X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=nonlinear_fader.cpp;h=06a929c39259c037a0d6bf27c9a0a36c0ea8efcd;hb=b9feb66845bf24465b7671ac9ff7a52b88f6032b;hp=7c26434aac743faeda9e29434758a78543e68b13;hpb=22bb590d54107446f09d0cb60f32e610cc9ed7ad;p=nageru

diff --git a/nonlinear_fader.cpp b/nonlinear_fader.cpp
index 7c26434..06a929c 100644
--- a/nonlinear_fader.cpp
+++ b/nonlinear_fader.cpp
@@ -1,79 +1,45 @@
+#include "nonlinear_fader.h"
+
 #include <assert.h>
 #include <math.h>
-#include <stdio.h>
-#include <vector>
-#include <utility>
-
-#include <QResizeEvent>
 #include <QPainter>
+#include <QPoint>
+#include <QRect>
 #include <QStyle>
-#include <QStyleOptionSlider>
+#include <QStyleOption>
+#include <memory>
+#include <utility>
+#include <vector>
 
-#include "nonlinear_fader.h"
+#include "piecewise_interpolator.h"
+
+class QPaintEvent;
+class QWidget;
 
 using namespace std;
 
 namespace {
 
-vector<pair<double, double>> fader_control_points = {
+PiecewiseInterpolator interpolator({
 	// The main area is from +6 to -12 dB (18 dB), and we use half the slider range for it.
-	{ 6.0, 0.0 },
-	{ -12.0, 0.5 },
+	// Adjust slightly so that the MIDI controller value of 106 becomes exactly 0.0 dB
+	// (cf. map_controller_to_float()); otherwise, we'd miss ever so slightly, which is
+	// really frustrating.
+	{ 6.0, 1.0 },
+	{ -12.0, 1.0 - (1.0 - 106.5/127.0) * 3.0 },  // About 0.492.
 
 	// -12 to -21 is half the range (9 dB). Halve.
-	{ -21.0, 0.625 },
+	{ -21.0, 0.325 },
 
 	// -21 to -30 (9 dB) gets the same range as the previous one.
-	{ -30.0, 0.75 },
+	{ -30.0, 0.25 },
 
 	// -30 to -48 (18 dB) gets half of half.
-	{ -48.0, 0.875 },
+	{ -48.0, 0.125 },
 
 	// -48 to -84 (36 dB) gets half of half of half.
-	{ -84.0, 1.0 },
-};
-
-double slider_fraction_to_db(double db)
-{
-	if (db <= fader_control_points[0].second) {
-		return fader_control_points[0].first;
-	}
-	if (db >= fader_control_points.back().second) {
-		return fader_control_points.back().first;
-	}
-	for (unsigned i = 1; i < fader_control_points.size(); ++i) {
-		const double x0 = fader_control_points[i - 1].second;
-		const double x1 = fader_control_points[i].second;
-		const double y0 = fader_control_points[i - 1].first;
-		const double y1 = fader_control_points[i].first;
-		if (db >= x0 && db <= x1) {
-			const double t = (db - x0) / (x1 - x0);
-			return y0 + t * (y1 - y0);
-		}
-	}
-	assert(false);
-}
-
-double db_to_slider_fraction(double x)
-{
-	if (x >= fader_control_points[0].first) {
-		return fader_control_points[0].second;
-	}
-	if (x <= fader_control_points.back().first) {
-		return fader_control_points.back().second;
-	}
-	for (unsigned i = 1; i < fader_control_points.size(); ++i) {
-		const double x0 = fader_control_points[i].first;
-		const double x1 = fader_control_points[i - 1].first;
-		const double y0 = fader_control_points[i].second;
-		const double y1 = fader_control_points[i - 1].second;
-		if (x >= x0 && x <= x1) {
-			const double t = (x - x0) / (x1 - x0);
-			return y0 + t * (y1 - y0);
-		}
-	}
-	assert(false);
-}
+	{ -84.0, 0.0 },
+});
 
 }  // namespace
 
@@ -100,8 +66,8 @@ void NonLinearFader::paintEvent(QPaintEvent *event)
 	// FIXME: Where does the slider_length / 2 come from? I can't really find it
 	// in the Qt code, but it seems to match up with reality.
 	int slider_length = sr.height();
-	int slider_min = gr.top() + (slider_length / 2);
-	int slider_max = gr.bottom() + (slider_length / 2) - slider_length + 1;
+	int slider_max = gr.top() + (slider_length / 2);
+	int slider_min = gr.bottom() + (slider_length / 2) - slider_length + 1;
 
 	QPainter p(this);
 
@@ -111,7 +77,7 @@ void NonLinearFader::paintEvent(QPaintEvent *event)
 	int x_margin = 5;
 	p.setPen(Qt::darkGray);
 	for (int db = -84; db <= 6; db += 6) {
-		int y = slider_min + lrint(db_to_slider_fraction(db) * (slider_max - slider_min));
+		int y = slider_min + lrint(interpolator.db_to_fraction(db) * (slider_max - slider_min));
 		p.drawLine(QPoint(0, y), QPoint(gr.left() - x_margin, y));
 		p.drawLine(QPoint(gr.right() + x_margin, y), QPoint(width() - 1, y));
 	}
@@ -119,15 +85,6 @@ void NonLinearFader::paintEvent(QPaintEvent *event)
 	QSlider::paintEvent(event);
 }
 
-void NonLinearFader::resizeEvent(QResizeEvent *event)
-{
-	QSlider::resizeEvent(event);
-	inhibit_updates = true;
-	setRange(0, event->size().height() - 1);
-	inhibit_updates = false;
-	update_slider_position();
-}
-
 void NonLinearFader::sliderChange(SliderChange change)
 {
 	QSlider::sliderChange(change);
@@ -135,8 +92,8 @@ void NonLinearFader::sliderChange(SliderChange change)
 		if (value() == 0) {
 			db_value = -HUGE_VAL;
 		} else {
-			double frac = 1.0 - value() / (height() - 1.0);
-			db_value = slider_fraction_to_db(frac);
+			double frac = double(value() - minimum()) / (maximum() - minimum());
+			db_value = interpolator.fraction_to_db(frac);
 		}
 		emit dbValueChanged(db_value);
 	}
@@ -145,6 +102,7 @@ void NonLinearFader::sliderChange(SliderChange change)
 void NonLinearFader::update_slider_position()
 {
 	inhibit_updates = true;
-	setValue(lrint((1.0 - db_to_slider_fraction(db_value)) * (height() - 1.0)));
+	double val = interpolator.db_to_fraction(db_value) * (maximum() - minimum()) + minimum();
+	setValue(lrint(val));
 	inhibit_updates = false;
 }