/*
*
* Copyright 1990-2007 Sun Microsystems, Inc. All Rights Reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER
*
* This program 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.
*
* This program 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 at /legal/license.txt).
*
* 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 Sun Microsystems, Inc., 4150 Network Circle, Santa
* Clara, CA 95054 or visit www.sun.com if you need additional
* information or have any questions.
*/
package com.sun.pisces;
public class Stroker extends LineSink {
private static final int MOVE_TO = 0;
private static final int LINE_TO = 1;
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;
LineSink output;
int lineWidth;
int capStyle;
int joinStyle;
int miterLimit;
Transform4 transform;
int m00, m01;
int m10, m11;
int lineWidth2;
long scaledLineWidth2;
// For any pen offset (pen_dx, pen_dy) that does not depend on
// the line orientation, the pen should be transformed so that:
//
// pen_dx' = m00*pen_dx + m01*pen_dy
// pen_dy' = m10*pen_dx + m11*pen_dy
//
// For a round pen, this means:
//
// pen_dx(r, theta) = r*cos(theta)
// pen_dy(r, theta) = r*sin(theta)
//
// pen_dx'(r, theta) = r*(m00*cos(theta) + m01*sin(theta))
// pen_dy'(r, theta) = r*(m10*cos(theta) + m11*sin(theta))
int numPenSegments;
int[] pen_dx;
int[] pen_dy;
boolean[] penIncluded;
int[] join;
int[] offset = new int[2];
int[] reverse = new int[100];
int[] miter = new int[2];
long miterLimitSq;
int prev;
int rindex;
boolean started;
boolean lineToOrigin;
boolean joinToOrigin;
int sx0, sy0, sx1, sy1, x0, y0, x1, y1;
int mx0, my0, mx1, my1, omx, omy;
int lx0, ly0, lx1, ly1, lx0p, ly0p, px0, py0;
double m00_2_m01_2;
double m10_2_m11_2;
double m00_m10_m01_m11;
/**
* Empty constructor. <code>setOutput</code> and
* <code>setParameters</code> must be called prior to calling any
* other methods.
*/
public Stroker() {}
/**
* Constructs a <code>Stroker</code>.
*
* @param output an output <code>LineSink</code>.
* @param lineWidth the desired line width in pixels, in S15.16
* format.
* @param capStyle the desired end cap style, one of
* <code>CAP_BUTT</code>, <code>CAP_ROUND</code> or
* <code>CAP_SQUARE</code>.
* @param joinStyle the desired line join style, one of
* <code>JOIN_MITER</code>, <code>JOIN_ROUND</code> or
* <code>JOIN_BEVEL</code>.
* @param miterLimit the desired miter limit, in S15.16 format.
* @param transform a <code>Transform4</code> object indicating
* the transform that has been previously applied to all incoming
* coordinates. This is required in order to produce consistently
* shaped end caps and joins.
*/
public Stroker(LineSink output,
int lineWidth,
int capStyle,
int joinStyle,
int miterLimit,
Transform4 transform) {
setOutput(output);
setParameters(lineWidth, capStyle, joinStyle, miterLimit, transform);
}
/**
* Sets the output <code>LineSink</code> of this
* <code>Stroker</code>.
*
* @param output an output <code>LineSink</code>.
*/
public void setOutput(LineSink output) {
this.output = output;
}
/**
* Sets the parameters of this <code>Stroker</code>.
* @param lineWidth the desired line width in pixels, in S15.16
* format.
* @param capStyle the desired end cap style, one of
* <code>CAP_BUTT</code>, <code>CAP_ROUND</code> or
* <code>CAP_SQUARE</code>.
* @param joinStyle the desired line join style, one of
* <code>JOIN_MITER</code>, <code>JOIN_ROUND</code> or
* <code>JOIN_BEVEL</code>.
* @param miterLimit the desired miter limit, in S15.16 format.
* @param transform a <code>Transform4</code> object indicating
* the transform that has been previously applied to all incoming
* coordinates. This is required in order to produce consistently
* shaped end caps and joins.
