--- old/src/java.desktop/share/classes/sun/java2d/pisces/Stroker.java 2017-11-06 15:02:38.868239274 -0800 +++ /dev/null 2017-08-10 09:28:49.381064065 -0700 @@ -1,1231 +0,0 @@ -/* - * 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.pisces; - -import java.util.Arrays; -import java.util.Iterator; -import static java.lang.Math.ulp; -import static java.lang.Math.sqrt; - -import sun.awt.geom.PathConsumer2D; - -// TODO: some of the arithmetic here is too verbose and prone to hard to -// debug typos. We should consider making a small Point/Vector class that -// has methods like plus(Point), minus(Point), dot(Point), cross(Point)and such -final class Stroker implements PathConsumer2D { - - private static final int MOVE_TO = 0; - private static final int DRAWING_OP_TO = 1; // ie. curve, line, or quad - private static final int CLOSE = 2; - - /** - * Constant value for join style. - */ - public static final int JOIN_MITER = 0; - - /** - * Constant value for join style. - */ - public static final int JOIN_ROUND = 1; - - /** - * Constant value for join style. - */ - public static final int JOIN_BEVEL = 2; - - /** - * Constant value for end cap style. - */ - public static final int CAP_BUTT = 0; - - /** - * Constant value for end cap style. - */ - public static final int CAP_ROUND = 1; - - /** - * Constant value for end cap style. - */ - public static final int CAP_SQUARE = 2; - - private final PathConsumer2D out; - - private final int capStyle; - private final int joinStyle; - - private final float lineWidth2; - - private final float[][] offset = new float[3][2]; - private final float[] miter = new float[2]; - private final float miterLimitSq; - - private int prev; - - // The starting point of the path, and the slope there. - private float sx0, sy0, sdx, sdy; - // the current point and the slope there. - private float cx0, cy0, cdx, cdy; // c stands for current - // vectors that when added to (sx0,sy0) and (cx0,cy0) respectively yield the - // first and last points on the left parallel path. Since this path is - // parallel, it's slope at any point is parallel to the slope of the - // original path (thought they may have different directions), so these - // could be computed from sdx,sdy and cdx,cdy (and vice versa), but that - // would be error prone and hard to read, so we keep these anyway. - private float smx, smy, cmx, cmy; - - private final PolyStack reverse = new PolyStack(); - - /** - * Constructs a {@code Stroker}. - * - * @param pc2d an output {@code PathConsumer2D}. - * @param lineWidth the desired line width in pixels - * @param capStyle the desired end cap style, one of - * {@code CAP_BUTT}, {@code CAP_ROUND} or - * {@code CAP_SQUARE}. - * @param joinStyle the desired line join style, one of - * {@code JOIN_MITER}, {@code JOIN_ROUND} or - * {@code JOIN_BEVEL}. - * @param miterLimit the desired miter limit - */ - public Stroker(PathConsumer2D pc2d, - float lineWidth, - int capStyle, - int joinStyle, - float miterLimit) - { - this.out = pc2d; - - this.lineWidth2 = lineWidth / 2; - this.capStyle = capStyle; - this.joinStyle = joinStyle; - - float limit = miterLimit * lineWidth2; - this.miterLimitSq = limit*limit; - - this.prev = CLOSE; - } - - private static void computeOffset(final float lx, final float ly, - final float w, final float[] m) - { - final float len = (float) sqrt(lx*lx + ly*ly); - if (len == 0) { - m[0] = m[1] = 0; - } else { - m[0] = (ly * w)/len; - m[1] = -(lx * w)/len; - } - } - - // Returns true if the vectors (dx1, dy1) and (dx2, dy2) are - // clockwise (if dx1,dy1 needs to be rotated clockwise to close - // the smallest angle between it and dx2,dy2). - // This is equivalent to detecting whether a point q is on the right side - // of a line passing through points p1, p2 where p2 = p1+(dx1,dy1) and - // q = p2+(dx2,dy2), which is the same as saying p1, p2, q are in a - // clockwise order. - // NOTE: "clockwise" here assumes coordinates with 0,0 at the bottom left. - private static boolean isCW(final float dx1, final float dy1, - final float dx2, final float dy2) - { - return dx1 * dy2 <= dy1 * dx2; - } - - // pisces used to use fixed point arithmetic with 16 decimal digits. I - // didn't want to change the values of the constant below when I converted - // it to floating point, so that's why the divisions by 2^16 are there. - private static final float ROUND_JOIN_THRESHOLD = 1000/65536f; - - private void drawRoundJoin(float x, float y, - float omx, float omy, float mx, float my, - boolean rev, - float threshold) - { - if ((omx == 0 && omy == 0) || (mx == 0 && my == 0)) { - return; - } - - float