jdk-sandbox: comparison jdk/src/java.desktop/share/classes/sun/java2d/marlin/Dasher.java

equal deleted inserted replaced

-:a947f6b4e0b3
+:14108cfd0823
+/*
+* Copyright (c) 2007, 2015, 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.marlin;
+import java.util.Arrays;
+import sun.awt.geom.PathConsumer2D;
+/**
+* The <code>Dasher</code> class takes a series of linear commands
+* (<code>moveTo</code>, <code>lineTo</code>, <code>close</code> and
+* <code>end</code>) and breaks them into smaller segments according to a
+* dash pattern array and a starting dash phase.
+*
+* <p> Issues: in J2Se, a zero length dash segment as drawn as a very
+* short dash, whereas Pisces does not draw anything.  The PostScript
+* semantics are unclear.
+*
+*/
+final class Dasher implements sun.awt.geom.PathConsumer2D, MarlinConst {
+static final int recLimit = 4;
+static final float ERR = 0.01f;
+static final float minTincrement = 1f / (1 << recLimit);
+private PathConsumer2D out;
+private float[] dash;
+private int dashLen;
+private float startPhase;
+private boolean startDashOn;
+private int startIdx;
+private boolean starting;
+private boolean needsMoveTo;
+private int idx;
+private boolean dashOn;
+private float phase;
+private float sx, sy;
+private float x0, y0;
+// temporary storage for the current curve
+private final float[] curCurvepts;
+// per-thread renderer context
+final RendererContext rdrCtx;
+// dashes array (dirty)
+final float[] dashes_initial = new float[INITIAL_ARRAY];
+// flag to recycle dash array copy
+boolean recycleDashes;
+// per-thread initial arrays (large enough to satisfy most usages
+// +1 to avoid recycling in Helpers.widenArray()
+private final float[] firstSegmentsBuffer_initial = new float[INITIAL_ARRAY + 1];
+/**
+* Constructs a <code>Dasher</code>.
+* @param rdrCtx per-thread renderer context
+*/
+Dasher(final RendererContext rdrCtx) {
+this.rdrCtx = rdrCtx;
+firstSegmentsBuffer = firstSegmentsBuffer_initial;
+// we need curCurvepts to be able to contain 2 curves because when
+// dashing curves, we need to subdivide it
+curCurvepts = new float[8 * 2];
+}
+/**
+* Initialize the <code>Dasher</code>.
+*
+* @param out an output <code>PathConsumer2D</code>.
+* @param dash an array of <code>float</code>s containing the dash pattern
+* @param dashLen length of the given dash array
+* @param phase a <code>float</code> containing the dash phase
+* @param recycleDashes true to indicate to recycle the given dash array
+* @return this instance
+*/
+Dasher init(final PathConsumer2D out, float[] dash, int dashLen,
+float phase, boolean recycleDashes)
+{
+if (phase < 0f) {
+throw new IllegalArgumentException("phase < 0 !");
+}
+this.out = out;
+// Normalize so 0 <= phase < dash[0]
+int idx = 0;
+dashOn = true;
+float d;
+while (phase >= (d = dash[idx])) {
+phase -= d;
+idx = (idx + 1) % dashLen;
+dashOn = !dashOn;
+}
+this.dash = dash;
+this.dashLen = dashLen;
+this.startPhase = this.phase = phase;
+this.startDashOn = dashOn;
+this.startIdx = idx;
+this.starting = true;
+needsMoveTo = false;
+firstSegidx = 0;
+this.recycleDashes = recycleDashes;
+return this; // fluent API
+}
+/**
+* Disposes this dasher:
+* clean up before reusing this instance
+*/
+void dispose() {
+if (doCleanDirty) {
+// Force zero-fill dirty arrays:
+Arrays.fill(curCurvepts, 0f);
+Arrays.fill(firstSegmentsBuffer, 0f);
+}
+// Return arrays:
+if (recycleDashes && dash != dashes_initial) {
+rdrCtx.putDirtyFloatArray(dash);
+dash = null;
+}
+if (firstSegmentsBuffer != firstSegmentsBuffer_initial) {
+rdrCtx.putDirtyFloatArray(firstSegmentsBuffer);
+firstSegmentsBuffer = firstSegmentsBuffer_initial;
+}
+}
+@Override
+public void moveTo(float x0, float y0) {
+if (firstSegidx > 0) {
+out.moveTo(sx, sy);
+emitFirstSegments();
+}
+needsMoveTo = true;
+this.idx = startIdx;
+this.dashOn = this.startDashOn;
+this.phase = this.startPhase;
+this.sx = this.x0 = x0;
+this.sy = this.y0 = y0;
+this.starting = true;
+}
+private void emitSeg(float[] buf, int off, int type) {
+switch (type) {
+case 8:
+out.curveTo(buf[off+0], buf[off+1],
+buf[off+2], buf[off+3],
+buf[off+4], buf[off+5]);
+return;
+case 6:
+out.quadTo(buf[off+0], buf[off+1],
+buf[off+2], buf[off+3]);
+return;
+case 4:
+out.lineTo(buf[off], buf[off+1]);
+return;
+default:
+}
+}
+private void emitFirstSegments() {
+final float[] fSegBuf = firstSegmentsBuffer;
+for (int i = 0; i < firstSegidx; ) {
+int type = (int)fSegBuf[i];
+emitSeg(fSegBuf, i + 1, type);
+i += (type - 1);
+}
+firstSegidx = 0;
+}
+// We don't emit the first dash right away. If we did, caps would be
+// drawn on it, but we need joins to be drawn if there's a closePath()
+// So, we store the path elements that make up the first dash in the
+// buffer below.
