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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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*
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* 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).
*
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package com.sun.marlin;
import java.util.Arrays;
import com.sun.javafx.geom.PathConsumer2D;
/**
* The Dasher
class takes a series of linear commands
* (moveTo
, lineTo
, close
and
* end
) and breaks them into smaller segments according to a
* dash pattern array and a starting dash phase.
*
*
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.
*
*/
public final class Dasher implements PathConsumer2D, MarlinConst {
static final int REC_LIMIT = 4;
static final float ERR = 0.01f;
static final float MIN_T_INC = 1f / (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 = 16000000f;
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 Dasher
.
* @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 Dasher
.
*
* @param out an output PathConsumer2D
.
* @param dash an array of float
s containing the dash pattern
* @param dashLen length of the given dash array
* @param phase a float
containing the dash phase
* @param recycleDashes true to indicate to recycle the given dash array
* @return this instance
*/
public 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 = 0f;
for (float d : dash) {
sum += d;
}
float cycles = phase / sum;
if (phase < 0f) {
if (-cycles >= MAX_CYCLES) {
phase = 0f;
} else {
int fullcycles = FloatMath.floor_int(-cycles);
if ((fullcycles & dash.length & 1) != 0) {
dashOn = !dashOn;
}
phase += fullcycles * sum;
while (phase < 0f) {
if (--sidx < 0) {
sidx = dash.length - 1;
}
phase += dash[sidx];
dashOn = !dashOn;
}
}
} else if (phase > 0) {
if (cycles >= MAX_CYCLES) {
phase = 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, 0f);
}
// Return arrays:
if (recycleDashes) {
dash = dashes_ref.putArray(dash);
}
firstSegmentsBuffer = firstSegmentsBuffer_ref.putArray(firstSegmentsBuffer);
}
public float[] copyDashArray(final float[] dashes) {
final int len = dashes.length;
final float[] newDashes;
if (len <= MarlinConst.INITIAL_ARRAY) {
newDashes = rdrCtx.dasher.dashes_ref.initial;
} else {
if (DO_STATS) {
rdrCtx.stats.stat_array_dasher_dasher.add(len);
}
newDashes = rdrCtx.dasher.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)
// 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 - 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 == 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<