src/custom_ctl.cpp

   1 /* Calf DSP Library
   2  * Custom controls (line graph, knob).
   3  * Copyright (C) 2007 Krzysztof Foltman
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Lesser General Public
   7  * License as published by the Free Software Foundation; either
   8  * version 2 of the License, or (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 GNU
  13  * Lesser General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU Lesser General
  16  * Public License along with this program; if not, write to the
  17  * Free Software Foundation, Inc., 59 Temple Place, Suite 330,
  18  * Boston, MA 02111-1307, USA.
  19  */
  20 #include "config.h"
  21 #include <calf/custom_ctl.h>
  22 #include <gdk/gdkkeysyms.h>
  23 #include <cairo/cairo.h>
  24 #include <math.h>
  25 #include <gdk/gdk.h>
  26
  27 /*
  28 I don't really know how to do it, or if it can be done this way.
  29 struct calf_ui_type_module
  30 {
  31     GTypeModule *module;
  32
  33     calf_ui_type_module()
  34     {
  35         module = g_type_module_new();
  36         g_type_module_set_name(module, "calf_custom_ctl");
  37         g_type_module_use(module);
  38     }
  39     ~calf_ui_type_module()
  40     {
  41         g_type_module_unuse(module);
  42     }
  43 };
  44
  45 static calf_ui_type_module type_module;
  46 */
  47
  48 static void
  49 calf_line_graph_copy_cache_to_window( CalfLineGraph *lg, cairo_t *c )
  50 {
  51     cairo_save( c );
  52     cairo_set_source_surface( c, lg->cache_surface, 0,0 );
  53     cairo_paint( c );
  54     cairo_restore( c );
  55 }
  56
  57 static void
  58 calf_line_graph_copy_window_to_cache( CalfLineGraph *lg, cairo_t *c )
  59 {
  60     cairo_t *cache_cr = cairo_create( lg->cache_surface );
  61     cairo_surface_t *window_surface = cairo_get_target( c );
  62     cairo_set_source_surface( cache_cr, window_surface, 0,0 );
  63     cairo_paint( cache_cr );
  64     cairo_destroy( cache_cr );
  65 }
  66
  67 static void
  68 calf_line_graph_draw_grid( cairo_t *c, std::string &legend, bool vertical, float pos, int phase, int sx, int sy )
  69 {
  70     int ox=1, oy=1;
  71     cairo_text_extents_t tx;
  72     if (!legend.empty())
  73         cairo_text_extents(c, legend.c_str(), &tx);
  74     if (vertical)
  75     {
  76         float x = floor(ox + pos * sx) + 0.5;
  77         if (phase == 1)
  78         {
  79             cairo_move_to(c, x, oy);
  80             cairo_line_to(c, x, oy + sy);
  81             cairo_stroke(c);
  82         }
  83         if (phase == 2 && !legend.empty()) {
  84
  85             cairo_set_source_rgba(c, 1.0, 1.0, 1.0, 0.75);
  86             cairo_move_to(c, x - (tx.x_bearing + tx.width / 2.0), oy + sy - 2);
  87             cairo_show_text(c, legend.c_str());
  88         }
  89     }
  90     else
  91     {
  92         float y = floor(oy + sy / 2 - (sy / 2 - 1) * pos) + 0.5;
  93         if (phase == 1)
  94         {
  95             cairo_move_to(c, ox, y);
  96             cairo_line_to(c, ox + sx, y);
  97             cairo_stroke(c);
  98         }
  99         if (phase == 2 && !legend.empty()) {
 100             cairo_set_source_rgba(c, 1.0, 1.0, 1.0, 0.75);
 101             cairo_move_to(c, ox + sx - 2 - tx.width, y + tx.height/2 - 1);
 102             cairo_show_text(c, legend.c_str());
 103         }
 104     }
 105 }
 106
 107 static void
 108 calf_line_graph_draw_graph( cairo_t *c, float *data, int sx, int sy )
 109 {
 110     int ox=1, oy=1;
 111
 112     for (int i = 0; i < 2 * sx; i++)
 113     {
 114         int y = (int)(oy + sy / 2 - (sy / 2 - 1) * data[i]);
 115         //if (y < oy) y = oy;
 116         //if (y >= oy + sy) y = oy + sy - 1;
 117         if (i)
 118             cairo_line_to(c, ox + i * 0.5, y);
 119         else
 120             cairo_move_to(c, ox, y);
 121     }
 122     cairo_stroke(c);
 123 }
 124
 125 static gboolean
 126 calf_line_graph_expose (GtkWidget *widget, GdkEventExpose *event)
 127 {
 128     g_assert(CALF_IS_LINE_GRAPH(widget));
 129
 130     CalfLineGraph *lg = CALF_LINE_GRAPH(widget);
 131     //int ox = widget->allocation.x + 1, oy = widget->allocation.y + 1;
 132     int ox = 1, oy = 1;
 133     int sx = widget->allocation.width - 2, sy = widget->allocation.height - 2;
 134
 135     cairo_t *c = gdk_cairo_create(GDK_DRAWABLE(widget->window));
 136
 137     GdkColor sc = { 0, 0, 0, 0 };
 138
 139     bool cache_dirty = 0;
 140
 141
 142
 143     if( lg->cache_surface == NULL ) {
 144         // looks like its either first call or the widget has been resized.
