src/calf/ctl_curve.h

   1 /* Calf DSP Library
   2  * Barely started curve editor widget. Standard GtkCurve is
   3  * unreliable and deprecated, so I need to make my own.
   4  *
   5  * Copyright (C) 2008 Krzysztof Foltman
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2 of the License, or (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General
  18  * Public License along with this program; if not, write to the
  19  * Free Software Foundation, Inc., 59 Temple Place, Suite 330,
  20  * Boston, MA 02111-1307, USA.
  21  */
  22 #ifndef CALF_CTL_CURVE_H
  23 #define CALF_CTL_CURVE_H
  24
  25 #include <gtk/gtk.h>
  26 #include <vector>
  27
  28 G_BEGIN_DECLS
  29
  30 #define CALF_TYPE_CURVE          (calf_curve_get_type())
  31 #define CALF_CURVE(obj)          (G_TYPE_CHECK_INSTANCE_CAST ((obj), CALF_TYPE_CURVE, CalfCurve))
  32 #define CALF_IS_CURVE(obj)       (G_TYPE_CHECK_INSTANCE_TYPE ((obj), CALF_TYPE_CURVE))
  33 #define CALF_CURVE_CLASS(klass)  (G_TYPE_CHECK_CLASS_CAST ((klass),  CALF_TYPE_CURVE, CalfCurveClass))
  34 #define CALF_IS_CURVE_CLASS(obj) (G_TYPE_CHECK_CLASS_TYPE ((klass),  CALF_TYPE_CURVE))
  35
  36 /// Mapping curve editor control. May be used for editing multisegment lines (key mapping,
  37 /// velocity mapping etc). This version isn't suitable for envelope editing because both
  38 /// ends (start and end) have fixed X coordinates and it doesn't resize.
  39 struct CalfCurve
  40 {
  41     /// A point with floating point X and Y coordinates
  42     typedef std::pair<float, float> point;
  43     /// A collection of points
  44     typedef std::vector<point> point_vector;
  45
  46     /// User callbacks for handling curve events
  47     struct EventSink
  48     {
  49         /// Called when a point has been edited, added or removed
  50         virtual void curve_changed(CalfCurve *src, const point_vector &data) = 0;
  51         /// Called to clip/snap/otherwise adjust candidate point coordinates
  52         virtual void clip(CalfCurve *src, int pt, float &x, float &y, bool &hide) = 0;
  53         virtual ~EventSink() {}
  54     };
  55
  56     /// Null implementation of EventSink
  57     struct EventAdapter: public EventSink
  58     {
  59         virtual void curve_changed(CalfCurve *src, const point_vector &data) {}
  60         virtual void clip(CalfCurve *src, int pt, float &x, float &y, bool &hide) {}
  61     };
  62
  63     /// Debug implementation of EventSink
  64     struct EventTester: public EventAdapter
  65     {
  66         virtual void curve_changed(CalfCurve *src, const point_vector &data) {
  67             for(size_t i = 0; i < data.size(); i++)
  68                 g_message("Point %d: (%f, %f)", (int)i, data[i].first, data[i].second);
  69         }
  70     };
  71
  72     /// Base class instance members
  73     GtkWidget parent;
  74     /// Array of points
  75     point_vector *points;
  76     /// Coordinate ranges (in logical coordinates for top left and bottom right)
  77     float x0, y0, x1, y1;
  78     /// Currently selected point (when dragging/adding), or -1 if none is selected
  79     int cur_pt;
  80     /// If currently selected point is a candidate for deletion (ie. outside of graph+margin range)
  81     bool hide_current;
  82     /// Interface for notification
  83     EventSink *sink;
  84     /// Cached hand (drag) cursor
  85     GdkCursor *hand_cursor;
  86     /// Cached pencil (add point) cursor
  87     GdkCursor *pencil_cursor;
  88     /// Cached arrow (do not add point) cursor
  89     GdkCursor *arrow_cursor;
  90     /// Maximum number of points
  91     unsigned int point_limit;
  92
  93     /// Convert logical (mapping) to physical (screen) coordinates
  94     void log2phys(float &x, float &y);
  95     /// Convert physical (screen) to logical (mapping) coordinates
  96     void phys2log(float &x, float &y);
  97     /// Clip function
  98     /// @param pt point being clipped
  99     /// @param x horizontal logical coordinate
 100     /// @param y vertical logical coordinate
 101     /// @param hide true if point is outside "valid" range and about to be deleted
 102     void clip(int pt, float &x, float &y, bool &hide);
 103 };
 104
 105 struct CalfCurveClass
 106 {
 107     GtkWidgetClass parent_class;
 108 };
 109
 110 /// Create a CalfCurve
 111 extern GtkWidget *calf_curve_new(unsigned int point_limit = -1);
 112
 113 /// Return a GObject type for class CalfCurve
 114 extern GType calf_curve_get_type();
 115
 116 /// Set points and update the widget
 117 extern void calf_curve_set_points(GtkWidget *widget, const CalfCurve::point_vector &src);
 118
 119 G_END_DECLS
 120
 121 #endif
 122