C++11 tidying.
[dcpomatic.git] / src / wx / audio_mapping_view.cc
index 27094d3b2b9eca099c939459089d87cd5e1d829a..7c12a16462d52eacad9e9e0e810c65d017ceb345 100644 (file)
@@ -1,5 +1,5 @@
 /*
-    Copyright (C) 2013-2019 Carl Hetherington <cth@carlh.net>
+    Copyright (C) 2013-2021 Carl Hetherington <cth@carlh.net>
 
     This file is part of DCP-o-matic.
 
 
 */
 
+
 /** @file  src/wx/audio_mapping_view.cc
  *  @brief AudioMappingView class and helpers.
  */
 
+
 #include "audio_mapping_view.h"
 #include "wx_util.h"
 #include "audio_gain_dialog.h"
 #include "lib/audio_mapping.h"
 #include "lib/util.h"
+#include "lib/warnings.h"
 #include <dcp/locale_convert.h>
 #include <dcp/types.h>
+DCPOMATIC_DISABLE_WARNINGS
 #include <wx/wx.h>
 #include <wx/renderer.h>
 #include <wx/grid.h>
 #include <wx/graphics.h>
-#include <boost/foreach.hpp>
+DCPOMATIC_ENABLE_WARNINGS
 #include <iostream>
 
+
 using std::cout;
 using std::list;
 using std::string;
@@ -44,41 +49,61 @@ using std::max;
 using std::vector;
 using std::pair;
 using std::make_pair;
-using boost::shared_ptr;
+using std::shared_ptr;
 using boost::optional;
+#if BOOST_VERSION >= 106100
+using namespace boost::placeholders;
+#endif
 using dcp::locale_convert;
 
-#define INDICATOR_SIZE 20
-#define GRID_SPACING 32
-#define LEFT_WIDTH (GRID_SPACING * 3)
-#define TOP_HEIGHT (GRID_SPACING * 2)
+
+static constexpr auto INDICATOR_SIZE = 20;
+static constexpr auto ROW_HEIGHT = 32;
+static constexpr auto MINIMUM_COLUMN_WIDTH = 32;
+static constexpr auto LEFT_WIDTH = MINIMUM_COLUMN_WIDTH * 3;
+static constexpr auto TOP_HEIGHT = ROW_HEIGHT * 2;
+static constexpr auto COLUMN_PADDING = 16;
+static constexpr auto HORIZONTAL_PAGE_SIZE = 32;
+
 
 enum {
        ID_off = 1,
-       ID_full = 2,
-       ID_minus6dB = 3,
-       ID_edit = 4
+       ID_minus6dB = 2,
+       ID_0dB = 3,
+       ID_plus3dB = 4,
+       ID_edit = 5
 };
 
-AudioMappingView::AudioMappingView (wxWindow* parent)
+
+AudioMappingView::AudioMappingView (wxWindow* parent, wxString left_label, wxString from, wxString top_label, wxString to)
        : wxPanel (parent, wxID_ANY)
        , _menu_input (0)
        , _menu_output (1)
+       , _left_label (left_label)
+       , _from (from)
+       , _top_label (top_label)
+       , _to (to)
 {
        _menu = new wxMenu;
        _menu->Append (ID_off, _("Off"));
-       _menu->Append (ID_full, _("Full"));
        _menu->Append (ID_minus6dB, _("-6dB"));
+       _menu->Append (ID_0dB, _("0dB (unchanged)"));
+       _menu->Append (ID_plus3dB, _("+3dB"));
        _menu->Append (ID_edit, _("Edit..."));
 
        _body = new wxPanel (this, wxID_ANY);
        _vertical_scroll = new wxScrollBar (this, wxID_ANY, wxDefaultPosition, wxDefaultSize, wxSB_VERTICAL);
        _horizontal_scroll = new wxScrollBar (this, wxID_ANY);
 
