Code Refactor

src/components/ble/SimpleWeatherService.cpp

@@ -153,6 +153,81 @@ std::optional<SimpleWeatherService::Forecast> SimpleWeatherService::GetForecast(
   return {};
 }
 
+//Linear gradient temperature color calculator :)
+
+    int16_t SimpleWeatherService::RoundTemperature(int16_t temp) {
+      return temp = temp / 100 + (temp % 100 >= 50 ? 1 : 0);
+    }
+  
+    const char* floatToRgbHex(std::tuple<float, float, float> rgb) {
+      char *rgbHex = new char[7];
+      snprintf(rgbHex, 7, "%02X%02X%02X", static_cast<int>(std::get<0>(rgb)), static_cast<int>(std::get<1>(rgb)), static_cast<int>(std::get<2>(rgb)));
+      return rgbHex;
+    }
+  
+    std::tuple<float, float, float> hexToFloat(int rgb) {
+      float r = ((rgb >> 16) & 0xFF);
+      float g = ((rgb >> 8) & 0xFF);
+      float b = (rgb & 0xFF);
+      return std::tuple<float, float, float>(r, g, b);
+    }
+    
+    float normalize(float value) {
+    if (value < 0.0f) {
+        return 0.0f;
+    } else if (value > 1.0f) {
+        return 1.0f;
+    } else {
+        return value;
+    }
+}
+    
+    // reference: https://dev.to/ndesmic/linear-color-gradients-from-scratch-1a0e
+    std::tuple<float, float, float> lerp(std::tuple<float, float, float> pointA, std::tuple<float, float, float> pointB, float normalValue) {
+      NRF_LOG_INFO("Normal value: %f", normalValue);
+      auto lerpOutput = std::tuple<float, float, float>(
+        get<0>(pointA) + (get<0>(pointB) - get<0>(pointA)) * normalValue,
+        get<1>(pointA) + (get<1>(pointB) - get<1>(pointA)) * normalValue,
+        get<2>(pointA) + (get<2>(pointB) - get<2>(pointA)) * normalValue
+        //std::lerp(get<0>(pointA), get<0>(pointB), normalValue),
+        //std::lerp(get<1>(pointA), get<1>(pointB), normalValue),
+        //std::lerp(get<2>(pointA), get<2>(pointB), normalValue)
+        );
+      NRF_LOG_INFO("pointA: %f, %f, %f", get<0>(pointA), get<1>(pointA), get<2>(pointA));
+      NRF_LOG_INFO("pointB: %f, %f, %f", get<0>(pointB), get<1>(pointB), get<2>(pointB));
+      NRF_LOG_INFO("lerp: %f, %f, %f", get<0>(lerpOutput), get<1>(lerpOutput), get<2>(lerpOutput));
+      return lerpOutput;
+    }
+    
+    const char* SimpleWeatherService::TemperatureColor(int16_t temperature) {
+      const std::vector<int> colors = {0x5555ff, 0x00c9ff, 0xff9b00, 0xff0000};
+      std::vector<std::tuple<float, float, float>> stops;
+      for (auto colorVal: colors) {
+       stops.emplace_back(hexToFloat(colorVal));
+      }
+      int tempRounded = RoundTemperature(temperature);
+      if (tempRounded < 0) {
+         tempRounded = 1;
+      }
+      // convert temperature to range between newMin and newMax
+      float oldMax = 50;
+      float oldMin = 0;
+      float newMax = 1;
+      float newMin = 0;
+      float oldRange = (oldMax - oldMin);
+      float newRange = (newMax - newMin);
+      float newValue = (((tempRounded - oldMin) * newRange) / oldRange) + newMin;
+      newValue = normalize(newValue);
+      if (newValue <= .33f) {
+        return floatToRgbHex(lerp(stops[0], stops[1], newValue));
+      } else if (newValue <= .66f) {
+        return floatToRgbHex(lerp(stops[1], stops[2], newValue));
+      } else {
+        return floatToRgbHex(lerp(stops[2], stops[3], newValue));
+      }
+    }
+
+
 bool SimpleWeatherService::CurrentWeather::operator==(const SimpleWeatherService::CurrentWeather& other) const {
   return this->iconId == other.iconId && this->temperature == other.temperature && this->timestamp == other.timestamp &&
          this->maxTemperature == other.maxTemperature && this->minTemperature == other.maxTemperature &&

src/components/ble/SimpleWeatherService.h

@@ -60,7 +60,7 @@ namespace Pinetime {
         Smog = 8, // Mist
         Unknown = 255
       };
-
+      
       using Location = std::array<char, 33>; // 32 char + \0 (end of string)
 
       struct CurrentWeather {
@@ -111,6 +111,10 @@ namespace Pinetime {
       static int16_t CelsiusToFahrenheit(int16_t celsius) {
         return celsius * 9 / 5 + 3200;
       }
+      
+      static const char* TemperatureColor(int16_t temperature);
+      
+      static int16_t RoundTemperature(int16_t temp);
 
     private:
       // 00050000-78fc-48fe-8e23-433b3a1942d0
@@ -125,7 +129,7 @@ namespace Pinetime {
       }
 
       ble_uuid128_t weatherUuid {BaseUuid()};
-
+      
       ble_uuid128_t weatherDataCharUuid {CharUuid(0x00, 0x01)};
 
       const struct ble_gatt_chr_def characteristicDefinition[2] = {{.uuid = &weatherDataCharUuid.u,