Improve waveform rendering performance

include/AutomationEditor.h

@@ -38,6 +38,7 @@
 #include "SampleClip.h"
 #include "TimePos.h"
 #include "lmms_basics.h"
+#include "SampleThumbnail.h"
 
 class QPainter;
 class QPixmap;
@@ -290,6 +291,8 @@ protected slots:
 	QColor m_ghostNoteColor;
 	QColor m_detuningNoteColor;
 	QColor m_ghostSampleColor;
+
+	SampleThumbnail m_sampleThumbnail;
 
 	friend class AutomationEditorWindow;
 

include/SampleClipView.h

@@ -27,6 +27,8 @@
 
 #include "ClipView.h"
 
+#include "SampleThumbnail.h"
+
 namespace lmms
 {
 
@@ -63,6 +65,7 @@ public slots:
 
 private:
 	SampleClip * m_clip;
+	SampleThumbnail m_sampleThumbnail;
 	QPixmap m_paintPixmap;
 	bool splitClip( const TimePos pos ) override;
 } ;

include/SampleThumbnail.h

@@ -0,0 +1,153 @@
+/*
+ * SampleThumbnail.h
+ *
+ * Copyright (c) 2024 Khoi Dau <[email protected]>
+ * Copyright (c) 2024 Sotonye Atemie <[email protected]>
+ *
+ * This file is part of LMMS - https://lmms.io
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program (see COPYING); if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301 USA.
+ *
+ */
+
+#ifndef LMMS_SAMPLE_THUMBNAIL_H
+#define LMMS_SAMPLE_THUMBNAIL_H
+
+#include <QDateTime>
+#include <QPainter>
+#include <QRect>
+#include <memory>
+
+#include "Sample.h"
+#include "lmms_export.h"
+
+namespace lmms {
+
+/**
+   Allows for visualizing sample data.
+
+   On construction, thumbnails will be generated
+   at logarathmic intervals of downsampling. Those cached thumbnails will then be further downsampled on the fly and
+   transformed in various ways to create the desired waveform.
+
+   Given that we are dealing with far less data to generate
+   the visualization however (i.e., we are not reading from original sample data when drawing), this provides a
+   significant performance boost that wouldn't be possible otherwise.
+ */
+class LMMS_EXPORT SampleThumbnail
+{
+public:
+	//! Maximum number of cached sample thumbnails.
+	//! This cache only allows for caching sample thumbnails that have an associated file path.
+	static constexpr auto MaxSampleThumbnailCacheSize = 32;
+
+	//! The number of samples to aggregate per zoom step when building the thumbnail cache.
+	static constexpr auto AggregationPerZoomStep = 10;
+
+	struct VisualizeParameters
+	{
+		QRect sampleRect; //!< A rectangle that covers the entire range of samples.
+
+		QRect drawRect; //!< Specifies the location in `sampleRect` where the waveform will be drawn. Equals
+						//!< `sampleRect` when null.
+
+		QRect viewportRect; //!< Clips `drawRect`. Equals `drawRect` when null.
+
+		float amplification = 1.0f; //!< The amount of amplification to apply to the waveform.
+
+		float sampleStart = 0.0f; //!< Where the sample begins for drawing.
+
+		float sampleEnd = 1.0f; //!< Where the sample ends for drawing.
+
+		bool reversed = false; //!< Determines if the waveform is drawn in reverse or not.
+	};
+
+	SampleThumbnail() = default;
+	SampleThumbnail(const Sample& sample);
+	void visualize(VisualizeParameters parameters, QPainter& painter) const;
+
+private:
+	class Thumbnail
+	{
+	public:
+		struct Peak
+		{
+			Peak() = default;
+
+			Peak(float min, float max)
+				: min(min)
+				, max(max)
+			{
+			}
+
+			Peak(const SampleFrame& frame)
+				: min(std::min(frame.left(), frame.right()))
+				, max(std::max(frame.left(), frame.right()))
+			{
+			}
+
+			Peak operator+(const Peak& other) const { return Peak(std::min(min, other.min), std::max(max, other.max)); }
+			Peak operator+(const SampleFrame& frame) const { return *this + Peak{frame}; }
+
+			float min = std::numeric_limits<float>::max();
+			float max = std::numeric_limits<float>::min();
+		};
+
+		Thumbnail() = default;
+		Thumbnail(std::vector<Peak> peaks, double samplesPerPeak);
+		Thumbnail(const float* buffer, size_t size, size_t width);
+
+		Thumbnail zoomOut(float factor) const;
+
+		Peak& operator[](size_t index) { return m_peaks[index]; }
+		const Peak& operator[](size_t index) const { return m_peaks[index]; }
+
+		Peak* peaks() { return m_peaks.data(); }
+		const Peak* peaks() const { return m_peaks.data(); }
+
+		int width() const { return m_peaks.size(); }
+		double samplesPerPeak() const { return m_samplesPerPeak; }
+
+	private:
+		std::vector<Peak> m_peaks;
+		double m_samplesPerPeak = 0.0;
+	};
+
+	struct SampleThumbnailEntry
+	{
+		QString filePath;
+		QDateTime lastModified;
+
+		friend bool operator==(const SampleThumbnailEntry& first, const SampleThumbnailEntry& second)
+		{
+			return first.filePath == second.filePath && first.lastModified == second.lastModified;
+		}
+	};
+
+	struct Hash
+	{
+		std::size_t operator()(const SampleThumbnailEntry& entry) const noexcept { return qHash(entry.filePath); }
+	};
+
+	using ThumbnailCache = std::vector<Thumbnail>;
+	std::shared_ptr<ThumbnailCache> m_thumbnailCache = std::make_shared<ThumbnailCache>();
+
+	inline static std::unordered_map<SampleThumbnailEntry, std::shared_ptr<ThumbnailCache>, Hash> s_sampleThumbnailCacheMap;
+};
+
+} // namespace lmms
+
+#endif // LMMS_SAMPLE_THUMBNAIL_H