 145         // create the cache_surface.
 146         cairo_surface_t *window_surface = cairo_get_target( c );
 147         lg->cache_surface = cairo_surface_create_similar( window_surface,
 148                                                           CAIRO_CONTENT_COLOR,
 149                                                           widget->allocation.width,
 150                                                           widget->allocation.height );
 151         //cairo_set_source_surface( cache_cr, window_surface, 0,0 );
 152         //cairo_paint( cache_cr );
 153
 154         cache_dirty = 1;
 155     }
 156
 157     gdk_cairo_set_source_color(c, &sc);
 158     cairo_rectangle(c, ox, oy, sx, sy);
 159     cairo_clip_preserve(c);
 160     cairo_fill(c);
 161     cairo_impl cimpl;
 162     cimpl.context = c;
 163     cairo_select_font_face(c, "Bitstream Vera Sans", CAIRO_FONT_SLANT_NORMAL, CAIRO_FONT_WEIGHT_NORMAL);
 164     cairo_set_font_size(c, 9);
 165
 166     if (lg->source) {
 167
 168         float pos = 0;
 169         bool vertical = false;
 170         std::string legend;
 171         float *data = new float[2 * sx];
 172         GdkColor sc2 = { 0, 0, 65535, 0 };
 173         float x, y;
 174         int size = 0;
 175         GdkColor sc3 = { 0, 32767, 65535, 0 };
 176
 177         int graph_n, grid_n, dot_n, grid_n_save;
 178
 179         int cache_graph_index, cache_dot_index, cache_grid_index;
 180         int gen_index = lg->source->get_changed_offsets( lg->last_generation, cache_graph_index, cache_dot_index, cache_grid_index );
 181
 182         if( cache_dirty || (gen_index != lg->last_generation) ) {
 183             lg->source->get_changed_offsets( gen_index, cache_graph_index, cache_dot_index, cache_grid_index );
 184             lg->last_generation = gen_index;
 185
 186             cairo_set_line_width(c, 1);
 187             for(int phase = 1; phase <= 2; phase++)
 188             {
 189                 for(grid_n = 0; legend = std::string(), cairo_set_source_rgba(c, 1, 1, 1, 0.5), (grid_n<cache_grid_index) &&  lg->source->get_gridline(lg->source_id, grid_n, pos, vertical, legend, &cimpl); grid_n++)
 190                 {
 191                     printf( "draw gridline %d\n", grid_n );
 192                     calf_line_graph_draw_grid( c, legend, vertical, pos, phase, sx, sy );
 193                 }
 194             }
 195             grid_n_save = grid_n-1;
 196
 197             gdk_cairo_set_source_color(c, &sc2);
 198             cairo_set_line_join(c, CAIRO_LINE_JOIN_MITER);
 199             cairo_set_line_width(c, 1);
 200             for(graph_n = 0; (graph_n<cache_graph_index) && lg->source->get_graph(lg->source_id, graph_n, data, 2 * sx, &cimpl); graph_n++)
 201             {
 202                 calf_line_graph_draw_graph( c, data, sx, sy );
 203             }
 204             gdk_cairo_set_source_color(c, &sc3);
 205             for(dot_n = 0; (dot_n<cache_dot_index) && lg->source->get_dot(lg->source_id, dot_n, x, y, size = 3, &cimpl); dot_n++)
 206             {
 207                 int yv = (int)(oy + sy / 2 - (sy / 2 - 1) * y);
 208                 cairo_arc(c, ox + x * sx, yv, size, 0, 2 * M_PI);
 209                 cairo_fill(c);
 210             }
 211
 212             // copy window to cache.