+#ifndef __WXOSX__
+       SetDoubleBuffered (true);
+#endif
+
        Bind (wxEVT_SIZE, boost::bind(&AudioMappingView::size, this, _1));
-       Bind (wxEVT_MENU, boost::bind(&AudioMappingView::off, this), ID_off);
-       Bind (wxEVT_MENU, boost::bind(&AudioMappingView::full, this), ID_full);
-       Bind (wxEVT_MENU, boost::bind(&AudioMappingView::minus6dB, this), ID_minus6dB);
+       Bind (wxEVT_MENU, boost::bind(&AudioMappingView::set_gain_from_menu, this, 0), ID_off);
+       Bind (wxEVT_MENU, boost::bind(&AudioMappingView::set_gain_from_menu, this, db_to_linear(-6)), ID_minus6dB);
+       Bind (wxEVT_MENU, boost::bind(&AudioMappingView::set_gain_from_menu, this, 1), ID_0dB);
+       Bind (wxEVT_MENU, boost::bind(&AudioMappingView::set_gain_from_menu, this, db_to_linear(3)), ID_plus3dB);
        Bind (wxEVT_MENU, boost::bind(&AudioMappingView::edit, this), ID_edit);
        Bind (wxEVT_MOUSEWHEEL, boost::bind(&AudioMappingView::mouse_wheel, this, _1));
        _body->Bind (wxEVT_PAINT, boost::bind(&AudioMappingView::paint, this));
@@ -103,6 +128,7 @@ AudioMappingView::AudioMappingView (wxWindow* parent)
        _horizontal_scroll->Bind (wxEVT_SCROLL_THUMBRELEASE, boost::bind(&AudioMappingView::scroll, this));
 }
 
+
 void
 AudioMappingView::size (wxSizeEvent& ev)
 {
@@ -110,10 +136,11 @@ AudioMappingView::size (wxSizeEvent& ev)
        ev.Skip ();
 }
 
+
 void
 AudioMappingView::setup ()
 {
-       wxSize const s = GetSize();
+       auto const s = GetSize();
        int const w = _vertical_scroll->GetSize().GetWidth();
        int const h = _horizontal_scroll->GetSize().GetHeight();
 
@@ -128,276 +155,350 @@ AudioMappingView::setup ()
        _vertical_scroll->SetScrollbar (
                _vertical_scroll->GetThumbPosition(),
                s.GetHeight() - h - 8,
-               GRID_SPACING * (2 + _input_channels.size()),
-               GRID_SPACING,
+               ROW_HEIGHT * (2 + _input_channels.size()),
+               ROW_HEIGHT,
                true
                );
 
+       wxClientDC dc (GetParent());
+       dc.SetFont (wxSWISS_FONT->Bold());
+
+       _column_widths.clear ();
+       _column_widths.reserve (_output_channels.size());
+       _column_widths_total = 0;
+
+       for (auto const& i: _output_channels) {
+               wxCoord width;
+               wxCoord height;
+               dc.GetTextExtent (std_to_wx(i.name), &width, &height);
+               auto const this_width = max(width + COLUMN_PADDING, MINIMUM_COLUMN_WIDTH);
+               _column_widths.push_back (this_width);
+               _column_widths_total += this_width;
+       }
+
        _horizontal_scroll->SetScrollbar (
                _horizontal_scroll->GetThumbPosition(),
                s.GetWidth() - w - 8,
-               GRID_SPACING * (3 + _output_channels.size()),
-               GRID_SPACING,
+               LEFT_WIDTH + _column_widths_total,
+               HORIZONTAL_PAGE_SIZE,
                true);
 }
 
+
 void
 AudioMappingView::scroll ()
 {
        Refresh ();
 }
 
+
 void
-AudioMappingView::paint_static (wxDC& dc, wxGraphicsContext* gc)
+AudioMappingView::paint_static (wxDC& dc)
 {
-       gc->SetAntialiasMode (wxANTIALIAS_DEFAULT);
        dc.SetFont (wxSWISS_FONT->Bold());
        wxCoord label_width;
        wxCoord label_height;
 
-       /* DCP label at the top */
-
-       dc.GetTextExtent (_("DCP"), &label_width, &label_height);
-       dc.DrawText (_("DCP"), LEFT_WIDTH + (_output_channels.size() * GRID_SPACING - label_width) / 2, (GRID_SPACING - label_height) / 2);
-
-       /* Content label on the left */
+       dc.GetTextExtent (_top_label, &label_width, &label_height);
+       dc.DrawText (_top_label, LEFT_WIDTH + (_column_widths_total - label_width) / 2, (ROW_HEIGHT - label_height) / 2);
 