domx = omx - mx; - float domy = omy - my; - float len = domx*domx + domy*domy; - if (len < threshold) { - return; - } - - if (rev) { - omx = -omx; - omy = -omy; - mx = -mx; - my = -my; - } - drawRoundJoin(x, y, omx, omy, mx, my, rev); - } - - private void drawRoundJoin(float cx, float cy, - float omx, float omy, - float mx, float my, - boolean rev) - { - // The sign of the dot product of mx,my and omx,omy is equal to the - // the sign of the cosine of ext - // (ext is the angle between omx,omy and mx,my). - final float cosext = omx * mx + omy * my; - // If it is >=0, we know that abs(ext) is <= 90 degrees, so we only - // need 1 curve to approximate the circle section that joins omx,omy - // and mx,my. - final int numCurves = (cosext >= 0f) ? 1 : 2; - - switch (numCurves) { - case 1: - drawBezApproxForArc(cx, cy, omx, omy, mx, my, rev); - break; - case 2: - // we need to split the arc into 2 arcs spanning the same angle. - // The point we want will be one of the 2 intersections of the - // perpendicular bisector of the chord (omx,omy)->(mx,my) and the - // circle. We could find this by scaling the vector - // (omx+mx, omy+my)/2 so that it has length=lineWidth2 (and thus lies - // on the circle), but that can have numerical problems when the angle - // between omx,omy and mx,my is close to 180 degrees. So we compute a - // normal of (omx,omy)-(mx,my). This will be the direction of the - // perpendicular bisector. To get one of the intersections, we just scale - // this vector that its length is lineWidth2 (this works because the - // perpendicular bisector goes through the origin). This scaling doesn't - // have numerical problems because we know that lineWidth2 divided by - // this normal's length is at least 0.5 and at most sqrt(2)/2 (because - // we know the angle of the arc is > 90 degrees). - float nx = my - omy, ny = omx - mx; - float nlen = (float) sqrt(nx*nx + ny*ny); - float scale = lineWidth2/nlen; - float mmx = nx * scale, mmy = ny * scale; - - // if (isCW(omx, omy, mx, my) != isCW(mmx, mmy, mx, my)) then we've - // computed the wrong intersection so we get the other one. - // The test above is equivalent to if (rev). - if (rev) { - mmx = -mmx; - mmy = -mmy; - } - drawBezApproxForArc(cx, cy, omx, omy, mmx, mmy, rev); - drawBezApproxForArc(cx, cy, mmx, mmy, mx, my, rev); - break; - } - } - - // the input arc defined by omx,omy and mx,my must span <= 90 degrees. - private void drawBezApproxForArc(final float cx, final float cy, - final float omx, final float omy, - final float mx, final float my, - boolean rev) - { - final float cosext2 = (omx * mx + omy * my) / (2f * lineWidth2 * lineWidth2); - - // check round off errors producing cos(ext) > 1 and a NaN below - // cos(ext) == 1 implies colinear segments and an empty join anyway - if (cosext2 >= 0.5f) { - // just return to avoid generating a flat curve: - return; - } - - // cv is the length of P1-P0 and P2-P3 divided by the radius of the arc - // (so, cv assumes the arc has radius 1). P0, P1, P2, P3 are the points that - // define the bezier curve we're computing. - // It is computed using the constraints that P1-P0 and P3-P2 are parallel - // to the arc tangents at the endpoints, and that |P1-P0|=|P3-P2|. - float cv = (float) ((4.0 / 3.0) * sqrt(0.5 - cosext2) / - (1.0 + sqrt(cosext2 + 0.5))); - // if clockwise, we need to negate cv. - if (rev) { // rev is equivalent to isCW(omx, omy, mx, my) - cv = -cv; - } - final float x1 = cx + omx; - final float y1 = cy + omy; - final float x2 = x1 - cv * omy; - final float y2 = y1 + cv * omx; - - final float x4 = cx + mx; - final float y4 = cy + my; - final float x3 = x4 + cv * my; - final float y3 = y4 - cv * mx; - - emitCurveTo(x1, y1, x2, y2, x3, y3, x4, y4, rev); - } - - private void drawRoundCap(float cx, float cy, float mx, float my) { - final float C = 0.5522847498307933f; - // the first and second arguments of the following two calls - // are really will be ignored by emitCurveTo (because of the false), - // but we put them in anyway, as opposed to just giving it 4 zeroes, - // because it's just 4 additions and it's not good to rely on this - // sort of assumption (right now it's true, but that may change). - emitCurveTo(cx+mx, cy+my, - cx+mx-C*my, cy+my+C*mx, - cx-my+C*mx, cy+mx+C*my, - cx-my, cy+mx, - false); - emitCurveTo(cx-my, cy+mx, - cx-my-C*mx, cy+mx-C*my, - cx-mx-C*my, cy-my+C*mx, - cx-mx, cy-my, - false); - } - - // Put the intersection point of the lines (x0, y0) -> (x1, y1) - // and (x0p, y0p) -> (x1p, y1p) in m[off] and m[off+1]. - // If the lines are parallel, it will put a non finite