comparison layer/SpectrumLayer.cpp @ 133:9e6b3e239b9d

* Add zoom thumbwheels to Pane.  Implement horizontal thumbwheel, and
  vertical depending on layer type (supported for waveform and spectrogram,
  though wrong for log-scale spectrogram at the moment).
* Add bare bones of a spectrum layer.
* Add window icon
* Add shortcut for "insert time instant" on laptops without keypad enter (";")
* Delete FFT processing thread when it exits (at least, next time we're asked
  for something interesting)
* Get audio file extensions from the file readers, and thus from libsndfile for
  the wave file reader -- leads to rather a wide combo box in file dialog though
* Better refresh order for spectrogram (redraw centre section first)

+
+/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
+
+/*
+    Sonic Visualiser
+    An audio file viewer and annotation editor.
+    Centre for Digital Music, Queen Mary, University of London.
+    This file copyright 2006 Chris Cannam.
+    
+    This program is free software; you can redistribute it and/or
+    modify it under the terms of the GNU General Public License as
+    published by the Free Software Foundation; either version 2 of the
+    License, or (at your option) any later version.  See the file
+    COPYING included with this distribution for more information.
+*/
+
+#include "SpectrumLayer.h"
+
+#include "data/model/FFTModel.h"
+#include "view/View.h"
+
+#include <QPainter>
+#include <QPainterPath>
+
+SpectrumLayer::SpectrumLayer() :
+    m_model(0),
+    m_fft(0),
+    m_colour(Qt::blue)
+{
+}
+
+SpectrumLayer::~SpectrumLayer()
+{
+    delete m_fft;
+}
+
+void
+SpectrumLayer::setModel(DenseTimeValueModel *model)
+{
+    m_model = model;
+    delete m_fft;
+    m_fft = new FFTModel(m_model,
+                         -1,
+                         HanningWindow,
+                         1024,
+                         256,
+                         1024,
+                         true);
+    m_fft->resume();
+}
+
+void
+SpectrumLayer::paint(View *v, QPainter &paint, QRect rect) const
+{
+    if (!m_fft) return;
+
+    int fftSize = 1024; //!!! ...
+    int windowIncrement = 256;
+    int windowSize = 1024;
+
+    size_t f = v->getCentreFrame();
+
+    int w = (v->width() * 2) / 3;
+    int xorigin = (v->width() / 2) - (w / 2);
+    
+    int h = (v->height() * 2) / 3;
+    int yorigin = (v->height() / 2) + (h / 2);
+
+    size_t column = f / windowIncrement;
+
+    paint.save();
+    paint.setPen(m_colour);
+    paint.setRenderHint(QPainter::Antialiasing, false);
+    
+    QPainterPath path;
+    float thresh = -80.f;
+
+    for (size_t bin = 0; bin < m_fft->getHeight(); ++bin) {
+
+        float mag = m_fft->getMagnitudeAt(column, bin);
+        float db = thresh;
+        if (mag > 0.f) db = 10.f * log10f(mag);
+        if (db < thresh) db = thresh;
+        float val = (db - thresh) / -thresh;
+        float x = xorigin + (float(w) * bin) / m_fft->getHeight();
+        float y = yorigin - (float(h) * val);
+
+        if (bin == 0) {
+            path.moveTo(x, y);
+        } else {
+            path.lineTo(x, y);
+        }
+    }
+
+    paint.drawPath(path);
+//    paint.setRenderHint(QPainter::Antialiasing, false);
+    paint.restore();
+
+}
+
+void
+SpectrumLayer::setProperties(const QXmlAttributes &attr)
+{
+}
+
+bool
+SpectrumLayer::getValueExtents(float &min, float &max, bool &logarithmic,
+                               QString &units) const
+{
+    return false;
+}
+