 213             calf_line_graph_copy_window_to_cache( lg, c );
 214         } else {
 215             grid_n_save = cache_grid_index;
 216             graph_n = cache_graph_index;
 217             dot_n = cache_dot_index;
 218             calf_line_graph_copy_cache_to_window( lg, c );
 219         }
 220
 221
 222         cairo_set_line_width(c, 1);
 223         for(int phase = 1; phase <= 2; phase++)
 224         {
 225             for(int gn=grid_n_save; legend = std::string(), cairo_set_source_rgba(c, 1, 1, 1, 0.5), lg->source->get_gridline(lg->source_id, gn, pos, vertical, legend, &cimpl); gn++)
 226             {
 227                 calf_line_graph_draw_grid( c, legend, vertical, pos, phase, sx, sy );
 228             }
 229         }
 230
 231         gdk_cairo_set_source_color(c, &sc2);
 232         cairo_set_line_join(c, CAIRO_LINE_JOIN_MITER);
 233         cairo_set_line_width(c, 1);
 234         for(int gn = graph_n; lg->source->get_graph(lg->source_id, gn, data, 2 * sx, &cimpl); gn++)
 235         {
 236             calf_line_graph_draw_graph( c, data, sx, sy );
 237         }
 238         gdk_cairo_set_source_color(c, &sc3);
 239         for(int gn = dot_n; lg->source->get_dot(lg->source_id, gn, x, y, size = 3, &cimpl); gn++)
 240         {
 241             int yv = (int)(oy + sy / 2 - (sy / 2 - 1) * y);
 242             cairo_arc(c, ox + x * sx, yv, size, 0, 2 * M_PI);
 243             cairo_fill(c);
 244         }
 245         delete []data;
 246     }
 247
 248     cairo_destroy(c);
 249
 250     gtk_paint_shadow(widget->style, widget->window, GTK_STATE_NORMAL, GTK_SHADOW_IN, NULL, widget, NULL, ox - 1, oy - 1, sx + 2, sy + 2);
 251     // printf("exposed %p %d+%d\n", widget->window, widget->allocation.x, widget->allocation.y);
 252
 253     return TRUE;
 254 }
 255
 256 void calf_line_graph_set_square(CalfLineGraph *graph, bool is_square)
 257 {
 258     g_assert(CALF_IS_LINE_GRAPH(graph));
 259     graph->is_square = is_square;
 260 }
 261
 262 static void
 263 calf_line_graph_size_request (GtkWidget *widget,
 264                            GtkRequisition *requisition)
 265 {
 266     g_assert(CALF_IS_LINE_GRAPH(widget));
 267
 268     // CalfLineGraph *lg = CALF_LINE_GRAPH(widget);
 269 }
 270
 271 static void
 272 calf_line_graph_size_allocate (GtkWidget *widget,
 273                            GtkAllocation *allocation)
 274 {
 275     g_assert(CALF_IS_LINE_GRAPH(widget));
 276     CalfLineGraph *lg = CALF_LINE_GRAPH(widget);
 277
 278     GtkWidgetClass *parent_class = (GtkWidgetClass *) g_type_class_peek_parent( CALF_LINE_GRAPH_GET_CLASS( lg ) );
 279
 280     if( lg->cache_surface )
 281         cairo_surface_destroy( lg->cache_surface );
 282     lg->cache_surface = NULL;
 283
 284     widget->allocation = *allocation;
 285     GtkAllocation &a = widget->allocation;
 286     if (lg->is_square)
 287     {
 288         if (a.width > a.height)
 289         {
 290             a.x += (a.width - a.height) / 2;
 291             a.width = a.height;
 292         }
 293         if (a.width < a.height)
 294         {
 295             a.y += (a.height - a.width) / 2;
 296             a.height = a.width;
 297         }
 298     }
 299     parent_class->size_allocate( widget, &a );
 300 }
 301
 302 static void
 303 calf_line_graph_class_init (CalfLineGraphClass *klass)
 304 {
 305     // GObjectClass *gobject_class = G_OBJECT_CLASS(klass);
 306     GtkWidgetClass *widget_class = GTK_WIDGET_CLASS(klass);
 307     widget_class->expose_event = calf_line_graph_expose;
 308     widget_class->size_request = calf_line_graph_size_request;
 309     widget_class->size_allocate = calf_line_graph_size_allocate;
 310 }
