# HG changeset patch
# User Chris Cannam
# Date 1537368104 -3600
# Node ID 5360f7aba1893a488039cd972c2f3230c1a298e2
# Parent  2f3a77472c8c7b0c303b9a535e0bf358380e2648
Pull out ZoomLevel, add inexact frame/pixel conversion functions and streaming

diff -r 2f3a77472c8c -r 5360f7aba189 base/BaseTypes.h
--- a/base/BaseTypes.h	Tue Sep 18 16:28:56 2018 +0100
+++ b/base/BaseTypes.h	Wed Sep 19 15:41:44 2018 +0100
@@ -55,62 +55,5 @@
 typedef std::vector<std::complex<float>,
                     breakfastquay::StlAllocator<std::complex<float>>> complexvec_t;
 
-/** Display zoom level. Can be an integer number of samples per pixel,
- *  or an integer number of pixels per sample.
- */
-struct ZoomLevel {
-
-    enum Zone {
-        FramesPerPixel, // zoomed out (as in classic SV)
-        PixelsPerFrame  // zoomed in beyond 1-1 (interpolating the waveform)
-    };
-    Zone zone;
-    int level;
-
-    ZoomLevel(Zone z, int l) : zone(z), level(l) { }
-    
-    bool operator<(const ZoomLevel &other) const {
-        if (zone == FramesPerPixel) {
-            if (other.zone == zone) {
-                return level < other.level;
-            } else {
-                return false;
-            }
-        } else {
-            if (other.zone == zone) {
-                return level > other.level;
-            } else {
-                return false;
-            }
-        }
-    }
-
-    bool operator==(const ZoomLevel &other) const {
-        return (zone == other.zone && level == other.level);
-    }
-    
-    ZoomLevel incremented() const {
-        if (zone == FramesPerPixel) {
-            return { zone, level + 1 };
-        } else if (level == 1) {
-            return { FramesPerPixel, 2 };
-        } else if (level == 2) {
-            return { FramesPerPixel, 1 };
-        } else {
-            return { zone, level - 1 };
-        }
-    }
-
-    ZoomLevel decremented() const {
-        if (zone == PixelsPerFrame) {
-            return { zone, level + 1 };
-        } else if (level == 1) {
-            return { PixelsPerFrame, 2 };
-        } else {
-            return { zone, level - 1 };
-        }
-    }
-};
-
 #endif
 
diff -r 2f3a77472c8c -r 5360f7aba189 base/ZoomConstraint.h
--- a/base/ZoomConstraint.h	Tue Sep 18 16:28:56 2018 +0100
+++ b/base/ZoomConstraint.h	Wed Sep 19 15:41:44 2018 +0100
@@ -18,7 +18,7 @@
 
 #include <stdlib.h>
 
-#include "BaseTypes.h"
+#include "ZoomLevel.h"
 
 /**
  * ZoomConstraint is a simple interface that describes a limitation on
diff -r 2f3a77472c8c -r 5360f7aba189 base/ZoomLevel.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/base/ZoomLevel.cpp	Wed Sep 19 15:41:44 2018 +0100
@@ -0,0 +1,25 @@
+/* -*- 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 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 "ZoomLevel.h"
+
+std::ostream &operator<<(std::ostream &s, const ZoomLevel &z) {
+    if (z.zone == ZoomLevel::PixelsPerFrame) {
+        s << "1/" << z.level;
+    } else {
+        s << z.level;
+    }
+    return s;
+}
+
diff -r 2f3a77472c8c -r 5360f7aba189 base/ZoomLevel.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/base/ZoomLevel.h	Wed Sep 19 15:41:44 2018 +0100
@@ -0,0 +1,98 @@
+/* -*- 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 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.
+*/
+
+#ifndef SV_ZOOM_LEVEL_H
+#define SV_ZOOM_LEVEL_H
+
+#include <ostream>
+
+/** Display zoom level. Can be an integer number of samples per pixel,
+ *  or an integer number of pixels per sample.
+ */
+struct ZoomLevel {
+
+    enum Zone {
+        FramesPerPixel, // zoomed out (as in classic SV)
+        PixelsPerFrame  // zoomed in beyond 1-1 (interpolating the waveform)
+    };
+    Zone zone;
+    int level;
+
+    ZoomLevel() : zone(FramesPerPixel), level(1) { }
+    ZoomLevel(Zone z, int lev) : zone(z), level(lev) { }
+    
+    bool operator<(const ZoomLevel &other) const {
+        if (zone == FramesPerPixel) {
+            if (other.zone == zone) {
+                return level < other.level;
+            } else {
+                return false;
+            }
+        } else {
+            if (other.zone == zone) {
+                return level > other.level;
+            } else {
+                return false;
+            }
+        }
+    }
+
+    bool operator==(const ZoomLevel &other) const {
+        return (zone == other.zone && level == other.level);
+    }
+
+    ZoomLevel incremented() const {
+        if (zone == FramesPerPixel) {
+            return { zone, level + 1 };
+        } else if (level == 1) {
+            return { FramesPerPixel, 2 };
+        } else if (level == 2) {
+            return { FramesPerPixel, 1 };
+        } else {
+            return { zone, level - 1 };
+        }
+    }
+
+    ZoomLevel decremented() const {
+        if (zone == PixelsPerFrame) {
+            return { zone, level + 1 };
+        } else if (level == 1) {
+            return { PixelsPerFrame, 2 };
+        } else {
+            return { zone, level - 1 };
+        }
+    }
+
+    /// Inexact
+    double framesToPixels(double frames) const {
+        if (zone == PixelsPerFrame) {
+            return frames * level;
+        } else {
+            return frames / level;
+        }
+    }
+
+    /// Inexact
+    double pixelsToFrames(double pixels) const {
+        if (zone == PixelsPerFrame) {
+            return pixels / level;
+        } else {
+            return pixels * level;
+        }
+    }
+};
+
+std::ostream &operator<<(std::ostream &s, const ZoomLevel &z);
+
+#endif
diff -r 2f3a77472c8c -r 5360f7aba189 files.pri
--- a/files.pri	Tue Sep 18 16:28:56 2018 +0100
+++ b/files.pri	Wed Sep 19 15:41:44 2018 +0100
@@ -43,6 +43,7 @@
            base/Window.h \
            base/XmlExportable.h \
            base/ZoomConstraint.h \
+           base/ZoomLevel.h \
            data/fileio/AudioFileReader.h \
            data/fileio/AudioFileReaderFactory.h \
            data/fileio/AudioFileSizeEstimator.h \
@@ -175,6 +176,7 @@
            base/UnitDatabase.cpp \
            base/ViewManagerBase.cpp \
            base/XmlExportable.cpp \
+           base/ZoomLevel.cpp \
            data/fileio/AudioFileReader.cpp \
            data/fileio/AudioFileReaderFactory.cpp \
            data/fileio/AudioFileSizeEstimator.cpp \