-       dc.GetTextExtent (_("Content"), &label_width, &label_height);
+       dc.GetTextExtent (_left_label, &label_width, &label_height);
        dc.DrawRotatedText (
-               _("Content"),
-               (GRID_SPACING - label_height) / 2,
-               TOP_HEIGHT + (_input_channels.size() * GRID_SPACING + label_width) / 2,
+               _left_label,
+               (ROW_HEIGHT - label_height) / 2,
+               TOP_HEIGHT + (_input_channels.size() * ROW_HEIGHT + label_width) / 2,
                90
                );
 
        dc.SetFont (*wxSWISS_FONT);
-       gc->SetPen (*wxBLACK_PEN);
 }
 
+
 void
-AudioMappingView::paint_column_labels (wxDC& dc, wxGraphicsContext* gc)
+AudioMappingView::paint_column_labels (wxDC& dc)
 {
        wxCoord label_width;
        wxCoord label_height;
-       int N = 0;
-       BOOST_FOREACH (string i, _output_channels) {
-               dc.GetTextExtent (std_to_wx(i), &label_width, &label_height);
-               dc.DrawText (std_to_wx(i), LEFT_WIDTH + GRID_SPACING * N + (GRID_SPACING - label_width) / 2, GRID_SPACING + (GRID_SPACING - label_height) / 2);
-               ++N;
+       int x = LEFT_WIDTH;
+       for (auto i = 0U; i < _output_channels.size(); ++i) {
+               auto const name = std_to_wx(_output_channels[i].name);
+               dc.GetTextExtent (name, &label_width, &label_height);
+               dc.DrawText (name, x + (_column_widths[i] - label_width) / 2, ROW_HEIGHT + (ROW_HEIGHT - label_height) / 2);
+               x += _column_widths[i];
        }
 
-       wxGraphicsPath lines = gc->CreatePath ();
-       lines.MoveToPoint (LEFT_WIDTH, GRID_SPACING);
-       lines.AddLineToPoint (LEFT_WIDTH + _output_channels.size() * GRID_SPACING, GRID_SPACING);
-       lines.MoveToPoint (LEFT_WIDTH, GRID_SPACING * 2);
-       lines.AddLineToPoint (LEFT_WIDTH + _output_channels.size() * GRID_SPACING, GRID_SPACING * 2);
-       gc->StrokePath (lines);
+       dc.DrawLine(wxPoint(LEFT_WIDTH, ROW_HEIGHT), wxPoint(LEFT_WIDTH + _column_widths_total, ROW_HEIGHT));
+       dc.DrawLine(wxPoint(LEFT_WIDTH, ROW_HEIGHT * 2), wxPoint(LEFT_WIDTH + _column_widths_total, ROW_HEIGHT * 2));
 }
 
+
 void
-AudioMappingView::paint_column_lines (wxGraphicsContext* gc)
+AudioMappingView::paint_column_lines (wxDC& dc)
 {
-       wxGraphicsPath lines = gc->CreatePath ();
+       int x = LEFT_WIDTH;
        for (size_t i = 0; i < _output_channels.size(); ++i) {
-               lines.MoveToPoint    (LEFT_WIDTH + GRID_SPACING * i, GRID_SPACING);
-               lines.AddLineToPoint (LEFT_WIDTH + GRID_SPACING * i, TOP_HEIGHT + _input_channels.size() * GRID_SPACING);
+               dc.DrawLine (
+                       wxPoint(x, ROW_HEIGHT),
+                       wxPoint(x, TOP_HEIGHT + _input_channels.size() * ROW_HEIGHT)
+                       );
+               x += _column_widths[i];
        }
-       lines.MoveToPoint    (LEFT_WIDTH + GRID_SPACING * _output_channels.size(), GRID_SPACING);
-       lines.AddLineToPoint (LEFT_WIDTH + GRID_SPACING * _output_channels.size(), TOP_HEIGHT + _input_channels.size() * GRID_SPACING);
-       gc->StrokePath (lines);
+
+       dc.DrawLine (
+               wxPoint(LEFT_WIDTH + _column_widths_total, ROW_HEIGHT),
+               wxPoint(LEFT_WIDTH + _column_widths_total, TOP_HEIGHT + _input_channels.size() * ROW_HEIGHT)
+               );
 }
 
+
 void
-AudioMappingView::paint_row_labels (wxDC& dc, wxGraphicsContext* gc)
+AudioMappingView::paint_row_labels (wxDC& dc)
 {
        wxCoord label_width;
        wxCoord label_height;
-       wxGraphicsPath lines = gc->CreatePath ();
 
