Java example source code file (Region.java)
The Region.java Java example source code
/*
* Copyright (c) 1998, 2013, Oracle and/or its affiliates. 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. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package sun.java2d.pipe;
import java.awt.Rectangle;
import java.awt.Shape;
import java.awt.geom.AffineTransform;
import java.awt.geom.RectangularShape;
/**
* This class encapsulates a definition of a two dimensional region which
* consists of a number of Y ranges each containing multiple X bands.
* <p>
* A rectangular Region is allowed to have a null band list in which
* case the rectangular shape is defined by the bounding box parameters
* (lox, loy, hix, hiy).
* <p>
* The band list, if present, consists of a list of rows in ascending Y
* order, ending at endIndex which is the index beyond the end of the
* last row. Each row consists of at least 3 + 2n entries (n >= 1)
* where the first 3 entries specify the Y range as start, end, and
* the number of X ranges in that Y range. These 3 entries are
* followed by pairs of X coordinates in ascending order:
* <pre>
* bands[rowstart+0] = Y0; // starting Y coordinate
* bands[rowstart+1] = Y1; // ending Y coordinate - endY > startY
* bands[rowstart+2] = N; // number of X bands - N >= 1
*
* bands[rowstart+3] = X10; // starting X coordinate of first band
* bands[rowstart+4] = X11; // ending X coordinate of first band
* bands[rowstart+5] = X20; // starting X coordinate of second band
* bands[rowstart+6] = X21; // ending X coordinate of second band
* ...
* bands[rowstart+3+N*2-2] = XN0; // starting X coord of last band
* bands[rowstart+3+N*2-1] = XN1; // ending X coord of last band
*
* bands[rowstart+3+N*2] = ... // start of next Y row
* </pre>
*/
public class Region {
static final int INIT_SIZE = 50;
static final int GROW_SIZE = 50;
/**
* Immutable Region.
*/
private static final class ImmutableRegion extends Region {
protected ImmutableRegion(int lox, int loy, int hix, int hiy) {
super(lox, loy, hix, hiy);
}
// Override all the methods that mutate the object
public void appendSpans(sun.java2d.pipe.SpanIterator si) {}
public void setOutputArea(java.awt.Rectangle r) {}
public void setOutputAreaXYWH(int x, int y, int w, int h) {}
public void setOutputArea(int[] box) {}
public void setOutputAreaXYXY(int lox, int loy, int hix, int hiy) {}
}
public static final Region EMPTY_REGION = new ImmutableRegion(0, 0, 0, 0);
public static final Region WHOLE_REGION = new ImmutableRegion(
Integer.MIN_VALUE,
Integer.MIN_VALUE,
Integer.MAX_VALUE,
Integer.MAX_VALUE);
int lox;
int loy;
int hix;
int hiy;
int endIndex;
int[] bands;
private static native void initIDs();
static {
initIDs();
}
/**
* Adds the dimension <code>dim to the coordinate
* <code>start with appropriate clipping. If
* <code>dim is non-positive then the method returns
* the start coordinate. If the sum overflows an integer
* data type then the method returns <code>Integer.MAX_VALUE.
*/
public static int dimAdd(int start, int dim) {
if (dim <= 0) return start;
if ((dim += start) < start) return Integer.MAX_VALUE;
return dim;
}
/**
* Adds the delta {@code dv} to the value {@code v} with
* appropriate clipping to the bounds of Integer resolution.
* If the answer would be greater than {@code Integer.MAX_VALUE}
* then {@code Integer.MAX_VALUE} is returned.
* If the answer would be less than {@code Integer.MIN_VALUE}
* then {@code Integer.MIN_VALUE} is returned.
* Otherwise the sum is returned.
*/
public static int clipAdd(int v, int dv) {
int newv = v + dv;
if ((newv > v) != (dv > 0)) {
newv = (dv < 0) ? Integer.MIN_VALUE : Integer.MAX_VALUE;
}
return newv;
}
/**
* Multiply the scale factor {@code sv} and the value {@code v} with
* appropriate clipping to the bounds of Integer resolution. If the answer
* would be greater than {@code Integer.MAX_VALUE} then {@code
* Integer.MAX_VALUE} is returned. If the answer would be less than {@code
* Integer.MIN_VALUE} then {@code Integer.MIN_VALUE} is returned. Otherwise
* the multiplication is returned.
*/
public static int clipScale(final int v, final double sv) {
if (sv == 1.0) {
return v;
}
final double newv = v * sv;
if (newv < Integer.MIN_VALUE) {
return Integer.MIN_VALUE;
}
if (newv > Integer.MAX_VALUE) {
return Integer.MAX_VALUE;
}
return (int) Math.round(newv);
}
protected Region(int lox, int loy, int hix, int hiy) {
this.lox = lox;
this.loy = loy;
this.hix = hix;
this.hiy = hiy;
}
/**
* Returns a Region object covering the pixels which would be
* touched by a fill or clip operation on a Graphics implementation
* on the specified Shape object under the optionally specified
* AffineTransform object.