+private float[] firstSegmentsBuffer; // dynamic array
+private int firstSegidx;
+// precondition: pts must be in relative coordinates (relative to x0,y0)
+// fullCurve is true iff the curve in pts has not been split.
+private void goTo(float[] pts, int off, final int type) {
+float x = pts[off + type - 4];
+float y = pts[off + type - 3];
+if (dashOn) {
+if (starting) {
+int len = type - 2 + 1;
+int segIdx = firstSegidx;
+float[] buf = firstSegmentsBuffer;
+if (segIdx + len  > buf.length) {
+if (doStats) {
+RendererContext.stats.stat_array_dasher_firstSegmentsBuffer
+.add(segIdx + len);
+}
+firstSegmentsBuffer = buf
+= rdrCtx.widenDirtyFloatArray(buf, segIdx, segIdx + len);
+}
+buf[segIdx++] = type;
+len--;
+// small arraycopy (2, 4 or 6) but with offset:
+System.arraycopy(pts, off, buf, segIdx, len);
+segIdx += len;
+firstSegidx = segIdx;
+} else {
+if (needsMoveTo) {
+out.moveTo(x0, y0);
+needsMoveTo = false;
+}
+emitSeg(pts, off, type);
+}
+} else {
+starting = false;
+needsMoveTo = true;
+}
+this.x0 = x;
+this.y0 = y;
+}
+@Override
+public void lineTo(float x1, float y1) {
+float dx = x1 - x0;
+float dy = y1 - y0;
+float len = dx*dx + dy*dy;
+if (len == 0f) {
+return;
+}
+len = (float) Math.sqrt(len);
+// The scaling factors needed to get the dx and dy of the
+// transformed dash segments.
+final float cx = dx / len;
+final float cy = dy / len;
+final float[] _curCurvepts = curCurvepts;
+final float[] _dash = dash;
+float leftInThisDashSegment;
+float dashdx, dashdy, p;
+while (true) {
+leftInThisDashSegment = _dash[idx] - phase;
+if (len <= leftInThisDashSegment) {
+_curCurvepts[0] = x1;
+_curCurvepts[1] = y1;
+goTo(_curCurvepts, 0, 4);
+// Advance phase within current dash segment
+phase += len;
+// TODO: compare float values using epsilon:
+if (len == leftInThisDashSegment) {
+phase = 0f;
+idx = (idx + 1) % dashLen;
+dashOn = !dashOn;
+}
+return;
+}
+dashdx = _dash[idx] * cx;
+dashdy = _dash[idx] * cy;
+if (phase == 0f) {
+_curCurvepts[0] = x0 + dashdx;
+_curCurvepts[1] = y0 + dashdy;
+} else {
+p = leftInThisDashSegment / _dash[idx];
+_curCurvepts[0] = x0 + p * dashdx;
+_curCurvepts[1] = y0 + p * dashdy;
+}
+goTo(_curCurvepts, 0, 4);
+len -= leftInThisDashSegment;
+// Advance to next dash segment
+idx = (idx + 1) % dashLen;
+dashOn = !dashOn;
+phase = 0f;
+}
+}
+// shared instance in Dasher
+private final LengthIterator li = new LengthIterator();
+// preconditions: curCurvepts must be an array of length at least 2 * type,
+// that contains the curve we want to dash in the first type elements
+private void somethingTo(int type) {
+if (pointCurve(curCurvepts, type)) {
+return;
+}
+li.initializeIterationOnCurve(curCurvepts, type);
+// initially the current curve is at curCurvepts[0...type]
+int curCurveoff = 0;
+float lastSplitT = 0f;
+float t;
+float leftInThisDashSegment = dash[idx] - phase;
+while ((t = li.next(leftInThisDashSegment)) < 1f) {
+if (t != 0f) {
+Helpers.subdivideAt((t - lastSplitT) / (1f - lastSplitT),
+curCurvepts, curCurveoff,
+curCurvepts, 0,
+curCurvepts, type, type);
+lastSplitT = t;
+goTo(curCurvepts, 2, type);
+curCurveoff = type;
+}
+// Advance to next dash segment
+idx = (idx + 1) % dashLen;
+dashOn = !dashOn;
+phase = 0f;
+leftInThisDashSegment = dash[idx];
+}
+goTo(curCurvepts, curCurveoff+2, type);
+phase += li.lastSegLen();
+if (phase >= dash[idx]) {
+phase = 0f;
+idx = (idx + 1) % dashLen;
+dashOn = !dashOn;
+}
+// reset LengthIterator:
+li.reset();
+}
+private static boolean pointCurve(float[] curve, int type) {
+for (int i = 2; i < type; i++) {
+if (curve[i] != curve[i-2]) {
+return false;
+}
+}
+return true;
+}
+// Objects of this class are used to iterate through curves. They return
+// t values where the left side of the curve has a specified length.