 311
 312 static void
 313 calf_line_graph_init (CalfLineGraph *self)
 314 {
 315     GtkWidget *widget = GTK_WIDGET(self);
 316     widget->requisition.width = 40;
 317     widget->requisition.height = 40;
 318     self->cache_surface = NULL;
 319     self->last_generation = 0;
 320 }
 321
 322 GtkWidget *
 323 calf_line_graph_new()
 324 {
 325     return GTK_WIDGET( g_object_new (CALF_TYPE_LINE_GRAPH, NULL ));
 326 }
 327
 328 GType
 329 calf_line_graph_get_type (void)
 330 {
 331     static GType type = 0;
 332     if (!type) {
 333         static const GTypeInfo type_info = {
 334             sizeof(CalfLineGraphClass),
 335             NULL, /* base_init */
 336             NULL, /* base_finalize */
 337             (GClassInitFunc)calf_line_graph_class_init,
 338             NULL, /* class_finalize */
 339             NULL, /* class_data */
 340             sizeof(CalfLineGraph),
 341             0,    /* n_preallocs */
 342             (GInstanceInitFunc)calf_line_graph_init
 343         };
 344
 345         GTypeInfo *type_info_copy = new GTypeInfo(type_info);
 346
 347         for (int i = 0; ; i++) {
 348             char *name = g_strdup_printf("CalfLineGraph%u%d", ((unsigned int)(intptr_t)calf_line_graph_class_init) >> 16, i);
 349             if (g_type_from_name(name)) {
 350                 free(name);
 351                 continue;
 352             }
 353             type = g_type_register_static( GTK_TYPE_DRAWING_AREA,
 354                                            name,
 355                                            type_info_copy,
 356                                            (GTypeFlags)0);
 357             free(name);
 358             break;
 359         }
 360     }
 361     return type;
 362 }
 363
 364 ///////////////////////////////////////// vu meter ///////////////////////////////////////////////
 365
 366 static gboolean
 367 calf_vumeter_expose (GtkWidget *widget, GdkEventExpose *event)
 368 {
 369     g_assert(CALF_IS_VUMETER(widget));
 370
 371
 372     CalfVUMeter *vu = CALF_VUMETER(widget);
 373     //int ox = widget->allocation.x + 1, oy = widget->allocation.y + 1;
 374     int ox = 1, oy = 1;
 375     int sx = widget->allocation.width - 2, sy = widget->allocation.height - 2;
 376
 377     cairo_t *c = gdk_cairo_create(GDK_DRAWABLE(widget->window));
 378
 379     GdkColor sc = { 0, 0, 0, 0 };
 380     gdk_cairo_set_source_color(c, &sc);
 381     cairo_rectangle(c, ox, oy, sx, sy);
 382     cairo_fill(c);
 383     cairo_set_line_width(c, 1);
 384
 385     CalfVUMeterMode mode = vu->mode;
 386
 387     for (int x = ox; x <= ox + sx; x += 3)
 388     {
 389         float ts = (x - ox) * 1.0 / sx;
 390         float r = 0.f, g = 0.f, b = 0.f;
 391         switch(mode)
 392         {
 393             case VU_STANDARD:
 394             default:
 395                 if (ts < 0.75)
 396                     r = ts / 0.75, g = 1, b = 0;
 397                 else
 398                     r = 1, g = 1 - (ts - 0.75) / 0.25, b = 0;
 399                 if (vu->value < ts || vu->value <= 0)
 400                     r *= 0.5, g *= 0.5, b *= 0.5;
 401                 break;
 402             case VU_MONOCHROME_REVERSE:
 403                 r = 1, g = 1, b = 0;
 404                 if (!(vu->value < ts) || vu->value >= 1.0)
 405                     r *= 0.5, g *= 0.5, b *= 0.5;
 406                 break;
 407             case VU_MONOCHROME:
 408                 r = 1, g = 1, b = 0;
 409                 if (vu->value < ts || vu->value <= 0)
 410                     r *= 0.5, g *= 0.5, b *= 0.5;
 411                 break;
 412         }
 413         GdkColor sc2 = { 0, (guint16)(65535 * r), (guint16)(65535 * g), (guint16)(65535 * b) };