*
* @param s a non-null Shape object specifying the geometry enclosing
* the pixels of interest
* @param at an optional <code>AffineTransform to be applied to the
* coordinates as they are returned in the iteration, or
* <code>null if untransformed coordinates are desired
*/
public static Region getInstance(Shape s, AffineTransform at) {
return getInstance(WHOLE_REGION, false, s, at);
}
/**
* Returns a Region object covering the pixels which would be
* touched by a fill or clip operation on a Graphics implementation
* on the specified Shape object under the optionally specified
* AffineTransform object further restricted by the specified
* device bounds.
* <p>
* Note that only the bounds of the specified Region are used to
* restrict the resulting Region.
* If devBounds is non-rectangular and clipping to the specific
* bands of devBounds is needed, then an intersection of the
* resulting Region with devBounds must be performed in a
* subsequent step.
*
* @param devBounds a non-null Region specifying some bounds to
* clip the geometry to
* @param s a non-null Shape object specifying the geometry enclosing
* the pixels of interest
* @param at an optional <code>AffineTransform to be applied to the
* coordinates as they are returned in the iteration, or
* <code>null if untransformed coordinates are desired
*/
public static Region getInstance(Region devBounds,
Shape s, AffineTransform at)
{
return getInstance(devBounds, false, s, at);
}
/**
* Returns a Region object covering the pixels which would be
* touched by a fill or clip operation on a Graphics implementation
* on the specified Shape object under the optionally specified
* AffineTransform object further restricted by the specified
* device bounds.
* If the normalize parameter is true then coordinate normalization
* is performed as per the 2D Graphics non-antialiasing implementation
* of the VALUE_STROKE_NORMALIZE hint.
* <p>
* Note that only the bounds of the specified Region are used to
* restrict the resulting Region.
* If devBounds is non-rectangular and clipping to the specific
* bands of devBounds is needed, then an intersection of the
* resulting Region with devBounds must be performed in a
* subsequent step.
*
* @param devBounds a non-null Region specifying some bounds to
* clip the geometry to
* @param normalize a boolean indicating whether or not to apply
* normalization
* @param s a non-null Shape object specifying the geometry enclosing
* the pixels of interest
* @param at an optional <code>AffineTransform to be applied to the
* coordinates as they are returned in the iteration, or
* <code>null if untransformed coordinates are desired
*/
public static Region getInstance(Region devBounds, boolean normalize,
Shape s, AffineTransform at)
{
// Optimize for empty shapes to avoid involving the SpanIterator
if (s instanceof RectangularShape &&
((RectangularShape)s).isEmpty())
{
return EMPTY_REGION;
}
int box[] = new int[4];
ShapeSpanIterator sr = new ShapeSpanIterator(normalize);
try {
sr.setOutputArea(devBounds);
sr.appendPath(s.getPathIterator(at));
sr.getPathBox(box);
Region r = Region.getInstance(box);
r.appendSpans(sr);
return r;
} finally {
sr.dispose();
}
}
/**
* Returns a Region object with a rectangle of interest specified
* by the indicated Rectangle object.
* <p>
* This method can also be used to create a simple rectangular
* region.
*/
public static Region getInstance(Rectangle r) {
return Region.getInstanceXYWH(r.x, r.y, r.width, r.height);
}
/**
* Returns a Region object with a rectangle of interest specified
* by the indicated rectangular area in x, y, width, height format.
* <p>
* This method can also be used to create a simple rectangular
* region.
*/
public static Region getInstanceXYWH(int x, int y, int w, int h) {
return Region.getInstanceXYXY(x, y, dimAdd(x, w), dimAdd(y, h));
}
/**
* Returns a Region object with a rectangle of interest specified
* by the indicated span array.
* <p>
* This method can also be used to create a simple rectangular
* region.
*/
public static Region getInstance(int box[]) {
return new Region(box[0], box[1], box[2], box[3]);
}
/**
* Returns a Region object with a rectangle of interest specified
* by the indicated rectangular area in lox, loy, hix, hiy format.
* <p>
* This method can also be used to create a simple rectangular
* region.
*/
public static Region getInstanceXYXY(int lox, int loy, int hix, int hiy) {
return new Region(lox, loy, hix, hiy);
}
/**
* Sets the rectangle of interest for storing and returning
* region bands.
* <p>
* This method can also be used to initialize a simple rectangular
* region.
*/
public void setOutputArea(Rectangle r) {
setOutputAreaXYWH(r.x, r.y, r.width, r.height);
}
/**
* Sets the rectangle of interest for storing and returning
* region bands. The rectangle is specified in x, y, width, height
* format and appropriate clipping is performed as per the method
* <code>dimAdd.