+// It does this by subdividing the input curve until a certain error
+// condition has been met. A recursive subdivision procedure would
+// return as many as 1<<limit curves, but this is an iterator and we
+// don't need all the curves all at once, so what we carry out a
+// lazy inorder traversal of the recursion tree (meaning we only move
+// through the tree when we need the next subdivided curve). This saves
+// us a lot of memory because at any one time we only need to store
+// limit+1 curves - one for each level of the tree + 1.
+// NOTE: the way we do things here is not enough to traverse a general
+// tree; however, the trees we are interested in have the property that
+// every non leaf node has exactly 2 children
+static final class LengthIterator {
+private enum Side {LEFT, RIGHT};
+// Holds the curves at various levels of the recursion. The root
+// (i.e. the original curve) is at recCurveStack[0] (but then it
+// gets subdivided, the left half is put at 1, so most of the time
+// only the right half of the original curve is at 0)
+private final float[][] recCurveStack; // dirty
+// sides[i] indicates whether the node at level i+1 in the path from
+// the root to the current leaf is a left or right child of its parent.
+private final Side[] sides; // dirty
+private int curveType;
+// lastT and nextT delimit the current leaf.
+private float nextT;
+private float lenAtNextT;
+private float lastT;
+private float lenAtLastT;
+private float lenAtLastSplit;
+private float lastSegLen;
+// the current level in the recursion tree. 0 is the root. limit
+// is the deepest possible leaf.
+private int recLevel;
+private boolean done;
+// the lengths of the lines of the control polygon. Only its first
+// curveType/2 - 1 elements are valid. This is an optimization. See
+// next(float) for more detail.
+private final float[] curLeafCtrlPolyLengths = new float[3];
+LengthIterator() {
+this.recCurveStack = new float[recLimit + 1][8];
+this.sides = new Side[recLimit];
+// if any methods are called without first initializing this object
+// on a curve, we want it to fail ASAP.
+this.nextT = Float.MAX_VALUE;
+this.lenAtNextT = Float.MAX_VALUE;
+this.lenAtLastSplit = Float.MIN_VALUE;
+this.recLevel = Integer.MIN_VALUE;
+this.lastSegLen = Float.MAX_VALUE;
+this.done = true;
+}
+/**
+* Reset this LengthIterator.
+*/
+void reset() {
+// keep data dirty
+// as it appears not useful to reset data:
+if (doCleanDirty) {
+final int recLimit = recCurveStack.length - 1;
+for (int i = recLimit; i >= 0; i--) {
+Arrays.fill(recCurveStack[i], 0f);
+}
+Arrays.fill(sides, Side.LEFT);
+Arrays.fill(curLeafCtrlPolyLengths, 0f);
+Arrays.fill(nextRoots, 0f);
+Arrays.fill(flatLeafCoefCache, 0f);
+flatLeafCoefCache[2] = -1f;
+}
+}
+void initializeIterationOnCurve(float[] pts, int type) {
+// optimize arraycopy (8 values faster than 6 = type):
+System.arraycopy(pts, 0, recCurveStack[0], 0, 8);
+this.curveType = type;
+this.recLevel = 0;
+this.lastT = 0f;
+this.lenAtLastT = 0f;
+this.nextT = 0f;
+this.lenAtNextT = 0f;
+goLeft(); // initializes nextT and lenAtNextT properly
+this.lenAtLastSplit = 0f;
+if (recLevel > 0) {
+this.sides[0] = Side.LEFT;
+this.done = false;
+} else {
+// the root of the tree is a leaf so we're done.