 414         gdk_cairo_set_source_color(c, &sc2);
 415         cairo_move_to(c, x, oy);
 416         cairo_line_to(c, x, oy + sy + 1);
 417         cairo_move_to(c, x, oy + sy);
 418         cairo_line_to(c, x, oy );
 419         cairo_stroke(c);
 420     }
 421
 422     cairo_destroy(c);
 423
 424     gtk_paint_shadow(widget->style, widget->window, GTK_STATE_NORMAL, GTK_SHADOW_IN, NULL, widget, NULL, ox - 1, oy - 1, sx + 2, sy + 2);
 425     printf("exposed %p %d+%d\n", widget->window, widget->allocation.x, widget->allocation.y);
 426
 427     return TRUE;
 428 }
 429
 430 static void
 431 calf_vumeter_size_request (GtkWidget *widget,
 432                            GtkRequisition *requisition)
 433 {
 434     g_assert(CALF_IS_VUMETER(widget));
 435
 436     requisition->width = 50;
 437     requisition->height = 14;
 438 }
 439
 440 static void
 441 calf_vumeter_size_allocate (GtkWidget *widget,
 442                            GtkAllocation *allocation)
 443 {
 444     g_assert(CALF_IS_VUMETER(widget));
 445
 446     widget->allocation = *allocation;
 447 }
 448
 449 static void
 450 calf_vumeter_class_init (CalfVUMeterClass *klass)
 451 {
 452     GtkWidgetClass *widget_class = GTK_WIDGET_CLASS(klass);
 453     widget_class->expose_event = calf_vumeter_expose;
 454     widget_class->size_request = calf_vumeter_size_request;
 455     //widget_class->size_allocate = calf_vumeter_size_allocate;
 456 }
 457
 458 static void
 459 calf_vumeter_init (CalfVUMeter *self)
 460 {
 461     GtkWidget *widget = GTK_WIDGET(self);
 462     //GTK_WIDGET_SET_FLAGS (widget, GTK_NO_WINDOW);
 463     widget->requisition.width = 50;
 464     widget->requisition.height = 15;
 465     self->value = 0.5;
 466 }
 467
 468 GtkWidget *
 469 calf_vumeter_new()
 470 {
 471     return GTK_WIDGET( g_object_new (CALF_TYPE_VUMETER, NULL ));
 472 }
 473
 474 GType
 475 calf_vumeter_get_type (void)
 476 {
 477     static GType type = 0;
 478     if (!type) {
 479         static const GTypeInfo type_info = {
 480             sizeof(CalfVUMeterClass),
 481             NULL, /* base_init */
 482             NULL, /* base_finalize */
 483             (GClassInitFunc)calf_vumeter_class_init,
 484             NULL, /* class_finalize */
 485             NULL, /* class_data */
 486             sizeof(CalfVUMeter),
 487             0,    /* n_preallocs */
 488             (GInstanceInitFunc)calf_vumeter_init
 489         };
 490
 491         GTypeInfo *type_info_copy = new GTypeInfo(type_info);
 492
 493         for (int i = 0; ; i++) {
 494             char *name = g_strdup_printf("CalfVUMeter%u%d", ((unsigned int)(intptr_t)calf_vumeter_class_init) >> 16, i);
 495             if (g_type_from_name(name)) {
 496                 free(name);
 497                 continue;
 498             }
 499             type = g_type_register_static( GTK_TYPE_DRAWING_AREA,
 500                                            name,
 501                                            type_info_copy,
 502                                            (GTypeFlags)0);
 503             free(name);
 504             break;
 505         }
 506     }
 507     return type;
 508 }
 509
 510 extern void calf_vumeter_set_value(CalfVUMeter *meter, float value)
 511 {
 512     if (value != meter->value)
 513     {
 514         meter->value = value;
 515         gtk_widget_queue_draw(GTK_WIDGET(meter));
 516     }
 517 }
 518
 519 extern float calf_vumeter_get_value(CalfVUMeter *meter)
 520 {
 521     return meter->value;
 522 }
 523
 524 extern void calf_vumeter_set_mode(CalfVUMeter *meter, CalfVUMeterMode mode)
 525 {
 526     if (mode != meter->mode)
 527     {
