| /* |
| * Copyright (c) 2007, 2011, 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.pisces; |
| |
| 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 { |
| |
| private final PathConsumer2D out; |
| private final float[] dash; |
| private final float startPhase; |
| private final boolean startDashOn; |
| private final 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 float[] curCurvepts; |
| |
| /** |
| * Constructs a <code>Dasher</code>. |
| * |
| * @param out an output <code>PathConsumer2D</code>. |
| * @param dash an array of <code>float</code>s containing the dash pattern |
| * @param phase a <code>float</code> containing the dash phase |
| */ |
| public Dasher(PathConsumer2D out, float[] dash, float phase) { |
| if (phase < 0) { |
| 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) % dash.length; |
| dashOn = !dashOn; |
| } |
| |
| this.dash = dash; |
| this.startPhase = this.phase = phase; |
| this.startDashOn = dashOn; |
| this.startIdx = idx; |
| this.starting = true; |
| |
| // we need curCurvepts to be able to contain 2 curves because when |
| // dashing curves, we need to subdivide it |
| curCurvepts = new float[8 * 2]; |
| } |
| |
| 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]); |
| break; |
| case 6: |
| out.quadTo(buf[off+0], buf[off+1], |
| buf[off+2], buf[off+3]); |
| break; |
| case 4: |
| out.lineTo(buf[off], buf[off+1]); |
| } |
| } |
| |
| private void emitFirstSegments() { |
| for (int i = 0; i < firstSegidx; ) { |
| emitSeg(firstSegmentsBuffer, i+1, (int)firstSegmentsBuffer[i]); |
| i += (((int)firstSegmentsBuffer[i]) - 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 = new float[7]; |
| private int firstSegidx = 0; |
| // 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) { |
| firstSegmentsBuffer = Helpers.widenArray(firstSegmentsBuffer, |
| firstSegidx, type - 2); |
| firstSegmentsBuffer[firstSegidx++] = type; |
| System.arraycopy(pts, off, firstSegmentsBuffer, firstSegidx, type - 2); |
| firstSegidx += type - 2; |
| } else { |
| if (needsMoveTo) { |
| out.moveTo(x0, y0); |
| needsMoveTo = false; |
| } |
| emitSeg(pts, off, type); |
| } |
| } else { |
| starting = false; |
| needsMoveTo = true; |
| } |
| this.x0 = x; |
| this.y0 = y; |
| } |
| |
| public void lineTo(float x1, float y1) { |
| float dx = x1 - x0; |
| float dy = y1 - y0; |
| |
| float len = (float) Math.sqrt(dx*dx + dy*dy); |
| |
| if (len == 0) { |
| return; |
| } |
| |
| // The scaling factors needed to get the dx and dy of the |
| // transformed dash segments. |
| float cx = dx / len; |
| float cy = dy / len; |
| |
| while (true) { |
| float 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; |
| if (len == leftInThisDashSegment) { |
| phase = 0f; |
| idx = (idx + 1) % dash.length; |
| dashOn = !dashOn; |
| } |
| return; |
| } |
| |
| float dashdx = dash[idx] * cx; |
| float dashdy = dash[idx] * cy; |
| if (phase == 0) { |
| curCurvepts[0] = x0 + dashdx; |
| curCurvepts[1] = y0 + dashdy; |
| } else { |
| float 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) % dash.length; |
| dashOn = !dashOn; |
| phase = 0; |
| } |
| } |
| |
| private LengthIterator li = null; |
| |
| // 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; |
| } |
| if (li == null) { |
| li = new LengthIterator(4, 0.01f); |
| } |
| li.initializeIterationOnCurve(curCurvepts, type); |
| |
| int curCurveoff = 0; // initially the current curve is at curCurvepts[0...type] |
| float lastSplitT = 0; |
| float t = 0; |
| float leftInThisDashSegment = dash[idx] - phase; |
| while ((t = li.next(leftInThisDashSegment)) < 1) { |
| if (t != 0) { |
| Helpers.subdivideAt((t - lastSplitT) / (1 - lastSplitT), |
| curCurvepts, curCurveoff, |
| curCurvepts, 0, |
| curCurvepts, type, type); |
| lastSplitT = t; |
| goTo(curCurvepts, 2, type); |
| curCurveoff = type; |
| } |
| // Advance to next dash segment |
| idx = (idx + 1) % dash.length; |
| dashOn = !dashOn; |
| phase = 0; |
| leftInThisDashSegment = dash[idx]; |
| } |
| goTo(curCurvepts, curCurveoff+2, type); |
| phase += li.lastSegLen(); |
| if (phase >= dash[idx]) { |
| phase = 0f; |
| idx = (idx + 1) % dash.length; |
