libs/canvas/wave_view.cc

   1 /*
   2     Copyright (C) 2011-2013 Paul Davis
   3     Author: Carl Hetherington <cth@carlh.net>
   4
   5     This program is free software; you can redistribute it and/or modify
   6     it under the terms of the GNU General Public License as published by
   7     the Free Software Foundation; either version 2 of the License, or
   8     (at your option) any later version.
   9
  10     This program is distributed in the hope that it will be useful,
  11     but WITHOUT ANY WARRANTY; without even the implied warranty of
  12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13     GNU General Public License for more details.
  14
  15     You should have received a copy of the GNU General Public License
  16     along with this program; if not, write to the Free Software
  17     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  18
  19 */
  20
  21 #include <cmath>
  22 #include <cairomm/cairomm.h>
  23
  24 #include <glibmm/threads.h>
  25
  26 #include "gtkmm2ext/utils.h"
  27 #include "gtkmm2ext/gui_thread.h"
  28
  29 #include "pbd/base_ui.h"
  30 #include "pbd/compose.h"
  31 #include "pbd/convert.h"
  32 #include "pbd/signals.h"
  33 #include "pbd/stacktrace.h"
  34
  35 #include "ardour/types.h"
  36 #include "ardour/dB.h"
  37 #include "ardour/lmath.h"
  38 #include "ardour/audioregion.h"
  39 #include "ardour/audiosource.h"
  40 #include "ardour/session.h"
  41
  42 #include "canvas/canvas.h"
  43 #include "canvas/colors.h"
  44 #include "canvas/debug.h"
  45 #include "canvas/utils.h"
  46 #include "canvas/wave_view.h"
  47
  48 #include "evoral/Range.hpp"
  49
  50 #include <gdkmm/general.h>
  51
  52 #include "gtkmm2ext/gui_thread.h"
  53
  54 using namespace std;
  55 using namespace ARDOUR;
  56 using namespace PBD;
  57 using namespace ArdourCanvas;
  58
  59 double WaveView::_global_gradient_depth = 0.6;
  60 bool WaveView::_global_logscaled = false;
  61 WaveView::Shape WaveView::_global_shape = WaveView::Normal;
  62 bool WaveView::_global_show_waveform_clipping = true;
  63 double WaveView::_clip_level = 0.98853;
  64
  65 WaveViewCache* WaveView::images = 0;
  66 gint WaveView::drawing_thread_should_quit = 0;
  67 Glib::Threads::Mutex WaveView::request_queue_lock;
  68 Glib::Threads::Mutex WaveView::current_image_lock;
  69 Glib::Threads::Cond WaveView::request_cond;
  70 Glib::Threads::Thread* WaveView::_drawing_thread = 0;
  71 WaveView::DrawingRequestQueue WaveView::request_queue;
  72
  73 PBD::Signal0<void> WaveView::VisualPropertiesChanged;
  74 PBD::Signal0<void> WaveView::ClipLevelChanged;
  75
  76 /* NO_THREAD_WAVEVIEWS is defined by the top level wscript
  77  * if --no-threaded-waveviws is provided at the configure step.
  78  */
  79
  80 #ifndef NO_THREADED_WAVEVIEWS
  81 #define ENABLE_THREADED_WAVEFORM_RENDERING
  82 #endif
  83
  84 WaveView::WaveView (Canvas* c, boost::shared_ptr<ARDOUR::AudioRegion> region)
  85         : Item (c)
  86         , _region (region)
  87         , _channel (0)
  88         , _samples_per_pixel (0)
  89         , _height (64)
  90         , _show_zero (false)
  91         , _zero_color (0xff0000ff)
  92         , _clip_color (0xff0000ff)
  93         , _logscaled (_global_logscaled)
  94         , _shape (_global_shape)
  95         , _gradient_depth (_global_gradient_depth)
  96         , _shape_independent (false)
  97         , _logscaled_independent (false)
  98         , _gradient_depth_independent (false)
  99         , _amplitude_above_axis (1.0)
 100         , _region_amplitude (region->scale_amplitude ())
 101         , _start_shift (0.0)
 102         , _region_start (region->start())
 103         , get_image_in_thread (false)
 104         , always_get_image_in_thread (false)
 105         , rendered (false)
 106 {
 107         if (!images) {
 108                 images = new WaveViewCache;
 109         }
 110
 111         VisualPropertiesChanged.connect_same_thread (invalidation_connection, boost::bind (&WaveView::handle_visual_property_change, this));
 112         ClipLevelChanged.connect_same_thread (invalidation_connection, boost::bind (&WaveView::handle_clip_level_change, this));
 113
 114         ImageReady.connect (image_ready_connection, invalidator (*this), boost::bind (&WaveView::image_ready, this), gui_context());
 115 }
 116
 117 WaveView::WaveView (Item* parent, boost::shared_ptr<ARDOUR::AudioRegion> region)
 118         : Item (parent)
 119         , _region (region)
 120         , _channel (0)
 121         , _samples_per_pixel (0)
 122         , _height (64)
 123         , _show_zero (false)
 124         , _zero_color (0xff0000ff)
 125         , _clip_color (0xff0000ff)
 126         , _logscaled (_global_logscaled)
 127         , _shape (_global_shape)
 128         , _gradient_depth (_global_gradient_depth)
 129         , _shape_independent (false)
 130         , _logscaled_independent (false)
 131         , _gradient_depth_independent (false)
 132         , _amplitude_above_axis (1.0)
 133         , _region_amplitude (region->scale_amplitude ())
 134         , _start_shift (0.0)
 135         , _region_start (region->start())
 136         , get_image_in_thread (false)
 137         , always_get_image_in_thread (false)
 138         , rendered (false)
 139 {
 140         if (!images) {
 141                 images = new WaveViewCache;
 142         }
 143
 144         VisualPropertiesChanged.connect_same_thread (invalidation_connection, boost::bind (&WaveView::handle_visual_property_change, this));
 145         ClipLevelChanged.connect_same_thread (invalidation_connection, boost::bind (&WaveView::handle_clip_level_change, this));
 146
 147         ImageReady.connect (image_ready_connection, invalidator (*this), boost::bind (&WaveView::image_ready, this), gui_context());
 148 }
 149
 150 WaveView::~WaveView ()
 151 {
 152         invalidate_image_cache ();
 153         if (images ) {
 154                 images->clear_cache ();
 155         }
 156 }
 157
 158 string
 159 WaveView::debug_name() const
 160 {
 161         return _region->name() + string (":") + PBD::to_string (_channel+1, std::dec);
 162 }
 163
 164 void
 165 WaveView::image_ready ()
 166 {
 167         DEBUG_TRACE (DEBUG::WaveView, string_compose ("queue draw for %1 at %2 (vis = %3 CR %4)\n", this, g_get_monotonic_time(), visible(), current_request));
 168         redraw ();
 169 }
 170
 171 void
 172 WaveView::set_always_get_image_in_thread (bool yn)
 173 {
 174         always_get_image_in_thread = yn;
 175 }
 176
 177 void
 178 WaveView::handle_visual_property_change ()
 179 {
 180         bool changed = false;
 181
 182         if (!_shape_independent && (_shape != global_shape())) {
 183                 _shape = global_shape();
 184                 changed = true;
 185         }
 186
 187         if (!_logscaled_independent && (_logscaled != global_logscaled())) {
 188                 _logscaled = global_logscaled();
 189                 changed = true;
 190         }
 191
 192         if (!_gradient_depth_independent && (_gradient_depth != global_gradient_depth())) {
 193                 _gradient_depth = global_gradient_depth();
 194                 changed = true;
 195         }
 196
 197         if (changed) {
 198                 begin_visual_change ();
 199                 invalidate_image_cache ();
 200                 end_visual_change ();
 201         }
 202 }
 203
 204 void
 205 WaveView::handle_clip_level_change ()
 206 {
 207         begin_visual_change ();
 208         invalidate_image_cache ();
 209         end_visual_change ();
 210 }
 211
 212 void
 213 WaveView::set_fill_color (Color c)
 214 {
 215         if (c != _fill_color) {
 216                 begin_visual_change ();
 217                 invalidate_image_cache ();
 218                 Fill::set_fill_color (c);
 219                 end_visual_change ();
 220         }
 221 }
 222
 223 void
 224 WaveView::set_outline_color (Color c)
 225 {
 226         if (c != _outline_color) {
 227                 begin_visual_change ();
 228                 invalidate_image_cache ();
 229                 Outline::set_outline_color (c);
 230                 end_visual_change ();
 231         }
 232 }
 233
 234 void
 235 WaveView::set_samples_per_pixel (double samples_per_pixel)
 236 {
 237         if (samples_per_pixel != _samples_per_pixel) {
 238                 begin_change ();
 239
 240                 invalidate_image_cache ();
 241                 _samples_per_pixel = samples_per_pixel;
 242                 _bounding_box_dirty = true;
 243
 244                 end_change ();
 245         }
 246 }
 247
 248 static inline float
 249 _log_meter (float power, double lower_db, double upper_db, double non_linearity)
 250 {
 251         return (power < lower_db ? 0.0 : pow((power-lower_db)/(upper_db-lower_db), non_linearity));
 252 }
 253
 254 static inline float
 255 alt_log_meter (float power)
 256 {
 257         return _log_meter (power, -192.0, 0.0, 8.0);
 258 }
 259
 260 void
 261 WaveView::set_clip_level (double dB)
 262 {
 263         const double clip_level = dB_to_coefficient (dB);
 264         if (clip_level != _clip_level) {
 265                 _clip_level = clip_level;
 266                 ClipLevelChanged ();
 267         }
 268 }
 269
 270 void
 271 WaveView::invalidate_image_cache ()
 272 {
 273         DEBUG_TRACE (DEBUG::WaveView, string_compose ("%1 invalidates image cache and cancels current request\n", this));
 274         cancel_my_render_request ();
 275         Glib::Threads::Mutex::Lock lci (current_image_lock);
 276         _current_image.reset ();
 277 }
 278
 279 void
 280 WaveView::compute_tips (PeakData const & peak, WaveView::LineTips& tips) const
 281 {
 282         const double effective_height  = _height;
 283
 284         /* remember: canvas (and cairo) coordinate space puts the origin at the upper left.