 528         meter->mode = mode;
 529         gtk_widget_queue_draw(GTK_WIDGET(meter));
 530     }
 531 }
 532
 533 extern CalfVUMeterMode calf_vumeter_get_mode(CalfVUMeter *meter)
 534 {
 535     return meter->mode;
 536 }
 537
 538 ///////////////////////////////////////// knob ///////////////////////////////////////////////
 539
 540 static gboolean
 541 calf_knob_expose (GtkWidget *widget, GdkEventExpose *event)
 542 {
 543     g_assert(CALF_IS_KNOB(widget));
 544
 545     CalfKnob *self = CALF_KNOB(widget);
 546     GdkWindow *window = widget->window;
 547     GtkAdjustment *adj = gtk_range_get_adjustment(GTK_RANGE(widget));
 548
 549     // printf("adjustment = %p value = %f\n", adj, adj->value);
 550     int ox = widget->allocation.x, oy = widget->allocation.y;
 551
 552     ox += (widget->allocation.width - 40) / 2;
 553     oy += (widget->allocation.height - 40) / 2;
 554
 555     int phase = (int)((adj->value - adj->lower) * 64 / (adj->upper - adj->lower));
 556     // skip middle phase except for true middle value
 557     if (self->knob_type == 1 && phase == 32) {
 558         double pt = (adj->value - adj->lower) * 2.0 / (adj->upper - adj->lower) - 1.0;
 559         if (pt < 0)
 560             phase = 31;
 561         if (pt > 0)
 562             phase = 33;
 563     }
 564     // endless knob: skip 90deg highlights unless the value is really a multiple of 90deg
 565     if (self->knob_type == 3 && !(phase % 16)) {
 566         if (phase == 64)
 567             phase = 0;
 568         double nom = adj->lower + phase * (adj->upper - adj->lower) / 64.0;
 569         double diff = (adj->value - nom) / (adj->upper - adj->lower);
 570         if (diff > 0.0001)
 571             phase = (phase + 1) % 64;
 572         if (diff < -0.0001)
 573             phase = (phase + 63) % 64;
 574     }
 575     gdk_draw_pixbuf(GDK_DRAWABLE(widget->window), widget->style->fg_gc[0], CALF_KNOB_CLASS(GTK_OBJECT_GET_CLASS(widget))->knob_image, phase * 40, self->knob_type * 40, ox, oy, 40, 40, GDK_RGB_DITHER_NORMAL, 0, 0);
 576     // printf("exposed %p %d+%d\n", widget->window, widget->allocation.x, widget->allocation.y);
 577     if (gtk_widget_is_focus(widget))
 578     {
 579         gtk_paint_focus(widget->style, window, GTK_STATE_NORMAL, NULL, widget, NULL, ox, oy, 40, 40);
 580     }
 581
 582     return TRUE;
 583 }
 584
 585 static void
 586 calf_knob_size_request (GtkWidget *widget,
 587                            GtkRequisition *requisition)
 588 {
 589     g_assert(CALF_IS_KNOB(widget));
 590
 591     // width/height is hardwired at 40px now
 592     requisition->width = 40;
 593     requisition->height = 40;
 594 }
 595
 596 static void
 597 calf_knob_incr (GtkWidget *widget, int dir_down)
 598 {
 599     g_assert(CALF_IS_KNOB(widget));
 600     CalfKnob *self = CALF_KNOB(widget);
 601     GtkAdjustment *adj = gtk_range_get_adjustment(GTK_RANGE(widget));
 602
 603     int oldstep = (int)(0.5f + (adj->value - adj->lower) / adj->step_increment);
 604     int step;
 605     int nsteps = (int)(0.5f + (adj->upper - adj->lower) / adj->step_increment); // less 1 actually
 606     if (dir_down)
 607         step = oldstep - 1;
 608     else
 609         step = oldstep + 1;
 610     if (self->knob_type == 3 && step >= nsteps)
 611         step %= nsteps;
 612     if (self->knob_type == 3 && step < 0)
 613         step = nsteps - (nsteps - step) % nsteps;
 614
 615     // trying to reduce error cumulation here, by counting from lowest or from highest
 616     float value = adj->lower + step * double(adj->upper - adj->lower) / nsteps;
 617     gtk_range_set_value(GTK_RANGE(widget), value);