number in m. - private void computeIntersection(final float x0, final float y0, - final float x1, final float y1, - final float x0p, final float y0p, - final float x1p, final float y1p, - final float[] m, int off) - { - float x10 = x1 - x0; - float y10 = y1 - y0; - float x10p = x1p - x0p; - float y10p = y1p - y0p; - - float den = x10*y10p - x10p*y10; - float t = x10p*(y0-y0p) - y10p*(x0-x0p); - t /= den; - m[off++] = x0 + t*x10; - m[off] = y0 + t*y10; - } - - private void drawMiter(final float pdx, final float pdy, - final float x0, final float y0, - final float dx, final float dy, - float omx, float omy, float mx, float my, - boolean rev) - { - if ((mx == omx && my == omy) || - (pdx == 0 && pdy == 0) || - (dx == 0 && dy == 0)) - { - return; - } - - if (rev) { - omx = -omx; - omy = -omy; - mx = -mx; - my = -my; - } - - computeIntersection((x0 - pdx) + omx, (y0 - pdy) + omy, x0 + omx, y0 + omy, - (dx + x0) + mx, (dy + y0) + my, x0 + mx, y0 + my, - miter, 0); - - float lenSq = (miter[0]-x0)*(miter[0]-x0) + (miter[1]-y0)*(miter[1]-y0); - - // If the lines are parallel, lenSq will be either NaN or +inf - // (actually, I'm not sure if the latter is possible. The important - // thing is that -inf is not possible, because lenSq is a square). - // For both of those values, the comparison below will fail and - // no miter will be drawn, which is correct. - if (lenSq < miterLimitSq) { - emitLineTo(miter[0], miter[1], rev); - } - } - - public void moveTo(float x0, float y0) { - if (prev == DRAWING_OP_TO) { - finish(); - } - this.sx0 = this.cx0 = x0; - this.sy0 = this.cy0 = y0; - this.cdx = this.sdx = 1; - this.cdy = this.sdy = 0; - this.prev = MOVE_TO; - } - - public void lineTo(float x1, float y1) { - float dx = x1 - cx0; - float dy = y1 - cy0; - if (dx == 0f && dy == 0f) { - dx = 1; - } - computeOffset(dx, dy, lineWidth2, offset[0]); - float mx = offset[0][0]; - float my = offset[0][1]; - - drawJoin(cdx, cdy, cx0, cy0, dx, dy, cmx, cmy, mx, my); - - emitLineTo(cx0 + mx, cy0 + my); - emitLineTo(x1 + mx, y1 + my); - - emitLineTo(cx0 - mx, cy0 - my, true); - emitLineTo(x1 - mx, y1 - my, true); - - this.cmx = mx; - this.cmy = my; - this.cdx = dx; - this.cdy = dy; - this.cx0 = x1; - this.cy0 = y1; - this.prev = DRAWING_OP_TO; - } - - public void closePath() { - if (prev != DRAWING_OP_TO) { - if (prev == CLOSE) { - return; - } - emitMoveTo(cx0, cy0 - lineWidth2); - this.cmx = this.smx = 0; - this.cmy = this.smy = -lineWidth2; - this.cdx = this.sdx = 1; - this.cdy = this.sdy = 0; - finish(); - return; - } - - if (cx0 != sx0 || cy0 != sy0) { - lineTo(sx0, sy0); - } - - drawJoin(cdx, cdy, cx0, cy0, sdx, sdy, cmx, cmy, smx, smy); - - emitLineTo(sx0 + smx, sy0 + smy); - - emitMoveTo(sx0 - smx, sy0 - smy); - emitReverse(); - - this.prev = CLOSE; - emitClose(); - } - - private void emitReverse() { - while(!reverse.isEmpty()) { - reverse.pop(out); - } - } - - public void pathDone() { - if (prev == DRAWING_OP_TO) { - finish(); - } - - out.pathDone(); - // this shouldn't matter since this object won't be used - // after the call to this method. - this.prev = CLOSE; - } - - private void finish() { - if (capStyle == CAP_ROUND) { - drawRoundCap(cx0, cy0, cmx, cmy); - } else if (capStyle == CAP_SQUARE) { - emitLineTo(cx0 - cmy + cmx, cy0 + cmx + cmy); - emitLineTo(cx0 - cmy - cmx, cy0 + cmx - cmy); - } - - emitReverse(); - - if (capStyle == CAP_ROUND) { - drawRoundCap(sx0, sy0, -smx, -smy); - } else if (capStyle == CAP_SQUARE) { - emitLineTo(sx0 + smy - smx, sy0 - smx - smy); - emitLineTo(sx0 + smy + smx, sy0 - smx + smy); - } - - emitClose(); - } - - private void emitMoveTo(final float x0, final float y0) { - out.moveTo(x0, y0); - } - - private void emitLineTo(final float x1, final float y1) { - out.lineTo(x1, y1); - } - - private void emitLineTo(final float x1, final float y1, - final boolean rev) - { - if (rev) { - reverse.pushLine(x1, y1); - } else { - emitLineTo(x1, y1); - } - } - - private void emitQuadTo(final float x0, final float y0, - final float x1, final float y1, - final float x2, final float y2, final boolean rev) - { - if (rev) { - reverse.pushQuad(x0, y0, x1, y1); - } else { - out.quadTo(x1, y1, x2, y2); - } - } - - private void emitCurveTo(final float x0, final float y0, - final float x1, final float y1, - final float x2, final float y2, - final float x3, final float y3, final boolean rev) - { - if (rev) { - reverse.pushCubic(x0, y0, x1, y1, x2, y2); - } else { - out.curveTo(x1, y1, x2, y2, x3, y3); - } - } - - private void emitClose() { - out.closePath(); - } - - private void drawJoin(float pdx, float pdy, - float