+this.sides[0] = Side.RIGHT;
+this.done = true;
+}
+this.lastSegLen = 0f;
+}
+// 0 == false, 1 == true, -1 == invalid cached value.
+private int cachedHaveLowAcceleration = -1;
+private boolean haveLowAcceleration(float err) {
+if (cachedHaveLowAcceleration == -1) {
+final float len1 = curLeafCtrlPolyLengths[0];
+final float len2 = curLeafCtrlPolyLengths[1];
+// the test below is equivalent to !within(len1/len2, 1, err).
+// It is using a multiplication instead of a division, so it
+// should be a bit faster.
+if (!Helpers.within(len1, len2, err*len2)) {
+cachedHaveLowAcceleration = 0;
+return false;
+}
+if (curveType == 8) {
+final float len3 = curLeafCtrlPolyLengths[2];
+// if len1 is close to 2 and 2 is close to 3, that probably
+// means 1 is close to 3 so the second part of this test might
+// not be needed, but it doesn't hurt to include it.
+final float errLen3 = err * len3;
+if (!(Helpers.within(len2, len3, errLen3) &&
+Helpers.within(len1, len3, errLen3))) {
+cachedHaveLowAcceleration = 0;
+return false;
+}
+}
+cachedHaveLowAcceleration = 1;
+return true;
+}
+return (cachedHaveLowAcceleration == 1);
+}
+// we want to avoid allocations/gc so we keep this array so we
+// can put roots in it,
+private final float[] nextRoots = new float[4];
+// caches the coefficients of the current leaf in its flattened
+// form (see inside next() for what that means). The cache is
+// invalid when it's third element is negative, since in any
+// valid flattened curve, this would be >= 0.
+private final float[] flatLeafCoefCache = new float[]{0f, 0f, -1f, 0f};
+// returns the t value where the remaining curve should be split in
+// order for the left subdivided curve to have length len. If len
+// is >= than the length of the uniterated curve, it returns 1.
+float next(final float len) {
+final float targetLength = lenAtLastSplit + len;
+while (lenAtNextT < targetLength) {
+if (done) {
+lastSegLen = lenAtNextT - lenAtLastSplit;
+return 1f;
+}
+goToNextLeaf();
+}
+lenAtLastSplit = targetLength;
+final float leaflen = lenAtNextT - lenAtLastT;
+float t = (targetLength - lenAtLastT) / leaflen;
+// cubicRootsInAB is a fairly expensive call, so we just don't do it
+// if the acceleration in this section of the curve is small enough.
+if (!haveLowAcceleration(0.05f)) {
+// We flatten the current leaf along the x axis, so that we're
+// left with a, b, c which define a 1D Bezier curve. We then
+// solve this to get the parameter of the original leaf that
+// gives us the desired length.
+final float[] _flatLeafCoefCache = flatLeafCoefCache;
+if (_flatLeafCoefCache[2] < 0) {
+float x = 0f + curLeafCtrlPolyLengths[0],
+y = x  + curLeafCtrlPolyLengths[1];
+if (curveType == 8) {
+float z = y + curLeafCtrlPolyLengths[2];
+_flatLeafCoefCache[0] = 3f * (x - y) + z;
+_flatLeafCoefCache[1] = 3f * (y - 2f * x);
+_flatLeafCoefCache[2] = 3f * x;
+_flatLeafCoefCache[3] = -z;
+} else if (curveType == 6) {
+_flatLeafCoefCache[0] = 0f;
+_flatLeafCoefCache[1] = y - 2f * x;
+_flatLeafCoefCache[2] = 2f * x;
+_flatLeafCoefCache[3] = -y;
+}
+}
+float a = _flatLeafCoefCache[0];
+float b = _flatLeafCoefCache[1];
+float c = _flatLeafCoefCache[2];
+float d = t * _flatLeafCoefCache[3];
+// we use cubicRootsInAB here, because we want only roots in 0, 1,
+// and our quadratic root finder doesn't filter, so it's just a
+// matter of convenience.
+int n = Helpers.cubicRootsInAB(a, b, c, d, nextRoots, 0, 0, 1);
+if (n == 1 && !Float.isNaN(nextRoots[0])) {
+t = nextRoots[0];
+}
+}
+// t is relative to the current leaf, so we must make it a valid parameter
+// of the original curve.