* <p>
* This method can also be used to initialize a simple rectangular
* region.
*/
public void setOutputAreaXYWH(int x, int y, int w, int h) {
setOutputAreaXYXY(x, y, dimAdd(x, w), dimAdd(y, h));
}
/**
* Sets the rectangle of interest for storing and returning
* region bands. The rectangle is specified as a span array.
* <p>
* This method can also be used to initialize a simple rectangular
* region.
*/
public void setOutputArea(int box[]) {
this.lox = box[0];
this.loy = box[1];
this.hix = box[2];
this.hiy = box[3];
}
/**
* Sets the rectangle of interest for storing and returning
* region bands. The rectangle is specified in lox, loy,
* hix, hiy format.
* <p>
* This method can also be used to initialize a simple rectangular
* region.
*/
public void setOutputAreaXYXY(int lox, int loy, int hix, int hiy) {
this.lox = lox;
this.loy = loy;
this.hix = hix;
this.hiy = hiy;
}
/**
* Appends the list of spans returned from the indicated
* SpanIterator. Each span must be at a higher starting
* Y coordinate than the previous data or it must have a
* Y range equal to the highest Y band in the region and a
* higher X coordinate than any of the spans in that band.
*/
public void appendSpans(SpanIterator si) {
int[] box = new int[6];
while (si.nextSpan(box)) {
appendSpan(box);
}
endRow(box);
calcBBox();
}
/**
* Returns a Region object that represents the same list of rectangles as
* the current Region object, scaled by the specified sx, sy factors.
*/
public Region getScaledRegion(final double sx, final double sy) {
if (sx == 0 || sy == 0 || this == EMPTY_REGION) {
return EMPTY_REGION;
}
if ((sx == 1.0 && sy == 1.0) || (this == WHOLE_REGION)) {
return this;
}
int tlox = clipScale(lox, sx);
int tloy = clipScale(loy, sy);
int thix = clipScale(hix, sx);
int thiy = clipScale(hiy, sy);
Region ret = new Region(tlox, tloy, thix, thiy);
int bands[] = this.bands;
if (bands != null) {
int end = endIndex;
int newbands[] = new int[end];
int i = 0; // index for source bands
int j = 0; // index for translated newbands
int ncol;
while (i < end) {
int y1, y2;
newbands[j++] = y1 = clipScale(bands[i++], sy);
newbands[j++] = y2 = clipScale(bands[i++], sy);
newbands[j++] = ncol = bands[i++];
int savej = j;
if (y1 < y2) {
while (--ncol >= 0) {
int x1 = clipScale(bands[i++], sx);
int x2 = clipScale(bands[i++], sx);
if (x1 < x2) {
newbands[j++] = x1;
newbands[j++] = x2;
}
}
} else {
i += ncol * 2;
}
// Did we get any non-empty bands in this row?
if (j > savej) {
newbands[savej-1] = (j - savej) / 2;
} else {
j = savej - 3;
}
}
if (j <= 5) {
if (j < 5) {
// No rows or bands were generated...
ret.lox = ret.loy = ret.hix = ret.hiy = 0;
} else {
// Only generated one single rect in the end...
ret.loy = newbands[0];
ret.hiy = newbands[1];
ret.lox = newbands[3];
ret.hix = newbands[4];
}
// ret.endIndex and ret.bands were never initialized...
// ret.endIndex = 0;
// ret.newbands = null;
} else {
// Generated multiple bands and/or multiple rows...
ret.endIndex = j;
ret.bands = newbands;
}
}
return ret;
}
/**
* Returns a Region object that represents the same list of
* rectangles as the current Region object, translated by
* the specified dx, dy translation factors.
*/
public Region getTranslatedRegion(int dx, int dy) {
if ((dx | dy) == 0) {
return this;
}
int tlox = lox + dx;
int tloy = loy + dy;
int thix = hix + dx;
int thiy = hiy + dy;
if ((tlox > lox) != (dx > 0) ||
(tloy > loy) != (dy > 0) ||
(thix > hix) != (dx > 0) ||
(thiy > hiy) != (dy > 0))
{
return getSafeTranslatedRegion(dx, dy);
}
Region ret = new Region(tlox, tloy, thix, thiy);
int bands[] = this.bands;
if (bands != null) {
int end = endIndex;
ret.endIndex = end;
int newbands[] = new int[end];
ret.bands = newbands;
int i = 0;
int ncol;
while (i < end) {
newbands[i] = bands[i] + dy; i++;
newbands[i] = bands[i] + dy; i++;
newbands[i] = ncol = bands[i]; i++;
while (--ncol >= 0) {
newbands[i] = bands[i] + dx; i++;
newbands[i] = bands[i] + dx; i++;
}
}
}
return ret;
}
private Region getSafeTranslatedRegion(int dx, int dy) {
int tlox = clipAdd(lox, dx);
int tloy = clipAdd(loy, dy);
int thix = clipAdd(hix, dx);
int thiy = clipAdd(hiy, dy);
Region ret = new Region(tlox, tloy, thix, thiy);
int bands[] = this.bands;
if (bands != null) {
int end = endIndex;
int newbands[] = new int[end];
int i = 0; // index for source bands
int j = 0; // index for translated newbands
int ncol;
while (i < end) {
int y1, y2;
newbands[j++] = y1 = clipAdd(bands[i++], dy);
newbands[j++] = y2 = clipAdd(bands[i++], dy);
newbands[j++] = ncol = bands[i++];
int savej = j;
if (y1 < y2) {
while (--ncol >= 0) {
int x1 = clipAdd(bands[i++], dx);
int x2 = clipAdd(bands[i++], dx);
if (x1 < x2) {
newbands[j++] = x1;
newbands[j++] = x2;
}
}
} else {
i += ncol * 2;
}
// Did we get any non-empty bands in this row?