x0, float y0, - float dx, float dy, - float omx, float omy, - float mx, float my) - { - if (prev != DRAWING_OP_TO) { - emitMoveTo(x0 + mx, y0 + my); - this.sdx = dx; - this.sdy = dy; - this.smx = mx; - this.smy = my; - } else { - boolean cw = isCW(pdx, pdy, dx, dy); - if (joinStyle == JOIN_MITER) { - drawMiter(pdx, pdy, x0, y0, dx, dy, omx, omy, mx, my, cw); - } else if (joinStyle == JOIN_ROUND) { - drawRoundJoin(x0, y0, - omx, omy, - mx, my, cw, - ROUND_JOIN_THRESHOLD); - } - emitLineTo(x0, y0, !cw); - } - prev = DRAWING_OP_TO; - } - - private static boolean within(final float x1, final float y1, - final float x2, final float y2, - final float ERR) - { - assert ERR > 0 : ""; - // compare taxicab distance. ERR will always be small, so using - // true distance won't give much benefit - return (Helpers.within(x1, x2, ERR) && // we want to avoid calling Math.abs - Helpers.within(y1, y2, ERR)); // this is just as good. - } - - private void getLineOffsets(float x1, float y1, - float x2, float y2, - float[] left, float[] right) { - computeOffset(x2 - x1, y2 - y1, lineWidth2, offset[0]); - left[0] = x1 + offset[0][0]; - left[1] = y1 + offset[0][1]; - left[2] = x2 + offset[0][0]; - left[3] = y2 + offset[0][1]; - right[0] = x1 - offset[0][0]; - right[1] = y1 - offset[0][1]; - right[2] = x2 - offset[0][0]; - right[3] = y2 - offset[0][1]; - } - - private int computeOffsetCubic(float[] pts, final int off, - float[] leftOff, float[] rightOff) - { - // if p1=p2 or p3=p4 it means that the derivative at the endpoint - // vanishes, which creates problems with computeOffset. Usually - // this happens when this stroker object is trying to winden - // a curve with a cusp. What happens is that curveTo splits - // the input curve at the cusp, and passes it to this function. - // because of inaccuracies in the splitting, we consider points - // equal if they're very close to each other. - final float x1 = pts[off + 0], y1 = pts[off + 1]; - final float x2 = pts[off + 2], y2 = pts[off + 3]; - final float x3 = pts[off + 4], y3 = pts[off + 5]; - final float x4 = pts[off + 6], y4 = pts[off + 7]; - - float dx4 = x4 - x3; - float dy4 = y4 - y3; - float dx1 = x2 - x1; - float dy1 = y2 - y1; - - // if p1 == p2 && p3 == p4: draw line from p1->p4, unless p1 == p4, - // in which case ignore if p1 == p2 - final boolean p1eqp2 = within(x1,y1,x2,y2, 6 * ulp(y2)); - final boolean p3eqp4 = within(x3,y3,x4,y4, 6 * ulp(y4)); - if (p1eqp2 && p3eqp4) { - getLineOffsets(x1, y1, x4, y4, leftOff, rightOff); - return 4; - } else if (p1eqp2) { - dx1 = x3 - x1; - dy1 = y3 - y1; - } else if (p3eqp4) { - dx4 = x4 - x2; - dy4 = y4 - y2; - } - - // if p2-p1 and p4-p3 are parallel, that must mean this curve is a line - float dotsq = (dx1 * dx4 + dy1 * dy4); - dotsq = dotsq * dotsq; - float l1sq = dx1 * dx1 + dy1 * dy1, l4sq = dx4 * dx4 + dy4 * dy4; - if (Helpers.within(dotsq, l1sq * l4sq, 4 * ulp(dotsq))) { - getLineOffsets(x1, y1, x4, y4, leftOff, rightOff); - return 4; - } - -// What we're trying to do in this function is to approximate an ideal -// offset curve (call it I) of the input curve B using a bezier curve Bp. -// The constraints I use to get the equations are: -// -// 1. The computed curve Bp should go through I(0) and I(1). These are -// x1p, y1p, x4p, y4p, which are p1p and p4p. We still need to find -// 4 variables: the x and y components of p2p and p3p (i.e. x2p, y2p, x3p, y3p). -// -// 2. Bp should have slope equal in absolute value to I at the endpoints. So, -// (by the way, the operator || in the comments below means "aligned with". -// It is defined on vectors, so when we say I'(0) || Bp'(0) we mean that -// vectors I'(0) and Bp'(0) are aligned, which is the same as saying -// that the tangent lines of I and Bp at 0 are parallel. Mathematically -// this means (I'(t) || Bp'(t)) <==> (I'(t) = c * Bp'(t)) where c is some -// nonzero constant.) -// I'(0) || Bp'(0) and I'(1) || Bp'(1). Obviously, I'(0) || B'(0) and -// I'(1) || B'(1); therefore, Bp'(0) || B'(0) and Bp'(1) || B'(1). -// We know that Bp'(0) || (p2p-p1p) and Bp'(1) || (p4p-p3p) and the same -// is true for any bezier curve; therefore, we get the equations -// (1) p2p = c1 * (p2-p1) + p1p -// (2) p3p = c2 * (p4-p3) + p4p -// We know p1p, p4p, p2, p1, p3, and p4; therefore, this reduces the number -// of unknowns from 4 to 2 (i.e. just c1 and c2). -// To eliminate these 2 unknowns we use the following constraint: -// -// 3. Bp(0.5) == I(0.5). Bp(0.5)=(x,y) and I(0.5)=(xi,yi), and I should note -// that I(0.5) is *the only* reason for computing dxm,dym. This gives us -// (3) Bp(0.5) = (p1p + 3 * (p2p + p3p) + p4p)/8, which is equivalent to -// (4) p2p + p3p = (Bp(0.5)*8 - p1p - p4p) / 3 -// We can substitute (1) and (2) from above into (4) and we get: -// (5) c1*(p2-p1) + c2*(p4-p3) = (Bp(0.5)*8 - p1p - p4p)/3 - p1p - p4p -// which is equivalent to -// (6) c1*(p2-p1) + c2*(p4-p3) = (4/3) * (Bp(0.5) * 2 - p1p - p4p) -// -// The right side of this is a 2D vector, and we know I(0.5), which gives us -// Bp(0.5), which gives us the value of the right side. -// The left side is just a matrix vector multiplication in disguise. It is -// -// [x2-x1, x4-x3][c1] -// [y2-y1, y4-y3][c2] -// which, is equal to -// [dx1, dx4][c1] -// [dy1, dy4][c2] -// At this point we are left with a simple linear system and we solve it by -// getting the inverse of the matrix above. Then we use [c1,c2] to compute -// p2p and p3p. - - float x = 0.125f * (x1 + 3 * (x2 + x3) + x4); - float y = 0.125f * (y1 + 3 * (y2 + y3) + y4); - // (dxm,dym) is some tangent of B at t=0.5. This means it's equal to - // c*B'(0.5) for some constant c. - float dxm = x3 + x4 - x1 - x2, dym = y3 + y4 - y1 - y2; - - // this computes the offsets at t=0, 0.5, 1, using the property that - // for any bezier curve the vectors p2-p1 and p4-p3 are parallel to - // the (dx/dt, dy/dt) vectors at the endpoints. - computeOffset(dx1, dy1, lineWidth2, offset[0]); - computeOffset(dxm, dym, lineWidth2, offset[1]); - computeOffset(dx4, dy4, lineWidth2, offset[2]); - float x1p = x1 + offset[0][0]; // start - float y1p = y1 + offset[0][1]; // point - float xi = x + offset[1][0]; // interpolation - float yi = y + offset[1][1]; // point - float x4p = x4 + offset[2][0]; // end - float y4p = y4 + offset[2][1]; // point - - float invdet43 = 4f / (3f * (dx1 * dy4 - dy1 * dx4)); - - float two_pi_m_p1_m_p4x = 2*xi - x1p - x4p; - float two_pi_m_p1_m_p4y = 2*yi - y1p - y4p; - float c1 = invdet43 * (dy4 * two_pi_m_p1_m_p4x - dx4 * two_pi_m_p1_m_p4y); - float c2 = invdet43 * (dx1 * two_pi_m_p1_m_p4y - dy1 * two_pi_m_p1_m_p4x); - - float x2p, y2p, x3p, y3p; - x2p = x1p + c1*dx1; - y2p = y1p + c1*dy1; - x3p = x4p + c2*dx4; - y3p = y4p + c2*dy4; - - leftOff[0] = x1p; leftOff[1] = y1p; - leftOff[2] = x2p; leftOff[3] = y2p; - leftOff[4] = x3p; leftOff[5] = y3p; - leftOff[6] = x4p; leftOff[7] = y4p; - - x1p = x1 - offset[0][0]; y1p = y1 - offset[0][1]; - xi = xi - 2 * offset[1][0]; yi = yi - 2 * offset[1][1]; - x4p = x4 - offset[2][0]; y4p = y4 - offset[2][1]; - - two_pi_m_p1_m_p4x = 2*xi - x1p - x4p; - two_pi_m_p1_m_p4y = 2*yi - y1p - y4p; - c1 = invdet43 * (dy4 * two_pi_m_p1_m_p4x - dx4 * two_pi_m_p1_m_p4y); - c2 = invdet43 * (dx1 * two_pi_m_p1_m_p4y - dy1 * two_pi_m_p1_m_p4x); - - x2p = x1p + c1*dx1; - y2p = y1p + c1*dy1; - x3p = x4p + c2*dx4; - y3p = y4p + c2*dy4; - - rightOff[0] = x1p; rightOff[1] = y1p; - rightOff[2] = x2p; rightOff[3] = y2p; - rightOff[4] = x3p; rightOff[5] = y3p; - rightOff[6] = x4p; rightOff[7] = y4p; - return 8; - } - - // return the kind of curve in the right and left arrays. - private int computeOffsetQuad(float[] pts, final int off, - float[] leftOff, float[] rightOff) - { - final float x1 = pts[off + 0], y1 = pts[off + 1]; - final float x2 = pts[off + 2], y2 = pts[off + 3]; - final float x3 = pts[off + 4], y3 = pts[off + 5]; - - final float dx3 = x3 - x2; - final float dy3 = y3 - y2; - final float dx1 = x2 - x1; - final float dy1 = y2 - y1; - - // this computes the offsets at t = 0, 1 - computeOffset(dx1, dy1, lineWidth2, offset[0]); - computeOffset(dx3, dy3, lineWidth2, offset[1]); - - leftOff[0] = x1 + offset[0][0]; leftOff[1] = y1 + offset[0][1]; - leftOff[4] = x3 + offset[1][0]; leftOff[5] = y3 + offset[1][1]; - rightOff[0] = x1 - offset[0][0]; rightOff[1] = y1 - offset[0][1]; - rightOff[4] = x3 - offset[1][0]; rightOff[5] = y3 - offset[1][1]; - - float x1p = leftOff[0]; // start - float y1p = leftOff[1]; // point - float x3p = leftOff[4]; // end - float y3p = leftOff[5]; // point - - // Corner cases: - // 1. If the two control vectors are parallel, we'll end up with NaN's - // in leftOff (and rightOff in the body of the if below), so we'll - // do getLineOffsets, which is right. - // 2. If the first or second two points are equal, then (dx1,dy1)==(0,0) - // or (dx3,dy3)==(0,0), so (x1p, y1p)==(x1p+dx1, y1p+dy1) - // or (x3p, y3p)==(x3p-dx3, y3p-dy3), which means that - // computeIntersection will put NaN's in leftOff and right off, and - // we will do getLineOffsets, which is right. - computeIntersection(x1p, y1p, x1p+dx1, y1p+dy1, x3p, y3p, x3p-dx3, y3p-dy3, leftOff, 2); - float cx = leftOff[2]; - float cy = leftOff[3]; - - if (!