2 This file is part of LilyPond, the GNU music typesetter.
4 Copyright (C) 1997--2012 Han-Wen Nienhuys <hanwen@xs4all.nl>
6 Jan Nieuwenhuizen <janneke@gnu.org>
8 LilyPond is free software: you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation, either version 3 of the License, or
11 (at your option) any later version.
13 LilyPond is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with LilyPond. If not, see <http://www.gnu.org/licenses/>.
28 #include "line-interface.hh"
30 #include "international.hh"
31 #include "dimensions.hh"
33 #include "file-path.hh"
35 #include "lily-guile.hh"
38 Lookup::beam (Real slope, Real width, Real thick, Real blot)
44 p = Offset (0, thick / 2);
46 p += Offset (1, -1) * (blot / 2);
50 points = scm_cons (scm_from_double (p[X_AXIS]),
51 scm_cons (scm_from_double (p[Y_AXIS]),
54 p = Offset (0, -thick / 2);
56 p += Offset (1, 1) * (blot / 2);
58 points = scm_cons (scm_from_double (p[X_AXIS]),
59 scm_cons (scm_from_double (p[Y_AXIS]),
62 p = Offset (width, width * slope - thick / 2);
64 p += Offset (-1, 1) * (blot / 2);
66 points = scm_cons (scm_from_double (p[X_AXIS]),
67 scm_cons (scm_from_double (p[Y_AXIS]),
70 p = Offset (width, width * slope + thick / 2);
72 p += Offset (-1, -1) * (blot / 2);
74 points = scm_cons (scm_from_double (p[X_AXIS]),
75 scm_cons (scm_from_double (p[Y_AXIS]),
78 SCM expr = scm_list_n (ly_symbol2scm ("polygon"),
79 ly_quote_scm (points),
80 scm_from_double (blot),
84 return Stencil (b, expr);
88 Lookup::rotated_box (Real slope, Real width, Real thick, Real blot)
91 Offset rot (1, slope);
95 rot /= sqrt (1 + slope * slope);
96 pts.push_back (Offset (0, -thick / 2) * rot);
97 pts.push_back (Offset (width, -thick / 2) * rot);
98 pts.push_back (Offset (width, thick / 2) * rot);
99 pts.push_back (Offset (0, thick / 2) * rot);
100 return Lookup::round_filled_polygon (pts, blot);
104 Lookup::horizontal_line (Interval w, Real th)
106 SCM at = scm_list_n (ly_symbol2scm ("draw-line"),
107 scm_from_double (th),
108 scm_from_double (w[LEFT]),
110 scm_from_double (w[RIGHT]),
116 box[Y_AXIS] = Interval (-th / 2, th / 2);
118 return Stencil (box, at);
122 Lookup::blank (Box b)
124 return Stencil (b, scm_from_locale_string (""));
128 Lookup::circle (Real rad, Real thick, bool filled)
130 Box b (Interval (-rad, rad), Interval (-rad, rad));
131 return Stencil (b, scm_list_4 (ly_symbol2scm ("circle"),
132 scm_from_double (rad),
133 scm_from_double (thick),
134 scm_from_bool (filled)));
138 Lookup::filled_box (Box b)
140 return round_filled_box (b, 0.0);
146 * __________________________________
151 * |\ _ _ / v \ _ _ /| |
154 * | <------>| | extent
155 * | blot | | (Y_AXIS)
163 * x\_____/______________\_____/|_____v
167 * |<-------------------------->|
168 * Box extent (X_AXIS)
171 Lookup::round_filled_box (Box b, Real blotdiameter)
173 Real width = b.x ().delta ();
174 blotdiameter = min (blotdiameter, width);
175 Real height = b.y ().delta ();
176 blotdiameter = min (blotdiameter, height);
178 if (blotdiameter < 0.0)
180 if (!isinf (blotdiameter))
181 warning (_f ("Not drawing a box with negative dimension, %.2f by %.2f.",
183 return Stencil (b, SCM_EOL);
186 SCM at = (scm_list_n (ly_symbol2scm ("round-filled-box"),
187 scm_from_double (-b[X_AXIS][LEFT]),
188 scm_from_double (b[X_AXIS][RIGHT]),
189 scm_from_double (-b[Y_AXIS][DOWN]),
190 scm_from_double (b[Y_AXIS][UP]),
191 scm_from_double (blotdiameter),
194 return Stencil (b, at);
198 * Create Stencil that represents a filled polygon with round edges.
