comparison layer/LogNumericalScale.cpp @ 696:e77b1673e17e tonioni

Pull out log and linear vertical scales into their own classes, make some improvements to log numbering

+/* -*- 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 2006-2013 Chris Cannam and QMUL.
+    
+    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 "LogNumericalScale.h"
+#include "VerticalScaleLayer.h"
+
+#include "base/LogRange.h"
+
+#include <QPainter>
+
+#include <cmath>
+
+#include "view/View.h"
+
+//#define DEBUG_TIME_VALUE_LAYER 1
+
+int
+LogNumericalScale::getWidth(View *,
+			    QPainter &paint)
+{
+    return paint.fontMetrics().width("-000.00");
+}
+
+void
+LogNumericalScale::paintVertical(View *v,
+				 const VerticalScaleLayer *layer,
+				 QPainter &paint,
+				 int x0,
+				 float minlog,
+				 float maxlog)
+{
+    int w = getWidth(v, paint) + x0;
+
+    int n = 10;
+
+    float val = minlog;
+    float inc = (maxlog - val) / n; // even increments of log scale
+
+    // smallest increment as displayed
+    float minDispInc = LogRange::unmap(minlog + inc) - LogRange::unmap(minlog);
+
+#ifdef DEBUG_TIME_VALUE_LAYER
+    cerr << "min = " << minlog << ", max = " << maxlog << ", inc = " << inc << ", minDispInc = " << minDispInc << endl;
+#endif
+
+    char buffer[40];
+
+    float round = 1.f;
+    int dp = 0;
+
+    if (minDispInc > 0) {
+        int prec = trunc(log10f(minDispInc));
+        if (prec < 0) dp = -prec;
+        round = powf(10.f, prec);
+#ifdef DEBUG_TIME_VALUE_LAYER
+        cerr << "round = " << round << ", prec = " << prec << ", dp = " << dp << endl;
+#endif
+    }
+
+    int prevy = -1;
+                
+    for (int i = 0; i < n; ++i) {
+
+	int y, ty;
+        bool drawText = true;
+
+	if (i == n-1 &&
+	    v->height() < paint.fontMetrics().height() * (n*2)) {
+	    if (layer->getScaleUnits() != "") drawText = false;
+	}
+
+        float dispval = LogRange::unmap(val);
+	dispval = floor(dispval / round) * round;
+
+#ifdef DEBUG_TIME_VALUE_LAYER
+	cerr << "val = " << val << ", dispval = " << dispval << endl;
+#endif
+
+	y = layer->getYForValue(v, dispval);
+
+	ty = y - paint.fontMetrics().height() + paint.fontMetrics().ascent() + 2;
+	
+	if (prevy >= 0 && (prevy - y) < paint.fontMetrics().height()) {
+	    val += inc;
+	    continue;
+        }
+
+	double dv = dispval;
+	int digits = trunc(log10f(dv));
+	int sf = dp + (digits > 0 ? digits : 0);
+	if (sf < 4) sf = 4;
+	sprintf(buffer, "%.*g", sf, dv);
+
+	QString label = QString(buffer);
+
+	paint.drawLine(w - 5, y, w, y);
+
+        if (drawText) {
+	    paint.drawText(w - paint.fontMetrics().width(label) - 6,
+			   ty, label);
+        }
+
+        prevy = y;
+	val += inc;
+    }
+}