 285
 286            So, a sample value of 1.0 (0dbFS) will be computed as:
 287
 288                  (1.0 - 1.0) * 0.5 * effective_height
 289
 290            which evaluates to 0, or the top of the image.
 291
 292            A sample value of -1.0 will be computed as
 293
 294                 (1.0 + 1.0) * 0.5 * effective height
 295
 296            which evaluates to effective height, or the bottom of the image.
 297         */
 298
 299         const double pmax = (1.0 - peak.max) * 0.5 * effective_height;
 300         const double pmin = (1.0 - peak.min) * 0.5 * effective_height;
 301
 302         /* remember that the bottom of the image (pmin) has larger y-coordinates
 303            than the top (pmax).
 304         */
 305
 306         double spread = (pmin - pmax) * 0.5;
 307
 308         /* find the nearest pixel to the nominal center. */
 309         const double center = round (pmin - spread);
 310
 311         if (spread < 1.0) {
 312                 /* minimum distance between line ends is 1 pixel, and we want it "centered" on a pixel,
 313                    as per cairo single-pixel line issues.
 314
 315                    NOTE: the caller will not draw a line between these two points if the spread is
 316                    less than 2 pixels. So only the tips.top value matters, which is where we will
 317                    draw a single pixel as part of the outline.
 318                  */
 319                 tips.top = center;
 320                 tips.bot = center + 1.0;
 321         } else {
 322                 /* round spread above and below center to an integer number of pixels */
 323                 spread = round (spread);
 324                 /* top and bottom are located equally either side of the center */
 325                 tips.top = center - spread;
 326                 tips.bot = center + spread;
 327         }
 328
 329         tips.top = min (effective_height, max (0.0, tips.top));
 330         tips.bot = min (effective_height, max (0.0, tips.bot));
 331 }
 332
 333
 334 Coord
 335 WaveView::y_extent (double s) const
 336 {
 337         assert (_shape == Rectified);
 338         return floor ((1.0 - s) * _height);
 339 }
 340
 341 void
 342 WaveView::draw_absent_image (Cairo::RefPtr<Cairo::ImageSurface>& image, PeakData* _peaks, int n_peaks) const
 343 {
 344         Cairo::RefPtr<Cairo::ImageSurface> stripe = Cairo::ImageSurface::create (Cairo::FORMAT_A8, n_peaks, _height);
 345
 346         Cairo::RefPtr<Cairo::Context> stripe_context = Cairo::Context::create (stripe);
 347         stripe_context->set_antialias (Cairo::ANTIALIAS_NONE);
 348
 349         uint32_t stripe_separation = 150;
 350         double start = - floor (_height / stripe_separation) * stripe_separation;
 351         int stripe_x = 0;
 352
 353         while (start < n_peaks) {
 354
 355                 stripe_context->move_to (start, 0);
 356                 stripe_x = start + _height;
 357                 stripe_context->line_to (stripe_x, _height);
 358                 start += stripe_separation;
 359         }
 360
 361         stripe_context->set_source_rgba (1.0, 1.0, 1.0, 1.0);
 362         stripe_context->set_line_cap (Cairo::LINE_CAP_SQUARE);
 363         stripe_context->set_line_width(50);
 364         stripe_context->stroke();
 365
 366         Cairo::RefPtr<Cairo::Context> context = Cairo::Context::create (image);
 367
 368         context->set_source_rgba (1.0, 1.0, 0.0, 0.3);
 369         context->mask (stripe, 0, 0);
 370         context->fill ();
 371 }
 372
 373 struct ImageSet {
 374         Cairo::RefPtr<Cairo::ImageSurface> wave;
 375         Cairo::RefPtr<Cairo::ImageSurface> outline;
 376         Cairo::RefPtr<Cairo::ImageSurface> clip;
 377         Cairo::RefPtr<Cairo::ImageSurface> zero;
 378
 379         ImageSet() :
 380                 wave (0), outline (0), clip (0), zero (0) {}
 381 };
 382
 383 void
 384 WaveView::draw_image (Cairo::RefPtr<Cairo::ImageSurface>& image, PeakData* _peaks, int n_peaks, boost::shared_ptr<WaveViewThreadRequest> req) const
 385 {
 386
 387         ImageSet images;
 388
 389         images.wave = Cairo::ImageSurface::create (Cairo::FORMAT_A8, n_peaks, _height);
 390         images.outline = Cairo::ImageSurface::create (Cairo::FORMAT_A8, n_peaks, _height);
 391         images.clip = Cairo::ImageSurface::create (Cairo::FORMAT_A8, n_peaks, _height);
 392         images.zero = Cairo::ImageSurface::create (Cairo::FORMAT_A8, n_peaks, _height);
 393
 394         Cairo::RefPtr<Cairo::Context> wave_context = Cairo::Context::create (images.wave);
 395         Cairo::RefPtr<Cairo::Context> outline_context = Cairo::Context::create (images.outline);
 396         Cairo::RefPtr<Cairo::Context> clip_context = Cairo::Context::create (images.clip);
 397         Cairo::RefPtr<Cairo::Context> zero_context = Cairo::Context::create (images.zero);
 398         wave_context->set_antialias (Cairo::ANTIALIAS_NONE);
 399         outline_context->set_antialias (Cairo::ANTIALIAS_NONE);
 400         clip_context->set_antialias (Cairo::ANTIALIAS_NONE);
 401         zero_context->set_antialias (Cairo::ANTIALIAS_NONE);
 402
 403         boost::scoped_array<LineTips> tips (new LineTips[n_peaks]);
 404
 405         /* Clip level nominally set to -0.9dBFS to account for inter-sample
 406            interpolation possibly clipping (value may be too low).
 407
 408            We adjust by the region's own gain (but note: not by any gain
 409            automation or its gain envelope) so that clip indicators are closer
 410            to providing data about on-disk data. This multiplication is
 411            needed because the data we get from AudioRegion::read_peaks()
 412            has been scaled by scale_amplitude() already.
