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Diffstat (limited to 'libjava/classpath/gnu/java/awt/font/opentype/truetype/ZonePathIterator.java')
| -rw-r--r-- | libjava/classpath/gnu/java/awt/font/opentype/truetype/ZonePathIterator.java | 393 |
1 files changed, 393 insertions, 0 deletions
diff --git a/libjava/classpath/gnu/java/awt/font/opentype/truetype/ZonePathIterator.java b/libjava/classpath/gnu/java/awt/font/opentype/truetype/ZonePathIterator.java new file mode 100644 index 000000000..f4534f36f --- /dev/null +++ b/libjava/classpath/gnu/java/awt/font/opentype/truetype/ZonePathIterator.java @@ -0,0 +1,393 @@ +/* ZonePathIterator.java -- A PathIterator over glyph zones. + Copyright (C) 2006 Free Software Foundation, Inc. + +This file is part of GNU Classpath. + +GNU Classpath is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 2, or (at your option) +any later version. + +GNU Classpath 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 for more details. + +You should have received a copy of the GNU General Public License +along with GNU Classpath; see the file COPYING. If not, write to the +Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA +02110-1301 USA. + +Linking this library statically or dynamically with other modules is +making a combined work based on this library. Thus, the terms and +conditions of the GNU General Public License cover the whole +combination. + +As a special exception, the copyright holders of this library give you +permission to link this library with independent modules to produce an +executable, regardless of the license terms of these independent +modules, and to copy and distribute the resulting executable under +terms of your choice, provided that you also meet, for each linked +independent module, the terms and conditions of the license of that +module. An independent module is a module which is not derived from +or based on this library. If you modify this library, you may extend +this exception to your version of the library, but you are not +obligated to do so. If you do not wish to do so, delete this +exception statement from your version. */ + +package gnu.java.awt.font.opentype.truetype; + +import java.awt.geom.PathIterator; + + +/** + * A PathIterator that enumerates the non-phantom points in a zone. + * + * <p><b>Lack of thread safety:</b> Instances of this class are + * <i>not</i> safe to access from multiple concurrent threads. + * + * @see Zone + * + * @author Sascha Brawer (brawer@dandelis.ch) + */ +final class ZonePathIterator + implements PathIterator +{ + /** + * If <code>state</code> has this value, <code>currentSegment</code> + * will emit a <code>SEG_LINETO</code> or <code>SEG_QUADTO</code> segment + * to the current point. For a discussion of subtleties of on-curve + * and off-curve points, please refer to the documentation for + * {@link #getSegment}. + */ + private static final int EMIT_SEGMENT = 0; + + + /** + * If <code>state</code> has this value, <code>currentSegment</code> + * will emit a <code>SEG_CLOSE</code> in order to close the sub-path + * for the current contour. + */ + private static final int EMIT_CLOSE = 1; + + + /** + * If <code>state</code> has this value, <code>currentSegment</code> + * will emit a <code>SEG_MOVETO</code> segment to the first point in + * the current contour. If the first point is off-curve, a suitable + * on-curve point is calculated. + * + * @see #getStartSegment + */ + private static final int EMIT_MOVETO = 2; + + + /** + * The state of the iterator, which is one of + * <code>EMIT_SEGMENT</code>, <code>EMIT_CLOSE</code>, or + * <code>EMIT_MOVETO</code>. + */ + private int state; + + + + /** + * The zone whose segments are enumerated by this iterator. + */ + private Zone zone; + + + /** + * The total number of points in the zone, not including the four + * phantom points at its end. + */ + private int numPoints; + + + /** + * The number of the current point. + */ + private int curPoint; + + + /** + * The number of the first point in the current contour. + */ + private int contourStart; + + + private int type; + + /** + * Constructs a ZonePathIterator for the specified zone. + * + * @param zone the zone whose segments will be enumerated + * by this iterator. + */ + ZonePathIterator(Zone zone, int t) + { + this.zone = zone; + type = t; + numPoints = zone.getSize() - /* four phantom points */ 4; + + // The first segment that needs to be emitted is a SEG_MOVETO. + state = EMIT_MOVETO; + } + + + /** + * Returns the winding rule. TrueType glyphs always use the non-zero + * winding rule, so this method will always return {@link + * PathIterator#WIND_NON_ZERO}. + */ + public int getWindingRule() + { + return PathIterator.WIND_NON_ZERO; + } + + + + public boolean isDone() + { + return (state != EMIT_CLOSE) && (curPoint >= numPoints); + } + + + public void next() + { + boolean onCurve; + + /* If the current point is the end of a segment, and no SEG_CLOSE + * has been emitted yet, this will be the next segment. + */ + if (zone.isContourEnd(curPoint) && (state != EMIT_CLOSE)) + { + state = EMIT_CLOSE; + return; + } + + /* If the previously emitted segment was a SEG_CLOSE, we are now + * at the beginning of a new contour. + */ + if (state == EMIT_CLOSE) + { + contourStart = ++curPoint; + state = EMIT_MOVETO; + return; + } + + onCurve = zone.isOnCurve(curPoint); + + /* If the last segment was a moveto, and the current point + * (which is the first