/*
This file is part of LilyPond, the GNU music typesetter.
- Copyright (C) 1997--2012 Han-Wen Nienhuys <hanwen@xs4all.nl>
+ Copyright (C) 1997--2015 Han-Wen Nienhuys <hanwen@xs4all.nl>
Jan Nieuwenhuizen <janneke@gnu.org>
#include "line-interface.hh"
#include "warn.hh"
+#include "international.hh"
#include "dimensions.hh"
#include "bezier.hh"
#include "file-path.hh"
scm_cons (scm_from_double (p[Y_AXIS]),
points));
- SCM expr = scm_list_n (ly_symbol2scm ("polygon"),
+ SCM expr = scm_list_4 (ly_symbol2scm ("polygon"),
ly_quote_scm (points),
scm_from_double (blot),
- SCM_BOOL_T,
- SCM_UNDEFINED);
+ SCM_BOOL_T);
return Stencil (b, expr);
}
Lookup::rotated_box (Real slope, Real width, Real thick, Real blot)
{
vector<Offset> pts;
- Offset rot (1, slope);
+ Offset rot = Offset (1, slope).direction ();
- thick -= 2 * blot;
- width -= 2 * blot;
- rot /= sqrt (1 + slope * slope);
pts.push_back (Offset (0, -thick / 2) * rot);
pts.push_back (Offset (width, -thick / 2) * rot);
pts.push_back (Offset (width, thick / 2) * rot);
Stencil
Lookup::blank (Box b)
{
- return Stencil (b, scm_from_locale_string (""));
+ return Stencil (b, scm_string (SCM_EOL));
}
Stencil
Stencil
Lookup::round_filled_box (Box b, Real blotdiameter)
{
- if (b.x ().length () < blotdiameter)
- blotdiameter = b.x ().length ();
- if (b.y ().length () < blotdiameter)
- blotdiameter = b.y ().length ();
+ Real width = b.x ().delta ();
+ blotdiameter = min (blotdiameter, width);
+ Real height = b.y ().delta ();
+ blotdiameter = min (blotdiameter, height);
+
+ if (blotdiameter < 0.0)
+ {
+ if (!isinf (blotdiameter))
+ warning (_f ("Not drawing a box with negative dimension, %.2f by %.2f.",
+ width, height));
+ return Stencil (b, SCM_EOL);
+ }
SCM at = (scm_list_n (ly_symbol2scm ("round-filled-box"),
scm_from_double (-b[X_AXIS][LEFT]),
* blotdiameter along all edges of the polygon (which is what the
* postscript routine in the backend effectively does, but on the
* shrinked polygon). --jr
+ *
+ * An extra parameter "extroversion" has been added since staying just
+ * inside of a polygon will reduce its visual size when tracing a
+ * rounded path. If extroversion is zero, the polygon is just traced
+ * as-is. If it is -1 (the default) the drawing will stay just within
+ * the given polygon. If it is 1, the traced line will stay just
+ * outside of the given polygon.
*/
Stencil
Lookup::round_filled_polygon (vector<Offset> const &points,
- Real blotdiameter)
+ Real blotdiameter,
+ Real extroversion)
{
/* TODO: Maybe print a warning if one of the above limitations
applies to the given polygon. However, this is quite complicated
to check. */
+#ifdef DEBUG
const Real epsilon = 0.01;
-#ifndef NDEBUG
/* remove consecutive duplicate points */
for (vsize i = 0; i < points.size (); i++)
{
return Stencil ();
if (points.size () == 1)
{
- Stencil circ = circle (0.5 * blotdiameter, 0, true);
+ Stencil circ = circle (0.5 * (1.0 + extroversion) * blotdiameter, 0, true);
circ.translate (points[0]);
return circ;
}
if (points.size () == 2)
- return Line_interface::make_line (blotdiameter, points[0], points[1]);
+ return Line_interface::make_line ((1.0 + extroversion) * blotdiameter, points[0], points[1]);
- /* shrink polygon in size by 0.5 * blotdiameter */
vector<Offset> shrunk_points;
- shrunk_points.resize (points.size ());
- bool ccw = 1; // true, if three adjacent points are counterclockwise ordered
- for (vsize i = 0; i < points.size (); i++)
+
+ if (extroversion == 0.0)
+ {
+ shrunk_points = points;
+ }
+ else
{
- int i0 = i;
- int i1 = (i + 1) % points.size ();
- int i2 = (i + 2) % points.size ();
- Offset p0 = points[i0];
- Offset p1 = points[i1];
- Offset p2 = points[i2];
- Offset p10 = p0 - p1;
- Offset p12 = p2 - p1;
- if (p10.length () != 0.0)
+ /* shrink polygon in size by 0.5 * blotdiameter */
+
+ // first we need to determine the orientation of the polygon in
+ // order to decide whether shrinking means moving the polygon to the
+ // left or to the right of the outline. We do that by calculating
+ // (double) the oriented area of the polygon. We first determine the
+ // center and do the area calculations relative to it.
