annotate base/ZoomLevel.h @ 1886:f803d3c33f76 tip

Switch off copious debug in soft synth driving
author Chris Cannam
date Fri, 14 Aug 2020 10:44:44 +0100 (2020-08-14)
parents 8f9e9cff141d
children 1ae6a19464a7
rev   line source
Chris@1532 1 /* -*- c-basic-offset: 4 indent-tabs-mode: nil -*- vi:set ts=8 sts=4 sw=4: */
Chris@1532 2
Chris@1532 3 /*
Chris@1532 4 Sonic Visualiser
Chris@1532 5 An audio file viewer and annotation editor.
Chris@1532 6 Centre for Digital Music, Queen Mary, University of London.
Chris@1532 7
Chris@1532 8 This program is free software; you can redistribute it and/or
Chris@1532 9 modify it under the terms of the GNU General Public License as
Chris@1532 10 published by the Free Software Foundation; either version 2 of the
Chris@1532 11 License, or (at your option) any later version. See the file
Chris@1532 12 COPYING included with this distribution for more information.
Chris@1532 13 */
Chris@1532 14
Chris@1532 15 #ifndef SV_ZOOM_LEVEL_H
Chris@1532 16 #define SV_ZOOM_LEVEL_H
Chris@1532 17
Chris@1534 18 #include "BaseTypes.h"
Chris@1534 19
Chris@1532 20 #include <ostream>
Chris@1533 21 #include <cmath>
Chris@1532 22
Chris@1532 23 /** Display zoom level. Can be an integer number of samples per pixel,
Chris@1532 24 * or an integer number of pixels per sample.
Chris@1532 25 */
Chris@1532 26 struct ZoomLevel {
Chris@1532 27
Chris@1532 28 enum Zone {
Chris@1532 29 FramesPerPixel, // zoomed out (as in classic SV)
Chris@1532 30 PixelsPerFrame // zoomed in beyond 1-1 (interpolating the waveform)
Chris@1532 31 };
Chris@1533 32
Chris@1532 33 Zone zone;
Chris@1532 34 int level;
Chris@1532 35
Chris@1532 36 ZoomLevel() : zone(FramesPerPixel), level(1) { }
Chris@1532 37 ZoomLevel(Zone z, int lev) : zone(z), level(lev) { }
Chris@1532 38
Chris@1532 39 bool operator<(const ZoomLevel &other) const {
Chris@1532 40 if (zone == FramesPerPixel) {
Chris@1532 41 if (other.zone == zone) {
Chris@1532 42 return level < other.level;
Chris@1532 43 } else {
Chris@1532 44 return false;
Chris@1532 45 }
Chris@1532 46 } else {
Chris@1532 47 if (other.zone == zone) {
Chris@1532 48 return level > other.level;
Chris@1532 49 } else {
Chris@1532 50 return false;
Chris@1532 51 }
Chris@1532 52 }
Chris@1532 53 }
Chris@1532 54
Chris@1532 55 bool operator==(const ZoomLevel &other) const {
Chris@1532 56 return (zone == other.zone && level == other.level);
Chris@1532 57 }
Chris@1532 58
Chris@1532 59 ZoomLevel incremented() const {
Chris@1532 60 if (zone == FramesPerPixel) {
Chris@1532 61 return { zone, level + 1 };
Chris@1532 62 } else if (level == 1) {
Chris@1532 63 return { FramesPerPixel, 2 };
Chris@1532 64 } else if (level == 2) {
Chris@1532 65 return { FramesPerPixel, 1 };
Chris@1532 66 } else {
Chris@1532 67 return { zone, level - 1 };
Chris@1532 68 }
Chris@1532 69 }
Chris@1532 70
Chris@1532 71 ZoomLevel decremented() const {
Chris@1532 72 if (zone == PixelsPerFrame) {
Chris@1532 73 return { zone, level + 1 };
Chris@1532 74 } else if (level == 1) {
Chris@1532 75 return { PixelsPerFrame, 2 };
Chris@1532 76 } else {
Chris@1532 77 return { zone, level - 1 };
Chris@1532 78 }
Chris@1532 79 }
Chris@1532 80
Chris@1533 81 /** Inexact conversion. The result is a whole number if we are
Chris@1533 82 * zoomed in enough (in PixelsPerFrame zone), a fraction
Chris@1533 83 * otherwise.
Chris@1533 84 */
Chris@1532 85 double framesToPixels(double frames) const {
Chris@1532 86 if (zone == PixelsPerFrame) {
Chris@1532 87 return frames * level;
Chris@1532 88 } else {
Chris@1532 89 return frames / level;
Chris@1532 90 }
Chris@1532 91 }
Chris@1532 92
Chris@1533 93 /** Inexact conversion. The result is a whole number if we are
Chris@1533 94 * zoomed out enough (in FramesPerPixel zone), a fraction
Chris@1533 95 * otherwise.
Chris@1533 96 */
Chris@1532 97 double pixelsToFrames(double pixels) const {
Chris@1532 98 if (zone == PixelsPerFrame) {
Chris@1532 99 return pixels / level;
Chris@1532 100 } else {
Chris@1532 101 return pixels * level;
Chris@1532 102 }
Chris@1532 103 }
Chris@1533 104
Chris@1533 105 /** Return a ZoomLevel that approximates the given ratio of pixels
Chris@1533 106 * to frames.
Chris@1533 107 */
Chris@1534 108 static ZoomLevel fromRatio(int pixels, sv_frame_t frames) {
Chris@1533 109 if (pixels < frames) {
Chris@1534 110 return { FramesPerPixel, int(round(double(frames)/pixels)) };
Chris@1533 111 } else {
Chris@1534 112 int r = int(round(pixels/double(frames)));
Chris@1533 113 if (r > 1) {
Chris@1533 114 return { PixelsPerFrame, r };
Chris@1533 115 } else {
Chris@1533 116 return { FramesPerPixel, 1 };
Chris@1533 117 }
Chris@1533 118 }
Chris@1533 119 }
Chris@1532 120 };
Chris@1532 121
Chris@1532 122 std::ostream &operator<<(std::ostream &s, const ZoomLevel &z);
Chris@1532 123
Chris@1532 124 #endif