if (j > savej) {
newbands[savej-1] = (j - savej) / 2;
} else {
j = savej - 3;
}
}
if (j <= 5) {
if (j < 5) {
// No rows or bands were generated...
ret.lox = ret.loy = ret.hix = ret.hiy = 0;
} else {
// Only generated one single rect in the end...
ret.loy = newbands[0];
ret.hiy = newbands[1];
ret.lox = newbands[3];
ret.hix = newbands[4];
}
// ret.endIndex and ret.bands were never initialized...
// ret.endIndex = 0;
// ret.newbands = null;
} else {
// Generated multiple bands and/or multiple rows...
ret.endIndex = j;
ret.bands = newbands;
}
}
return ret;
}
/**
* Returns a Region object that represents the intersection of
* this object with the specified Rectangle. The return value
* may be this same object if no clipping occurs.
*/
public Region getIntersection(Rectangle r) {
return getIntersectionXYWH(r.x, r.y, r.width, r.height);
}
/**
* Returns a Region object that represents the intersection of
* this object with the specified rectangular area. The return
* value may be this same object if no clipping occurs.
*/
public Region getIntersectionXYWH(int x, int y, int w, int h) {
return getIntersectionXYXY(x, y, dimAdd(x, w), dimAdd(y, h));
}
/**
* Returns a Region object that represents the intersection of
* this object with the specified rectangular area. The return
* value may be this same object if no clipping occurs.
*/
public Region getIntersectionXYXY(int lox, int loy, int hix, int hiy) {
if (isInsideXYXY(lox, loy, hix, hiy)) {
return this;
}
Region ret = new Region((lox < this.lox) ? this.lox : lox,
(loy < this.loy) ? this.loy : loy,
(hix > this.hix) ? this.hix : hix,
(hiy > this.hiy) ? this.hiy : hiy);
if (bands != null) {
ret.appendSpans(this.getSpanIterator());
}
return ret;
}
/**
* Returns a Region object that represents the intersection of this
* object with the specified Region object.
* <p>
* If {@code A} and {@code B} are both Region Objects and
* <code>C = A.getIntersection(B); then a point will
* be contained in {@code C} iff it is contained in both
* {@code A} and {@code B}.
* <p>
* The return value may be this same object or the argument
* Region object if no clipping occurs.
*/
public Region getIntersection(Region r) {
if (this.isInsideQuickCheck(r)) {
return this;
}
if (r.isInsideQuickCheck(this)) {
return r;
}
Region ret = new Region((r.lox < this.lox) ? this.lox : r.lox,
(r.loy < this.loy) ? this.loy : r.loy,
(r.hix > this.hix) ? this.hix : r.hix,
(r.hiy > this.hiy) ? this.hiy : r.hiy);
if (!ret.isEmpty()) {
ret.filterSpans(this, r, INCLUDE_COMMON);
}
return ret;
}
/**
* Returns a Region object that represents the union of this
* object with the specified Region object.
* <p>
* If {@code A} and {@code B} are both Region Objects and
* <code>C = A.getUnion(B); then a point will
* be contained in {@code C} iff it is contained in either
* {@code A} or {@code B}.
* <p>
* The return value may be this same object or the argument
* Region object if no augmentation occurs.
*/
public Region getUnion(Region r) {
if (r.isEmpty() || r.isInsideQuickCheck(this)) {
return this;
}
if (this.isEmpty() || this.isInsideQuickCheck(r)) {
return r;
}
Region ret = new Region((r.lox > this.lox) ? this.lox : r.lox,
(r.loy > this.loy) ? this.loy : r.loy,
(r.hix < this.hix) ? this.hix : r.hix,
(r.hiy < this.hiy) ? this.hiy : r.hiy);
ret.filterSpans(this, r, INCLUDE_A | INCLUDE_B | INCLUDE_COMMON);
return ret;
}
/**
* Returns a Region object that represents the difference of the
* specified Region object subtracted from this object.
