Add natural dimer (#106)

apps/backlight_dimming_timer.cpp

@@ -1,4 +1,5 @@
 #include "backlight_dimming_timer.h"
+#include "global_preferences.h"
 
 BacklightDimmingTimer::BacklightDimmingTimer() :
   Timer(k_idleBeforeDimmingDuration/Timer::TickDuration)
@@ -6,6 +7,33 @@ BacklightDimmingTimer::BacklightDimmingTimer() :
 }
 
 bool BacklightDimmingTimer::fire() {
-  Ion::Backlight::setBrightness(k_dimBacklightBrightness);
+  if (m_dimerExecutions == 0) {
+    m_brightnessLevel = GlobalPreferences::sharedGlobalPreferences()->brightnessLevel();
+    m_dimerSteps = m_brightnessLevel / decreaseby;
+    m_timeToSleep = decreasetime / m_dimerSteps;
+    m_period = m_timeToSleep / Timer::TickDuration;
+    if (m_period == 0) {
+      m_period = 1;
+    }
+    resetTimer();
+  }
+  if (m_dimerExecutions < m_dimerSteps) {
+    m_nextbrightness = (m_brightnessLevel-k_dimBacklightBrightness)/m_dimerSteps * (m_dimerSteps-m_dimerExecutions);
+    Ion::Backlight::setBrightness(m_nextbrightness);
+    resetTimer();
+  } else if (m_dimerExecutions == m_dimerSteps) {
+    Ion::Backlight::setBrightness(k_dimBacklightBrightness);
+  }
+  m_dimerExecutions++;
   return false;
 }
+
+void BacklightDimmingTimer::reset() {
+  m_dimerExecutions = 0;
+  m_period = k_idleBeforeDimmingDuration / Timer::TickDuration;
+  resetTimer();
+}
+
+void BacklightDimmingTimer::resetTimer() {
+  BacklightDimmingTimer::m_numberOfTicksBeforeFire = BacklightDimmingTimer::m_period;
+}

apps/backlight_dimming_timer.h

@@ -6,10 +6,19 @@
 class BacklightDimmingTimer : public Timer {
 public:
   BacklightDimmingTimer();
+  void reset();
 private:
   constexpr static int k_idleBeforeDimmingDuration = 30*1000; // In miliseconds
   constexpr static int k_dimBacklightBrightness = 0;
+  constexpr static int decreaseby = 15;
+  constexpr static int decreasetime = 1*1000; // In miliseconds
+  int m_dimerExecutions = 0;
+  int m_brightnessLevel;
+  int m_dimerSteps;
+  int m_nextbrightness;
+  float m_timeToSleep; // In miliseconds
   bool fire() override;
+  void resetTimer();
 };
 
 #endif

escher/include/escher/timer.h

@@ -18,11 +18,10 @@ public:
   Timer(uint32_t period); // Period is in ticks
   bool tick();
   void reset();
-protected:
-  virtual bool fire() = 0;
-private:
   uint32_t m_period;
   uint32_t m_numberOfTicksBeforeFire;
+protected:
+  virtual bool fire() = 0;
 };
 
 #endif