 413         */
 414
 415         const double clip_level = _clip_level * _region_amplitude;
 416
 417         if (_shape == WaveView::Rectified) {
 418
 419                 /* each peak is a line from the bottom of the waveview
 420                  * to a point determined by max (_peaks[i].max,
 421                  * _peaks[i].min)
 422                  */
 423
 424                 if (_logscaled) {
 425                         for (int i = 0; i < n_peaks; ++i) {
 426
 427                                 tips[i].bot = height() - 1.0;
 428                                 const double p = alt_log_meter (fast_coefficient_to_dB (max (fabs (_peaks[i].max), fabs (_peaks[i].min))));
 429                                 tips[i].top = y_extent (p);
 430                                 tips[i].spread = p * _height;
 431
 432                                 if (_peaks[i].max >= clip_level) {
 433                                         tips[i].clip_max = true;
 434                                 }
 435
 436                                 if (-(_peaks[i].min) >= clip_level) {
 437                                         tips[i].clip_min = true;
 438                                 }
 439                         }
 440
 441                 } else {
 442                         for (int i = 0; i < n_peaks; ++i) {
 443
 444                                 tips[i].bot = height() - 1.0;
 445                                 const double p = max(fabs (_peaks[i].max), fabs (_peaks[i].min));
 446                                 tips[i].top = y_extent (p);
 447                                 tips[i].spread = p * _height;
 448                                 if (p >= clip_level) {
 449                                         tips[i].clip_max = true;
 450                                 }
 451                         }
 452
 453                 }
 454
 455         } else {
 456
 457                 if (_logscaled) {
 458                         for (int i = 0; i < n_peaks; ++i) {
 459                                 PeakData p;
 460                                 p.max = _peaks[i].max;
 461                                 p.min = _peaks[i].min;
 462
 463                                 if (_peaks[i].max >= clip_level) {
 464                                         tips[i].clip_max = true;
 465                                 }
 466                                 if (-(_peaks[i].min) >= clip_level) {
 467                                         tips[i].clip_min = true;
 468                                 }
 469
 470                                 if (p.max > 0.0) {
 471                                         p.max = alt_log_meter (fast_coefficient_to_dB (p.max));
 472                                 } else if (p.max < 0.0) {
 473                                         p.max =-alt_log_meter (fast_coefficient_to_dB (-p.max));
 474                                 } else {
 475                                         p.max = 0.0;
 476                                 }
 477
 478                                 if (p.min > 0.0) {
 479                                         p.min = alt_log_meter (fast_coefficient_to_dB (p.min));
 480                                 } else if (p.min < 0.0) {
 481                                         p.min = -alt_log_meter (fast_coefficient_to_dB (-p.min));
 482                                 } else {
 483                                         p.min = 0.0;
 484                                 }
 485
 486                                 compute_tips (p, tips[i]);
 487                                 tips[i].spread = tips[i].bot - tips[i].top;
 488                         }
 489
 490                 } else {
 491                         for (int i = 0; i < n_peaks; ++i) {
 492                                 if (_peaks[i].max >= clip_level) {
 493                                         tips[i].clip_max = true;
 494                                 }
 495                                 if (-(_peaks[i].min) >= clip_level) {
 496                                         tips[i].clip_min = true;
 497                                 }
 498
 499                                 compute_tips (_peaks[i], tips[i]);
 500                                 tips[i].spread = tips[i].bot - tips[i].top;
 501                         }
 502
 503                 }
 504         }
 505
 506         if (req->should_stop()) {
 507                 return;
 508         }
 509
 510         Color alpha_one = rgba_to_color (0, 0, 0, 1.0);
 511
 512         set_source_rgba (wave_context, alpha_one);
 513         set_source_rgba (outline_context, alpha_one);
 514         set_source_rgba (clip_context, alpha_one);
 515         set_source_rgba (zero_context, alpha_one);
 516
 517         /* ensure single-pixel lines */
 518
 519         wave_context->set_line_width (1.0);
 520         wave_context->translate (0.5, 0.5);
 521
 522         outline_context->set_line_width (1.0);
 523         outline_context->translate (0.5, 0.5);
 524
 525         clip_context->set_line_width (1.0);
 526         clip_context->translate (0.5, 0.5);
 527
 528         zero_context->set_line_width (1.0);
 529         zero_context->translate (0.5, 0.5);
 530
 531         /* the height of the clip-indicator should be at most 7 pixels,
 532          * or 5% of the height of the waveview item.
 533          */
 534
 535         const double clip_height = min (7.0, ceil (_height * 0.05));
 536
 537         /* There are 3 possible components to draw at each x-axis position: the
 538            waveform "line", the zero line and an outline/clip indicator.  We
 539            have to decide which of the 3 to draw at each position, pixel by
 540            pixel. This makes the rendering less efficient but it is the only
 541            way I can see to do this correctly.
 542
 543            To avoid constant source swapping and stroking, we draw the components separately
 544            onto four alpha only image surfaces for use as a mask.
 545
 546            With only 1 pixel of spread between the top and bottom of the line,
 547            we just draw the upper outline/clip indicator.
 548
 549            With 2 pixels of spread, we draw the upper and lower outline clip
 550            indicators.
 551
 552            With 3 pixels of spread we draw the upper and lower outline/clip
 553            indicators and at least 1 pixel of the waveform line.
 554
 555            With 5 pixels of spread, we draw all components.
 556
 557            We can do rectified as two separate passes because we have a much
 558            easier decision regarding whether to draw the waveform line. We
 559            always draw the clip/outline indicators.
 560         */
 561
 562         if (_shape == WaveView::Rectified) {
 563
 564                 for (int i = 0; i < n_peaks; ++i) {
 565
 566                         /* waveform line */
 567
 568                         if (tips[i].spread >= 1.0) {
 569                                 wave_context->move_to (i, tips[i].top);
 570                                 wave_context->line_to (i, tips[i].bot);
 571                         }
 572
 573                         /* clip indicator */
 574
 575                         if (_global_show_waveform_clipping && (tips[i].clip_max || tips[i].clip_min)) {
 576                                 clip_context->move_to (i, tips[i].top);
 577                                 /* clip-indicating upper terminal line */
 578                                 clip_context->rel_line_to (0, min (clip_height, ceil(tips[i].spread + .5)));
 579                         } else {
 580                                 outline_context->move_to (i, tips[i].top);
 581                                 /* normal upper terminal dot */
 582                                 outline_context->rel_line_to (0, -1.0);
 583                         }
 584                 }
 585
 586                 wave_context->stroke ();
 587                 clip_context->stroke ();
 588                 outline_context->stroke ();
 589
 590         } else {
 591                 const int height_zero = floor( _height * .5);
 592
 593                 for (int i = 0; i < n_peaks; ++i) {
 594
 595                         /* waveform line */
 596
 597                         if (tips[i].spread >= 2.0) {
 598                                 wave_context->move_to (i, tips[i].top);
 599                                 wave_context->line_to (i, tips[i].bot);
 600                         }
 601
 602                         /* draw square waves and other discontiguous points clearly */
 603                         if (i > 0) {
 604                                 if (tips[i-1].top + 2 < tips[i].top) {
 605                                         wave_context->move_to (i-1, tips[i-1].top);
 606                                         wave_context->line_to (i-1, (tips[i].bot + tips[i-1].top)/2);
 607                                         wave_context->move_to (i, (tips[i].bot + tips[i-1].top)/2);
 608                                         wave_context->line_to (i, tips[i].top);
 609                                 } else if (tips[i-1].bot > tips[i].bot + 2) {
 610                                         wave_context->move_to (i-1, tips[i-1].bot);
 611                                         wave_context->line_to (i-1, (tips[i].top + tips[i-1].bot)/2);
 612                                         wave_context->move_to (i, (tips[i].top + tips[i-1].bot)/2);
 613                                         wave_context->line_to (i, tips[i].bot);
 614                                 }
 615                         }
 616
 617                         /* zero line, show only if there is enough spread
 618                         or the waveform line does not cross zero line */
 619
 620                         if (show_zero_line() && ((tips[i].spread >= 5.0) || (tips[i].top > height_zero ) || (tips[i].bot < height_zero)) ) {
 621                                 zero_context->move_to (i, height_zero);
 622                                 zero_context->rel_line_to (1.0, 0);
 623                         }
 624
 625                         if (tips[i].spread > 1.0) {
 626                                 bool clipped = false;
 627                                 /* outline/clip indicators */
 628                                 if (_global_show_waveform_clipping && tips[i].clip_max) {
 629                                         clip_context->move_to (i, tips[i].top);
 630                                         /* clip-indicating upper terminal line */
 631                                         clip_context->rel_line_to (0, min (clip_height, ceil(tips[i].spread + 0.5)));
 632                                         clipped = true;
 633                                 }
 634
 635                                 if (_global_show_waveform_clipping && tips[i].clip_min) {
 636                                         clip_context->move_to (i, tips[i].bot);
 637                                         /* clip-indicating lower terminal line */
 638                                         clip_context->rel_line_to (0, - min (clip_height, ceil(tips[i].spread + 0.5)));
 639                                         clipped = true;
 640                                 }
 641
 642                                 if (!clipped && tips[i].spread > 2.0) {
 643                                         /* only draw the outline if the spread
 644                                            implies 3 or more pixels (so that we see 1
 645                                            white pixel in the middle).