202 * (a) Only outer (convex) edges are rounded.
204 * (b) This algorithm works as expected only for polygons whose edges
205 * do not intersect. For example, the polygon ((0, 0), (q, 0), (0,
206 * q), (q, q)) has an intersection at point (q/2, q/2) and therefore
207 * will give a strange result. Even non-adjacent edges that just
208 * touch each other will in general not work as expected for non-null
211 * (c) Given a polygon ((x0, y0), (x1, y1), ... , (x (n-1), y (n-1))),
212 * if there is a natural number k such that blotdiameter is greater
213 * than the maximum of { | (x (k mod n), y (k mod n)) - (x ((k+1) mod n),
214 * y ((k+1) mod n)) |, | (x (k mod n), y (k mod n)) - (x ((k+2) mod n),
215 * y ((k+2) mod n)) |, | (x ((k+1) mod n), y ((k+1) mod n)) - (x ((k+2)
216 * mod n), y ((k+2) mod n)) | }, then the outline of the rounded
217 * polygon will exceed the outline of the core polygon. In other
218 * words: Do not draw rounded polygons that have a leg smaller or
219 * thinner than blotdiameter (or set blotdiameter to a sufficiently
220 * small value -- maybe even 0.0)!
222 * NOTE: Limitations (b) and (c) arise from the fact that round edges
223 * are made by moulding sharp edges to round ones rather than adding
224 * to a core filled polygon. For details of these two different
225 * approaches, see the thread upon the ledger lines patch that started
226 * on March 25, 2002 on the devel mailing list. The below version of
227 * round_filled_polygon () sticks to the moulding model, which the
228 * majority of the list participants finally voted for. This,
229 * however, results in the above limitations and a much increased
230 * complexity of the algorithm, since it has to compute a shrinked
231 * polygon -- which is not trivial define precisely and unambigously.
232 * With the other approach, one simply could move a circle of size
233 * blotdiameter along all edges of the polygon (which is what the
234 * postscript routine in the backend effectively does, but on the
235 * shrinked polygon). --jr
238 Lookup::round_filled_polygon (vector<Offset> const &points,
241 /* TODO: Maybe print a warning if one of the above limitations
242 applies to the given polygon. However, this is quite complicated
245 const Real epsilon = 0.01;
248 /* remove consecutive duplicate points */
249 for (vsize i = 0; i < points.size (); i++)
251 int next = (i + 1) % points.size ();
252 Real d = (points[i] - points[next]).length ();
254 programming_error ("Polygon should not have duplicate points");
258 /* special cases: degenerated polygons */
259 if (points.size () == 0)
261 if (points.size () == 1)
263 Stencil circ = circle (0.5 * blotdiameter, 0, true);
264 circ.translate (points[0]);
267 if (points.size () == 2)
268 return Line_interface::make_line (blotdiameter, points[0], points[1]);
270 /* shrink polygon in size by 0.5 * blotdiameter */
271 vector<Offset> shrunk_points;
272 shrunk_points.resize (points.size ());
273 bool ccw = 1; // true, if three adjacent points are counterclockwise ordered
274 for (vsize i = 0; i < points.size (); i++)
277 int i1 = (i + 1) % points.size ();
278 int i2 = (i + 2) % points.size ();
279 Offset p0 = points[i0];
280 Offset p1 = points[i1];
281 Offset p2 = points[i2];
282 Offset p10 = p0 - p1;
283 Offset p12 = p2 - p1;
284 if (p10.length () != 0.0)
287 Real phi = p10.arg ();
288 // rotate (p2 - p0) by (-phi)
289 Offset q = complex_multiply (p2 - p0, complex_exp (Offset (1.0, -phi)));