* <p>
* If {@code A} and {@code B} are both Region Objects and
* <code>C = A.getDifference(B); then a point will
* be contained in {@code C} iff it is contained in
* {@code A} but not contained in {@code B}.
* <p>
* The return value may be this same object or the argument
* Region object if no clipping occurs.
*/
public Region getDifference(Region r) {
if (!r.intersectsQuickCheck(this)) {
return this;
}
if (this.isInsideQuickCheck(r)) {
return EMPTY_REGION;
}
Region ret = new Region(this.lox, this.loy, this.hix, this.hiy);
ret.filterSpans(this, r, INCLUDE_A);
return ret;
}
/**
* Returns a Region object that represents the exclusive or of this
* object with the specified Region object.
* <p>
* If {@code A} and {@code B} are both Region Objects and
* <code>C = A.getExclusiveOr(B); then a point will
* be contained in {@code C} iff it is contained in either
* {@code A} or {@code B}, but not if it is contained in both.
* <p>
* The return value may be this same object or the argument
* Region object if either is empty.
*/
public Region getExclusiveOr(Region r) {
if (r.isEmpty()) {
return this;
}
if (this.isEmpty()) {
return r;
}
Region ret = new Region((r.lox > this.lox) ? this.lox : r.lox,
(r.loy > this.loy) ? this.loy : r.loy,
(r.hix < this.hix) ? this.hix : r.hix,
(r.hiy < this.hiy) ? this.hiy : r.hiy);
ret.filterSpans(this, r, INCLUDE_A | INCLUDE_B);
return ret;
}
static final int INCLUDE_A = 1;
static final int INCLUDE_B = 2;
static final int INCLUDE_COMMON = 4;
private void filterSpans(Region ra, Region rb, int flags) {
int abands[] = ra.bands;
int bbands[] = rb.bands;
if (abands == null) {
abands = new int[] {ra.loy, ra.hiy, 1, ra.lox, ra.hix};
}
if (bbands == null) {
bbands = new int[] {rb.loy, rb.hiy, 1, rb.lox, rb.hix};
}
int box[] = new int[6];
int acolstart = 0;
int ay1 = abands[acolstart++];
int ay2 = abands[acolstart++];
int acolend = abands[acolstart++];
acolend = acolstart + 2 * acolend;
int bcolstart = 0;
int by1 = bbands[bcolstart++];
int by2 = bbands[bcolstart++];
int bcolend = bbands[bcolstart++];
bcolend = bcolstart + 2 * bcolend;
int y = loy;
while (y < hiy) {
if (y >= ay2) {
if (acolend < ra.endIndex) {
acolstart = acolend;
ay1 = abands[acolstart++];
ay2 = abands[acolstart++];
acolend = abands[acolstart++];
acolend = acolstart + 2 * acolend;
} else {
if ((flags & INCLUDE_B) == 0) break;
ay1 = ay2 = hiy;
}
continue;
}
if (y >= by2) {
if (bcolend < rb.endIndex) {
bcolstart = bcolend;
by1 = bbands[bcolstart++];
by2 = bbands[bcolstart++];
bcolend = bbands[bcolstart++];
bcolend = bcolstart + 2 * bcolend;
} else {
if ((flags & INCLUDE_A) == 0) break;
by1 = by2 = hiy;
}
continue;
}
int yend;
if (y < by1) {
if (y < ay1) {
y = Math.min(ay1, by1);
continue;
}
// We are in a set of rows that belong only to A
yend = Math.min(ay2, by1);
if ((flags & INCLUDE_A) != 0) {
box[1] = y;
box[3] = yend;
int acol = acolstart;
while (acol < acolend) {
box[0] = abands[acol++];
box[2] = abands[acol++];
appendSpan(box);
}
}
} else if (y < ay1) {
// We are in a set of rows that belong only to B
yend = Math.min(by2, ay1);
if ((flags & INCLUDE_B) != 0) {
box[1] = y;
box[3] = yend;
int bcol = bcolstart;
while (bcol < bcolend) {
box[0] = bbands[bcol++];
box[2] = bbands[bcol++];
appendSpan(box);
}
}
} else {
// We are in a set of rows that belong to both A and B
yend = Math.min(ay2, by2);
box[1] = y;
box[3] = yend;
int acol = acolstart;
int bcol = bcolstart;
int ax1 = abands[acol++];
int ax2 = abands[acol++];
int bx1 = bbands[bcol++];
int bx2 = bbands[bcol++];
int x = Math.min(ax1, bx1);
if (x < lox) x = lox;
while (x < hix) {
if (x >= ax2) {
if (acol < acolend) {
ax1 = abands[acol++];
ax2 = abands[acol++];
} else {
if ((flags & INCLUDE_B) == 0) break;
ax1 = ax2 = hix;
}
continue;
}
if (x >= bx2) {
if (bcol < bcolend) {
bx1 = bbands[bcol++];
bx2 = bbands[bcol++];
} else {
if ((flags & INCLUDE_A) == 0) break;
bx1 = bx2 = hix;
}
continue;
}
int xend;
boolean appendit;
if (x < bx1) {
if (x < ax1) {
xend = Math.min(ax1, bx1);
appendit = false;
} else {
xend = Math.min(ax2, bx1);
appendit = ((flags & INCLUDE_A) != 0);
}
} else if (x < ax1) {
xend = Math.min(ax1, bx2);
appendit = ((flags & INCLUDE_B) != 0);
} else {
xend = Math.min(ax2, bx2);
appendit = ((flags & INCLUDE_COMMON) != 0);
}
if (appendit) {
box[0] = x;
box[2] = xend;
appendSpan(box);
}
x = xend;
}
}
y = yend;
}
endRow(box);
calcBBox();
}
/**
* Returns a Region object that represents the bounds of the
* intersection of this object with the bounds of the specified
* Region object.