 646                                         */
 647                                         outline_context->move_to (i, tips[i].bot);
 648                                         /* normal lower terminal dot; line moves up */
 649                                         outline_context->rel_line_to (0, -1.0);
 650
 651                                         outline_context->move_to (i, tips[i].top);
 652                                         /* normal upper terminal dot, line moves down */
 653                                         outline_context->rel_line_to (0, 1.0);
 654                                 }
 655                         } else {
 656                                 bool clipped = false;
 657                                 /* outline/clip indicator */
 658                                 if (_global_show_waveform_clipping && (tips[i].clip_max || tips[i].clip_min)) {
 659                                         clip_context->move_to (i, tips[i].top);
 660                                         /* clip-indicating upper / lower terminal line */
 661                                         clip_context->rel_line_to (0, 1.0);
 662                                         clipped = true;
 663                                 }
 664
 665                                 if (!clipped) {
 666                                         /* special case where only 1 pixel of
 667                                          * the waveform line is drawn (and
 668                                          * nothing else).
 669                                          *
 670                                          * we draw a 1px "line", pretending
 671                                          * that the span is 1.0 (whether it is
 672                                          * zero or 1.0)
 673                                          */
 674                                         wave_context->move_to (i, tips[i].top);
 675                                         wave_context->rel_line_to (0, 1.0);
 676                                 }
 677                         }
 678                 }
 679
 680                 wave_context->stroke ();
 681                 outline_context->stroke ();
 682                 clip_context->stroke ();
 683                 zero_context->stroke ();
 684         }
 685
 686         if (req->should_stop()) {
 687                 return;
 688         }
 689
 690         Cairo::RefPtr<Cairo::Context> context = Cairo::Context::create (image);
 691
 692         /* Here we set a source colour and use the various components as a mask. */
 693
 694         if (gradient_depth() != 0.0) {
 695
 696                 Cairo::RefPtr<Cairo::LinearGradient> gradient (Cairo::LinearGradient::create (0, 0, 0, _height));
 697
 698                 double stops[3];
 699
 700                 double r, g, b, a;
 701
 702                 if (_shape == Rectified) {
 703                         stops[0] = 0.1;
 704                         stops[1] = 0.3;
 705                         stops[2] = 0.9;
 706                 } else {
 707                         stops[0] = 0.1;
 708                         stops[1] = 0.5;
 709                         stops[2] = 0.9;
 710                 }
 711
 712                 color_to_rgba (_fill_color, r, g, b, a);
 713                 gradient->add_color_stop_rgba (stops[1], r, g, b, a);
 714                 /* generate a new color for the middle of the gradient */
 715                 double h, s, v;
 716                 color_to_hsv (_fill_color, h, s, v);
 717                 /* change v towards white */
 718                 v *= 1.0 - gradient_depth();
 719                 Color center = hsva_to_color (h, s, v, a);
 720                 color_to_rgba (center, r, g, b, a);
 721
 722                 gradient->add_color_stop_rgba (stops[0], r, g, b, a);
 723                 gradient->add_color_stop_rgba (stops[2], r, g, b, a);
 724
 725                 context->set_source (gradient);
 726         } else {
 727                 set_source_rgba (context, _fill_color);
 728         }
 729
 730         if (req->should_stop()) {
 731                 return;
 732         }
 733
 734         context->mask (images.wave, 0, 0);
 735         context->fill ();
 736
 737         set_source_rgba (context, _outline_color);
 738         context->mask (images.outline, 0, 0);
 739         context->fill ();
 740
 741         set_source_rgba (context, _clip_color);
 742         context->mask (images.clip, 0, 0);
 743         context->fill ();
 744
 745         set_source_rgba (context, _zero_color);
 746         context->mask (images.zero, 0, 0);
 747         context->fill ();
 748 }
 749
 750 boost::shared_ptr<WaveViewCache::Entry>
 751 WaveView::cache_request_result (boost::shared_ptr<WaveViewThreadRequest> req) const
 752 {
 753         if (!req->image) {
 754                 // cerr << "asked to cache null image!!!\n";
 755                 return boost::shared_ptr<WaveViewCache::Entry> ();
 756         }
 757
 758         boost::shared_ptr<WaveViewCache::Entry> ret (new WaveViewCache::Entry (req->channel,
 759                                                                                req->height,
 760                                                                                req->amplitude,
 761                                                                                req->fill_color,
 762                                                                                req->samples_per_pixel,
 763                                                                                req->start,
 764                                                                                req->end,
 765                                                                                req->image));
 766         images->add (_region->audio_source (_channel), ret);
 767
 768         /* consolidate cache first (removes fully-contained
 769          * duplicate images)
 770          */
 771
 772         images->consolidate_image_cache (_region->audio_source (_channel),
 773                                          req->channel, req->height, req->amplitude,
 774                                          req->fill_color, req->samples_per_pixel);
 775
 776         return ret;
 777 }
 778
 779 boost::shared_ptr<WaveViewCache::Entry>
 780 WaveView::get_image (framepos_t start, framepos_t end, bool& full_image) const
 781 {
 782         boost::shared_ptr<WaveViewCache::Entry> ret;
 783
 784         full_image = true;
 785
 786         /* this is called from a ::render() call, when we need an image to
 787            draw with.
 788         */
 789
 790         DEBUG_TRACE (DEBUG::WaveView, string_compose ("%1 needs image from %2 .. %3\n", name, start, end));
 791
 792
 793         {
 794                 Glib::Threads::Mutex::Lock lmq (request_queue_lock);
 795
 796                 /* if there's a draw request outstanding, check to see if we
 797                  * have an image there. if so, use it (and put it in the cache
 798                  * while we're here.
 799                  */
 800
 801                 DEBUG_TRACE (DEBUG::WaveView, string_compose ("%1 CR %2 stop? %3 image %4\n", this, current_request,
 802                                         (current_request ? current_request->should_stop() : false),
 803                                         (current_request ? (current_request->image ? "yes" : "no") : "n/a")));
 804
 805                 if (current_request && !current_request->should_stop() && current_request->image) {
 806
 807                         /* put the image into the cache so that other
 808                          * WaveViews can use it if it is useful
 809                          */
 810
 811                         if (current_request->start <= start && current_request->end >= end) {
 812
 813                                 ret.reset (new WaveViewCache::Entry (current_request->channel,
 814                                                                      current_request->height,
 815                                                                      current_request->amplitude,
 816                                                                      current_request->fill_color,
 817                                                                      current_request->samples_per_pixel,
 818                                                                      current_request->start,
 819                                                                      current_request->end,
 820                                                                      current_request->image));
 821
 822                                 cache_request_result (current_request);
 823                                 DEBUG_TRACE (DEBUG::WaveView, string_compose ("%1: got image from completed request, spans %2..%3\n",
 824                                                                               name, current_request->start, current_request->end));
 825                         }
 826
 827                         /* drop our handle on the current request */
 828                         current_request.reset ();
 829                 }
 830         }
 831
 832         if (!ret) {
 833
 834                 /* no current image draw request, so look in the cache */
 835
 836                 ret = get_image_from_cache (start, end, full_image);
 837                 DEBUG_TRACE (DEBUG::WaveView, string_compose ("%1: lookup from cache gave %2 (full %3)\n",
 838                                                               name, ret, full_image));
 839
 840         }
 841
 842
 843
 844         if (!ret || !full_image) {
 845
 846 #ifndef ENABLE_THREADED_WAVEFORM_RENDERING
 847                 if (1)
 848 #else
 849                 if ((rendered && get_image_in_thread) || always_get_image_in_thread)
 850 #endif
 851                 {
 852
 853                         DEBUG_TRACE (DEBUG::WaveView, string_compose ("%1: generating image in caller thread\n", name));
 854
 855                         boost::shared_ptr<WaveViewThreadRequest> req (new WaveViewThreadRequest);
 856
 857                         req->type = WaveViewThreadRequest::Draw;
 858                         req->start = start;
 859                         req->end = end;
 860                         req->samples_per_pixel = _samples_per_pixel;
 861                         req->region = _region; /* weak ptr, to avoid storing a reference in the request queue */
 862                         req->channel = _channel;
 863                         req->height = _height;
 864                         req->fill_color = _fill_color;
 865                         req->amplitude = _region_amplitude * _amplitude_above_axis;
 866                         req->width = desired_image_width ();
 867
 868                         /* draw image in this (the GUI thread) */
 869
 870                         generate_image (req, false);
 871
 872                         /* cache the result */
 873
 874                         ret = cache_request_result (req);
 875
 876                         /* reset this so that future missing images are
 877                          * generated in a a worker thread.
