turkowski, _Fixed-Point Square Root_, In Graphics Gems V
public static int isqrt(int x) {
int fracbits = 16;
int root = 0;
int remHi = 0;
int remLo = x;
int count = 15 + fracbits / 2;
do {
remHi = (remHi << 2) | (remLo >>> 30); // N.B. - unsigned shift R
remLo <<= 2;
root <<= 1;
int testdiv = (root << 1) + 1;
if (remHi >= testdiv) {
remHi -= testdiv;
root++;
}
} while (count-- != 0);
return root;
}
public static long lsqrt(long x) {
int fracbits = 16;
long root = 0;
long remHi = 0;
long remLo = x;
int count = 31 + fracbits / 2;
do {
remHi = (remHi << 2) | (remLo >>> 62); // N.B. - unsigned shift R
remLo <<= 2;
root <<= 1;
long testDiv = (root << 1) + 1;
if (remHi >= testDiv) {
remHi -= testDiv;
root++;
}
} while (count-- != 0);
return root;
}
public static double hypot(double x, double y) {
return Math.sqrt(x * x + y * y);
}
public static int hypot(int x, int y) {
return (int) ((lsqrt((long) x * x + (long) y * y) + 128) >> 8);
}
public static long hypot(long x, long y) {
return (lsqrt(x * x + y * y) + 128) >> 8;
}
static int FloatToS15_16(float flt) {
flt = flt * 65536f + 0.5f;
if (flt <= -(65536f * 65536f)) {
return Integer.MIN_VALUE;
} else if (flt >= (65536f * 65536f)) {
return Integer.MAX_VALUE;
} else {
return (int) Math.floor(flt);
}
}
static float S15_16ToFloat(int fix) {
return (fix / 65536f);
}
}