 618     // printf("step %d:%d nsteps %d value %f:%f\n", oldstep, step, nsteps, oldvalue, value);
 619 }
 620
 621 static gboolean
 622 calf_knob_key_press (GtkWidget *widget, GdkEventKey *event)
 623 {
 624     g_assert(CALF_IS_KNOB(widget));
 625     CalfKnob *self = CALF_KNOB(widget);
 626     GtkAdjustment *adj = gtk_range_get_adjustment(GTK_RANGE(widget));
 627
 628     switch(event->keyval)
 629     {
 630         case GDK_Home:
 631             gtk_range_set_value(GTK_RANGE(widget), adj->lower);
 632             return TRUE;
 633
 634         case GDK_End:
 635             gtk_range_set_value(GTK_RANGE(widget), adj->upper);
 636             return TRUE;
 637
 638         case GDK_Up:
 639             calf_knob_incr(widget, 0);
 640             return TRUE;
 641
 642         case GDK_Down:
 643             calf_knob_incr(widget, 1);
 644             return TRUE;
 645
 646         case GDK_Shift_L:
 647         case GDK_Shift_R:
 648             self->start_value = gtk_range_get_value(GTK_RANGE(widget));
 649             self->start_y = self->last_y;
 650             return TRUE;
 651     }
 652
 653     return FALSE;
 654 }
 655
 656 static gboolean
 657 calf_knob_key_release (GtkWidget *widget, GdkEventKey *event)
 658 {
 659     g_assert(CALF_IS_KNOB(widget));
 660     CalfKnob *self = CALF_KNOB(widget);
 661
 662     if(event->keyval == GDK_Shift_L || event->keyval == GDK_Shift_R)
 663     {
 664         self->start_value = gtk_range_get_value(GTK_RANGE(widget));
 665         self->start_y = self->last_y;
 666         return TRUE;
 667     }
 668
 669     return FALSE;
 670 }
 671
 672 static gboolean
 673 calf_knob_button_press (GtkWidget *widget, GdkEventButton *event)
 674 {
 675     g_assert(CALF_IS_KNOB(widget));
 676     CalfKnob *self = CALF_KNOB(widget);
 677
 678     // CalfKnob *lg = CALF_KNOB(widget);
 679     gtk_widget_grab_focus(widget);
 680     gtk_grab_add(widget);
 681     self->start_x = event->x;
 682     self->start_y = event->y;
 683     self->start_value = gtk_range_get_value(GTK_RANGE(widget));
 684
 685     return TRUE;
 686 }
 687
 688 static gboolean
 689 calf_knob_button_release (GtkWidget *widget, GdkEventButton *event)
 690 {
 691     g_assert(CALF_IS_KNOB(widget));
 692
 693     if (GTK_WIDGET_HAS_GRAB(widget))
 694         gtk_grab_remove(widget);
 695     return FALSE;
 696 }
 697
 698 static inline float endless(float value)
 699 {
 700     if (value >= 0)
 701         return fmod(value, 1.f);
 702     else
 703         return fmod(1.f - fmod(1.f - value, 1.f), 1.f);
 704 }
 705
 706 static inline float deadzone(float value, float incr, float scale)
 707 {
 708     float dzw = 10 / scale;
 709     if (value >= 0.501)
 710         value += dzw;
 711     if (value < 0.499)
 712         value -= dzw;
 713
 714     value += incr;
 715
 716     if (value >= (0.5 - dzw) && value <= (0.5 + dzw))
 717         return 0.5;
 718     if (value < 0.5)
 719         return value + dzw;
 720     return value - dzw;
 721 }
 722
 723 static gboolean
 724 calf_knob_pointer_motion (GtkWidget *widget, GdkEventMotion *event)
 725 {
 726     g_assert(CALF_IS_KNOB(widget));
 727     CalfKnob *self = CALF_KNOB(widget);
 728
 729     float scale = (event->state & GDK_SHIFT_MASK) ? 1000 : 100;
 730     gboolean moved = FALSE;
 731
 732     if (GTK_WIDGET_HAS_GRAB(widget))
 733     {
 734         if (self->knob_type == 3)
 735         {
 736             gtk_range_set_value(GTK_RANGE(widget), endless(self->start_value - (event->y - self->start_y) / scale));
 737         }
 738         else
 739         if (self->knob_type == 1)
 740         {
 741             gtk_range_set_value(GTK_RANGE(widget), deadzone(self->start_value, -(event->y - self->start_y) / scale, scale));
