Fix problem of transitions getting faster with each call of setTargetFPS (#275)

Author: geeksville

src/OLEDDisplayUi.cpp

@@ -48,8 +48,6 @@ OLEDDisplayUi::OLEDDisplayUi(OLEDDisplay *display) {
   inactiveSymbol = ANIMATION_inactiveSymbol;
   frameAnimationDirection   = SLIDE_RIGHT;
   lastTransitionDirection = 1;
-  ticksPerFrame = 151; // ~ 5000ms at 30 FPS
-  ticksPerTransition = 15;  // ~  500ms at 30 FPS
   frameCount = 0;
   nextFrameNumber = -1;
   overlayCount = 0;
@@ -66,20 +64,19 @@ OLEDDisplayUi::OLEDDisplayUi(OLEDDisplay *display) {
   state.userData = NULL;
   shouldDrawIndicators = true;
   autoTransition = true;
+  setTimePerFrame(5000);
+  setTimePerTransition(500);
 }
 
 void OLEDDisplayUi::init() {
   this->display->init();
 }
 
 void OLEDDisplayUi::setTargetFPS(uint8_t fps){
-  float oldInterval = this->updateInterval;
   this->updateInterval = ((float) 1.0 / (float) fps) * 1000;
 
-  // Calculate new ticksPerFrame
-  float changeRatio = oldInterval / (float) this->updateInterval;
-  this->ticksPerFrame *= changeRatio;
-  this->ticksPerTransition *= changeRatio;
+  this->ticksPerFrame = timePerFrame / updateInterval;
+  this->ticksPerTransition = timePerTransition / updateInterval;
 }
 
 // -/------ Automatic controll ------\-
@@ -99,10 +96,12 @@ void OLEDDisplayUi::setAutoTransitionBackwards(){
   this->lastTransitionDirection = -1;
 }
 void OLEDDisplayUi::setTimePerFrame(uint16_t time){
-  this->ticksPerFrame = (uint16_t) ( (float) time / (float) updateInterval);
+  this->timePerFrame = time;
+  this->ticksPerFrame = timePerFrame / updateInterval;
 }
 void OLEDDisplayUi::setTimePerTransition(uint16_t time){
-  this->ticksPerTransition = (uint16_t) ( (float) time / (float) updateInterval);
+  this->timePerTransition = time;
+  this->ticksPerTransition = timePerTransition / updateInterval;
 }
 
 // -/------ Customize indicator position and style -------\-

src/OLEDDisplayUi.h

@@ -159,6 +159,9 @@ class OLEDDisplayUi {
     // Bookeeping for update
     uint16_t            updateInterval            = 33;
 
+    uint16_t            timePerFrame;
+    uint16_t            timePerTransition;
+
     uint8_t             getNextFrameNumber();
     void                drawIndicator();
     void                drawFrame();