(isFinite(cx) && isFinite(cy))) { - // maybe the right path is not degenerate. - x1p = rightOff[0]; - y1p = rightOff[1]; - x3p = rightOff[4]; - y3p = rightOff[5]; - computeIntersection(x1p, y1p, x1p+dx1, y1p+dy1, x3p, y3p, x3p-dx3, y3p-dy3, rightOff, 2); - cx = rightOff[2]; - cy = rightOff[3]; - if (!(isFinite(cx) && isFinite(cy))) { - // both are degenerate. This curve is a line. - getLineOffsets(x1, y1, x3, y3, leftOff, rightOff); - return 4; - } - // {left,right}Off[0,1,4,5] are already set to the correct values. - leftOff[2] = 2*x2 - cx; - leftOff[3] = 2*y2 - cy; - return 6; - } - - // rightOff[2,3] = (x2,y2) - ((left_x2, left_y2) - (x2, y2)) - // == 2*(x2, y2) - (left_x2, left_y2) - rightOff[2] = 2*x2 - cx; - rightOff[3] = 2*y2 - cy; - return 6; - } - - private static boolean isFinite(float x) { - return (Float.NEGATIVE_INFINITY < x && x < Float.POSITIVE_INFINITY); - } - - // This is where the curve to be processed is put. We give it - // enough room to store 2 curves: one for the current subdivision, the - // other for the rest of the curve. - private float[] middle = new float[2*8]; - private float[] lp = new float[8]; - private float[] rp = new float[8]; - private static final int MAX_N_CURVES = 11; - private float[] subdivTs = new float[MAX_N_CURVES - 1]; - - // If this class is compiled with ecj, then Hotspot crashes when OSR - // compiling this function. See bugs 7004570 and 6675699 - // TODO: until those are fixed, we should work around that by - // manually inlining this into curveTo and quadTo. -/******************************* WORKAROUND ********************************** - private void somethingTo(final int type) { - // need these so we can update the state at the end of this method - final float xf = middle[type-2], yf = middle[type-1]; - float dxs = middle[2] - middle[0]; - float dys = middle[3] - middle[1]; - float dxf = middle[type - 2] - middle[type - 4]; - float dyf = middle[type - 1] - middle[type - 3]; - switch(type) { - case 6: - if ((dxs == 0f && dys == 0f) || - (dxf == 0f && dyf == 0f)) { - dxs = dxf = middle[4] - middle[0]; - dys = dyf = middle[5] - middle[1]; - } - break; - case 8: - boolean p1eqp2 = (dxs == 0f && dys == 0f); - boolean p3eqp4 = (dxf == 0f && dyf == 0f); - if (p1eqp2) { - dxs = middle[4] - middle[0]; - dys = middle[5] - middle[1]; - if (dxs == 0f && dys == 0f) { - dxs = middle[6] - middle[0]; - dys = middle[7] - middle[1]; - } - } - if (p3eqp4) { - dxf = middle[6] - middle[2]; - dyf = middle[7] - middle[3]; - if (dxf == 0f && dyf == 0f) { - dxf = middle[6] - middle[0]; - dyf = middle[7] - middle[1]; - } - } - } - if (dxs == 0f && dys == 0f) { - // this happens iff the "curve" is just a point - lineTo(middle[0], middle[1]); - return; - } - // if these vectors are too small, normalize them, to avoid future - // precision problems. - if (Math.abs(dxs) < 0.1f && Math.abs(dys) < 0.1f) { - float len = (float) sqrt(dxs*dxs + dys*dys); - dxs /= len; - dys /= len; - } - if (Math.abs(dxf) < 0.1f && Math.abs(dyf) < 0.1f) { - float len = (float) sqrt(dxf*dxf + dyf*dyf); - dxf /= len; - dyf /= len; - } - - computeOffset(dxs, dys, lineWidth2, offset[0]); - final float mx = offset[0][0]; - final float my = offset[0][1]; - drawJoin(cdx, cdy, cx0, cy0, dxs, dys, cmx, cmy, mx, my); - - int nSplits = findSubdivPoints(middle, subdivTs, type, lineWidth2); - - int kind = 0; - Iterator it = Curve.breakPtsAtTs(middle, type, subdivTs, nSplits); - while(it.hasNext()) { - int curCurveOff = it.next(); - - switch (type) { - case 8: - kind = computeOffsetCubic(middle, curCurveOff, lp, rp); - break; - case 6: - kind = computeOffsetQuad(middle, curCurveOff, lp, rp); - break; - } - emitLineTo(lp[0], lp[1]); - switch(kind) { - case 8: - emitCurveTo(lp[0], lp[1], lp[2], lp[3], lp[4], lp[5], lp[6], lp[7], false); - emitCurveTo(rp[0], rp[1], rp[2], rp[3], rp[4], rp[5], rp[6], rp[7], true); - break; - case 6: - emitQuadTo(lp[0], lp[1], lp[2], lp[3], lp[4], lp[5], false); - emitQuadTo(rp[0], rp[1], rp[2], rp[3], rp[4], rp[5], true); - break; - case 4: - emitLineTo(lp[2], lp[3]); - emitLineTo(rp[0], rp[1], true); - break; - } - emitLineTo(rp[kind - 2], rp[kind - 1], true); - } - - this.cmx = (lp[kind - 2] - rp[kind - 2]) / 2; - this.cmy = (lp[kind - 1] - rp[kind - 1]) / 2; - this.cdx = dxf; - this.cdy = dyf; - this.cx0 = xf; - this.cy0 = yf; - this.prev = DRAWING_OP_TO; - } -****************************** END WORKAROUND *******************************/ - - // finds values of t where the curve in pts should be subdivided in order - // to get good offset curves a distance of w away from the middle curve. - // Stores the points in