*/
public void setParameters(int lineWidth,
int capStyle,
int joinStyle,
int miterLimit,
Transform4 transform) {
this.lineWidth = lineWidth;
this.lineWidth2 = lineWidth >> 1;
this.scaledLineWidth2 = (long)transform.m00*lineWidth2;
this.capStyle = capStyle;
this.joinStyle = joinStyle;
this.miterLimit = miterLimit;
this.transform = transform;
this.m00 = transform.m00;
this.m01 = transform.m01;
this.m10 = transform.m10;
this.m11 = transform.m11;
this.m00_2_m01_2 = (double)m00*m00 + (double)m01*m01;
this.m10_2_m11_2 = (double)m10*m10 + (double)m11*m11;
this.m00_m10_m01_m11 = (double)m00*m10 + (double)m01*m11;
double dm00 = m00/65536.0;
double dm01 = m01/65536.0;
double dm10 = m10/65536.0;
double dm11 = m11/65536.0;
double determinant = dm00*dm11 - dm01*dm10;
if (joinStyle == JOIN_MITER) {
double limit =
(miterLimit/65536.0)*(lineWidth2/65536.0)*determinant;
double limitSq = limit*limit;
this.miterLimitSq = (long)(limitSq*65536.0*65536.0);
}
this.numPenSegments = (int)(3.14159f*lineWidth/65536.0f);
if (pen_dx == null || pen_dx.length < numPenSegments) {
this.pen_dx = new int[numPenSegments];
this.pen_dy = new int[numPenSegments];
this.penIncluded = new boolean[numPenSegments];
this.join = new int[2*numPenSegments];
}
for (int i = 0; i < numPenSegments; i++) {
double r = lineWidth/2.0;
double theta = (double)i*2.0*Math.PI/numPenSegments;
double cos = Math.cos(theta);
double sin = Math.sin(theta);
pen_dx[i] = (int)(r*(dm00*cos + dm01*sin));
pen_dy[i] = (int)(r*(dm10*cos + dm11*sin));
}
prev = CLOSE;
rindex = 0;
started = false;
lineToOrigin = false;
}
private void computeOffset(int x0, int y0, int x1, int y1, int[] m) {
long lx = (long)x1 - (long)x0;
long ly = (long)y1 - (long)y0;
int dx, dy;
if (m00 > 0 && m00 == m11 && m01 == 0 & m10 == 0) {
long ilen = PiscesMath.hypot(lx, ly);
if (ilen == 0) {
dx = dy = 0;
} else {
dx = (int)( (ly*scaledLineWidth2)/ilen >> 16);
dy = (int)(-(lx*scaledLineWidth2)/ilen >> 16);
}
} else {
double dlx = x1 - x0;
double dly = y1 - y0;
double det = (double)m00*m11 - (double)m01*m10;
int sdet = (det > 0) ? 1 : -1;
double a = dly*m00 - dlx*m10;
double b = dly*m01 - dlx*m11;
double dh = PiscesMath.hypot(a, b);
double div = sdet*lineWidth2/(65536.0*dh);
double ddx = dly*m00_2_m01_2 - dlx*m00_m10_m01_m11;
double ddy = dly*m00_m10_m01_m11 - dlx*m10_2_m11_2;
dx = (int)(ddx*div);
dy = (int)(ddy*div);
}
m[0] = dx;
m[1] = dy;
}
private void ensureCapacity(int newrindex) {
if (reverse.length < newrindex) {
int[] tmp = new int[Math.max(newrindex, 6*reverse.length/5)];
System.arraycopy(reverse, 0, tmp, 0, rindex);
this.reverse = tmp;
}
}
private boolean isCCW(int x0, int y0,
int x1, int y1,
int x2, int y2) {
int dx0 = x1 - x0;
int dy0 = y1 - y0;
int dx1 = x2 - x1;
int dy1 = y2 - y1;
return (long)dx0*dy1 < (long)dy0*dx1;
}
private boolean side(int x, int y, int x0, int y0, int x1, int y1) {
long lx = x;
long ly = y;
long lx0 = x0;
long ly0 = y0;
long lx1 = x1;
long ly1 = y1;
return (ly0 - ly1)*lx + (lx1 - lx0)*ly + (lx0*ly1 - lx1*ly0) > 0;
}
private int computeRoundJoin(int cx, int cy,
int xa, int ya,