        /* Row channel labels */
 
-       int N = 0;
-       BOOST_FOREACH (string i, _input_channels) {
-               dc.GetTextExtent (std_to_wx(i), &label_width, &label_height);
-               dc.DrawText (std_to_wx(i), GRID_SPACING * 2 + (GRID_SPACING - label_width) / 2, TOP_HEIGHT + GRID_SPACING * N + (GRID_SPACING - label_height) / 2);
-               ++N;
+       for (auto i = 0U; i < _input_channels.size(); ++i) {
+               auto const name = std_to_wx(_input_channels[i].name);
+               dc.GetTextExtent (name, &label_width, &label_height);
+               dc.DrawText (name, LEFT_WIDTH - MINIMUM_COLUMN_WIDTH + (MINIMUM_COLUMN_WIDTH - label_width) / 2, TOP_HEIGHT + ROW_HEIGHT * i + (ROW_HEIGHT - label_height) / 2);
        }
 
        /* Vertical lines on the left */
 
        for (int i = 1; i < 3; ++i) {
-               lines.MoveToPoint    (GRID_SPACING * i, TOP_HEIGHT);
-               lines.AddLineToPoint (GRID_SPACING * i, TOP_HEIGHT + _input_channels.size() * GRID_SPACING);
+               dc.DrawLine (
+                       wxPoint(MINIMUM_COLUMN_WIDTH * i, TOP_HEIGHT),
+                       wxPoint(MINIMUM_COLUMN_WIDTH * i, TOP_HEIGHT + _input_channels.size() * ROW_HEIGHT)
+                       );
        }
 
-       /* Group labels and lines */
-
        int y = TOP_HEIGHT;
-       BOOST_FOREACH (Group i, _input_groups) {
-               dc.GetTextExtent (std_to_wx(i.name), &label_width, &label_height);
-               int const height = (i.to - i.from + 1) * GRID_SPACING;
-               dc.DrawRotatedText (
-                       std_to_wx(i.name),
-                       GRID_SPACING + (GRID_SPACING - label_height) / 2,
-                       y + (height + label_width) / 2,
-                       90
-                       );
-               lines.MoveToPoint    (GRID_SPACING,     y);
-               lines.AddLineToPoint (GRID_SPACING * 2, y);
-               y += height;
+       for (auto const& i: _input_groups) {
+               dc.DrawLine (wxPoint(MINIMUM_COLUMN_WIDTH, y), wxPoint(MINIMUM_COLUMN_WIDTH * 2, y));
+               y += (i.to - i.from + 1) * ROW_HEIGHT;
        }
+       dc.DrawLine (wxPoint(MINIMUM_COLUMN_WIDTH, y), wxPoint(MINIMUM_COLUMN_WIDTH * 2, y));
+
+       /* Group labels and lines; be careful here as wxDCClipper does not restore the old
+        * clipping rectangle after it is destroyed
+        */
+       y = TOP_HEIGHT;
+       for (auto const& i: _input_groups) {
+               int const height = (i.to - i.from + 1) * ROW_HEIGHT;
+               dc.GetTextExtent (std_to_wx(i.name), &label_width, &label_height);
+               if (label_width > height) {
+                       label_width = height - 8;
+               }
 
-       lines.MoveToPoint    (GRID_SPACING,     y);
-       lines.AddLineToPoint (GRID_SPACING * 2, y);
+               {
+                       wxDCClipper clip (dc, wxRect(MINIMUM_COLUMN_WIDTH, y, ROW_HEIGHT, height));
+                       int yp = y;
+                       if ((yp - 2 * ROW_HEIGHT) < dc.GetLogicalOrigin().y) {
+                               yp += dc.GetLogicalOrigin().y;
+                       }
 
-       gc->StrokePath (lines);
+                       dc.DrawRotatedText (
+                               std_to_wx(i.name),
+                               ROW_HEIGHT + (ROW_HEIGHT - label_height) / 2,
+                               y + (height + label_width) / 2,
+                               90
+                               );
+               }
+
+               y += height;
+       }
 }
 
+
 void
-AudioMappingView::paint_row_lines (wxGraphicsContext* gc)
+AudioMappingView::paint_row_lines (wxDC& dc)
 {
-       wxGraphicsPath lines = gc->CreatePath ();
        for (size_t i = 0; i < _input_channels.size(); ++i) {
-               lines.MoveToPoint (GRID_SPACING * 2, TOP_HEIGHT + GRID_SPACING * i);
-               lines.AddLineToPoint (LEFT_WIDTH + _output_channels.size() * GRID_SPACING, TOP_HEIGHT + GRID_SPACING * i);
+               dc.DrawLine (
+                       wxPoint(MINIMUM_COLUMN_WIDTH * 2, TOP_HEIGHT + ROW_HEIGHT * i),
+                       wxPoint(LEFT_WIDTH + _column_widths_total, TOP_HEIGHT + ROW_HEIGHT * i)
+                       );
        }
-       lines.MoveToPoint (GRID_SPACING * 2, TOP_HEIGHT + GRID_SPACING * _input_channels.size());
-       lines.AddLineToPoint (LEFT_WIDTH + _output_channels.size() * GRID_SPACING, TOP_HEIGHT + GRID_SPACING * _input_channels.size());
-       gc->StrokePath (lines);
+       dc.DrawLine (
+               wxPoint(MINIMUM_COLUMN_WIDTH * 2, TOP_HEIGHT + ROW_HEIGHT * _input_channels.size()),
+               wxPoint(LEFT_WIDTH + _column_widths_total, TOP_HEIGHT + ROW_HEIGHT * _input_channels.size())
+               );
 }
 