 878                          */
 879
 880                         get_image_in_thread = false;
 881
 882                 } else {
 883                         queue_get_image (_region, start, end);
 884                 }
 885         }
 886
 887         if (ret) {
 888                 DEBUG_TRACE (DEBUG::WaveView, string_compose ("%1 got an image from %2 .. %3 (full ? %4)\n", name, ret->start, ret->end, full_image));
 889         } else {
 890                 DEBUG_TRACE (DEBUG::WaveView, string_compose ("%1 no useful image available\n", name));
 891         }
 892
 893         return ret;
 894 }
 895
 896 boost::shared_ptr<WaveViewCache::Entry>
 897 WaveView::get_image_from_cache (framepos_t start, framepos_t end, bool& full) const
 898 {
 899         if (!images) {
 900                 return boost::shared_ptr<WaveViewCache::Entry>();
 901         }
 902
 903         return images->lookup_image (_region->audio_source (_channel), start, end, _channel,
 904                                      _height, _region_amplitude * _amplitude_above_axis, _fill_color, _samples_per_pixel, full);
 905 }
 906
 907 framecnt_t
 908 WaveView::desired_image_width () const
 909 {
 910         /* compute how wide the image should be, in samples.
 911          *
 912          * We want at least 1 canvas width's worth, but if that
 913          * represents less than 1/10th of a second, use 1/10th of
 914          * a second instead.
 915          */
 916
 917         framecnt_t canvas_width_samples = _canvas->visible_area().width() * _samples_per_pixel;
 918         const framecnt_t one_tenth_of_second = _region->session().frame_rate() / 10;
 919
 920         if (canvas_width_samples > one_tenth_of_second) {
 921                 return  canvas_width_samples;
 922         }
 923
 924         return one_tenth_of_second;
 925 }
 926
 927 void
 928 WaveView::queue_get_image (boost::shared_ptr<const ARDOUR::Region> region, framepos_t start, framepos_t end) const
 929 {
 930         boost::shared_ptr<WaveViewThreadRequest> req (new WaveViewThreadRequest);
 931
 932         req->type = WaveViewThreadRequest::Draw;
 933         req->start = start;
 934         req->end = end;
 935         req->samples_per_pixel = _samples_per_pixel;
 936         req->region = _region; /* weak ptr, to avoid storing a reference in the request queue */
 937         req->channel = _channel;
 938         req->height = _height;
 939         req->fill_color = _fill_color;
 940         req->amplitude = _region_amplitude * _amplitude_above_axis;
 941         req->width = desired_image_width ();
 942
 943         if (current_request) {
 944                 /* this will stop rendering in progress (which might otherwise
 945                    be long lived) for any current request.
 946                 */
 947                 Glib::Threads::Mutex::Lock lm (request_queue_lock);
 948                 if (current_request) {
 949                         current_request->cancel ();
 950                 }
 951         }
 952
 953         start_drawing_thread ();
 954
 955         /* swap requests (protected by lock) */
 956
 957         {
 958                 Glib::Threads::Mutex::Lock lm (request_queue_lock);
 959                 current_request = req;
 960
 961                 DEBUG_TRACE (DEBUG::WaveView, string_compose ("%1 now has current request %2\n", this, req));
 962
 963                 if (request_queue.insert (this).second) {
 964                         /* this waveview was not already in the request queue, make sure we wake
 965                                  the rendering thread in case it is asleep.
 966                                  */
 967                         request_cond.signal ();
 968                 }
 969         }
 970 }
 971
 972 void
 973 WaveView::generate_image (boost::shared_ptr<WaveViewThreadRequest> req, bool in_render_thread) const
 974 {
 975         if (!req->should_stop()) {
 976
 977                 /* sample position is canonical here, and we want to generate
 978                  * an image that spans about 3x the canvas width. We get to that
 979                  * width by using an image sample count of the screen width added
 980                  * on each side of the desired image center.
 981                  */
 982
 983                 const framepos_t center = req->start + ((req->end - req->start) / 2);
 984                 const framecnt_t image_samples = req->width;
 985
 986                 /* we can request data from anywhere in the Source, between 0 and its length
 987                  */
 988
 989                 framepos_t sample_start = max (_region_start, (center - image_samples));
 990                 framepos_t sample_end = min (center + image_samples, region_end());
 991                 const int n_peaks = std::max (1LL, llrint (ceil ((sample_end - sample_start) / (req->samples_per_pixel))));
 992
 993                 assert (n_peaks > 0 && n_peaks < 32767);
 994
 995                 boost::scoped_array<ARDOUR::PeakData> peaks (new PeakData[n_peaks]);
 996
 997                 /* Note that Region::read_peaks() takes a start position based on an
 998                    offset into the Region's **SOURCE**, rather than an offset into
 999                    the Region itself.
1000                 */
1001
1002                 framecnt_t peaks_read = _region->read_peaks (peaks.get(), n_peaks,
1003                                                              sample_start, sample_end - sample_start,
1004                                                              req->channel,
1005                                                              req->samples_per_pixel);
1006
1007                 if (req->should_stop()) {
1008                         // cerr << "Request stopped after reading peaks\n";
1009                         return;
1010                 }
1011
1012                 req->image = Cairo::ImageSurface::create (Cairo::FORMAT_ARGB32, n_peaks, req->height);
1013
1014                 // http://cairographics.org/manual/cairo-Image-Surfaces.html#cairo-image-surface-create
1015                 // This function always returns a valid pointer, but it will return a pointer to a "nil" surface..
1016                 // but there's some evidence that req->image can be NULL.
1017                 // http://tracker.ardour.org/view.php?id=6478
1018                 assert (req->image);
1019
1020                 /* make sure we record the sample positions that were actually used */
1021                 req->start = sample_start;
1022                 req->end = sample_end;
1023
1024                 if (peaks_read > 0) {
1025
1026                         /* region amplitude will have been used to generate the
1027                          * peak values already, but not the visual-only
1028                          * amplitude_above_axis. So apply that here before
1029                          * rendering.
1030                          */
1031
1032                         if (_amplitude_above_axis != 1.0) {
1033                                 for (framecnt_t i = 0; i < n_peaks; ++i) {
1034                                         peaks[i].max *= _amplitude_above_axis;
1035                                         peaks[i].min *= _amplitude_above_axis;
1036                                 }
1037                         }
1038
1039                         draw_image (req->image, peaks.get(), n_peaks, req);
1040                 } else {
1041                         draw_absent_image (req->image, peaks.get(), n_peaks);
1042                 }
1043         } else {
1044                 // cerr << "Request stopped before image generation\n";
1045         }
1046
1047         if (in_render_thread && !req->should_stop()) {
1048                 DEBUG_TRACE (DEBUG::WaveView, string_compose ("done with request for %1 at %2 CR %3 req %4 range %5 .. %6\n", this, g_get_monotonic_time(), current_request, req, req->start, req->end));
1049                 const_cast<WaveView*>(this)->ImageReady (); /* emit signal */
1050         }
1051
1052         return;
1053 }
1054
1055 /** Given a waveform that starts at window x-coordinate @param wave_origin
1056  * and the first pixel that we will actually draw @param draw_start, return
1057  * the offset into an image of the entire waveform that we will need to use.
1058  *
1059  * Note: most of our cached images are NOT of the entire waveform, this is just
1060  * computationally useful when determining which the sample range span for
1061  * the image we need.
1062  */
1063 static inline double
1064 window_to_image (double wave_origin, double image_start)
1065 {
1066         return image_start - wave_origin;
1067 }
1068
1069 void
1070 WaveView::render (Rect const & area, Cairo::RefPtr<Cairo::Context> context) const
1071 {
1072         assert (_samples_per_pixel != 0);
1073
1074         if (!_region) {
1075                 return;
1076         }
1077
1078         DEBUG_TRACE (DEBUG::WaveView, string_compose ("render %1 at %2\n", this, g_get_monotonic_time()));
1079
1080         /* a WaveView is intimately connected to an AudioRegion. It will
1081          * display the waveform within the region, anywhere from the start of
1082          * the region to its end.
1083          *
1084          * the area we've been aked to render may overlap with area covered
1085          * by the region in any of the normal ways:
1086          *
1087          *  - it may begin and end within the area covered by the region
1088          *  - it may start before and end after the area covered by region
1089          *  - it may start before and end within the area covered by the region
1090          *  - it may start within and end after the area covered by the region
1091          *  - it may be precisely coincident with the area covered by region.
1092          *
1093          * So let's start by determining the area covered by the region, in
1094          * window coordinates. It begins at zero (in item coordinates for this
1095          * waveview, and extends to region_length() / _samples_per_pixel.
1096          */
1097
1098         Rect self = item_to_window (Rect (0.0, 0.0, region_length() / _samples_per_pixel, _height));
1099
1100         // cerr << name << " RENDER " << area << " self = " << self << endl;
1101
1102         /* Now lets get the intersection with the area we've been asked to draw */
1103
1104         boost::optional<Rect> d = self.intersection (area);
1105
1106         if (!d) {
1107                 return;
1108         }
1109
1110         Rect draw = d.get();
1111
1112         /* "draw" is now a rectangle that defines the rectangle we need to
1113          * update/render the waveview into, in window coordinate space.
