Add SlewDistortion effect and oversampling support (#7641)

src/gui/CMakeLists.txt

@@ -105,6 +105,7 @@ SET(LMMS_SRCS
 	gui/widgets/CaptionMenu.cpp
 	gui/widgets/ComboBox.cpp
 	gui/widgets/CustomTextKnob.cpp
+	gui/widgets/Draggable.cpp
 	gui/widgets/Fader.cpp
 	gui/widgets/FloatModelEditorBase.cpp
 	gui/widgets/Graph.cpp

src/gui/widgets/Draggable.cpp

@@ -0,0 +1,128 @@
+/*
+ * Draggable.cpp
+ *
+ * Copyright (c) 2025 Lost Robot <r94231/at/gmail/dot/com>
+ *
+ * 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.
+ *
+ */
+
+#include "Draggable.h"
+#include "SimpleTextFloat.h"
+#include "interpolation.h"
+
+#include <QPixmap>
+#include <QMouseEvent>
+#include <QPainter>
+
+namespace lmms::gui
+{
+
+Draggable::Draggable(DirectionOfManipulation directionOfManipulation, 
+	FloatModel* floatModel, const QPixmap& pixmap, int pointA, int pointB, QWidget* parent)
+	: FloatModelEditorBase(directionOfManipulation, parent),
+	  m_pixmap(pixmap),
+	  m_defaultValPixmap(),
+	  m_pointA(pointA),
+	  m_pointB(pointB),
+	  m_defaultValue(0),
+	  m_hasDefaultValPixmap(false)
+{
+	setModel(floatModel);
+	connect(model(), &FloatModel::dataChanged, this, &Draggable::handleMovement);
+	handleMovement();
+}
+
+QSize Draggable::sizeHint() const
+{
+	return m_pixmap.size();
+}
+
+void Draggable::setPixmap(const QPixmap& pixmap)
+{
+	m_pixmap = pixmap;
+	update();
+}
+
+void Draggable::setDefaultValPixmap(const QPixmap& pixmap, float value)
+{
+	m_defaultValPixmap = pixmap;
+	m_defaultValue = value;
+	m_hasDefaultValPixmap = true;
+	update();
+}
+
+void Draggable::paintEvent(QPaintEvent* event)
+{
+	Q_UNUSED(event);
+	QPainter painter(this);
+	
+	if (m_hasDefaultValPixmap && model()->value() == m_defaultValue)
+	{
+		painter.drawPixmap(rect(), m_defaultValPixmap, m_defaultValPixmap.rect());
+	}
+	else
+	{
+		painter.drawPixmap(rect(), m_pixmap, m_pixmap.rect());
+	}
+}
+
+void Draggable::mouseMoveEvent(QMouseEvent* me)
+{
+	QPoint pPos = mapToParent(me->pos());
+
+	if (m_buttonPressed && pPos != m_lastMousePos)
+	{
+		float point = (m_directionOfManipulation == DirectionOfManipulation::Vertical) ? pPos.y() : pPos.x();
+		float progress = (point - m_pointA) / (m_pointB - m_pointA);
+
+		if (progress >= 0 && progress <= 1)
+		{
+			float newVal = progress * (model()->maxValue() - model()->minValue()) + model()->minValue();
+			model()->setValue(newVal);
+		}
+		else if (progress < 0)
+		{
+			model()->setValue(model()->minValue());
+		}
+		else
+		{
+			model()->setValue(model()->maxValue());
+		}
+
+		emit sliderMoved(model()->value());
+		m_lastMousePos = pPos;
+		s_textFloat->setText(displayValue());
+		s_textFloat->moveGlobal(this, QPoint(width() + 2, 0));
+	}
+}
+
+void Draggable::handleMovement()
+{
+	float newCoord = std::lerp(m_pointA, m_pointB, (model()->value() - model()->minValue()) / (model()->maxValue() - model()->minValue()));
+	if (m_directionOfManipulation == DirectionOfManipulation::Vertical)
+	{
+		move(x(), newCoord - m_pixmap.height() / 2.f);
+	}
+	else if (m_directionOfManipulation == DirectionOfManipulation::Horizontal)
+	{
+		move(newCoord - m_pixmap.width() / 2.f, y());
+	}
+}
+
+} // namespace lmms::gui