plugins/AudioFileProcessor/AudioFileProcessorWaveView.cpp

@@ -24,16 +24,16 @@
 
 #include "AudioFileProcessorWaveView.h"
 
+#include "Sample.h"
 #include "ConfigManager.h"
+#include "SampleThumbnail.h"
 #include "FontHelper.h"
-#include "SampleWaveform.h"
 
 #include <QPainter>
 #include <QMouseEvent>
 
 #include <algorithm>
 
-
 namespace lmms
 {
 
@@ -81,7 +81,8 @@ AudioFileProcessorWaveView::AudioFileProcessorWaveView(QWidget* parent, int w, i
 	m_isDragging(false),
 	m_reversed(false),
 	m_framesPlayed(0),
-	m_animation(ConfigManager::inst()->value("ui", "animateafp").toInt())
+	m_animation(ConfigManager::inst()->value("ui", "animateafp").toInt()),
+	m_sampleThumbnail(*buf)
 {
 	setFixedSize(w, h);
 	setMouseTracking(true);
@@ -338,13 +339,16 @@ void AudioFileProcessorWaveView::updateGraph()
 	m_graph.fill(Qt::transparent);
 	QPainter p(&m_graph);
 	p.setPen(QColor(255, 255, 255));
-
-	const auto dataOffset = m_reversed ? m_sample->sampleSize() - m_to : m_from;
 
-	const auto rect = QRect{0, 0, m_graph.width(), m_graph.height()};
-	const auto waveform = SampleWaveform::Parameters{
-		m_sample->data() + dataOffset, static_cast<size_t>(range()), m_sample->amplification(), m_sample->reversed()};
-	SampleWaveform::visualize(waveform, p, rect);
+	m_sampleThumbnail = SampleThumbnail{*m_sample};
+
+	auto param = SampleThumbnail::VisualizeParameters{};
+	param.amplification = m_sample->amplification();
+	param.reversed = m_sample->reversed();
+	param.sampleStart = static_cast<float>(m_from) / m_sample->sampleSize();
+	param.sampleEnd = static_cast<float>(m_to) / m_sample->sampleSize();
+	param.sampleRect = m_graph.rect();
+	m_sampleThumbnail.visualize(param, p);
 }
 
 void AudioFileProcessorWaveView::zoom(const bool out)

plugins/AudioFileProcessor/AudioFileProcessorWaveView.h

@@ -27,6 +27,7 @@
 
 
 #include "Knob.h"
+#include "SampleThumbnail.h"
 
 
 namespace lmms
@@ -144,6 +145,7 @@ public slots:
 	bool m_reversed;
 	f_cnt_t m_framesPlayed;
 	bool m_animation;
+	SampleThumbnail m_sampleThumbnail;
 