1114          */
1115
1116         /* window coordinates - pixels where x=0 is the left edge of the canvas
1117          * window. We round down in case we were asked to
1118          * draw "between" pixels at the start and/or end.
1119          */
1120
1121         double draw_start = floor (draw.x0);
1122         const double draw_end = floor (draw.x1);
1123
1124         // cerr << "Need to draw " << draw_start << " .. " << draw_end << " vs. " << area << " and self = " << self << endl;
1125
1126         /* image coordnates: pixels where x=0 is the start of this waveview,
1127          * wherever it may be positioned. thus image_start=N means "an image
1128          * that begins N pixels after the start of region that this waveview is
1129          * representing.
1130          */
1131
1132         const framepos_t image_start = window_to_image (self.x0, draw_start);
1133         const framepos_t image_end = window_to_image (self.x0, draw_end);
1134
1135         // cerr << "Image/WV space: " << image_start << " .. " << image_end << endl;
1136
1137         /* sample coordinates - note, these are not subject to rounding error
1138          *
1139          * "sample_start = N" means "the first sample we need to represent is N
1140          * samples after the first sample of the region"
1141          */
1142
1143         framepos_t sample_start = _region_start + (image_start * _samples_per_pixel);
1144         framepos_t sample_end   = _region_start + (image_end * _samples_per_pixel);
1145
1146         // cerr << "Sample space: " << sample_start << " .. " << sample_end << " @ " << _samples_per_pixel << " rs = " << _region_start << endl;
1147
1148         /* sample_start and sample_end are bounded by the region
1149          * limits. sample_start, because of the was just computed, must already
1150          * be greater than or equal to the _region_start value.
1151          */
1152
1153         sample_end = min (region_end(), sample_end);
1154
1155         // cerr << debug_name() << " will need image spanning " << sample_start << " .. " << sample_end << " region spans " << _region_start << " .. " << region_end() << endl;
1156
1157         double image_origin_in_self_coordinates;
1158         boost::shared_ptr<WaveViewCache::Entry> image_to_draw;
1159
1160         Glib::Threads::Mutex::Lock lci (current_image_lock);
1161         if (_current_image) {
1162
1163                 /* check it covers the right sample range */
1164
1165                 if (_current_image->start > sample_start || _current_image->end < sample_end) {
1166                         /* doesn't cover the area we need ... reset */
1167                         _current_image.reset ();
1168                 } else {
1169                         /* timestamp our continuing use of this image/cache entry */
1170                         images->use (_region->audio_source (_channel), _current_image);
1171                         image_to_draw = _current_image;
1172                 }
1173         }
1174
1175         if (!image_to_draw) {
1176
1177                 /* look it up */
1178
1179                 bool full_image;
1180                 image_to_draw = get_image (sample_start, sample_end, full_image);
1181
1182                 DEBUG_TRACE (DEBUG::WaveView, string_compose ("%1 image to draw = %2 (full? %3)\n", name, image_to_draw, full_image));
1183
1184                 if (!image_to_draw) {
1185                         /* image not currently available. A redraw will be scheduled
1186                            when it is ready.
1187                         */
1188                         return;
1189                 }
1190
1191                 if (full_image) {
1192                         /* found an image that covers our entire sample range,
1193                          * so keep a reference to it.
1194                          */
1195                         _current_image = image_to_draw;
1196                 }
1197         }
1198
1199         /* compute the first pixel of the image that should be used when we
1200          * render the specified range.
1201          */
1202
1203         image_origin_in_self_coordinates = (image_to_draw->start - _region_start) / _samples_per_pixel;
1204
1205         if (_start_shift && (sample_start == _region_start) && (self.x0 == draw.x0)) {
1206                 /* we are going to draw the first pixel for this region, but
1207                    we may not want this to overlap a border around the
1208                    waveform. If so, _start_shift will be set.
1209                 */
1210                 //cerr << name.substr (23) << " ss = " << sample_start << " rs = " << _region_start << " sf = " << _start_shift << " ds = " << draw_start << " self = " << self << " draw = " << draw << endl;
1211                 //draw_start += _start_shift;
1212                 //image_origin_in_self_coordinates += _start_shift;
1213         }
1214
1215         /* the image may only be a best-effort ... it may not span the entire
1216          * range requested, though it is guaranteed to cover the start. So
1217          * determine how many pixels we can actually draw.
1218          */
1219
1220         double draw_width;
1221
1222         if (image_to_draw != _current_image) {
1223                 lci.release ();
1224
1225                 /* the image is guaranteed to start at or before
1226                  * draw_start. But if it starts before draw_start, that reduces
1227                  * the maximum available width we can render with.
1228                  *
1229                  * so .. clamp the draw width to the smaller of what we need to
1230                  * draw or the available width of the image.
1231                  */
1232
1233                 draw_width = min ((double) image_to_draw->image->get_width(), (draw_end - draw_start));
1234
1235
1236                 DEBUG_TRACE (DEBUG::WaveView, string_compose ("%1 draw just %2 of %3 @ %8 (iwidth %4 off %5 img @ %6 rs @ %7)\n", name, draw_width, (draw_end - draw_start),
1237                                                               image_to_draw->image->get_width(), image_origin_in_self_coordinates,
1238                                                               image_to_draw->start, _region_start, draw_start));
1239         } else {
1240                 draw_width = draw_end - draw_start;
1241                 DEBUG_TRACE (DEBUG::WaveView, string_compose ("use current image, span entire render width %1..%2\n", draw_start, draw_end));
1242         }
1243
1244         context->rectangle (draw_start, draw.y0, draw_width, draw.height());
1245
1246         /* round image origin position to an exact pixel in device space to
1247          * avoid blurring
1248          */
1249
1250         double x  = self.x0 + image_origin_in_self_coordinates;
1251         double y  = self.y0;
1252         context->user_to_device (x, y);
1253         x = round (x);
1254         y = round (y);
1255         context->device_to_user (x, y);
1256
1257         /* the coordinates specify where in "user coordinates" (i.e. what we
1258          * generally call "canvas coordinates" in this code) the image origin
1259          * will appear. So specifying (10,10) will put the upper left corner of
1260          * the image at (10,10) in user space.
1261          */
1262
1263         context->set_source (image_to_draw->image, x, y);
1264         context->fill ();
1265
1266         /* image obtained, some of it painted to display: we are rendered.
1267            Future calls to get_image_in_thread are now meaningful.
1268         */
1269
1270         rendered = true;
1271 }
1272
1273 void
1274 WaveView::compute_bounding_box () const
1275 {
1276         if (_region) {
1277                 _bounding_box = Rect (0.0, 0.0, region_length() / _samples_per_pixel, _height);
1278         } else {
1279                 _bounding_box = boost::optional<Rect> ();
1280         }
1281
1282         _bounding_box_dirty = false;
1283 }
1284
1285 void
1286 WaveView::set_height (Distance height)
1287 {
1288         if (height != _height) {
1289                 begin_change ();
1290
1291                 invalidate_image_cache ();
1292                 _height = height;
1293                 get_image_in_thread = true;
1294
1295                 _bounding_box_dirty = true;
1296                 end_change ();
1297         }
1298 }
1299
1300 void
1301 WaveView::set_channel (int channel)
1302 {
1303         if (channel != _channel) {
1304                 begin_change ();
1305
1306                 invalidate_image_cache ();
1307                 _channel = channel;
1308
1309                 _bounding_box_dirty = true;
1310                 end_change ();
1311         }
1312 }
1313
1314 void
1315 WaveView::set_logscaled (bool yn)
1316 {
1317         if (_logscaled != yn) {
1318                 begin_visual_change ();
1319                 invalidate_image_cache ();
1320                 _logscaled = yn;
1321                 end_visual_change ();
1322         }
1323 }
1324
1325 void
1326 WaveView::gain_changed ()
1327 {
1328         begin_visual_change ();
1329         invalidate_image_cache ();
1330         _region_amplitude = _region->scale_amplitude ();
1331         get_image_in_thread = true;
1332         end_visual_change ();
1333 }
1334
1335 void
1336 WaveView::set_zero_color (Color c)
1337 {
1338         if (_zero_color != c) {
1339                 begin_visual_change ();
1340                 invalidate_image_cache ();
1341                 _zero_color = c;
1342                 end_visual_change ();
1343         }
1344 }
1345
1346 void
1347 WaveView::set_clip_color (Color c)
1348 {
1349         if (_clip_color != c) {
1350                 begin_visual_change ();
1351                 invalidate_image_cache ();
1352                 _clip_color = c;
1353                 end_visual_change ();
1354         }
1355 }
1356
1357 void
1358 WaveView::set_show_zero_line (bool yn)
1359 {
1360         if (_show_zero != yn) {
1361                 begin_visual_change ();
1362                 invalidate_image_cache ();
1363                 _show_zero = yn;
1364                 end_visual_change ();
1365         }
1366 }
1367
1368 void
1369 WaveView::set_shape (Shape s)
1370 {
1371         if (_shape != s) {
1372                 begin_visual_change ();
1373                 invalidate_image_cache ();
1374                 _shape = s;
1375                 end_visual_change ();
1376         }
1377 }
1378
1379 void
1380 WaveView::set_amplitude_above_axis (double a)
1381 {
1382         if (fabs (_amplitude_above_axis - a) > 0.01) {
1383                 begin_visual_change ();
1384                 invalidate_image_cache ();
1385                 _amplitude_above_axis = a;
1386                 get_image_in_thread = true;
1387                 end_visual_change ();
1388         }
1389 }
1390
1391 void
1392 WaveView::set_global_shape (Shape s)
1393 {
1394         if (_global_shape != s) {
1395                 _global_shape = s;
1396                 if (images) {
1397                         images->clear_cache ();
1398                 }
1399                 VisualPropertiesChanged (); /* EMIT SIGNAL */
1400         }
1401 }
1402
1403 void
1404 WaveView::set_global_logscaled (bool yn)
1405 {
1406         if (_global_logscaled != yn) {
1407                 _global_logscaled = yn;
1408                 if (images) {
1409                         images->clear_cache ();
1410                 }
1411                 VisualPropertiesChanged (); /* EMIT SIGNAL */
1412         }
1413 }
1414
1415 framecnt_t
1416 WaveView::region_length() const
1417 {
1418         return _region->length() - (_region_start - _region->start());
1419 }
1420
1421 framepos_t
1422 WaveView::region_end() const
1423 {
1424         return _region_start + region_length();
1425 }
1426
1427 void
1428 WaveView::set_region_start (frameoffset_t start)
1429 {
1430         if (!_region) {
1431                 return;
1432         }
1433
1434         if (_region_start == start) {
1435                 return;
1436         }
1437
1438         begin_change ();
1439         _region_start = start;
1440         _bounding_box_dirty = true;
1441         end_change ();
1442 }
1443
1444 void
1445 WaveView::region_resized ()
1446 {
1447         /* Called when the region start or end (thus length) has changed.