ts, and returns how many of them there were. - private static Curve c = new Curve(); - private static int findSubdivPoints(float[] pts, float[] ts, final int type, final float w) - { - final float x12 = pts[2] - pts[0]; - final float y12 = pts[3] - pts[1]; - // if the curve is already parallel to either axis we gain nothing - // from rotating it. - if (y12 != 0f && x12 != 0f) { - // we rotate it so that the first vector in the control polygon is - // parallel to the x-axis. This will ensure that rotated quarter - // circles won't be subdivided. - final float hypot = (float) sqrt(x12 * x12 + y12 * y12); - final float cos = x12 / hypot; - final float sin = y12 / hypot; - final float x1 = cos * pts[0] + sin * pts[1]; - final float y1 = cos * pts[1] - sin * pts[0]; - final float x2 = cos * pts[2] + sin * pts[3]; - final float y2 = cos * pts[3] - sin * pts[2]; - final float x3 = cos * pts[4] + sin * pts[5]; - final float y3 = cos * pts[5] - sin * pts[4]; - switch(type) { - case 8: - final float x4 = cos * pts[6] + sin * pts[7]; - final float y4 = cos * pts[7] - sin * pts[6]; - c.set(x1, y1, x2, y2, x3, y3, x4, y4); - break; - case 6: - c.set(x1, y1, x2, y2, x3, y3); - break; - } - } else { - c.set(pts, type); - } - - int ret = 0; - // we subdivide at values of t such that the remaining rotated - // curves are monotonic in x and y. - ret += c.dxRoots(ts, ret); - ret += c.dyRoots(ts, ret); - // subdivide at inflection points. - if (type == 8) { - // quadratic curves can't have inflection points - ret += c.infPoints(ts, ret); - } - - // now we must subdivide at points where one of the offset curves will have - // a cusp. This happens at ts where the radius of curvature is equal to w. - ret += c.rootsOfROCMinusW(ts, ret, w, 0.0001f); - - ret = Helpers.filterOutNotInAB(ts, 0, ret, 0.0001f, 0.9999f); - Helpers.isort(ts, 0, ret); - return ret; - } - - @Override public void curveTo(float x1, float y1, - float x2, float y2, - float x3, float y3) - { - middle[0] = cx0; middle[1] = cy0; - middle[2] = x1; middle[3] = y1; - middle[4] = x2; middle[5] = y2; - middle[6] = x3; middle[7] = y3; - - // inlined version of somethingTo(8); - // See the TODO on somethingTo - - // need these so we can update the state at the end of this method - final float xf = middle[6], yf = middle[7]; - float dxs = middle[2] - middle[0]; - float dys = middle[3] - middle[1]; - float dxf = middle[6] - middle[4]; - float dyf = middle[7] - middle[5]; - - boolean p1eqp2 = (dxs == 0f && dys == 0f); - boolean p3eqp4 = (dxf == 0f && dyf == 0f); - if (p1eqp2) { - dxs = middle[4] - middle[0]; - dys = middle[5] - middle[1]; - if (dxs == 0f && dys == 0f) { - dxs = middle[6] - middle[0]; - dys = middle[7] - middle[1]; - } - } - if (p3eqp4) { - dxf = middle[6] - middle[2]; - dyf = middle[7] - middle[3]; - if (dxf == 0f && dyf == 0f) { - dxf = middle[6] - middle[0]; - dyf = middle[7] - middle[1]; - } - } - if (dxs == 0f && dys == 0f) { - // this happens iff the "curve" is just a point - lineTo(middle[0], middle[1]); - return; - } - - // if these vectors are too small, normalize them, to avoid future - // precision problems. - if (Math.abs(dxs) < 0.1f && Math.abs(dys) < 0.1f) { - float len = (float) sqrt(dxs*dxs + dys*dys); - dxs /= len; - dys /= len; - } - if (Math.abs(dxf) < 0.1f && Math.abs(dyf) < 0.1f) { - float len = (float) sqrt(dxf*dxf + dyf*dyf); - dxf /= len; - dyf /= len; - } - - computeOffset(dxs, dys, lineWidth2, offset[0]); - final float mx = offset[0][0]; - final float my = offset[0][1]; - drawJoin(cdx, cdy, cx0, cy0, dxs, dys, cmx, cmy, mx, my); - - int nSplits = findSubdivPoints(middle, subdivTs, 8, lineWidth2); - - int kind = 0; - Iterator it = Curve.breakPtsAtTs(middle, 8, subdivTs, nSplits); - while(it.hasNext()) { - int curCurveOff = it.next(); - - kind = computeOffsetCubic(middle, curCurveOff, lp, rp); - emitLineTo(lp[0], lp[1]); - switch(kind) { - case 8: - emitCurveTo(lp[0], lp[1], lp[2], lp[3], lp[4], lp[5], lp[6], lp[7], false); - emitCurveTo(rp[0], rp[1], rp[2], rp[3], rp[4], rp[5], rp[6], rp[7], true); - break; - case 4: - emitLineTo(lp[2], lp[3]); - emitLineTo(rp[0], rp[1], true); - break; - } - emitLineTo(rp[kind - 2], rp[kind - 1], true); - } - - this.cmx = (lp[kind - 2] - rp[kind - 2]) / 2; - this.cmy = (lp[kind - 1] - rp[kind - 1]) / 2; - this.cdx = dxf; - this.cdy = dyf; - this.cx0 = xf; - this.cy0 = yf; - this.prev = DRAWING_OP_TO; - } - - @Override public void quadTo(float x1, float y1, float x2, float y2) { - middle[0] = cx0; middle[1] = cy0; - middle[2] = x1; middle[3] = y1; - middle[4] = x2; middle[5] = y2; - - // inlined version