# HG changeset patch
# User Chris Cannam
# Date 1140717691 0
# Node ID 51e158b505da8acf6b3519dfde9559c94dc32436
# Parent  5e28cbb431d04e2dac943f9998fcf94835f0e5e2
* Rearrange spectrogram cacheing so that gain, normalization, instantaneous
  frequency calculations etc can be done from the cached data (increasing the
  size of the cache, but also the usability).

diff -r 5e28cbb431d0 -r 51e158b505da base/View.cpp
--- a/base/View.cpp	Mon Feb 20 17:23:40 2006 +0000
+++ b/base/View.cpp	Thu Feb 23 18:01:31 2006 +0000
@@ -255,6 +255,70 @@
     return (long(x) * long(m_zoomLevel)) + getStartFrame();
 }
 
+float
+View::getYForFrequency(float frequency,
+		       float minf,
+		       float maxf, 
+		       bool logarithmic) const
+{
+    int h = height();
+
+    if (logarithmic) {
+
+	static float lastminf = 0.0, lastmaxf = 0.0;
+	static float logminf = 0.0, logmaxf = 0.0;
+
+	if (lastminf != minf) {
+	    lastminf = (minf == 0.0 ? 1.0 : minf);
+	    logminf = log10f(minf);
+	}
+	if (lastmaxf != maxf) {
+	    lastmaxf = (maxf < lastminf ? lastminf : maxf);
+	    logmaxf = log10f(maxf);
+	}
+
+	if (logminf == logmaxf) return 0;
+	return h - (h * (log10f(frequency) - logminf)) / (logmaxf - logminf);
+
+    } else {
+	
+	if (minf == maxf) return 0;
+	return h - (h * (frequency - minf)) / (maxf - minf);
+    }
+}
+
+float
+View::getFrequencyForY(int y,
+		       float minf,
+		       float maxf,
+		       bool logarithmic) const
+{
+    int h = height();
+
+    if (logarithmic) {
+
+	static float lastminf = 0.0, lastmaxf = 0.0;
+	static float logminf = 0.0, logmaxf = 0.0;
+
+	if (lastminf != minf) {
+	    lastminf = (minf == 0.0 ? 1.0 : minf);
+	    logminf = log10f(minf);
+	}
+	if (lastmaxf != maxf) {
+	    lastmaxf = (maxf < lastminf ? lastminf : maxf);
+	    logmaxf = log10f(maxf);
+	}
+
+	if (logminf == logmaxf) return 0;
+	return pow(10.f, logminf + ((logmaxf - logminf) * (h - y)) / h);
+
+    } else {
+
+	if (minf == maxf) return 0;
+	return minf + ((h - y) * (maxf - minf)) / h;
+    }
+}
+
 int
 View::getZoomLevel() const
 {
diff -r 5e28cbb431d0 -r 51e158b505da base/View.h
--- a/base/View.h	Mon Feb 20 17:23:40 2006 +0000
+++ b/base/View.h	Thu Feb 23 18:01:31 2006 +0000
@@ -96,6 +96,26 @@
     long getFrameForX(int x) const;
 
     /**
+     * Return the pixel y-coordinate corresponding to a given
+     * frequency, if the frequency range is as specified.  This does
+     * not imply any policy about layer frequency ranges, but it might
+     * be useful for layers to match theirs up if desired.
+     *
+     * Not thread-safe in logarithmic mode.  Call only from GUI thread.
+     */
+    float getYForFrequency(float frequency, float minFreq, float maxFreq, 
+			   bool logarithmic) const;
+
+    /**
+     * Return the closest frequency to the given pixel y-coordinate,
+     * if the frequency range is as specified.
+     *
+     * Not thread-safe in logarithmic mode.  Call only from GUI thread.
+     */
+    float getFrequencyForY(int y, float minFreq, float maxFreq,
+			   bool logarithmic) const;
+
+    /**
      * Return the zoom level, i.e. the number of frames per pixel
      */
     int getZoomLevel() const;