+t = t * (nextT - lastT) + lastT;
+if (t >= 1f) {
+t = 1f;
+done = true;
+}
+// even if done = true, if we're here, that means targetLength
+// is equal to, or very, very close to the total length of the
+// curve, so lastSegLen won't be too high. In cases where len
+// overshoots the curve, this method will exit in the while
+// loop, and lastSegLen will still be set to the right value.
+lastSegLen = len;
+return t;
+}
+float lastSegLen() {
+return lastSegLen;
+}
+// go to the next leaf (in an inorder traversal) in the recursion tree
+// preconditions: must be on a leaf, and that leaf must not be the root.
+private void goToNextLeaf() {
+// We must go to the first ancestor node that has an unvisited
+// right child.
+int _recLevel = recLevel;
+final Side[] _sides = sides;
+_recLevel--;
+while(_sides[_recLevel] == Side.RIGHT) {
+if (_recLevel == 0) {
+recLevel = 0;
+done = true;
+return;
+}
+_recLevel--;
+}
+_sides[_recLevel] = Side.RIGHT;
+// optimize arraycopy (8 values faster than 6 = type):
+System.arraycopy(recCurveStack[_recLevel], 0,
+recCurveStack[_recLevel+1], 0, 8);
+_recLevel++;
+recLevel = _recLevel;
+goLeft();
+}
+// go to the leftmost node from the current node. Return its length.
+private void goLeft() {
+float len = onLeaf();
+if (len >= 0f) {
+lastT = nextT;
+lenAtLastT = lenAtNextT;
+nextT += (1 << (recLimit - recLevel)) * minTincrement;
+lenAtNextT += len;
+// invalidate caches
+flatLeafCoefCache[2] = -1f;
+cachedHaveLowAcceleration = -1;
+} else {
+Helpers.subdivide(recCurveStack[recLevel], 0,
+recCurveStack[recLevel+1], 0,
+recCurveStack[recLevel], 0, curveType);
+sides[recLevel] = Side.LEFT;
+recLevel++;
+goLeft();
+}
+}
+// this is a bit of a hack. It returns -1 if we're not on a leaf, and
+// the length of the leaf if we are on a leaf.
+private float onLeaf() {
+float[] curve = recCurveStack[recLevel];
+float polyLen = 0f;
+float x0 = curve[0], y0 = curve[1];
+for (int i = 2; i < curveType; i += 2) {
+final float x1 = curve[i], y1 = curve[i+1];
+final float len = Helpers.linelen(x0, y0, x1, y1);
+polyLen += len;
+curLeafCtrlPolyLengths[i/2 - 1] = len;
+x0 = x1;
+y0 = y1;
+}
+final float lineLen = Helpers.linelen(curve[0], curve[1],
+curve[curveType-2],
+curve[curveType-1]);
+if ((polyLen - lineLen) < ERR || recLevel == recLimit) {
+return (polyLen + lineLen) / 2f;
+}
+return -1f;
+}
+}
+@Override
+public void curveTo(float x1, float y1,
+float x2, float y2,
+float x3, float y3)
+{
+final float[] _curCurvepts = curCurvepts;
+_curCurvepts[0] = x0;        _curCurvepts[1] = y0;
+_curCurvepts[2] = x1;        _curCurvepts[3] = y1;
+_curCurvepts[4] = x2;        _curCurvepts[5] = y2;
+_curCurvepts[6] = x3;        _curCurvepts[7] = y3;
+somethingTo(8);
+}
+@Override
+public void quadTo(float x1, float y1, float x2, float y2) {
+final float[] _curCurvepts = curCurvepts;
+_curCurvepts[0] = x0;        _curCurvepts[1] = y0;
+_curCurvepts[2] = x1;        _curCurvepts[3] = y1;
+_curCurvepts[4] = x2;        _curCurvepts[5] = y2;
+somethingTo(6);
+}
+@Override
+public void closePath() {
+lineTo(sx, sy);
+if (firstSegidx > 0) {
+if (!dashOn || needsMoveTo) {
+out.moveTo(sx, sy);
+}
+emitFirstSegments();
+}
+moveTo(sx, sy);
+}
+@Override
+public void pathDone() {
+if (firstSegidx > 0) {
+out.moveTo(sx, sy);
+emitFirstSegments();
+}
+out.pathDone();
+// Dispose this instance:
+dispose();
+}
+@Override
+public long getNativeConsumer() {
+throw new InternalError("Dasher does not use a native consumer");
+}
+}

changeset 34419	14108cfd0823
parent 34417	57a3863abbb4
child 39519	21bfc4452441