293 else if (q[Y_AXIS] < 0)
295 else {} // keep ccw unchanged
297 else {} // keep ccw unchanged
298 Offset p10n = (1.0 / p10.length ()) * p10; // normalize length to 1.0
299 Offset p12n = (1.0 / p12.length ()) * p12;
300 Offset p13n = 0.5 * (p10n + p12n);
301 Offset p14n = 0.5 * (p10n - p12n);
303 Real d = p13n.length () * p14n.length (); // distance p3n to line (p1..p0)
305 // special case: p0, p1, p2 are on a single line => build
306 // vector orthogonal to (p2-p0) of length 0.5 blotdiameter
308 p13[X_AXIS] = p10[Y_AXIS];
309 p13[Y_AXIS] = -p10[X_AXIS];
310 p13 = (0.5 * blotdiameter / p13.length ()) * p13;
313 p13 = (0.5 * blotdiameter / d) * p13n;
314 shrunk_points[i1] = p1 + ((ccw) ? p13 : -p13);
317 /* build scm expression and bounding box */
318 SCM shrunk_points_scm = SCM_EOL;
320 for (vsize i = 0; i < shrunk_points.size (); i++)
322 SCM x = scm_from_double (shrunk_points[i][X_AXIS]);
323 SCM y = scm_from_double (shrunk_points[i][Y_AXIS]);
324 shrunk_points_scm = scm_cons (x, scm_cons (y, shrunk_points_scm));
325 box.add_point (points[i]);
327 SCM polygon_scm = scm_list_n (ly_symbol2scm ("polygon"),
328 ly_quote_scm (shrunk_points_scm),
329 scm_from_double (blotdiameter),
333 Stencil polygon = Stencil (box, polygon_scm);
334 shrunk_points.clear ();
342 Lookup::frame (Box b, Real thick, Real blot)
345 for (Axis a = X_AXIS; a < NO_AXES; a = Axis (a + 1))
347 Axis o = Axis ((a + 1) % NO_AXES);
348 for (LEFT_and_RIGHT (d))
351 edges[a] = b[a][d] + 0.5 * thick * Interval (-1, 1);
352 edges[o][DOWN] = b[o][DOWN] - thick / 2;
353 edges[o][UP] = b[o][UP] + thick / 2;
355 m.add_stencil (round_filled_box (edges, blot));
362 Make a smooth curve along the points
365 Lookup::slur (Bezier curve, Real curvethick, Real linethick,
368 Stencil return_value;
371 calculate the offset for the two beziers that make the sandwich
374 Real alpha = (curve.control_[3] - curve.control_[0]).arg ();
376 Offset perp = curvethick * complex_exp (Offset (0, alpha + M_PI / 2)) * 0.5;
377 back.control_[1] += perp;
378 back.control_[2] += perp;
380 curve.control_[1] -= perp;
381 curve.control_[2] -= perp;
383 if (!scm_is_pair (dash_details))
386 return_value = bezier_sandwich (back, curve, linethick);
390 /* dashed or combination slur */
391 int num_segments = scm_to_int (scm_length (dash_details));
392 for (int i = 0; i < num_segments; i++)
394 SCM dash_pattern = scm_list_ref (dash_details, scm_from_int (i));
395 Real t_min = robust_scm2double (scm_car (dash_pattern), 0);
396 Real t_max = robust_scm2double (scm_cadr (dash_pattern), 1.0);
398 = robust_scm2double (scm_caddr (dash_pattern), 1.0);
400 = robust_scm2double (scm_cadddr (dash_pattern), 0.75);
401 Bezier back_segment = back.extract (t_min, t_max);
402 Bezier curve_segment = curve.extract (t_min, t_max);
403 if (dash_fraction == 1.0)
404 return_value.add_stencil (bezier_sandwich (back_segment,
409 Bezier back_dash, curve_dash;
410 Real seg_length = (back_segment.control_[3]
411 - back_segment.control_[0]).length ();
412 int pattern_count = (int) (seg_length / dash_period);
413 Real pattern_length = 1.0 / (pattern_count + dash_fraction);
415 for (int p = 0; p <= pattern_count; p++)
417 start_t = p * pattern_length;
418 end_t = (p + dash_fraction) * pattern_length;
420 = back_segment.extract (start_t, end_t);
422 = curve_segment.extract (start_t, end_t);
423 return_value.add_stencil (bezier_sandwich (back_dash,