* <p>
* The return value may be this same object if no clipping occurs
* and this Region is rectangular.
*/
public Region getBoundsIntersection(Rectangle r) {
return getBoundsIntersectionXYWH(r.x, r.y, r.width, r.height);
}
/**
* Returns a Region object that represents the bounds of the
* intersection of this object with the bounds of the specified
* rectangular area in x, y, width, height format.
* <p>
* The return value may be this same object if no clipping occurs
* and this Region is rectangular.
*/
public Region getBoundsIntersectionXYWH(int x, int y, int w, int h) {
return getBoundsIntersectionXYXY(x, y, dimAdd(x, w), dimAdd(y, h));
}
/**
* Returns a Region object that represents the bounds of the
* intersection of this object with the bounds of the specified
* rectangular area in lox, loy, hix, hiy format.
* <p>
* The return value may be this same object if no clipping occurs
* and this Region is rectangular.
*/
public Region getBoundsIntersectionXYXY(int lox, int loy,
int hix, int hiy)
{
if (this.bands == null &&
this.lox >= lox && this.loy >= loy &&
this.hix <= hix && this.hiy <= hiy)
{
return this;
}
return new Region((lox < this.lox) ? this.lox : lox,
(loy < this.loy) ? this.loy : loy,
(hix > this.hix) ? this.hix : hix,
(hiy > this.hiy) ? this.hiy : hiy);
}
/**
* Returns a Region object that represents the intersection of
* this object with the bounds of the specified Region object.
* <p>
* The return value may be this same object or the argument
* Region object if no clipping occurs and the Regions are
* rectangular.
*/
public Region getBoundsIntersection(Region r) {
if (this.encompasses(r)) {
return r;
}
if (r.encompasses(this)) {
return this;
}
return new Region((r.lox < this.lox) ? this.lox : r.lox,
(r.loy < this.loy) ? this.loy : r.loy,
(r.hix > this.hix) ? this.hix : r.hix,
(r.hiy > this.hiy) ? this.hiy : r.hiy);
}
/**
* Appends a single span defined by the 4 parameters
* spanlox, spanloy, spanhix, spanhiy.
* This span must be at a higher starting Y coordinate than
* the previous data or it must have a Y range equal to the
* highest Y band in the region and a higher X coordinate
* than any of the spans in that band.