1448         */
1449
1450         if (!_region) {
1451                 return;
1452         }
1453
1454         begin_change ();
1455         _region_start = _region->start();
1456         _bounding_box_dirty = true;
1457         end_change ();
1458 }
1459
1460 void
1461 WaveView::set_global_gradient_depth (double depth)
1462 {
1463         if (_global_gradient_depth != depth) {
1464                 _global_gradient_depth = depth;
1465                 VisualPropertiesChanged (); /* EMIT SIGNAL */
1466         }
1467 }
1468
1469 void
1470 WaveView::set_global_show_waveform_clipping (bool yn)
1471 {
1472         if (_global_show_waveform_clipping != yn) {
1473                 _global_show_waveform_clipping = yn;
1474                 ClipLevelChanged ();
1475         }
1476 }
1477
1478 void
1479 WaveView::set_start_shift (double pixels)
1480 {
1481         if (pixels < 0) {
1482                 return;
1483         }
1484
1485         begin_visual_change ();
1486         _start_shift = pixels;
1487         end_visual_change ();
1488 }
1489
1490 void
1491 WaveView::cancel_my_render_request () const
1492 {
1493         if (!images) {
1494                 return;
1495         }
1496
1497         /* try to stop any current rendering of the request, or prevent it from
1498          * ever starting up.
1499          */
1500
1501         Glib::Threads::Mutex::Lock lm (request_queue_lock);
1502
1503         if (current_request) {
1504                 current_request->cancel ();
1505         }
1506
1507         /* now remove it from the queue and reset our request pointer so that
1508            have no outstanding request (that we know about)
1509         */
1510
1511         request_queue.erase (this);
1512         current_request.reset ();
1513         DEBUG_TRACE (DEBUG::WaveView, string_compose ("%1 now has no request %2\n", this));
1514
1515 }
1516
1517 void
1518 WaveView::set_image_cache_size (uint64_t sz)
1519 {
1520         if (!images) {
1521                 images = new WaveViewCache;
1522         }
1523
1524         images->set_image_cache_threshold (sz);
1525 }
1526
1527 /*-------------------------------------------------*/
1528
1529 void
1530 WaveView::start_drawing_thread ()
1531 {
1532         if (!_drawing_thread) {
1533                 _drawing_thread = Glib::Threads::Thread::create (sigc::ptr_fun (WaveView::drawing_thread));
1534         }
1535 }
1536
1537 void
1538 WaveView::stop_drawing_thread ()
1539 {
1540         while (_drawing_thread) {
1541                 Glib::Threads::Mutex::Lock lm (request_queue_lock);
1542                 g_atomic_int_set (&drawing_thread_should_quit, 1);
1543                 request_cond.signal ();
1544         }
1545 }
1546
1547 void
1548 WaveView::drawing_thread ()
1549 {
1550         using namespace Glib::Threads;
1551
1552         WaveView const * requestor;
1553         Mutex::Lock lm (request_queue_lock);
1554         bool run = true;
1555
1556         while (run) {
1557
1558                 /* remember that we hold the lock at this point, no matter what */
1559
1560                 if (g_atomic_int_get (&drawing_thread_should_quit)) {
1561                         break;
1562                 }
1563
1564                 if (request_queue.empty()) {
1565                         request_cond.wait (request_queue_lock);
1566                 }
1567
1568                 if (request_queue.empty()) {
1569                         continue;
1570                 }
1571
1572                 /* remove the request from the queue (remember: the "request"
1573                  * is just a pointer to a WaveView object)
1574                  */
1575
1576                 requestor = *(request_queue.begin());
1577                 request_queue.erase (request_queue.begin());
1578
1579                 DEBUG_TRACE (DEBUG::WaveView, string_compose ("start request for %1 at %2\n", requestor, g_get_monotonic_time()));
1580
1581                 boost::shared_ptr<WaveViewThreadRequest> req = requestor->current_request;
1582
1583                 if (!req) {
1584                         continue;
1585                 }
1586
1587                 /* Generate an image. Unlock the request queue lock
1588                  * while we do this, so that other things can happen
1589                  * as we do rendering.
1590                  */
1591
1592                 lm.release (); /* some RAII would be good here */
1593
1594                 try {
1595                         requestor->generate_image (req, true);
1596                 } catch (...) {
1597                         req->image.clear(); /* just in case it was set before the exception, whatever it was */
1598                 }
1599
1600                 lm.acquire ();
1601
1602                 req.reset (); /* drop/delete request as appropriate */
1603         }
1604
1605         /* thread is vanishing */
1606         _drawing_thread = 0;
1607 }
1608
1609 /*-------------------------------------------------*/
1610
1611 WaveViewCache::WaveViewCache ()
1612         : image_cache_size (0)
1613         , _image_cache_threshold (100 * 1048576) /* bytes */
1614 {
1615 }
1616
1617 WaveViewCache::~WaveViewCache ()
1618 {
1619 }
1620
1621
1622 boost::shared_ptr<WaveViewCache::Entry>
1623 WaveViewCache::lookup_image (boost::shared_ptr<ARDOUR::AudioSource> src,
1624                              framepos_t start, framepos_t end,
1625                              int channel,
1626                              Coord height,
1627                              float amplitude,
1628                              Color fill_color,
1629                              double samples_per_pixel,
1630                              bool& full_coverage)
1631 {
1632         ImageCache::iterator x;
1633
1634         if ((x = cache_map.find (src)) == cache_map.end ()) {
1635                 /* nothing in the cache for this audio source at all */
1636                 return boost::shared_ptr<WaveViewCache::Entry> ();
1637         }
1638
1639         CacheLine& caches = x->second;
1640         boost::shared_ptr<Entry> best_partial;
1641         framecnt_t max_coverage = 0;
1642
1643         /* Find a suitable ImageSurface, if it exists.