+
 void
 AudioMappingView::paint_indicators (wxDC& dc)
 {
-       for (size_t x = 0; x < _output_channels.size(); ++x) {
-               for (size_t y = 0; y < _input_channels.size(); ++y) {
+       /* _{input,output}_channels and _map may not always be in sync, be careful here */
+       size_t const output = min(_output_channels.size(), size_t(_map.output_channels()));
+       size_t const input = min(_input_channels.size(), size_t(_map.input_channels()));
+
+       int xp = LEFT_WIDTH;
+       for (size_t x = 0; x < output; ++x) {
+               for (size_t y = 0; y < input; ++y) {
                        dc.SetBrush (*wxWHITE_BRUSH);
                        dc.DrawRectangle (
                                wxRect(
-                                       LEFT_WIDTH + x * GRID_SPACING + (GRID_SPACING - INDICATOR_SIZE) / 2,
-                                       TOP_HEIGHT + y * GRID_SPACING + (GRID_SPACING - INDICATOR_SIZE) / 2,
+                                       xp + (_column_widths[x] - INDICATOR_SIZE) / 2,
+                                       TOP_HEIGHT + y * ROW_HEIGHT + (ROW_HEIGHT - INDICATOR_SIZE) / 2,
                                        INDICATOR_SIZE, INDICATOR_SIZE
                                        )
                                );
 
-                       float const value_dB = 20 * log10 (_map.get(y, x));
+                       float const value_dB = linear_to_db(_map.get(_input_channels[y].index, _output_channels[x].index));
+                       auto const colour = value_dB <= 0 ? wxColour(0, 255, 0) : wxColour(255, 150, 0);
                        int const range = 18;
                        int height = 0;
                        if (value_dB > -range) {
-                               height = INDICATOR_SIZE * (1 + value_dB / range);
+                               height = min(INDICATOR_SIZE, static_cast<int>(INDICATOR_SIZE * (1 + value_dB / range)));
                        }
 
-                       dc.SetBrush (*wxTheBrushList->FindOrCreateBrush(wxColour (0, 255, 0), wxBRUSHSTYLE_SOLID));
+                       dc.SetBrush (*wxTheBrushList->FindOrCreateBrush(colour, wxBRUSHSTYLE_SOLID));
                        dc.DrawRectangle (
                                wxRect(
-                                       LEFT_WIDTH + x * GRID_SPACING + (GRID_SPACING - INDICATOR_SIZE) / 2,
-                                       TOP_HEIGHT + y * GRID_SPACING + (GRID_SPACING - INDICATOR_SIZE) / 2 + INDICATOR_SIZE - height,
+                                       xp + (_column_widths[x] - INDICATOR_SIZE) / 2,
+                                       TOP_HEIGHT + y * ROW_HEIGHT + (ROW_HEIGHT - INDICATOR_SIZE) / 2 + INDICATOR_SIZE - height,
                                        INDICATOR_SIZE, height
                                        )
                                );
+
                }
+               xp += _column_widths[x];
        }
 }
 
-static
-void clip (wxDC& dc, wxGraphicsContext* gc, int x, int y, int w, int h)
-{
-       dc.SetClippingRegion (x, y, w, h);
-       gc->Clip (x, y, w, h);
-}
-
-static
-void translate (wxDC& dc, wxGraphicsContext* gc, int x, int y)
-{
-       gc->PushState ();
-       gc->Translate (-x, -y);
-       dc.SetLogicalOrigin (x, y);
-}
 
 static
-void restore (wxDC& dc, wxGraphicsContext* gc)
+void restore (wxDC& dc)
 {
        dc.SetLogicalOrigin (0, 0);
-       gc->PopState ();
        dc.DestroyClippingRegion ();
-       gc->ResetClip ();
 }
 