int xb, int yb,
int side,
boolean flip,
int[] join) {
int px, py;
int ncoords = 0;
boolean centerSide;
if (side == 0) {
centerSide = side(cx, cy, xa, ya, xb, yb);
} else {
centerSide = (side == 1) ? true : false;
}
for (int i = 0; i < numPenSegments; i++) {
px = cx + pen_dx[i];
py = cy + pen_dy[i];
boolean penSide = side(px, py, xa, ya, xb, yb);
if (penSide != centerSide) {
penIncluded[i] = true;
} else {
penIncluded[i] = false;
}
}
int start = -1, end = -1;
for (int i = 0; i < numPenSegments; i++) {
if (penIncluded[i] &&
!penIncluded[(i + numPenSegments - 1) % numPenSegments]) {
start = i;
}
if (penIncluded[i] &&
!penIncluded[(i + 1) % numPenSegments]) {
end = i;
}
}
if (end < start) {
end += numPenSegments;
}
if (start != -1 && end != -1) {
long dxa = cx + pen_dx[start] - xa;
long dya = cy + pen_dy[start] - ya;
long dxb = cx + pen_dx[start] - xb;
long dyb = cy + pen_dy[start] - yb;
boolean rev = (dxa*dxa + dya*dya > dxb*dxb + dyb*dyb);
int i = rev ? end : start;
int incr = rev ? -1 : 1;
while (true) {
int idx = i % numPenSegments;
px = cx + pen_dx[idx];
py = cy + pen_dy[idx];
join[ncoords++] = px;
join[ncoords++] = py;
if (i == (rev ? start : end)) {
break;
}
i += incr;
}
}
return ncoords/2;
}
private static final long ROUND_JOIN_THRESHOLD = 1000L;
private static final long ROUND_JOIN_INTERNAL_THRESHOLD = 1000000000L;
private void drawRoundJoin(int x, int y,
int omx, int omy, int mx, int my,
int side,
boolean flip,
boolean rev,
long threshold) {
if ((omx == 0 && omy == 0) || (mx == 0 && my == 0)) {
return;
}
long domx = (long)omx - mx;
long domy = (long)omy - my;
long len = domx*domx + domy*domy;
if (len < threshold) {
return;
}
if (rev) {
omx = -omx;
omy = -omy;
mx = -mx;
my = -my;
}
int bx0 = x + omx;
int by0 = y + omy;
int bx1 = x + mx;
int by1 = y + my;
int npoints = computeRoundJoin(x, y,
bx0, by0, bx1, by1, side, flip,
join);
for (int i = 0; i < npoints; i++) {
emitLineTo(join[2*i], join[2*i + 1], rev);
}
}
// Return the intersection point of the lines (ix0, iy0) -> (ix1, iy1)
// and (ix0p, iy0p) -> (ix1p, iy1p) in m[0] and m[1]
private void computeMiter(int ix0, int iy0, int ix1, int iy1,
int ix0p, int iy0p, int ix1p, int iy1p,
int[] m) {
long x0 = ix0;
long y0 = iy0;
long x1 = ix1;
long y1 = iy1;
long x0p = ix0p;
long y0p = iy0p;
long x1p = ix1p;
long y1p = iy1p;
long x10 = x1 - x0;
long y10 = y1 - y0;
long x10p = x1p - x0p;
long y10p = y1p - y0p;
long den = (x10*y10p - x10p*y10) >> 16;
if (den == 0) {
m[0] = ix0;
m[1] = iy0;
return;
}
long t = (x1p*(y0 - y0p) - x0*y10p + x0p*(y1p - y0)) >> 16;
m[0] = (int)(x0 + (t*x10)/den);
m[1] = (int)(y0 + (t*y10)/den);
}
private void drawMiter(int px0, int py0,
int x0, int y0,
int x1, int y1,
int omx, int omy, int mx, int my,
boolean rev) {
if (mx == omx && my == omy) {
return;
}
if (px0 == x0 && py0 == y0) {
return;
}
if (x0 == x1 && y0 == y1) {
return;
}
if (rev) {
omx = -omx;
omy = -omy;
mx = -mx;
my = -my;
}
computeMiter(px0 + omx, py0 + omy, x0 + omx, y0 + omy,
x0 + mx, y0 + my, x1 + mx, y1 + my,
miter);
// Compute miter length in untransformed coordinates