457 Lookup::bezier_sandwich (Bezier top_curve, Bezier bottom_curve, Real thickness)
459 SCM commands = scm_list_n (ly_symbol2scm ("moveto"),
460 scm_from_double (top_curve.control_[0][X_AXIS]),
461 scm_from_double (top_curve.control_[0][Y_AXIS]),
462 ly_symbol2scm ("curveto"),
463 scm_from_double (top_curve.control_[1][X_AXIS]),
464 scm_from_double (top_curve.control_[1][Y_AXIS]),
465 scm_from_double (top_curve.control_[2][X_AXIS]),
466 scm_from_double (top_curve.control_[2][Y_AXIS]),
467 scm_from_double (top_curve.control_[3][X_AXIS]),
468 scm_from_double (top_curve.control_[3][Y_AXIS]),
469 ly_symbol2scm ("curveto"),
470 scm_from_double (bottom_curve.control_[2][X_AXIS]),
471 scm_from_double (bottom_curve.control_[2][Y_AXIS]),
472 scm_from_double (bottom_curve.control_[1][X_AXIS]),
473 scm_from_double (bottom_curve.control_[1][Y_AXIS]),
474 scm_from_double (bottom_curve.control_[0][X_AXIS]),
475 scm_from_double (bottom_curve.control_[0][Y_AXIS]),
476 ly_symbol2scm ("closepath"),
479 SCM horizontal_bend = scm_list_n (ly_symbol2scm ("path"),
480 scm_from_double (thickness),
481 ly_quote_scm (commands),
482 ly_quote_scm (ly_symbol2scm ("round")),
483 ly_quote_scm (ly_symbol2scm ("round")),
487 Interval x_extent = top_curve.extent (X_AXIS);
488 x_extent.unite (bottom_curve.extent (X_AXIS));
489 Interval y_extent = top_curve.extent (Y_AXIS);
490 y_extent.unite (bottom_curve.extent (Y_AXIS));
491 Box b (x_extent, y_extent);
493 b.widen (0.5 * thickness, 0.5 * thickness);
494 return Stencil (b, horizontal_bend);
498 Lookup::repeat_slash (Real w, Real s, Real t)
501 Real x_width = sqrt ((t * t) + ((t / s) * (t / s)));
504 SCM controls = scm_list_n (ly_symbol2scm ("moveto"),
507 ly_symbol2scm ("rlineto"),
508 scm_from_double (x_width),
510 ly_symbol2scm ("rlineto"),
512 scm_from_double (height),
513 ly_symbol2scm ("rlineto"),
514 scm_from_double (-x_width),
516 ly_symbol2scm ("closepath"),
519 SCM slashnodot = scm_list_n (ly_symbol2scm ("path"),
521 ly_quote_scm (controls),
522 ly_quote_scm (ly_symbol2scm ("round")),
523 ly_quote_scm (ly_symbol2scm ("round")),
527 Box b (Interval (0, w + sqrt (sqr (t / s) + sqr (t))),
528 Interval (0, w * s));
530 return Stencil (b, slashnodot); // http://slashnodot.org
534 Lookup::bracket (Axis a, Interval iv, Real thick, Real protrude, Real blot)
537 Axis other = Axis ((a + 1) % 2);
539 b[other] = Interval (-1, 1) * thick * 0.5;
541 Stencil m = round_filled_box (b, blot);
543 b[a] = Interval (iv[UP] - thick, iv[UP]);
544 Interval oi = Interval (-thick / 2, thick / 2 + fabs (protrude));
545 oi *= sign (protrude);
547 m.add_stencil (round_filled_box (b, blot));
548 b[a] = Interval (iv[DOWN], iv[DOWN] + thick);
549 m.add_stencil (round_filled_box (b, blot));
555 Lookup::triangle (Interval iv, Real thick, Real protrude)
558 b[X_AXIS] = Interval (0, iv.length ());
559 b[Y_AXIS] = Interval (min (0., protrude), max (0.0, protrude));
561 vector<Offset> points;
562 points.push_back (Offset (iv[LEFT], 0));
563 points.push_back (Offset (iv[RIGHT], 0));
564 points.push_back (Offset (iv.center (), protrude));
565 points.push_back (Offset (iv[LEFT], 0)); // close triangle
567 return points_to_line_stencil (thick, points);
572 Lookup::points_to_line_stencil (Real thick, vector<Offset> const &points)
575 for (vsize i = 1; i < points.size (); i++)
577 if (points[i - 1].is_sane () && points[i].is_sane ())
580 = Line_interface::make_line (thick, points[i - 1], points[i]);
581 ret.add_stencil (line);