+ // Mathematically, the result is not affected by this shift, but
+ // numerically a lot of cancellation is going on and this keeps its
+ // effects in check.
+
+ Offset center;
+ for (vsize i = 0; i < points.size (); i++)
+ center += points[i];
+ center /= points.size ();
+
+ Real area = 0.0;
+ Offset last = points.back () - center;
+
+ for (vsize i = 0; i < points.size (); i++)
{
- // recompute ccw
- Real phi = p10.arg ();
- // rotate (p2 - p0) by (-phi)
- Offset q = complex_multiply (p2 - p0, complex_exp (Offset (1.0, -phi)));
-
- if (q[Y_AXIS] > 0)
- ccw = 1;
- else if (q[Y_AXIS] < 0)
- ccw = 0;
- else {} // keep ccw unchanged
+ Offset here = points[i] - center;
+ area += cross_product (last, here);
+ last = here;
}
- else {} // keep ccw unchanged
- Offset p10n = (1.0 / p10.length ()) * p10; // normalize length to 1.0
- Offset p12n = (1.0 / p12.length ()) * p12;
- Offset p13n = 0.5 * (p10n + p12n);
- Offset p14n = 0.5 * (p10n - p12n);
- Offset p13;
- Real d = p13n.length () * p14n.length (); // distance p3n to line (p1..p0)
- if (d < epsilon)
- // special case: p0, p1, p2 are on a single line => build
- // vector orthogonal to (p2-p0) of length 0.5 blotdiameter
+
+ bool ccw = area >= 0.0; // true if whole shape is counterclockwise oriented
+
+ shrunk_points.resize (points.size ());
+
+ for (vsize i = 0; i < points.size (); i++)
{
- p13[X_AXIS] = p10[Y_AXIS];
- p13[Y_AXIS] = -p10[X_AXIS];
- p13 = (0.5 * blotdiameter / p13.length ()) * p13;
+ int i0 = i;
+ int i1 = (i + 1) % points.size ();
+ int i2 = (i + 2) % points.size ();
+ Offset p0 = points[i0];
+ Offset p1 = points[i1];
+ Offset p2 = points[i2];
+ Offset p01 = p1 - p0;
+ Offset p12 = p2 - p1;
+ Offset inward0 = Offset(-p01[Y_AXIS], p01[X_AXIS]).direction ();
+ Offset inward2 = Offset(-p12[Y_AXIS], p12[X_AXIS]).direction ();
+
+ if (!ccw)
+ {
+ inward0 = -inward0;
+ inward2 = -inward2;
+ }
+
+ Offset middle = 0.5*(inward0 + inward2);
+
+ // "middle" now is a vector in the right direction for the
+ // shrinkage. Its size needs to be large enough that the
+ // projection on either of the inward vectors has a size of 1.
+
+ Real proj = dot_product (middle, inward0);
+
+ // What's the size of proj? Assuming that we have a corner
+ // angle of phi where 0 corresponds to a continuing line, the
+ // length of middle is 0.5 |(1+cos phi, sin phi)| = cos (phi/2),
+ // so its projection has length
+ // cos^2 (phi/2) = 0.5 + 0.5 cos (phi).
+ // We don't really want to move inwards more than 3 blob
+ // diameters corresponding to 6 blob radii. So
+ // cos (phi/2) = 1/6 gives phi ~ 161, meaning that a 20 degree
+ // corner necessitates moving 3 blob diameters from the corner
+ // in order to stay inside the lines. Ruler and circle agree.
+ // 0.03 is close enough to 1/36. Basically we want to keep the
+ // shape from inverting from pulling too far inward.