+
 void
 AudioMappingView::paint ()
 {
        wxPaintDC dc (_body);
 
-       wxGraphicsContext* gc = wxGraphicsContext::Create (dc);
-       if (!gc) {
-               return;
-       }
-
        int const hs = _horizontal_scroll->GetThumbPosition ();
        int const vs = _vertical_scroll->GetThumbPosition ();
 
-       paint_static (dc, gc);
-
-       clip (dc, gc, LEFT_WIDTH, 0, GRID_SPACING * _output_channels.size(), GRID_SPACING * (2 + _input_channels.size()));
-       translate (dc, gc, hs, 0);
-       paint_column_labels (dc, gc);
-       restore (dc, gc);
-
-       clip (dc, gc, 0, TOP_HEIGHT, GRID_SPACING * (3 + _output_channels.size()), GRID_SPACING * _input_channels.size() + 1);
-       translate (dc, gc, 0, vs);
-       paint_row_labels (dc, gc);
-       restore (dc, gc);
+       paint_static (dc);
 
-       clip (dc, gc, GRID_SPACING * 2, TOP_HEIGHT, GRID_SPACING * (1 + _output_channels.size()), GRID_SPACING * _input_channels.size() + 1);
-       translate (dc, gc, hs, vs);
-       paint_row_lines (gc);
-       restore (dc, gc);
-
-       clip (dc, gc, LEFT_WIDTH, GRID_SPACING, GRID_SPACING * (1 + _output_channels.size()), GRID_SPACING * (1 + _input_channels.size()));
-       translate (dc, gc, hs, vs);
-       paint_column_lines (gc);
-       restore (dc, gc);
-
-       clip (dc, gc, LEFT_WIDTH, TOP_HEIGHT, GRID_SPACING * _output_channels.size(), GRID_SPACING * _input_channels.size());
-       translate (dc, gc, hs, vs);
+       dc.SetClippingRegion (
+               LEFT_WIDTH,
+               0,
+               _column_widths_total,
+               ROW_HEIGHT * (2 + _input_channels.size())
+               );
+       dc.SetLogicalOrigin (hs, 0);
+       paint_column_labels (dc);
+       restore (dc);
+
+       dc.SetClippingRegion(
+               0,
+               TOP_HEIGHT,
+               LEFT_WIDTH,
+               min(int(ROW_HEIGHT * _input_channels.size()), GetSize().GetHeight() - TOP_HEIGHT) + 1
+            );
+       dc.SetLogicalOrigin  (0, vs);
+       paint_row_labels (dc);
+       restore (dc);
+
+       dc.SetClippingRegion(
+               MINIMUM_COLUMN_WIDTH * 2,
+               TOP_HEIGHT,
+               MINIMUM_COLUMN_WIDTH + _column_widths_total,
+               min(int(ROW_HEIGHT * (2 + _input_channels.size())), GetSize().GetHeight() - TOP_HEIGHT)
+            );
+       dc.SetLogicalOrigin (hs, vs);
+       paint_row_lines (dc);
+       restore (dc);
+
+       dc.SetClippingRegion(
+               LEFT_WIDTH,
+               MINIMUM_COLUMN_WIDTH,
+               MINIMUM_COLUMN_WIDTH + _column_widths_total,
+               min(int(ROW_HEIGHT * (1 + _input_channels.size())), GetSize().GetHeight() - ROW_HEIGHT)
+            );
+       dc.SetLogicalOrigin(hs, vs);
+       paint_column_lines (dc);
+       restore (dc);
+
+       dc.SetClippingRegion (
+               LEFT_WIDTH,
+               TOP_HEIGHT,
+               _column_widths_total,
+               min(int(ROW_HEIGHT * _input_channels.size()), GetSize().GetHeight() - TOP_HEIGHT)
+            );
+       dc.SetLogicalOrigin(hs, vs);
        paint_indicators (dc);
-       restore (dc, gc);
-
-       delete gc;
+       restore (dc);
 }
 
-optional<pair<int, int> >
+
+optional<pair<NamedChannel, NamedChannel>>
 AudioMappingView::mouse_event_to_channels (wxMouseEvent& ev) const
 {
-       int const x = ev.GetX() + _horizontal_scroll->GetThumbPosition();
+       int x = ev.GetX() + _horizontal_scroll->GetThumbPosition();
        int const y = ev.GetY() + _vertical_scroll->GetThumbPosition();
 
        if (x <= LEFT_WIDTH || y < TOP_HEIGHT) {
-               return optional<pair<int, int> >();
+               return {};
        }
 