*/
private void appendSpan(int box[]) {
int spanlox, spanloy, spanhix, spanhiy;
if ((spanlox = box[0]) < lox) spanlox = lox;
if ((spanloy = box[1]) < loy) spanloy = loy;
if ((spanhix = box[2]) > hix) spanhix = hix;
if ((spanhiy = box[3]) > hiy) spanhiy = hiy;
if (spanhix <= spanlox || spanhiy <= spanloy) {
return;
}
int curYrow = box[4];
if (endIndex == 0 || spanloy >= bands[curYrow + 1]) {
if (bands == null) {
bands = new int[INIT_SIZE];
} else {
needSpace(5);
endRow(box);
curYrow = box[4];
}
bands[endIndex++] = spanloy;
bands[endIndex++] = spanhiy;
bands[endIndex++] = 0;
} else if (spanloy == bands[curYrow] &&
spanhiy == bands[curYrow + 1] &&
spanlox >= bands[endIndex - 1]) {
if (spanlox == bands[endIndex - 1]) {
bands[endIndex - 1] = spanhix;
return;
}
needSpace(2);
} else {
throw new InternalError("bad span");
}
bands[endIndex++] = spanlox;
bands[endIndex++] = spanhix;
bands[curYrow + 2]++;
}
private void needSpace(int num) {
if (endIndex + num >= bands.length) {
int[] newbands = new int[bands.length + GROW_SIZE];
System.arraycopy(bands, 0, newbands, 0, endIndex);
bands = newbands;
}
}
private void endRow(int box[]) {
int cur = box[4];
int prev = box[5];
if (cur > prev) {
int[] bands = this.bands;
if (bands[prev + 1] == bands[cur] &&
bands[prev + 2] == bands[cur + 2])
{
int num = bands[cur + 2] * 2;
cur += 3;
prev += 3;
while (num > 0) {
if (bands[cur++] != bands[prev++]) {
break;
}
num--;
}
if (num == 0) {
// prev == box[4]
bands[box[5] + 1] = bands[prev + 1];
endIndex = prev;
return;
}
}
}
box[5] = box[4];
box[4] = endIndex;
}
private void calcBBox() {
int[] bands = this.bands;
if (endIndex <= 5) {
if (endIndex == 0) {
lox = loy = hix = hiy = 0;
} else {
loy = bands[0];
hiy = bands[1];
lox = bands[3];
hix = bands[4];
endIndex = 0;
}
this.bands = null;
return;
}
int lox = this.hix;
int hix = this.lox;
int hiyindex = 0;
int i = 0;
while (i < endIndex) {
hiyindex = i;
int numbands = bands[i + 2];
i += 3;
if (lox > bands[i]) {
lox = bands[i];
}
i += numbands * 2;
if (hix < bands[i - 1]) {
hix = bands[i - 1];
}
}
this.lox = lox;
this.loy = bands[0];
this.hix = hix;
this.hiy = bands[hiyindex + 1];
}
/**
* Returns the lowest X coordinate in the Region.
*/
public final int getLoX() {
return lox;
}
/**
* Returns the lowest Y coordinate in the Region.
*/
public final int getLoY() {
return loy;
}
/**
* Returns the highest X coordinate in the Region.
*/
public final int getHiX() {
return hix;
}
/**
* Returns the highest Y coordinate in the Region.
*/
public final int getHiY() {
return hiy;
}
/**
* Returns the width of this Region clipped to the range (0 - MAX_INT).
*/
public final int getWidth() {
if (hix < lox) return 0;
int w;
if ((w = hix - lox) < 0) {
w = Integer.MAX_VALUE;
}
return w;
}
/**
* Returns the height of this Region clipped to the range (0 - MAX_INT).
*/
public final int getHeight() {
if (hiy < loy) return 0;
int h;
if ((h = hiy - loy) < 0) {
h = Integer.MAX_VALUE;
}
return h;
}
/**
* Returns true iff this Region encloses no area.
*/
public boolean isEmpty() {
return (hix <= lox || hiy <= loy);
}
/**
* Returns true iff this Region represents a single simple
* rectangular area.
*/
public boolean isRectangular() {
return (bands == null);
}
/**
* Returns true iff this Region contains the specified coordinate.
*/
public boolean contains(int x, int y) {
if (x < lox || x >= hix || y < loy || y >= hiy) return false;
if (bands == null) return true;
int i = 0;
while (i < endIndex) {
if (y < bands[i++]) {
return false;
}
if (y >= bands[i++]) {
int numspans = bands[i++];
i += numspans * 2;
} else {
int end = bands[i++];
end = i + end * 2;
while (i < end) {
if (x < bands[i++]) return false;
if (x < bands[i++]) return true;
}
return false;
}
}
return false;
}
/**
* Returns true iff this Region lies inside the indicated
* rectangular area specified in x, y, width, height format
* with appropriate clipping performed as per the dimAdd method.
*/
public boolean isInsideXYWH(int x, int y, int w, int h) {
return isInsideXYXY(x, y, dimAdd(x, w), dimAdd(y, h));
}
/**
* Returns true iff this Region lies inside the indicated
* rectangular area specified in lox, loy, hix, hiy format.
*/
public boolean isInsideXYXY(int lox, int loy, int hix, int hiy) {
return (this.lox >= lox && this.loy >= loy &&
this.hix <= hix && this.hiy <= hiy);
}
/**
* Quickly checks if this Region lies inside the specified
* Region object.
* <p>
* This method will return false if the specified Region
* object is not a simple rectangle.
*/
public boolean isInsideQuickCheck(Region r) {
return (r.bands == null &&
r.lox <= this.lox && r.loy <= this.loy &&
r.hix >= this.hix && r.hiy >= this.hiy);
}
/**
* Quickly checks if this Region intersects the specified
* rectangular area specified in lox, loy, hix, hiy format.
* <p>
* This method tests only against the bounds of this region
* and does not bother to test if the rectangular region
* actually intersects any bands.
*/
public boolean intersectsQuickCheckXYXY(int lox, int loy,
int hix, int hiy)
{
return (hix > this.lox && lox < this.hix &&
hiy > this.loy && loy < this.hiy);
}
/**
* Quickly checks if this Region intersects the specified
* Region object.