 742         }
 743         else
 744         {
 745             gtk_range_set_value(GTK_RANGE(widget), self->start_value - (event->y - self->start_y) / scale);
 746         }
 747         moved = TRUE;
 748     }
 749     self->last_y = event->y;
 750     return moved;
 751 }
 752
 753 static gboolean
 754 calf_knob_scroll (GtkWidget *widget, GdkEventScroll *event)
 755 {
 756     calf_knob_incr(widget, event->direction);
 757     return TRUE;
 758 }
 759
 760 static void
 761 calf_knob_class_init (CalfKnobClass *klass)
 762 {
 763     // GObjectClass *gobject_class = G_OBJECT_CLASS(klass);
 764     GtkWidgetClass *widget_class = GTK_WIDGET_CLASS(klass);
 765     widget_class->expose_event = calf_knob_expose;
 766     widget_class->size_request = calf_knob_size_request;
 767     widget_class->button_press_event = calf_knob_button_press;
 768     widget_class->button_release_event = calf_knob_button_release;
 769     widget_class->motion_notify_event = calf_knob_pointer_motion;
 770     widget_class->key_press_event = calf_knob_key_press;
 771     widget_class->key_release_event = calf_knob_key_release;
 772     widget_class->scroll_event = calf_knob_scroll;
 773     GError *error = NULL;
 774     klass->knob_image = gdk_pixbuf_new_from_file(PKGLIBDIR "/knob.png", &error);
 775     g_assert(klass->knob_image != NULL);
 776 }
 777
 778 static void
 779 calf_knob_init (CalfKnob *self)
 780 {
 781     GtkWidget *widget = GTK_WIDGET(self);
 782     GTK_WIDGET_SET_FLAGS (GTK_WIDGET(self), GTK_CAN_FOCUS);
 783     widget->requisition.width = 40;
 784     widget->requisition.height = 40;
 785 }
 786
 787 GtkWidget *
 788 calf_knob_new()
 789 {
 790     GtkAdjustment *adj = (GtkAdjustment *)gtk_adjustment_new(0, 0, 1, 0.01, 0.5, 0);
 791     return calf_knob_new_with_adjustment(adj);
 792 }
 793
 794 static gboolean calf_knob_value_changed(gpointer obj)
 795 {
 796     GtkWidget *widget = (GtkWidget *)obj;
 797     gtk_widget_queue_draw(widget);
 798     return FALSE;
 799 }
 800
 801 GtkWidget *calf_knob_new_with_adjustment(GtkAdjustment *_adjustment)
 802 {
 803     GtkWidget *widget = GTK_WIDGET( g_object_new (CALF_TYPE_KNOB, NULL ));
 804     if (widget) {
 805         gtk_range_set_adjustment(GTK_RANGE(widget), _adjustment);
 806         gtk_signal_connect(GTK_OBJECT(widget), "value-changed", G_CALLBACK(calf_knob_value_changed), widget);
 807     }
 808     return widget;
 809 }
 810
 811 GType
 812 calf_knob_get_type (void)
 813 {
 814     static GType type = 0;
 815     if (!type) {
 816
 817         static const GTypeInfo type_info = {
 818             sizeof(CalfKnobClass),
 819             NULL, /* base_init */
 820             NULL, /* base_finalize */
 821             (GClassInitFunc)calf_knob_class_init,
 822             NULL, /* class_finalize */
 823             NULL, /* class_data */
 824             sizeof(CalfKnob),
 825             0,    /* n_preallocs */
 826             (GInstanceInitFunc)calf_knob_init
 827         };
 828
 829         for (int i = 0; ; i++) {
 830             char *name = g_strdup_printf("CalfKnob%u%d",
 831                 ((unsigned int)(intptr_t)calf_knob_class_init) >> 16, i);
 832             if (g_type_from_name(name)) {
 833                 free(name);
 834                 continue;
 835             }
 836             type = g_type_register_static(GTK_TYPE_RANGE,
 837                                           name,
 838                                           &type_info,
 839                                           (GTypeFlags)0);
 840             free(name);
 841             break;
 842         }
 843     }
 844     return type;
 845 }
 846