-       int const input = (y - TOP_HEIGHT) / GRID_SPACING;
-       int const output = (x - LEFT_WIDTH) / GRID_SPACING;
+       int const input = (y - TOP_HEIGHT) / ROW_HEIGHT;
+
+       x -= LEFT_WIDTH;
+       int output = 0;
+       for (auto const i: _column_widths) {
+               x -= i;
+               if (x < 0) {
+                       break;
+               }
+               ++output;
+       }
 
        if (input >= int(_input_channels.size()) || output >= int(_output_channels.size())) {
-               return optional<pair<int, int> >();
+               return {};
        }
 
-       return make_pair (input, output);
+       return make_pair(_input_channels[input], _output_channels[output]);
+}
+
+optional<string>
+AudioMappingView::mouse_event_to_input_group_name (wxMouseEvent& ev) const
+{
+       int const x = ev.GetX() + _horizontal_scroll->GetThumbPosition();
+       if (x < MINIMUM_COLUMN_WIDTH || x > (2 * MINIMUM_COLUMN_WIDTH)) {
+               return {};
+       }
+
+       int const y = (ev.GetY() + _vertical_scroll->GetThumbPosition() - TOP_HEIGHT) / ROW_HEIGHT;
+       for (auto i: _input_groups) {
+               if (i.from <= y && y <= i.to) {
+                       return i.name;
+               }
+       }
+
+       return {};
 }
 
 void
 AudioMappingView::left_down (wxMouseEvent& ev)
 {
-       optional<pair<int, int> > channels = mouse_event_to_channels (ev);
+       auto channels = mouse_event_to_channels (ev);
        if (!channels) {
                return;
        }
 
-       if (_map.get(channels->first, channels->second) > 0) {
-               _map.set (channels->first, channels->second, 0);
+       if (_map.get(channels->first.index, channels->second.index) > 0) {
+               _map.set (channels->first.index, channels->second.index, 0);
        } else {
-               _map.set (channels->first, channels->second, 1);
+               _map.set (channels->first.index, channels->second.index, 1);
        }
 
        map_values_changed ();
@@ -406,13 +507,13 @@ AudioMappingView::left_down (wxMouseEvent& ev)
 void
 AudioMappingView::right_down (wxMouseEvent& ev)
 {
-       optional<pair<int, int> > channels = mouse_event_to_channels (ev);
+       auto channels = mouse_event_to_channels (ev);
        if (!channels) {
                return;
        }
 
-       _menu_input = channels->first;
-       _menu_output = channels->second;
+       _menu_input = channels->first.index;
+       _menu_output = channels->second.index;
        PopupMenu (_menu, ev.GetPosition());
 }
 
@@ -421,12 +522,12 @@ AudioMappingView::mouse_wheel (wxMouseEvent& ev)
 {
        if (ev.ShiftDown()) {
                _horizontal_scroll->SetThumbPosition (
-                       _horizontal_scroll->GetThumbPosition() + (ev.GetWheelRotation() > 0 ? -GRID_SPACING : GRID_SPACING)
+                       _horizontal_scroll->GetThumbPosition() + (ev.GetWheelRotation() > 0 ? -HORIZONTAL_PAGE_SIZE : HORIZONTAL_PAGE_SIZE)
                        );
 
        } else {
                _vertical_scroll->SetThumbPosition (
-                       _vertical_scroll->GetThumbPosition() + (ev.GetWheelRotation() > 0 ? -GRID_SPACING : GRID_SPACING)
+                       _vertical_scroll->GetThumbPosition() + (ev.GetWheelRotation() > 0 ? -ROW_HEIGHT : ROW_HEIGHT)
                        );
        }
        Refresh ();
@@ -437,39 +538,23 @@ void
 AudioMappingView::map_values_changed ()
 {
        Changed (_map);
-       _last_tooltip_channels = optional<pair<int, int> >();
+       _last_tooltip_channels = boost::none;
        Refresh ();
 }
 
 void
-AudioMappingView::off ()
-{
-       _map.set (_menu_input, _menu_output, 0);
-       map_values_changed ();
-}
-
-void
-AudioMappingView::full ()
-{
-       _map.set (_menu_input, _menu_output, 1);
-       map_values_changed ();
-}
-
-void
-AudioMappingView::minus6dB ()
+AudioMappingView::set_gain_from_menu (double linear)
 {
-       _map.set (_menu_input, _menu_output, pow (10, -6.0 / 20));
+       _map.set (_menu_input, _menu_output, linear);
        map_values_changed ();
 }
 
 void
 AudioMappingView::edit ()
 {
-       int const d = _menu_output - 1;
-
-       AudioGainDialog* dialog = new AudioGainDialog (this, _menu_input, _menu_output - 1, _map.get(_menu_input, d));
+       auto dialog = new AudioGainDialog (this, _menu_input, _menu_output, _map.get(_menu_input, _menu_output));
        if (dialog->ShowModal() == wxID_OK) {
-               _map.set (_menu_input, d, dialog->value ());
+               _map.set (_menu_input, _menu_output, dialog->value ());
                map_values_changed ();
        }
 