 	friend class AudioFileProcessorView;
 

plugins/SlicerT/SlicerTWaveform.cpp

@@ -27,7 +27,7 @@
 #include <QBitmap>
 #include <qpainterpath.h>
 
-#include "SampleWaveform.h"
+#include "SampleThumbnail.h"
 #include "SlicerT.h"
 #include "SlicerTView.h"
 #include "embed.h"
@@ -115,10 +115,17 @@ void SlicerTWaveform::drawSeekerWaveform()
 	brush.setPen(s_waveformColor);
 
 	const auto& sample = m_slicerTParent->m_originalSample;
-	const auto waveform
-		= SampleWaveform::Parameters{sample.data(), sample.sampleSize(), sample.amplification(), sample.reversed()};
-	const auto rect = QRect(0, 0, m_seekerWaveform.width(), m_seekerWaveform.height());
-	SampleWaveform::visualize(waveform, brush, rect);
+
+	m_sampleThumbnail = SampleThumbnail{sample};
+
+	auto param = SampleThumbnail::VisualizeParameters{};
+	param.amplification = sample.amplification();
+	param.reversed = sample.reversed();
+	param.sampleRect = m_seekerWaveform.rect();
+	param.sampleStart = static_cast<float>(sample.startFrame()) / sample.sampleSize();
+	param.sampleEnd = static_cast<float>(sample.endFrame()) / sample.sampleSize();
+	m_sampleThumbnail.visualize(param, brush);
+
 
 	// increase brightness in inner color
 	QBitmap innerMask = m_seekerWaveform.createMaskFromColor(s_waveformMaskColor, Qt::MaskMode::MaskOutColor);
@@ -171,13 +178,19 @@ void SlicerTWaveform::drawEditorWaveform()
 	size_t endFrame = m_seekerEnd * m_slicerTParent->m_originalSample.sampleSize();
 
 	brush.setPen(s_waveformColor);
-	float zoomOffset = (m_editorHeight - m_zoomLevel * m_editorHeight) / 2;
+	long zoomOffset = (m_editorHeight - m_zoomLevel * m_editorHeight) / 2;
 
 	const auto& sample = m_slicerTParent->m_originalSample;
-	const auto waveform = SampleWaveform::Parameters{
-		sample.data() + startFrame, endFrame - startFrame, sample.amplification(), sample.reversed()};
-	const auto rect = QRect(0, zoomOffset, m_editorWidth, m_zoomLevel * m_editorHeight);
-	SampleWaveform::visualize(waveform, brush, rect);
+
+	m_sampleThumbnail = SampleThumbnail{sample};
+
+	auto param = SampleThumbnail::VisualizeParameters{};
+	param.amplification = sample.amplification();
+	param.reversed = sample.reversed();
+	param.sampleStart = static_cast<float>(startFrame) / sample.sampleSize();
+	param.sampleEnd = static_cast<float>(endFrame) / sample.sampleSize();
+	param.sampleRect = QRect(0, zoomOffset, m_editorWidth, static_cast<long>(m_zoomLevel * m_editorHeight));
+	m_sampleThumbnail.visualize(param, brush);
 
 	// increase brightness in inner color
 	QBitmap innerMask = m_editorWaveform.createMaskFromColor(s_waveformMaskColor, Qt::MaskMode::MaskOutColor);

plugins/SlicerT/SlicerTWaveform.h

@@ -32,6 +32,8 @@
 #include <QMouseEvent>
 #include <QPainter>
 
+#include "SampleThumbnail.h"
+
 namespace lmms {
 
 class SlicerT;
@@ -108,6 +110,8 @@ public slots:
 	QPixmap m_editorWaveform;
 	QPixmap m_sliceEditor;
 	QPixmap m_emptySampleIcon;
+
+	SampleThumbnail m_sampleThumbnail;
 
 	SlicerT* m_slicerTParent;
 

src/gui/CMakeLists.txt

@@ -35,7 +35,7 @@ SET(LMMS_SRCS
 	gui/RowTableView.cpp
 	gui/SampleLoader.cpp
 	gui/SampleTrackWindow.cpp
-	gui/SampleWaveform.cpp
+	gui/SampleThumbnail.cpp
 	gui/SendButtonIndicator.cpp
 	gui/SideBar.cpp
 	gui/SideBarWidget.cpp