| dashOn = !dashOn; |
| } |
| } |
| |
| 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 |
| private static 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 float[][] recCurveStack; |
| // 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 Side[] sides; |
| private int curveType; |
| private final int limit; |
| private final float ERR; |
| private final float minTincrement; |
| // 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 float[] curLeafCtrlPolyLengths = new float[3]; |
| |
| public LengthIterator(int reclimit, float err) { |
| this.limit = reclimit; |
| this.minTincrement = 1f / (1 << limit); |
| this.ERR = err; |
| 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; |
| } |
| |
| public void initializeIterationOnCurve(float[] pts, int type) { |
| System.arraycopy(pts, 0, recCurveStack[0], 0, type); |
| this.curveType = type; |
| this.recLevel = 0; |
| this.lastT = 0; |
| this.lenAtLastT = 0; |
| this.nextT = 0; |
| this.lenAtNextT = 0; |
| goLeft(); // initializes nextT and lenAtNextT properly |
| this.lenAtLastSplit = 0; |
| 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; |
| } |
| |
| // 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. |
| if (!(Helpers.within(len2, len3, err*len3) && |
| Helpers.within(len1, len3, err*len3))) { |
| 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 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 float[] flatLeafCoefCache = new float[] {0, 0, -1, 0}; |
| // 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. |
| public float next(final float len) { |
| final float targetLength = lenAtLastSplit + len; |
| while(lenAtNextT < targetLength) { |
| if (done) { |
| lastSegLen = lenAtNextT - lenAtLastSplit; |
| return 1; |
| } |
| 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. |
| |
| if (flatLeafCoefCache[2] < 0) { |
| float x = 0+curLeafCtrlPolyLengths[0], |
| y = x+curLeafCtrlPolyLengths[1]; |
| if (curveType == 8) { |
| float z = y + curLeafCtrlPolyLengths[2]; |
| flatLeafCoefCache[0] = 3*(x - y) + z; |
| flatLeafCoefCache[1] = 3*(y - 2*x); |
| flatLeafCoefCache[2] = 3*x; |
| flatLeafCoefCache[3] = -z; |
| } else if (curveType == 6) { |
| flatLeafCoefCache[0] = 0f; |
| flatLeafCoefCache[1] = y - 2*x; |
| flatLeafCoefCache[2] = 2*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 >= 1) { |
| t = 1; |
| 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; |
| } |
| |
| public 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. |
| recLevel--; |
| while(sides[recLevel] == Side.RIGHT) { |
| if (recLevel == 0) { |
| done = true; |
| return; |
| } |
| recLevel--; |
| } |
| |
| sides[recLevel] = Side.RIGHT; |
| System.arraycopy(recCurveStack[recLevel], 0, recCurveStack[recLevel+1], 0, curveType); |
| recLevel++; |
| goLeft(); |
| } |
| |
| // go to the leftmost node from the current node. Return its length. |
| private void goLeft() { |
| float len = onLeaf(); |
| if (len >= 0) { |
| lastT = nextT; |
| lenAtLastT = lenAtNextT; |
| nextT += (1 << (limit - recLevel)) * minTincrement; |
| lenAtNextT += len; |
| // invalidate caches |
| flatLeafCoefCache[2] = -1; |
| 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; |
| |
| 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 == limit) { |
| return (polyLen + lineLen)/2; |
| } |
| return -1; |
| } |
| } |
| |
| @Override |
| public void curveTo(float x1, float y1, |
| float x2, float y2, |
| float x3, float y3) |
| { |
| 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) { |
| curCurvepts[0] = x0; curCurvepts[1] = y0; |
| curCurvepts[2] = x1; curCurvepts[3] = y1; |
| curCurvepts[4] = x2; curCurvepts[5] = y2; |
| somethingTo(6); |
| } |
| |
| public void closePath() { |
| lineTo(sx, sy); |
| if (firstSegidx > 0) { |
| if (!dashOn || needsMoveTo) { |
| out.moveTo(sx, sy); |
| } |
| emitFirstSegments(); |
| } |
| moveTo(sx, sy); |
| } |
| |
| public void pathDone() { |
| if (firstSegidx > 0) { |
| out.moveTo(sx, sy); |
| emitFirstSegments(); |
| } |
| out.pathDone(); |
| } |
| |
| @Override |
| public long getNativeConsumer() { |
| throw new InternalError("Dasher does not use a native consumer"); |
| } |
| } |
| |