@@ -484,47 +569,88 @@ AudioMappingView::set (AudioMapping map)
 }
 
 void
-AudioMappingView::set_input_channels (vector<string> const & names)
+AudioMappingView::set_input_channels (vector<NamedChannel> const& channels)
 {
-       _input_channels = names;
+       _input_channels = channels;
        setup ();
        Refresh ();
 }
 
 void
-AudioMappingView::set_output_channels (vector<string> const & names)
+AudioMappingView::set_output_channels (vector<NamedChannel> const & channels)
 {
-       _output_channels = names;
+       _output_channels = channels;
        setup ();
        Refresh ();
 }
 
+
+wxString
+AudioMappingView::input_channel_name_with_group (NamedChannel const& n) const
+{
+       optional<wxString> group;
+       for (auto i: _input_groups) {
+               if (i.from <= n.index && n.index <= i.to) {
+                       group = std_to_wx (i.name);
+               }
+       }
+
+       if (group && !group->IsEmpty()) {
+               return wxString::Format ("%s/%s", group->data(), std_to_wx(n.name).data());
+       }
+
+       return std_to_wx(n.name);
+}
+
+
 void
 AudioMappingView::motion (wxMouseEvent& ev)
 {
-       optional<pair<int, int> > channels = mouse_event_to_channels (ev);
-       if (!channels) {
-               SetToolTip ("");
-               _last_tooltip_channels = channels;
-               return;
-       }
+       auto channels = mouse_event_to_channels (ev);
+       if (channels) {
+               if (channels != _last_tooltip_channels) {
+                       wxString s;
+                       auto const gain = _map.get(channels->first.index, channels->second.index);
+                       if (gain == 0) {
+                               s = wxString::Format (
+                                       _("No audio will be passed from %s channel '%s' to %s channel '%s'."),
+                                       _from,
+                                       input_channel_name_with_group(channels->first),
+                                       _to,
+                                       std_to_wx(channels->second.name)
+                                       );
+                       } else if (gain == 1) {
+                               s = wxString::Format (
+                                       _("Audio will be passed from %s channel %s to %s channel %s unaltered."),
+                                       _from,
+                                       input_channel_name_with_group(channels->first),
+                                       _to,
+                                       std_to_wx(channels->second.name)
+                                       );
+                       } else {
+                               auto const dB = linear_to_db(gain);
+                               s = wxString::Format (
+                                       _("Audio will be passed from %s channel %s to %s channel %s with gain %.1fdB."),
+                                       _from,
+                                       input_channel_name_with_group(channels->first),
+                                       _to,
+                                       std_to_wx(channels->second.name),
+                                       dB
+                                       );
+                       }
 
-       if (channels != _last_tooltip_channels) {
-               wxString s;
-               float const gain = _map.get(channels->first, channels->second);
-               if (gain == 0) {
-                       s = wxString::Format (_("No audio will be passed from content channel %d to DCP channel %d."), channels->first + 1, channels->second + 1);
-               } else if (gain == 1) {
-                       s = wxString::Format (_("Audio will be passed from content channel %d to DCP channel %d unaltered."), channels->first + 1, channels->second + 1);
+                       SetToolTip (s + " " + _("Right click to change gain."));
+               }
+       } else {
+               auto group = mouse_event_to_input_group_name (ev);
+               if (group) {
+                       SetToolTip (std_to_wx(*group));
                } else {
-                       float const dB = 20 * log10 (gain);
-                       s = wxString::Format (_("Audio will be passed from content channel %d to DCP channel %d with gain %.1fdB."), channels->first + 1, channels->second + 1, dB);
+                       SetToolTip ("");
                }
-
-               SetToolTip (s + " " + _("Right click to change gain."));
-               _last_tooltip_channels = channels;
        }
 
+       _last_tooltip_channels = channels;
         ev.Skip ();
 }