8180055: Upgrade the Marlin renderer in Java2D
Summary: added the double-precision variant + MarlinFX backports + Improved MarlinTileGenerator + higher precision of the cubic / quadratic curve
Reviewed-by: flar, pnarayanan
/*
* Copyright (c) 2007, 2017, 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 PathConsumer2D, MarlinConst {
static final int REC_LIMIT = 4;
static final float ERR = 0.01f;
static final float MIN_T_INC = 1.0f / (1 << REC_LIMIT);
// More than 24 bits of mantissa means we can no longer accurately
// measure the number of times cycled through the dash array so we
// punt and override the phase to just be 0 past that point.
static final float MAX_CYCLES = 16000000.0f;
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;
// flag to recycle dash array copy
boolean recycleDashes;
// dashes ref (dirty)
final FloatArrayCache.Reference dashes_ref;
// firstSegmentsBuffer ref (dirty)
final FloatArrayCache.Reference firstSegmentsBuffer_ref;
/**
* Constructs a <code>Dasher</code>.
* @param rdrCtx per-thread renderer context
*/
Dasher(final RendererContext rdrCtx) {
this.rdrCtx = rdrCtx;
dashes_ref = rdrCtx.newDirtyFloatArrayRef(INITIAL_ARRAY); // 1K
firstSegmentsBuffer_ref = rdrCtx.newDirtyFloatArrayRef(INITIAL_ARRAY); // 1K
firstSegmentsBuffer = firstSegmentsBuffer_ref.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)
{
this.out = out;
// Normalize so 0 <= phase < dash[0]
int sidx = 0;
dashOn = true;
float sum = 0.0f;
for (float d : dash) {
sum += d;
}
float cycles = phase / sum;
if (phase < 0.0f) {
if (-cycles >= MAX_CYCLES) {
phase = 0.0f;
} else {
int fullcycles = FloatMath.floor_int(-cycles);
if ((fullcycles & dash.length & 1) != 0) {
dashOn = !dashOn;
}
phase += fullcycles * sum;
while (phase < 0.0f) {
if (--sidx < 0) {
sidx = dash.length - 1;
}
phase += dash[sidx];
dashOn = !dashOn;
}
}
} else if (phase > 0) {
if (cycles >= MAX_CYCLES) {
phase = 0.0f;
} else {
int fullcycles = FloatMath.floor_int(cycles);
if ((fullcycles & dash.length & 1) != 0) {
dashOn = !dashOn;
}
phase -= fullcycles * sum;
float d;
while (phase >= (d = dash[sidx])) {
phase -= d;
sidx = (sidx + 1) % dash.length;
dashOn = !dashOn;
}
}
}
this.dash = dash;
this.dashLen = dashLen;
this.startPhase = this.phase = phase;
this.startDashOn = dashOn;
this.startIdx = sidx;
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 (DO_CLEAN_DIRTY) {
// Force zero-fill dirty arrays:
Arrays.fill(curCurvepts, 0.0f);
}
// Return arrays:
if (recycleDashes) {
dash = dashes_ref.putArray(dash);
}
firstSegmentsBuffer = firstSegmentsBuffer_ref.putArray(firstSegmentsBuffer);
}
float[] copyDashArray(final float[] dashes) {
final int len = dashes.length;
final float[] newDashes;
if (len <= MarlinConst.INITIAL_ARRAY) {
newDashes = dashes_ref.initial;
} else {
if (DO_STATS) {
rdrCtx.stats.stat_array_dasher_dasher.add(len);
}
newDashes = dashes_ref.getArray(len);
}
System.arraycopy(dashes, 0, newDashes, 0, len);
return newDashes;
}
@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)
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 - 1; // - 2 + 1
int segIdx = firstSegidx;
float[] buf = firstSegmentsBuffer;
if (segIdx + len > buf.length) {
if (DO_STATS) {
rdrCtx.stats.stat_array_dasher_firstSegmentsBuffer
.add(segIdx + len);
}
firstSegmentsBuffer = buf
= firstSegmentsBuffer_ref.widenArray(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 == 0.0f) {
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 = 0.0f;
idx = (idx + 1) % dashLen;
dashOn = !dashOn;
}
return;
}
dashdx = _dash[idx] * cx;
dashdy = _dash[idx] * cy;
if (phase == 0.0f) {
_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 = 0.0f;
}
}
// 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 = 0.0f;
float t;
float leftInThisDashSegment = dash[idx] - phase;
while ((t = li.next(leftInThisDashSegment)) < 1.0f) {
if (t != 0.0f) {
Helpers.subdivideAt((t - lastSplitT) / (1.0f - 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 = 0.0f;
leftInThisDashSegment = dash[idx];
}
goTo(curCurvepts, curCurveoff+2, type);
phase += li.lastSegLen();
if (phase >= dash[idx]) {
phase = 0.0f;
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() for more detail.
private final float[] curLeafCtrlPolyLengths = new float[3];
LengthIterator() {
this.recCurveStack = new float[REC_LIMIT + 1][8];
this.sides = new Side[REC_LIMIT];
// 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 (DO_CLEAN_DIRTY) {
final int recLimit = recCurveStack.length - 1;
for (int i = recLimit; i >= 0; i--) {
Arrays.fill(recCurveStack[i], 0.0f);
}
Arrays.fill(sides, Side.LEFT);
Arrays.fill(curLeafCtrlPolyLengths, 0.0f);
Arrays.fill(nextRoots, 0.0f);
Arrays.fill(flatLeafCoefCache, 0.0f);
flatLeafCoefCache[2] = -1.0f;
}
}
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 = 0.0f;
this.lenAtLastT = 0.0f;
this.nextT = 0.0f;
this.lenAtNextT = 0.0f;
goLeft(); // initializes nextT and lenAtNextT properly
this.lenAtLastSplit = 0.0f;
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 = 0.0f;
}
// 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[]{0.0f, 0.0f, -1.0f, 0.0f};
// 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 1.0f;
}
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] < 0.0f) {
float x = curLeafCtrlPolyLengths[0],
y = x + curLeafCtrlPolyLengths[1];
if (curveType == 8) {
float z = y + curLeafCtrlPolyLengths[2];
_flatLeafCoefCache[0] = 3.0f * (x - y) + z;
_flatLeafCoefCache[1] = 3.0f * (y - 2.0f * x);
_flatLeafCoefCache[2] = 3.0f * x;
_flatLeafCoefCache[3] = -z;
} else if (curveType == 6) {
_flatLeafCoefCache[0] = 0.0f;
_flatLeafCoefCache[1] = y - 2.0f * x;
_flatLeafCoefCache[2] = 2.0f * 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, 0.0f, 1.0f);
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 >= 1.0f) {
t = 1.0f;
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 >= 0.0f) {
lastT = nextT;
lenAtLastT = lenAtNextT;
nextT += (1 << (REC_LIMIT - recLevel)) * MIN_T_INC;
lenAtNextT += len;
// invalidate caches
flatLeafCoefCache[2] = -1.0f;
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 = 0.0f;
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 == REC_LIMIT) {
return (polyLen + lineLen) / 2.0f;
}
return -1.0f;
}
}
@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");
}
}