of somethingTo(8); - // See the TODO on somethingTo - - // need these so we can update the state at the end of this method - final float xf = middle[4], yf = middle[5]; - float dxs = middle[2] - middle[0]; - float dys = middle[3] - middle[1]; - float dxf = middle[4] - middle[2]; - float dyf = middle[5] - middle[3]; - if ((dxs == 0f && dys == 0f) || (dxf == 0f && dyf == 0f)) { - dxs = dxf = middle[4] - middle[0]; - dys = dyf = middle[5] - middle[1]; - } - if (dxs == 0f && dys == 0f) { - // this happens iff the "curve" is just a point - lineTo(middle[0], middle[1]); - return; - } - // if these vectors are too small, normalize them, to avoid future - // precision problems. - if (Math.abs(dxs) < 0.1f && Math.abs(dys) < 0.1f) { - float len = (float) sqrt(dxs*dxs + dys*dys); - dxs /= len; - dys /= len; - } - if (Math.abs(dxf) < 0.1f && Math.abs(dyf) < 0.1f) { - float len = (float) sqrt(dxf*dxf + dyf*dyf); - dxf /= len; - dyf /= len; - } - - computeOffset(dxs, dys, lineWidth2, offset[0]); - final float mx = offset[0][0]; - final float my = offset[0][1]; - drawJoin(cdx, cdy, cx0, cy0, dxs, dys, cmx, cmy, mx, my); - - int nSplits = findSubdivPoints(middle, subdivTs, 6, lineWidth2); - - int kind = 0; - Iterator it = Curve.breakPtsAtTs(middle, 6, subdivTs, nSplits); - while(it.hasNext()) { - int curCurveOff = it.next(); - - kind = computeOffsetQuad(middle, curCurveOff, lp, rp); - emitLineTo(lp[0], lp[1]); - switch(kind) { - case 6: - emitQuadTo(lp[0], lp[1], lp[2], lp[3], lp[4], lp[5], false); - emitQuadTo(rp[0], rp[1], rp[2], rp[3], rp[4], rp[5], true); - break; - case 4: - emitLineTo(lp[2], lp[3]); - emitLineTo(rp[0], rp[1], true); - break; - } - emitLineTo(rp[kind - 2], rp[kind - 1], true); - } - - this.cmx = (lp[kind - 2] - rp[kind - 2]) / 2; - this.cmy = (lp[kind - 1] - rp[kind - 1]) / 2; - this.cdx = dxf; - this.cdy = dyf; - this.cx0 = xf; - this.cy0 = yf; - this.prev = DRAWING_OP_TO; - } - - @Override public long getNativeConsumer() { - throw new InternalError("Stroker doesn't use a native consumer"); - } - - // a stack of polynomial curves where each curve shares endpoints with - // adjacent ones. - private static final class PolyStack { - float[] curves; - int end; - int[] curveTypes; - int numCurves; - - private static final int INIT_SIZE = 50; - - PolyStack() { - curves = new float[8 * INIT_SIZE]; - curveTypes = new int[INIT_SIZE]; - end = 0; - numCurves = 0; - } - - public boolean isEmpty() { - return numCurves == 0; - } - - private void ensureSpace(int n) { - if (end + n >= curves.length) { - int newSize = (end + n) * 2; - curves = Arrays.copyOf(curves, newSize); - } - if (numCurves >= curveTypes.length) { - int newSize = numCurves * 2; - curveTypes = Arrays.copyOf(curveTypes, newSize); - } - } - - public void pushCubic(float x0, float y0, - float x1, float y1, - float x2, float y2) - { - ensureSpace(6); - curveTypes[numCurves++] = 8; - // assert(x0 == lastX && y0 == lastY) - - // we reverse the coordinate order to make popping easier - curves[end++] = x2; curves[end++] = y2; - curves[end++] = x1; curves[end++] = y1; - curves[end++] = x0; curves[end++] = y0; - } - - public void pushQuad(float x0, float y0, - float x1, float y1) - { - ensureSpace(4); - curveTypes[numCurves++] = 6; - // assert(x0 == lastX && y0 == lastY) - curves[end++] = x1; curves[end++] = y1; - curves[end++] = x0; curves[end++] = y0; - } - - public void pushLine(float x, float y) { - ensureSpace(2); - curveTypes[numCurves++] = 4; - // assert(x0 == lastX && y0 == lastY) - curves[end++] = x; curves[end++] = y; - } - - @SuppressWarnings("unused") - public int pop(float[] pts) { - int ret = curveTypes[numCurves - 1]; - numCurves--; - end -= (ret - 2); - System.arraycopy(curves, end, pts, 0, ret - 2); - return ret; - } - - public void pop(PathConsumer2D io) { - numCurves--; - int type = curveTypes[numCurves]; - end -= (type - 2); - switch(type) { - case 8: - io.curveTo(curves[end+0], curves[end+1], - curves[end+2], curves[end+3], - curves[end+4], curves[end+5]); - break; - case 6: - io.quadTo(curves[end+0], curves[end+1], - curves[end+2], curves[end+3]); - break; - case 4: - io.lineTo(curves[end], curves[end+1]); - } - } - - @Override - public String toString() { - String ret = ""; - int nc = numCurves; - int end = this.end; - while (nc > 0) { - nc--; - int type = curveTypes[numCurves]; - end -= (type - 2); - switch(type) { - case 8: - ret += "cubic: "; - break; - case 6: - ret += "quad: "; - break; - case 4: - ret += "line: "; - break; - } - ret += Arrays.toString(Arrays.copyOfRange(curves, end, end+type-2)) + "\n"; - } - return ret; - } - } -}