+ // 3 diameters is pretty much a handwaving guess.
+
+ if (abs (proj) < 0.03)
+ proj = proj < 0 ? -0.03 : 0.03;
+
+ shrunk_points[i1] = p1 - (0.5 * blotdiameter / proj) * middle
+ * extroversion;
}
- else
- p13 = (0.5 * blotdiameter / d) * p13n;
- shrunk_points[i1] = p1 + ((ccw) ? p13 : -p13);
}
/* build scm expression and bounding box */
SCM shrunk_points_scm = SCM_EOL;
Box box;
+ Box shrunk_box;
for (vsize i = 0; i < shrunk_points.size (); i++)
{
SCM x = scm_from_double (shrunk_points[i][X_AXIS]);
SCM y = scm_from_double (shrunk_points[i][Y_AXIS]);
shrunk_points_scm = scm_cons (x, scm_cons (y, shrunk_points_scm));
box.add_point (points[i]);
+ shrunk_box.add_point (shrunk_points[i]);
}
- SCM polygon_scm = scm_list_n (ly_symbol2scm ("polygon"),
+ shrunk_box.widen (0.5*blotdiameter, 0.5*blotdiameter);
+ box.unite (shrunk_box);
+ SCM polygon_scm = scm_list_4 (ly_symbol2scm ("polygon"),
ly_quote_scm (shrunk_points_scm),
scm_from_double (blotdiameter),
- SCM_BOOL_T,
- SCM_UNDEFINED);
+ SCM_BOOL_T);
Stencil polygon = Stencil (box, polygon_scm);
- shrunk_points.clear ();
return polygon;
}
Lookup::frame (Box b, Real thick, Real blot)
{
Stencil m;
- Direction d = LEFT;
for (Axis a = X_AXIS; a < NO_AXES; a = Axis (a + 1))
{
Axis o = Axis ((a + 1) % NO_AXES);
- do
+ for (LEFT_and_RIGHT (d))
{
Box edges;
edges[a] = b[a][d] + 0.5 * thick * Interval (-1, 1);
m.add_stencil (round_filled_box (edges, blot));
}
- while (flip (&d) != LEFT);
}
return m;
}
calculate the offset for the two beziers that make the sandwich
for the slur
*/
- Real alpha = (curve.control_[3] - curve.control_[0]).arg ();
+ Offset dir = (curve.control_[3] - curve.control_[0]).direction ();
Bezier back = curve;
- Offset perp = curvethick * complex_exp (Offset (0, alpha + M_PI / 2)) * 0.5;
+ Offset perp = 0.5 * curvethick * Offset (-dir[Y_AXIS], dir[X_AXIS]);
back.control_[1] += perp;
back.control_[2] += perp;
scm_from_double (top_curve.control_[2][Y_AXIS]),
scm_from_double (top_curve.control_[3][X_AXIS]),
scm_from_double (top_curve.control_[3][Y_AXIS]),
+ ly_symbol2scm ("lineto"),
+ scm_from_double (bottom_curve.control_[3][X_AXIS]),
+ scm_from_double (bottom_curve.control_[3][Y_AXIS]),
ly_symbol2scm ("curveto"),
scm_from_double (bottom_curve.control_[2][X_AXIS]),
scm_from_double (bottom_curve.control_[2][Y_AXIS]),
Lookup::repeat_slash (Real w, Real s, Real t)
{
- Real x_width = sqrt ((t * t) + ((t / s) * (t / s)));
+ Real x_width = hypot (t, t/s);
Real height = w * s;
SCM controls = scm_list_n (ly_symbol2scm ("moveto"),
SCM_BOOL_T,
SCM_UNDEFINED);
- Box b (Interval (0, w + sqrt (sqr (t / s) + sqr (t))),
- Interval (0, w * s));
+ Box b (Interval (0, w + x_width),
+ Interval (0, height));
return Stencil (b, slashnodot); // http://slashnodot.org
}
Lookup::bracket (Axis a, Interval iv, Real thick, Real protrude, Real blot)
{
Box b;
- Axis other = Axis ((a + 1) % 2);
+ Axis other = other_axis (a);
b[a] = iv;
b[other] = Interval (-1, 1) * thick * 0.5;
projects / lilypond.git / blobdiff