long dx = (long)miter[0] - x0;
long dy = (long)miter[1] - y0;
long a = (dy*m00 - dx*m10) >> 16;
long b = (dy*m01 - dx*m11) >> 16;
long lenSq = a*a + b*b;
if (lenSq < miterLimitSq) {
emitLineTo(miter[0], miter[1], rev);
}
}
public void moveTo(int x0, int y0) {
// System.out.println("Stroker.moveTo(" + x0/65536.0 + ", " + y0/65536.0 + ")");
if (lineToOrigin) {
// not closing the path, do the previous lineTo
lineToImpl(sx0, sy0, joinToOrigin);
lineToOrigin = false;
}
if (prev == LINE_TO) {
finish();
}
this.sx0 = this.x0 = x0;
this.sy0 = this.y0 = y0;
this.rindex = 0;
this.started = false;
this.joinSegment = false;
this.prev = MOVE_TO;
}
boolean joinSegment = false;
public void lineJoin() {
// System.out.println("Stroker.lineJoin()");
this.joinSegment = true;
}
public void lineTo(int x1, int y1) {
// System.out.println("Stroker.lineTo(" + x1/65536.0 + ", " + y1/65536.0 + ")");
if (lineToOrigin) {
if (x1 == sx0 && y1 == sy0) {
// staying in the starting point
return;
}
// not closing the path, do the previous lineTo
lineToImpl(sx0, sy0, joinToOrigin);
lineToOrigin = false;
} else if (x1 == x0 && y1 == y0) {
return;
} else if (x1 == sx0 && y1 == sy0) {
lineToOrigin = true;
joinToOrigin = joinSegment;
joinSegment = false;
return;
}
lineToImpl(x1, y1, joinSegment);
joinSegment = false;
}
private void lineToImpl(int x1, int y1, boolean joinSegment) {
computeOffset(x0, y0, x1, y1, offset);
int mx = offset[0];
int my = offset[1];
if (!started) {
emitMoveTo(x0 + mx, y0 + my);
this.sx1 = x1;
this.sy1 = y1;
this.mx0 = mx;
this.my0 = my;
started = true;
} else {
boolean ccw = isCCW(px0, py0, x0, y0, x1, y1);
if (joinSegment) {
if (joinStyle == JOIN_MITER) {
drawMiter(px0, py0, x0, y0, x1, y1, omx, omy, mx, my,
ccw);
} else if (joinStyle == JOIN_ROUND) {
drawRoundJoin(x0, y0,
omx, omy,
mx, my, 0, false, ccw,
ROUND_JOIN_THRESHOLD);
}
} else {
// Draw internal joins as round
drawRoundJoin(x0, y0,
omx, omy,
mx, my, 0, false, ccw,
ROUND_JOIN_INTERNAL_THRESHOLD);
}
emitLineTo(x0, y0, !ccw);
}
emitLineTo(x0 + mx, y0 + my, false);
emitLineTo(x1 + mx, y1 + my, false);
emitLineTo(x0 - mx, y0 - my, true);
emitLineTo(x1 - mx, y1 - my, true);
lx0 = x1 + mx; ly0 = y1 + my;
lx0p = x1 - mx; ly0p = y1 - my;
lx1 = x1; ly1 = y1;
this.omx = mx;
this.omy = my;
this.px0 = x0;
this.py0 = y0;
this.x0 = x1;
this.y0 = y1;
this.prev = LINE_TO;
}
public void close() {
// System.out.println("Stroker.close()");
if (lineToOrigin) {
// ignore the previous lineTo
lineToOrigin = false;
}
if (!started) {
finish();
return;
}
computeOffset(x0, y0, sx0, sy0, offset);
int mx = offset[0];
int my = offset[1];
// Draw penultimate join
boolean ccw = isCCW(px0, py0, x0, y0, sx0, sy0);
if (joinSegment) {
if (joinStyle == JOIN_MITER) {
drawMiter(px0, py0, x0, y0, sx0, sy0, omx, omy, mx, my, ccw);
} else if (joinStyle == JOIN_ROUND) {
drawRoundJoin(x0, y0, omx, omy, mx, my, 0, false, ccw,
ROUND_JOIN_THRESHOLD);
}
} else {
// Draw internal joins as round
drawRoundJoin(x0, y0,
omx, omy,
mx, my, 0, false, ccw,
ROUND_JOIN_INTERNAL_THRESHOLD);
}
emitLineTo(x0 + mx, y0 + my);