* <p>
* This method tests only against the bounds of this region
* and does not bother to test if the rectangular region
* actually intersects any bands.
*/
public boolean intersectsQuickCheck(Region r) {
return (r.hix > this.lox && r.lox < this.hix &&
r.hiy > this.loy && r.loy < this.hiy);
}
/**
* Quickly checks if this Region surrounds the specified
* Region object.
* <p>
* This method will return false if this Region object is
* not a simple rectangle.
*/
public boolean encompasses(Region r) {
return (this.bands == null &&
this.lox <= r.lox && this.loy <= r.loy &&
this.hix >= r.hix && this.hiy >= r.hiy);
}
/**
* Quickly checks if this Region surrounds the specified
* rectangular area specified in x, y, width, height format.
* <p>
* This method will return false if this Region object is
* not a simple rectangle.
*/
public boolean encompassesXYWH(int x, int y, int w, int h) {
return encompassesXYXY(x, y, dimAdd(x, w), dimAdd(y, h));
}
/**
* Quickly checks if this Region surrounds the specified
* rectangular area specified in lox, loy, hix, hiy format.
* <p>
* This method will return false if this Region object is
* not a simple rectangle.
*/
public boolean encompassesXYXY(int lox, int loy, int hix, int hiy) {
return (this.bands == null &&
this.lox <= lox && this.loy <= loy &&
this.hix >= hix && this.hiy >= hiy);
}
/**
* Gets the bbox of the available spans, clipped to the OutputArea.
*/
public void getBounds(int pathbox[]) {
pathbox[0] = lox;
pathbox[1] = loy;
pathbox[2] = hix;
pathbox[3] = hiy;
}
/**
* Clips the indicated bbox array to the bounds of this Region.
*/
public void clipBoxToBounds(int bbox[]) {
if (bbox[0] < lox) bbox[0] = lox;
if (bbox[1] < loy) bbox[1] = loy;
if (bbox[2] > hix) bbox[2] = hix;
if (bbox[3] > hiy) bbox[3] = hiy;
}
/**
* Gets an iterator object to iterate over the spans in this region.
*/
public RegionIterator getIterator() {
return new RegionIterator(this);
}
/**
* Gets a span iterator object that iterates over the spans in this region
*/
public SpanIterator getSpanIterator() {
return new RegionSpanIterator(this);
}
/**
* Gets a span iterator object that iterates over the spans in this region
* but clipped to the bounds given in the argument (xlo, ylo, xhi, yhi).
*/
public SpanIterator getSpanIterator(int bbox[]) {
SpanIterator result = getSpanIterator();
result.intersectClipBox(bbox[0], bbox[1], bbox[2], bbox[3]);
return result;
}
/**
* Returns a SpanIterator that is the argument iterator filtered by
* this region.
*/
public SpanIterator filter(SpanIterator si) {
if (bands == null) {
si.intersectClipBox(lox, loy, hix, hiy);
} else {
si = new RegionClipSpanIterator(this, si);
}
return si;
}
public String toString() {
StringBuffer sb = new StringBuffer();
sb.append("Region[[");
sb.append(lox);
sb.append(", ");
sb.append(loy);
sb.append(" => ");
sb.append(hix);
sb.append(", ");
sb.append(hiy);
sb.append("]");
if (bands != null) {
int col = 0;
while (col < endIndex) {
sb.append("y{");
sb.append(bands[col++]);
sb.append(",");
sb.append(bands[col++]);
sb.append("}[");
int end = bands[col++];
end = col + end * 2;
while (col < end) {
sb.append("x(");
sb.append(bands[col++]);
sb.append(", ");
sb.append(bands[col++]);
sb.append(")");
}
sb.append("]");
}
}
sb.append("]");
return sb.toString();
}
public int hashCode() {
return (isEmpty() ? 0 : (lox * 3 + loy * 5 + hix * 7 + hiy * 9));
}
public boolean equals(Object o) {
if (!(o instanceof Region)) {
return false;
}
Region r = (Region) o;
if (this.isEmpty()) {
return r.isEmpty();
} else if (r.isEmpty()) {
return false;
}
if (r.lox != this.lox || r.loy != this.loy ||
r.hix != this.hix || r.hiy != this.hiy)
{
return false;
}
if (this.bands == null) {
return (r.bands == null);
} else if (r.bands == null) {
return false;
}
if (this.endIndex != r.endIndex) {
return false;
}
int abands[] = this.bands;
int bbands[] = r.bands;
for (int i = 0; i < endIndex; i++) {
if (abands[i] != bbands[i]) {
return false;
}
}
return true;
}
}
Other Java examples (source code examples)Here is a short list of links related to this Java Region.java source code file: |
The search page
Other Java source code examples at this package level
Click here to learn more about this project
