void EpsFileWriter::Bezier(SBezier *sb) {
Vector c, n = Vector::From(0, 0, 1);
double r;
if(sb->deg == 1) {
MaybeMoveTo(sb->ctrl[0], sb->ctrl[1]);
fprintf(f, " %.3f %.3f lineto\r\n",
MmToPts(sb->ctrl[1].x - ptMin.x),
MmToPts(sb->ctrl[1].y - ptMin.y));
} else if(sb->IsCircle(n, &c, &r)) {
Vector p0 = sb->ctrl[0], p1 = sb->ctrl[2];
double theta0 = atan2(p0.y - c.y, p0.x - c.x),
theta1 = atan2(p1.y - c.y, p1.x - c.x),
dtheta = WRAP_SYMMETRIC(theta1 - theta0, 2*PI);
MaybeMoveTo(p0, p1);
fprintf(f,
" %.3f %.3f %.3f %.3f %.3f %s\r\n",
MmToPts(c.x - ptMin.x), MmToPts(c.y - ptMin.y),
MmToPts(r),
theta0*180/PI, theta1*180/PI,
dtheta < 0 ? "arcn" : "arc");
} else if(sb->deg == 3 && !sb->IsRational()) {
MaybeMoveTo(sb->ctrl[0], sb->ctrl[3]);
fprintf(f,
" %.3f %.3f %.3f %.3f %.3f %.3f curveto\r\n",
MmToPts(sb->ctrl[1].x - ptMin.x), MmToPts(sb->ctrl[1].y - ptMin.y),
MmToPts(sb->ctrl[2].x - ptMin.x), MmToPts(sb->ctrl[2].y - ptMin.y),
MmToPts(sb->ctrl[3].x - ptMin.x), MmToPts(sb->ctrl[3].y - ptMin.y));
} else {
BezierAsNonrationalCubic(sb);
}
}
void VectorFileWriter::BezierAsNonrationalCubic(SBezier *sb, int depth) {
Vector t0 = sb->TangentAt(0), t1 = sb->TangentAt(1);
// The curve is correct, and the first derivatives are correct, at the
// endpoints.
SBezier bnr = SBezier::From(
sb->Start(),
sb->Start().Plus(t0.ScaledBy(1.0/3)),
sb->Finish().Minus(t1.ScaledBy(1.0/3)),
sb->Finish());
double tol = SS.ChordTolMm() / SS.exportScale;
// Arbitrary choice, but make it a little finer than pwl tolerance since
// it should be easier to achieve that with the smooth curves.
tol /= 2;
bool closeEnough = true;
int i;
for(i = 1; i <= 3; i++) {
double t = i/4.0;
Vector p0 = sb->PointAt(t),
pn = bnr.PointAt(t);
double d = (p0.Minus(pn)).Magnitude();
if(d > tol) {
closeEnough = false;
}
}
if(closeEnough || depth > 3) {
Bezier(&bnr);
} else {
SBezier bef, aft;
sb->SplitAt(0.5, &bef, &aft);
BezierAsNonrationalCubic(&bef, depth+1);
BezierAsNonrationalCubic(&aft, depth+1);
}
}
void PdfFileWriter::Bezier(SBezier *sb) {
if(sb->deg == 1) {
MaybeMoveTo(sb->ctrl[0], sb->ctrl[1]);
fprintf(f,
"%.3f %.3f l\r\n",
MmToPts(sb->ctrl[1].x - ptMin.x), MmToPts(sb->ctrl[1].y - ptMin.y));
} else if(sb->deg == 3 && !sb->IsRational()) {
MaybeMoveTo(sb->ctrl[0], sb->ctrl[3]);
fprintf(f,
"%.3f %.3f %.3f %.3f %.3f %.3f c\r\n",
MmToPts(sb->ctrl[1].x - ptMin.x), MmToPts(sb->ctrl[1].y - ptMin.y),
MmToPts(sb->ctrl[2].x - ptMin.x), MmToPts(sb->ctrl[2].y - ptMin.y),
MmToPts(sb->ctrl[3].x - ptMin.x), MmToPts(sb->ctrl[3].y - ptMin.y));
} else {
BezierAsNonrationalCubic(sb);
}
}
void SvgFileWriter::Bezier(SBezier *sb) {
Vector c, n = Vector::From(0, 0, 1);
double r;
if(sb->deg == 1) {
MaybeMoveTo(sb->ctrl[0], sb->ctrl[1]);
fprintf(f, "L%.3f,%.3f ",
(sb->ctrl[1].x - ptMin.x), (ptMax.y - sb->ctrl[1].y));
} else if(sb->IsCircle(n, &c, &r)) {
Vector p0 = sb->ctrl[0], p1 = sb->ctrl[2];
double theta0 = atan2(p0.y - c.y, p0.x - c.x),
theta1 = atan2(p1.y - c.y, p1.x - c.x),
dtheta = WRAP_SYMMETRIC(theta1 - theta0, 2*PI);
// The arc must be less than 180 degrees, or else it couldn't have
// been represented as a single rational Bezier. So large-arc-flag
// must be false. sweep-flag is determined by the sign of dtheta.
// Note that clockwise and counter-clockwise are backwards in SVG's
// mirrored csys.
MaybeMoveTo(p0, p1);
fprintf(f, "A%.3f,%.3f 0 0,%d %.3f,%.3f ",
r, r,
(dtheta < 0) ? 1 : 0,
p1.x - ptMin.x, ptMax.y - p1.y);
} else if(!sb->IsRational()) {
if(sb->deg == 2) {
MaybeMoveTo(sb->ctrl[0], sb->ctrl[2]);
fprintf(f, "Q%.3f,%.3f %.3f,%.3f ",
sb->ctrl[1].x - ptMin.x, ptMax.y - sb->ctrl[1].y,
sb->ctrl[2].x - ptMin.x, ptMax.y - sb->ctrl[2].y);
} else if(sb->deg == 3) {
MaybeMoveTo(sb->ctrl[0], sb->ctrl[3]);
fprintf(f, "C%.3f,%.3f %.3f,%.3f %.3f,%.3f ",
sb->ctrl[1].x - ptMin.x, ptMax.y - sb->ctrl[1].y,
sb->ctrl[2].x - ptMin.x, ptMax.y - sb->ctrl[2].y,
sb->ctrl[3].x - ptMin.x, ptMax.y - sb->ctrl[3].y);
}
} else {
BezierAsNonrationalCubic(sb);
}
}