1644         */
1645
1646         for (CacheLine::iterator c = caches.begin(); c != caches.end(); ++c) {
1647
1648                 boost::shared_ptr<Entry> e (*c);
1649
1650                 if (channel != e->channel
1651                     || height != e->height
1652                     || amplitude != e->amplitude
1653                     || samples_per_pixel != e->samples_per_pixel
1654                     || fill_color != e->fill_color) {
1655                         continue;
1656                 }
1657
1658                 switch (Evoral::coverage (start, end, e->start, e->end)) {
1659                         case Evoral::OverlapExternal:  /* required range is inside image range */
1660                                 DEBUG_TRACE (DEBUG::WaveView, string_compose ("found image spanning %1..%2 covers %3..%4\n",
1661                                                         e->start, e->end, start, end));
1662                                 use (src, e);
1663                                 full_coverage = true;
1664                                 return e;
1665
1666                         case Evoral::OverlapStart: /* required range start is covered by image range */
1667                                 if ((e->end - start) > max_coverage) {
1668                                         best_partial = e;
1669                                         max_coverage = e->end - start;
1670                                 }
1671                                 break;
1672
1673                         case Evoral::OverlapNone:
1674                         case Evoral::OverlapEnd:
1675                         case Evoral::OverlapInternal:
1676                                 break;
1677                 }
1678         }
1679
1680         if (best_partial) {
1681                 DEBUG_TRACE (DEBUG::WaveView, string_compose ("found PARTIAL image spanning %1..%2 partially covers %3..%4\n",
1682                                                               best_partial->start, best_partial->end, start, end));
1683                 use (src, best_partial);
1684                 full_coverage = false;
1685                 return best_partial;
1686         }
1687
1688         return boost::shared_ptr<Entry> ();
1689 }
1690
1691 void
1692 WaveViewCache::consolidate_image_cache (boost::shared_ptr<ARDOUR::AudioSource> src,
1693                                         int channel,
1694                                         Coord height,
1695                                         float amplitude,
1696                                         Color fill_color,
1697                                         double samples_per_pixel)
1698 {
1699         list <uint32_t> deletion_list;
1700         uint32_t other_entries = 0;
1701         ImageCache::iterator x;
1702
1703         /* MUST BE CALLED FROM (SINGLE) GUI THREAD */
1704
1705         if ((x = cache_map.find (src)) == cache_map.end ()) {
1706                 return;
1707         }
1708
1709         CacheLine& caches  = x->second;
1710
1711         for (CacheLine::iterator c1 = caches.begin(); c1 != caches.end(); ) {
1712
1713                 CacheLine::iterator nxt = c1;
1714                 ++nxt;
1715
1716                 boost::shared_ptr<Entry> e1 (*c1);
1717
1718                 if (channel != e1->channel
1719                     || height != e1->height
1720                     || amplitude != e1->amplitude
1721                     || samples_per_pixel != e1->samples_per_pixel
1722                     || fill_color != e1->fill_color) {
1723
1724                         /* doesn't match current properties, ignore and move on
1725                          * to the next one.
1726                          */
1727
1728                         other_entries++;
1729                         c1 = nxt;
1730                         continue;
1731                 }
1732
1733                 /* c1 now points to a cached image entry that matches current
1734                  * properties. Check all subsequent cached imaged entries to
1735                  * see if there are others that also match but represent
1736                  * subsets of the range covered by this one.
1737                  */
1738
1739                 for (CacheLine::iterator c2 = c1; c2 != caches.end(); ) {
1740
1741                         CacheLine::iterator nxt2 = c2;
1742                         ++nxt2;
1743
1744                         boost::shared_ptr<Entry> e2 (*c2);
1745
1746                         if (e1 == e2 || channel != e2->channel
1747                             || height != e2->height
1748                             || amplitude != e2->amplitude
1749                             || samples_per_pixel != e2->samples_per_pixel
1750                             || fill_color != e2->fill_color) {
1751
1752                                 /* properties do not match, ignore for the
1753                                  * purposes of consolidation.
1754                                  */
1755                                 c2 = nxt2;
1756                                 continue;
1757                         }
1758
1759                         if (e2->start >= e1->start && e2->end <= e1->end) {
1760                                 /* c2 is fully contained by c1, so delete it */
1761                                 caches.erase (c2);
1762
1763                                 /* and re-start the whole iteration */
1764                                 nxt = caches.begin ();
1765                                 break;
1766                         }
1767
1768                         c2 = nxt2;
1769                 }
1770
1771                 c1 = nxt;
1772         }
1773 }
1774
1775 void
1776 WaveViewCache::use (boost::shared_ptr<ARDOUR::AudioSource> src, boost::shared_ptr<Entry> ce)
1777 {
1778         ce->timestamp = g_get_monotonic_time ();
1779 }
1780
1781 void
1782 WaveViewCache::add (boost::shared_ptr<ARDOUR::AudioSource> src, boost::shared_ptr<Entry> ce)
1783 {
1784         /* MUST BE CALLED FROM (SINGLE) GUI THREAD */
1785
1786         Cairo::RefPtr<Cairo::ImageSurface> img (ce->image);
1787
1788         image_cache_size += img->get_height() * img->get_width () * 4; /* 4 = bytes per FORMAT_ARGB32 pixel */
1789
1790         if (cache_full()) {
1791                 cache_flush ();
1792         }
1793
1794         ce->timestamp = g_get_monotonic_time ();
1795
1796         cache_map[src].push_back (ce);
1797 }
1798
1799 uint64_t
1800 WaveViewCache::compute_image_cache_size()
1801 {
1802         uint64_t total = 0;
1803         for (ImageCache::iterator s = cache_map.begin(); s != cache_map.end(); ++s) {
1804                 CacheLine& per_source_cache (s->second);
1805                 for (CacheLine::iterator c = per_source_cache.begin(); c != per_source_cache.end(); ++c) {
1806                         Cairo::RefPtr<Cairo::ImageSurface> img ((*c)->image);
1807                         total += img->get_height() * img->get_width() * 4; /* 4 = bytes per FORMAT_ARGB32 pixel */
1808                 }
1809         }
1810         return total;
1811 }
1812
1813 bool
1814 WaveViewCache::cache_full()
1815 {
1816         return image_cache_size > _image_cache_threshold;
1817 }
1818
1819 void
1820 WaveViewCache::cache_flush ()
1821 {
1822         /* Build a sortable list of all cache entries */
1823
1824         CacheList cache_list;
1825
1826         for (ImageCache::const_iterator cm = cache_map.begin(); cm != cache_map.end(); ++cm) {
1827                 for (CacheLine::const_iterator cl = cm->second.begin(); cl != cm->second.end(); ++cl) {
1828                         cache_list.push_back (make_pair (cm->first, *cl));
1829                 }
1830         }
1831
1832         /* sort list in LRU order */
1833         SortByTimestamp sorter;
1834         sort (cache_list.begin(), cache_list.end(), sorter);
1835
1836         while (image_cache_size > _image_cache_threshold && !cache_map.empty() && !cache_list.empty()) {
1837
1838                 ListEntry& le (cache_list.front());
1839
1840                 ImageCache::iterator x;
1841
1842                 if ((x = cache_map.find (le.first)) != cache_map.end ()) {
1843
1844                         CacheLine& cl  = x->second;
1845
1846                         for (CacheLine::iterator c = cl.begin(); c != cl.end(); ++c) {
1847
1848                                 if (*c == le.second) {
1849
1850                                         DEBUG_TRACE (DEBUG::WaveView, string_compose ("Removing cache line entry for %1\n", x->first->name()));
1851
1852                                         /* Remove this entry from this cache line */
1853                                         cl.erase (c);
1854
1855                                         if (cl.empty()) {
1856                                                 /* remove cache line from main cache: no more entries */
1857                                                 cache_map.erase (x);
1858                                         }
1859
1860                                         break;
1861                                 }
1862                         }
1863
1864                         Cairo::RefPtr<Cairo::ImageSurface> img (le.second->image);
1865                         uint64_t size = img->get_height() * img->get_width() * 4; /* 4 = bytes per FORMAT_ARGB32 pixel */
1866
1867                         if (image_cache_size > size) {
1868                                 image_cache_size -= size;
1869                         } else {
1870                                 image_cache_size = 0;
1871                         }
1872                         DEBUG_TRACE (DEBUG::WaveView, string_compose ("cache shrunk to %1\n", image_cache_size));
1873                 }
1874
1875                 /* Remove from the linear list, even if we didn't find it in
1876                  * the actual cache_mao
1877                  */
1878                 cache_list.erase (cache_list.begin());
1879         }
1880 }
1881
1882 void
1883 WaveViewCache::clear_cache ()
1884 {
1885         DEBUG_TRACE (DEBUG::WaveView, "clear cache\n");
1886         const uint64_t image_cache_threshold = _image_cache_threshold;
1887         _image_cache_threshold = 0;
1888         cache_flush ();
1889         _image_cache_threshold = image_cache_threshold;
1890 }
1891
1892 void
1893 WaveViewCache::set_image_cache_threshold (uint64_t sz)
1894 {
1895         DEBUG_TRACE (DEBUG::WaveView, string_compose ("new image cache size %1\n", sz));
1896         _image_cache_threshold = sz;
1897         cache_flush ();
1898 }