emitLineTo(sx0 + mx, sy0 + my);
ccw = isCCW(x0, y0, sx0, sy0, sx1, sy1);
// Draw final join on the outside
if (!ccw) {
if (joinStyle == JOIN_MITER) {
drawMiter(x0, y0, sx0, sy0, sx1, sy1,
mx, my, mx0, my0, false);
} else if (joinStyle == JOIN_ROUND) {
drawRoundJoin(sx0, sy0, mx, my, mx0, my0, 0, false, false,
ROUND_JOIN_THRESHOLD);
}
}
emitLineTo(sx0 + mx0, sy0 + my0);
emitLineTo(sx0 - mx0, sy0 - my0); // same as reverse[0], reverse[1]
// Draw final join on the inside
if (ccw) {
if (joinStyle == JOIN_MITER) {
drawMiter(x0, y0, sx0, sy0, sx1, sy1,
-mx, -my, -mx0, -my0, false);
} else if (joinStyle == JOIN_ROUND) {
drawRoundJoin(sx0, sy0, -mx, -my, -mx0, -my0, 0,
true, false,
ROUND_JOIN_THRESHOLD);
}
}
emitLineTo(sx0 - mx, sy0 - my);
emitLineTo(x0 - mx, y0 - my);
for (int i = rindex - 2; i >= 0; i -= 2) {
emitLineTo(reverse[i], reverse[i + 1]);
}
this.joinSegment = false;
this.prev = CLOSE;
emitClose();
}
public void end() {
// System.out.println("Stroker.end()");
if (lineToOrigin) {
// not closing the path, do the previous lineTo
lineToImpl(sx0, sy0, joinToOrigin);
lineToOrigin = false;
}
if (prev == LINE_TO) {
finish();
}
output.end();
this.joinSegment = false;
this.prev = MOVE_TO;
}
long lineLength(long ldx, long ldy) {
long ldet = ((long)m00*m11 - (long)m01*m10) >> 16;
long la = ((long)ldy*m00 - (long)ldx*m10)/ldet;
long lb = ((long)ldy*m01 - (long)ldx*m11)/ldet;
long llen = (int)PiscesMath.hypot(la, lb);
return llen;
}
private void finish() {
if (capStyle == CAP_ROUND) {
drawRoundJoin(x0, y0,
omx, omy, -omx, -omy, 1, false, false,
ROUND_JOIN_THRESHOLD);
} else if (capStyle == CAP_SQUARE) {
long ldx = (long)(px0 - x0);
long ldy = (long)(py0 - y0);
long llen = lineLength(ldx, ldy);
long s = (long)lineWidth2*65536/llen;
int capx = x0 - (int)(ldx*s >> 16);
int capy = y0 - (int)(ldy*s >> 16);
emitLineTo(capx + omx, capy + omy);
emitLineTo(capx - omx, capy - omy);
}
for (int i = rindex - 2; i >= 0; i -= 2) {
emitLineTo(reverse[i], reverse[i + 1]);
}
if (capStyle == CAP_ROUND) {
drawRoundJoin(sx0, sy0,
-mx0, -my0, mx0, my0, 1, false, false,
ROUND_JOIN_THRESHOLD);
} else if (capStyle == CAP_SQUARE) {
long ldx = (long)(sx1 - sx0);
long ldy = (long)(sy1 - sy0);
long llen = lineLength(ldx, ldy);
long s = (long)lineWidth2*65536/llen;
int capx = sx0 - (int)(ldx*s >> 16);
int capy = sy0 - (int)(ldy*s >> 16);
emitLineTo(capx - mx0, capy - my0);
emitLineTo(capx + mx0, capy + my0);
}
emitClose();
this.joinSegment = false;
}
private void emitMoveTo(int x0, int y0) {
// System.out.println("Stroker.emitMoveTo(" + x0/65536.0 + ", " + y0/65536.0 + ")");
output.moveTo(x0, y0);
}
private void emitLineTo(int x1, int y1) {
// System.out.println("Stroker.emitLineTo(" + x0/65536.0 + ", " + y0/65536.0 + ")");
output.lineTo(x1, y1);
}
private void emitLineTo(int x1, int y1, boolean rev) {
if (rev) {
ensureCapacity(rindex + 2);
reverse[rindex++] = x1;
reverse[rindex++] = y1;
} else {
emitLineTo(x1, y1);
}
}
private void emitClose() {
// System.out.println("Stroker.emitClose()");
output.close();
}
}
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