--- a/jdk/src/share/classes/sun/java2d/pisces/Stroker.java Wed Apr 27 12:15:34 2011 +0400
+++ b/jdk/src/share/classes/sun/java2d/pisces/Stroker.java Thu Apr 28 08:55:19 2011 -0400
@@ -27,6 +27,8 @@
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;
@@ -130,7 +132,7 @@
private static void computeOffset(final float lx, final float ly,
final float w, final float[] m)
{
- final float len = (float)Math.sqrt(lx*lx + ly*ly);
+ final float len = (float) sqrt(lx*lx + ly*ly);
if (len == 0) {
m[0] = m[1] = 0;
} else {
@@ -217,7 +219,7 @@
// 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)Math.sqrt(nx*nx + ny*ny);
+ float nlen = (float) sqrt(nx*nx + ny*ny);
float scale = lineWidth2/nlen;
float mmx = nx * scale, mmy = ny * scale;
@@ -246,8 +248,8 @@
// 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) * Math.sqrt(0.5-cosext2) /
- (1.0 + Math.sqrt(cosext2+0.5)));
+ 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;
@@ -284,28 +286,20 @@
false);
}
- // Return the intersection point of the lines (x0, y0) -> (x1, y1)
- // and (x0p, y0p) -> (x1p, y1p) in m[0] and m[1]
- private void computeMiter(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)
+ // 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;
- // if this is 0, the lines are parallel. If they go in the
- // same direction, there is no intersection so m[off] and
- // m[off+1] will contain infinity, so no miter will be drawn.
- // If they go in the same direction that means that the start of the
- // current segment and the end of the previous segment have the same
- // tangent, in which case this method won't even be involved in
- // miter drawing because it won't be called by drawMiter (because
- // (mx == omx && my == omy) will be true, and drawMiter will return
- // immediately).
float den = x10*y10p - x10p*y10;
float t = x10p*(y0-y0p) - y10p*(x0-x0p);
t /= den;
@@ -321,7 +315,8 @@
{
if ((mx == omx && my == omy) ||
(pdx == 0 && pdy == 0) ||
- (dx == 0 && dy == 0)) {
+ (dx == 0 && dy == 0))
+ {
return;
}
@@ -332,12 +327,17 @@
my = -my;
}
- computeMiter((x0 - pdx) + omx, (y0 - pdy) + omy, x0 + omx, y0 + omy,
- (dx + x0) + mx, (dy + y0) + my, x0 + mx, y0 + my,
- miter, 0);
+ 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);
}
@@ -566,8 +566,8 @@
// 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 * Math.ulp(y2));
- final boolean p3eqp4 = within(x3,y3,x4,y4, 6 * Math.ulp(y4));
+ 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;
@@ -583,7 +583,7 @@
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 * Math.ulp(dotsq))) {
+ if (Helpers.within(dotsq, l1sq * l4sq, 4 * ulp(dotsq))) {
getLineOffsets(x1, y1, x4, y4, leftOff, rightOff);
return 4;
}
@@ -693,8 +693,6 @@
return 8;
}
- // compute offset curves using bezier spline through t=0.5 (i.e.
- // ComputedCurve(0.5) == IdealParallelCurve(0.5))
// return the kind of curve in the right and left arrays.
private int computeOffsetQuad(float[] pts, final int off,
float[] leftOff, float[] rightOff)
@@ -703,56 +701,67 @@
final float x2 = pts[off + 2], y2 = pts[off + 3];
final float x3 = pts[off + 4], y3 = pts[off + 5];
- float dx3 = x3 - x2;
- float dy3 = y3 - y2;
- float dx1 = x2 - x1;
- float dy1 = y2 - y1;
+ 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
- // 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.
+ // 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 p1 == p2 && p3 == p4: draw line from p1->p4, unless p1 == p4,
- // in which case ignore.
- final boolean p1eqp2 = within(x1,y1,x2,y2, 6 * Math.ulp(y2));
- final boolean p2eqp3 = within(x2,y2,x3,y3, 6 * Math.ulp(y3));
- if (p1eqp2 || p2eqp3) {
- getLineOffsets(x1, y1, x3, y3, leftOff, rightOff);
- return 4;
+ 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;
}
- // if p2-p1 and p4-p3 are parallel, that must mean this curve is a line
- float dotsq = (dx1 * dx3 + dy1 * dy3);
- dotsq = dotsq * dotsq;
- float l1sq = dx1 * dx1 + dy1 * dy1, l3sq = dx3 * dx3 + dy3 * dy3;
- if (Helpers.within(dotsq, l1sq * l3sq, 4 * Math.ulp(dotsq))) {
- getLineOffsets(x1, y1, x3, y3, leftOff, rightOff);
- return 4;
- }
+ // 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;
+ }
- // 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(dx3, dy3, lineWidth2, offset[1]);
- float x1p = x1 + offset[0][0]; // start
- float y1p = y1 + offset[0][1]; // point
- float x3p = x3 + offset[1][0]; // end
- float y3p = y3 + offset[1][1]; // point
-
- computeMiter(x1p, y1p, x1p+dx1, y1p+dy1, x3p, y3p, x3p-dx3, y3p-dy3, leftOff, 2);
- leftOff[0] = x1p; leftOff[1] = y1p;
- leftOff[4] = x3p; leftOff[5] = y3p;
- x1p = x1 - offset[0][0]; y1p = y1 - offset[0][1];
- x3p = x3 - offset[1][0]; y3p = y3 - offset[1][1];
- computeMiter(x1p, y1p, x1p+dx1, y1p+dy1, x3p, y3p, x3p-dx3, y3p-dy3, rightOff, 2);
- rightOff[0] = x1p; rightOff[1] = y1p;
- rightOff[4] = x3p; rightOff[5] = y3p;
- 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
@@ -812,12 +821,12 @@
// 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)Math.sqrt(dxs*dxs + dys*dys);
+ 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)Math.sqrt(dxf*dxf + dyf*dyf);
+ float len = (float) sqrt(dxf*dxf + dyf*dyf);
dxf /= len;
dyf /= len;
}
@@ -834,7 +843,6 @@
while(it.hasNext()) {
int curCurveOff = it.next();
- kind = 0;
switch (type) {
case 8:
kind = computeOffsetCubic(middle, curCurveOff, lp, rp);
@@ -843,24 +851,22 @@
kind = computeOffsetQuad(middle, curCurveOff, lp, rp);
break;
}
- if (kind != 0) {
- 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);
+ 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;
@@ -887,7 +893,7 @@
// 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)Math.sqrt(x12 * x12 + y12 * y12);
+ 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];
@@ -976,12 +982,12 @@
// 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)Math.sqrt(dxs*dxs + dys*dys);
+ 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)Math.sqrt(dxf*dxf + dyf*dyf);
+ float len = (float) sqrt(dxf*dxf + dyf*dyf);
dxf /= len;
dyf /= len;
}
@@ -999,20 +1005,18 @@
int curCurveOff = it.next();
kind = computeOffsetCubic(middle, curCurveOff, lp, rp);
- if (kind != 0) {
- 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);
+ 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;
@@ -1050,12 +1054,12 @@
// 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)Math.sqrt(dxs*dxs + dys*dys);
+ 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)Math.sqrt(dxf*dxf + dyf*dyf);
+ float len = (float) sqrt(dxf*dxf + dyf*dyf);
dxf /= len;
dyf /= len;
}
@@ -1073,20 +1077,18 @@
int curCurveOff = it.next();
kind = computeOffsetQuad(middle, curCurveOff, lp, rp);
- if (kind != 0) {
- 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);
+ 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;