2 Copyright (C) 2013 Paul Davis
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 2 of the License, or
7 (at your option) any later version.
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, write to the Free Software
16 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
24 #include "canvas/framed_curve.h"
26 using namespace ArdourCanvas;
30 FramedCurve::FramedCurve (Canvas* c)
33 , points_per_segment (16)
38 FramedCurve::FramedCurve (Item* parent)
41 , points_per_segment (16)
46 /** When rendering the curve, we will always draw a fixed number of straight
47 * line segments to span the x-axis extent of the curve. More segments:
48 * smoother visual rendering. Less rendering: closer to a visibily poly-line
52 FramedCurve::set_points_per_segment (uint32_t n)
54 /* this only changes our appearance rather than the bounding box, so we
55 just need to schedule a redraw rather than notify the parent of any
58 points_per_segment = max (n, (uint32_t) 3);
64 FramedCurve::compute_bounding_box () const
66 PolyItem::compute_bounding_box ();
68 /* possibly add extents of any point indicators here if we ever do that */
72 FramedCurve::set (Points const& p)
79 FramedCurve::interpolate ()
81 Points curve_points = _points;
83 if (curve_points.size()) {
84 curve_points.erase (curve_points.begin());
88 InterpolatedCurve::interpolate (curve_points, points_per_segment, CatmullRomCentripetal, false, samples);
89 n_samples = samples.size();
93 FramedCurve::render (Rect const & area, Cairo::RefPtr<Cairo::Context> context) const
95 if (!_outline || _points.size() < 3 || !_bounding_box) {
99 Rect self = item_to_window (_bounding_box.get());
100 boost::optional<Rect> d = self.intersection (area);
102 Rect draw = d.get ();
104 /* Our approach is to always draw n_segments across our total size.
106 * This is very inefficient if we are asked to only draw a small
107 * section of the curve. For now we rely on cairo clipping to help
111 /* x-axis limits of the curve, in window space coordinates */
113 Duple w1 = item_to_window (Duple (_points.front().x, 0.0));
114 Duple w2 = item_to_window (Duple (_points.back().x, 0.0));
116 /* clamp actual draw to area bound by points, rather than our bounding box which is slightly different */
119 context->rectangle (draw.x0, draw.y0, draw.width(), draw.height());
122 /* expand drawing area by several pixels on each side to avoid cairo stroking effects at the boundary.
123 they will still occur, but cairo's clipping will hide them.
126 draw = draw.expand (4.0);
128 /* now clip it to the actual points in the curve */
130 if (draw.x0 < w1.x) {
134 if (draw.x1 >= w2.x) {
138 setup_outline_context (context);
140 if (_points.size() == 3) {
145 Points::const_iterator it = _points.begin();
146 window_space = item_to_window (*it);
147 context->move_to (window_space.x, window_space.y);
149 window_space = item_to_window (*it, false);
150 context->line_to (window_space.x, window_space.y);
151 window_space = item_to_window (_points.back(), false);
152 context->line_to (window_space.x, window_space.y);
154 switch (curve_fill) {
159 context->stroke_preserve ();
160 window_space = item_to_window (Duple(_points.back().x, draw.height()));
161 context->line_to (window_space.x, window_space.y);
162 window_space = item_to_window (Duple(_points.front().x, draw.height()));
163 context->line_to (window_space.x, window_space.y);
164 context->close_path();
165 setup_fill_context(context);
169 context->stroke_preserve ();
170 window_space = item_to_window (Duple(_points.back().x, 0.0));
171 context->line_to (window_space.x, window_space.y);
172 window_space = item_to_window (Duple(_points.front().x, 0.0));
173 context->line_to (window_space.x, window_space.y);
174 context->close_path();
175 setup_fill_context(context);
181 /* curve of at least 3 points */
183 /* find left and right-most sample */
185 Points::size_type left = 0;
186 Points::size_type right = n_samples - 1;
188 for (Points::size_type idx = 0; idx < n_samples - 1; ++idx) {
189 window_space = item_to_window (Duple (samples[idx].x, 0.0));
190 if (window_space.x >= draw.x0) {
196 for (Points::size_type idx = left; idx < n_samples - 1; ++idx) {
197 window_space = item_to_window (Duple (samples[idx].x, 0.0));
198 if (window_space.x > draw.x1) {
204 const Duple first_sample = Duple (samples[left].x, samples[left].y);
206 /* move to the first sample's x and the draw height */
207 window_space = item_to_window (Duple (first_sample.x, draw.height()));
208 context->move_to (window_space.x, window_space.y);
210 /* draw line to first sample and then between samples */
211 for (uint32_t idx = left; idx <= right; ++idx) {
212 window_space = item_to_window (Duple (samples[idx].x, samples[idx].y), false);
213 context->line_to (window_space.x, window_space.y);
216 /* a redraw may have been requested between the last sample and the last point.
217 if so, draw a line to the last _point.
219 Duple last_sample = Duple (samples[right].x, samples[right].y);
221 if (draw.x1 > last_sample.x) {
222 last_sample = Duple (_points.back().x, _points.back().y);
223 window_space = item_to_window (last_sample, false);
224 context->line_to (window_space.x, window_space.y);
227 switch (curve_fill) {
232 context->stroke_preserve ();
233 /* close the frame, possibly using the last _point's x rather than samples[right].x */
234 window_space = item_to_window (Duple (last_sample.x, draw.height()));
235 context->line_to (window_space.x, window_space.y);
236 window_space = item_to_window (Duple (first_sample.x, draw.height()));
237 context->line_to (window_space.x, window_space.y);
238 context->close_path();
239 setup_fill_context(context);
243 context->stroke_preserve ();
244 window_space = item_to_window (Duple (last_sample.x, 0.0));
245 context->line_to (window_space.x, window_space.y);
246 window_space = item_to_window (Duple (first_sample.x, 0.0));
247 context->line_to (window_space.x, window_space.y);
248 context->close_path();
249 setup_fill_context(context);
258 setup_outline_context (context);
259 for (Points::const_iterator p = _points.begin(); p != _points.end(); ++p) {
260 Duple window_space (item_to_window (*p));
261 context->arc (window_space.x, window_space.y, 5.0, 0.0, 2 * M_PI);
268 FramedCurve::covers (Duple const & pc) const
270 Duple point = window_to_item (pc);
272 /* O(N) N = number of points, and not accurate */
274 for (Points::const_iterator p = _points.begin(); p != _points.end(); ++p) {
276 const Coord dx = point.x - (*p).x;
277 const Coord dy = point.y - (*p).y;
278 const Coord dx2 = dx * dx;
279 const Coord dy2 = dy * dy;
281 if ((dx2 < 2.0 && dy2 < 2.0) || (dx2 + dy2 < 4.0)) {