point in the contour) is off-curve, + * we need to emit a quadto segment for the first point. + */ + if ((state == EMIT_MOVETO) && !onCurve) + { + state = EMIT_SEGMENT; + return; + } + + + curPoint++; + + /* If the last point has been off-curve, and the now current + * point is on-curve, the last segment was a quadto that + * had the now current point at its end. In this case, we can + * skip a segment. + */ + if (!onCurve && zone.isOnCurve(curPoint)) + { + /* But if the skipped point is the end of a contour, we must not + * skip the SEG_CLOSE. An example where this matters is the 'o' + * glyph in the Helvetica font face that comes with MacOS X + * 10.1.5. + */ + if (zone.isContourEnd(curPoint)) + { + state = EMIT_CLOSE; + return; + } + + curPoint++; + } + + state = EMIT_SEGMENT; + } + + + /** + * Determines the successor of the current point in the current + * contour. The successor of the last point in a contour is the + * start of that contour. + * + * @return the number of the point that follows the current point in + * the same contour. + */ + private int getSuccessor(int p) + { + if (zone.isContourEnd(p)) + return contourStart; + else + return p + 1; + } + + + + /** + * Retrieves the current path segment using single-precision + * coordinate values. + */ + public int currentSegment(float[] coords) + { + switch (state) + { + case EMIT_CLOSE: + return PathIterator.SEG_CLOSE; + + case EMIT_MOVETO: + return getStartSegment(curPoint, coords); + + default: + return getSegment(curPoint, coords); + } + } + + + /** + * A helper array that is used by {@link + * #currentSegment(double[])}. + */ + float[] floats; + + + /** + * Retrieves the current path segment using double-precision + * coordinate values. + */ + public int currentSegment(double[] coords) + { + if (floats == null) + floats = new float[6]; + int result; + + result = currentSegment(floats); + for (int i = 0; i < 6; i++) + coords[i] = floats[i]; + return result; + } + + + /** + * Returns the segment for the specified point. + * + * <p><img src="doc-files/ZonePathIterator-1.png" width="426" + * height="194" alt="An example curve" /></p> + * + * <p>If <code>cur</code> is an on-curve point, the returned segment + * is a straight line to <code>cur</code>. In the illustration, this + * would be the case for <code>cur = 4</code>.</p> + * + * <p>If <code>cur</code> is an off-curve point, and + * <code>cur</code>’s successor <code>succ</code> is also + * off-curve, the returned segment is a quadratic Bézier + * spline whose control point is <code>cur</code>, and whose end + * point is located at the middle of the line connecting + * <code>cur</code> and <code>succ</code>. In the illustration, + * this would be the case for <code>cur = 5</code>.</p> + * + * <p>If <code>cur</code> is an off-curve point, and + * <code>cur</code>’s successor <code>succ</code> is + * on-curve, the returned segment is a quadratic Bézier + * spline whose control point is <code>cur</code>, and whose end + * point is <code>succ</code>. In the illustration, this would + * be the case for <code>cur = 6</code>.</p> + * + * @return either <code>PathIterator.SEG_LINETO</code> or + * <code>PathIterator.SEG_QUADTO</code>. + */ + private int getSegment(int cur, float[] coords) + { + int curX, curY; + int succ, succX, succY; + + curX = zone.getX(cur, type); + curY = zone.getY(cur, type); + coords[0] = Fixed.floatValue(curX); + coords[1] = Fixed.floatValue(curY); + + if (zone.isOnCurve(cur)) + return PathIterator.SEG_LINETO; + + succ = getSuccessor(cur); + succX = zone.getX(succ, type); + succY = zone.getY(succ, type); + + if (zone.isOnCurve(succ)) + { + coords[2] = Fixed.floatValue(succX); + coords[3] = Fixed.floatValue(succY); + } + else + { + coords[2] = Fixed.floatValue((curX + succX) / 2); + coords[3] = Fixed.floatValue((curY + succY) / 2); + } + return PathIterator.SEG_QUADTO; + } + + + /** + * Returns the start segment for the contour which starts + * at the specified point. + * + * <p>If the contour starts with an on-curve point, the returned + * segment is a <code>SEG_MOVETO</code> to that point.</p> + * + * <p>If the contour starts with an off-curve point, and the contour + * ends with an on-curve point, the returned segment is a + * <code>SEG_MOVETO</code> to the end point.</p> + * + * <p>If the contour starts with an off-curve point, and the contour + * also ends with an off-curve point, the returned segment is a + * <code>SEG_MOVETO</code> to the location at the middle between the + * start and end points of the contour.</p> + * + * @return <code>PathIterator.SEG_MOVETO</code>. + */ + private int getStartSegment(int contourStart, float[] coords) + { + int x, y; + + if (zone.isOnCurve(contourStart)) + { + x = zone.getX(contourStart, type); + y = zone.getY(contourStart, type); + } + else + { + /* Find the last point of the current contour. */ + int contourEnd = contourStart; + while (!zone.isContourEnd(contourEnd)) + ++contourEnd; + + if (zone.isOnCurve(contourEnd)) + { + /* An example is the 'o' glyph of the Helvetica which comes + * with Apple MacOS X 10.1.5. + */ + x = zone.getX(contourEnd, type); + y = zone.getY(contourEnd, type); + } + else + { + x = (zone.getX(contourStart, type) + zone.getX(contourEnd, type)) / 2; + y = (zone.getY(contourStart, type) + zone.getY(contourEnd, type)) / 2; + } + } + + coords[0] = Fixed.floatValue(x); + coords[1] = Fixed.floatValue(y); + return PathIterator.SEG_MOVETO; + } +} |