From 17a4890fdcd9adac77e17de14d98e59020aac67e Mon Sep 17 00:00:00 2001
From: BlackMark <me@blackmark.me>
Date: Fri, 17 Jul 2020 14:54:31 +0200
Subject: [PATCH] Refactor clamped and rounded linear interpolation

---
 AdaptiveBrightness/main_window.cpp | 13 +++++--------
 AdaptiveBrightness/monitor_win.cpp |  5 ++---
 AdaptiveBrightness/sensor.cpp      |  3 +--
 AdaptiveBrightness/utils.hpp       | 15 ++++++++++++++-
 4 files changed, 22 insertions(+), 14 deletions(-)

diff --git a/AdaptiveBrightness/main_window.cpp b/AdaptiveBrightness/main_window.cpp
index 53fbfb6..bcb0c13 100644
--- a/AdaptiveBrightness/main_window.cpp
+++ b/AdaptiveBrightness/main_window.cpp
@@ -123,8 +123,7 @@ void MainWindow::setupMonitorsTab()
             [this](int state) { m_ui.monitorOverallBrightnessSlider->setEnabled(state == Qt::CheckState::Checked); });
 
     connect(m_ui.monitorBrightnessSlider, &QSlider::valueChanged, [this](int value) {
-        const auto mappedBrightness = utils::map(value, 0, 100, 0.f, 1.f);
-        const auto newBrightness = std::clamp(mappedBrightness, 0.f, 1.f);
+        const auto newBrightness = utils::map(value, 0, 100, 0.f, 1.f);
         qDebug(ltr("Overriding brightness with %1").arg(newBrightness));
         m_brightness = newBrightness;
     });
@@ -183,9 +182,9 @@ void MainWindow::setupCallbackTimer()
 
 void MainWindow::updateCurrentMonitorGUI(int index)
 {
-    const auto brightness = std::clamp<int>(utils::map(m_monitors[index].brightness, 0.f, 1.f, 0, 100), 0, 100);
-    const auto minimum = std::clamp<int>(utils::map(m_monitors[index].minBrightness, 0.f, 1.f, 0, 100), 0, 100);
-    const auto maximum = std::clamp<int>(utils::map(m_monitors[index].maxBrightness, 0.f, 1.f, 0, 100), 0, 100);
+    const auto brightness = utils::map(m_monitors[index].brightness, 0.f, 1.f, 0, 100);
+    const auto minimum = utils::map(m_monitors[index].minBrightness, 0.f, 1.f, 0, 100);
+    const auto maximum = utils::map(m_monitors[index].maxBrightness, 0.f, 1.f, 0, 100);
 
     m_ui.monitorMinBrightnessSlider->setValue(minimum);
     m_ui.monitorMinBrightnessValueLabel->setText(QString("%1%").arg(minimum, 3, 10));
@@ -205,7 +204,6 @@ void MainWindow::updateState()
 
     bool sensorError = false;
     bool monitorError = false;
-    size_t iconBrightness = 0;
 
     const auto getAverageSensorValue = [this](float& brightness) {
         if(m_sensors.empty()) {
@@ -246,8 +244,7 @@ void MainWindow::updateState()
         sensorError = true;
     }
 
-    const auto roundedBrightness = std::round(utils::map(m_brightness, 0.f, 1.f, 0, 8));
-    iconBrightness = std::clamp<size_t>(roundedBrightness, 0, 8);
+    const auto iconBrightness = utils::map(m_brightness, 0.f, 1.f, size_t{0}, size_t{8});
 
     if(!setAllMonitorsBrightness(m_brightness)) {
         enumMonitors();
diff --git a/AdaptiveBrightness/monitor_win.cpp b/AdaptiveBrightness/monitor_win.cpp
index fd1e6c8..b2490de 100644
--- a/AdaptiveBrightness/monitor_win.cpp
+++ b/AdaptiveBrightness/monitor_win.cpp
@@ -64,8 +64,7 @@ bool Monitor::setBrightness(float percentage)
             return false;
     }
 
-    const auto mappedBrightness = utils::map(percentage, 0.f, 1.f, m_brightnessRange->first, m_brightnessRange->second);
-    const auto newBrightness = std::clamp<DWORD>(std::round(mappedBrightness), m_brightnessRange->first, m_brightnessRange->second);
+    const auto newBrightness = utils::map(percentage, 0.f, 1.f, m_brightnessRange->first, m_brightnessRange->second);
 
     if(!SetMonitorBrightness(m_physicalMonitor.handle, newBrightness)) {
         qCritical(ltr("Failed to set brightness of monitor '%1' with handle '0x%2' and physical handle '0x%3', error: %4")
@@ -110,7 +109,7 @@ float Monitor::getBrightness()
     m_brightnessRange = std::pair{minBrightness, maxBrightness};
     m_errorOccurred = false;
 
-    return std::clamp(utils::map(brightness, minBrightness, maxBrightness, 0.f, 1.f), 0.f, 1.f);
+    return utils::map(brightness, minBrightness, maxBrightness, 0.f, 1.f);
 }
 
 QString Monitor::getName() const
diff --git a/AdaptiveBrightness/sensor.cpp b/AdaptiveBrightness/sensor.cpp
index 904c40f..906bd43 100644
--- a/AdaptiveBrightness/sensor.cpp
+++ b/AdaptiveBrightness/sensor.cpp
@@ -47,8 +47,7 @@ std::vector<float> Sensor::readValues()
     std::vector<float> normalizedValues;
 
     for(const auto& value: values) {
-        const auto mappedValue = utils::map(value, m_range->first, m_range->second, 0.f, 1.f);
-        normalizedValues.push_back(std::clamp(mappedValue, 0.f, 1.f));
+        normalizedValues.push_back(utils::map(value, m_range->first, m_range->second, 0.f, 1.f));
     }
 
     return normalizedValues;
diff --git a/AdaptiveBrightness/utils.hpp b/AdaptiveBrightness/utils.hpp
index 918b2d0..3563e81 100644
--- a/AdaptiveBrightness/utils.hpp
+++ b/AdaptiveBrightness/utils.hpp
@@ -1,17 +1,30 @@
 #pragma once
 
+#include <algorithm>
 #include <array>
+#include <type_traits>
 
+#include <cmath>
 #include <cstddef>
 
 namespace utils {
 
 template<typename InType, typename OutType>
-auto map(InType value, InType inMin, InType inMax, OutType outMin, OutType outMax)
+auto interpolate(InType value, InType inMin, InType inMax, OutType outMin, OutType outMax)
 {
     return (value - inMin) * (outMax - outMin) / (inMax - inMin) + outMin;
 }
 
+template<typename InType, typename OutType>
+auto map(InType value, InType inMin, InType inMax, OutType outMin, OutType outMax)
+{
+    if constexpr(std::is_integral_v<OutType>) {
+        return std::clamp(static_cast<OutType>(std::round(interpolate(value, inMin, inMax, outMin, outMax))), outMin, outMax);
+    }
+
+    return std::clamp(static_cast<OutType>(interpolate(value, inMin, inMax, outMin, outMax)), outMin, outMax);
+}
+
 template<typename>
 struct array_size;