From 4ef189b9dd9f5c705dac31924e20233b2222e8f6 Mon Sep 17 00:00:00 2001
From: structix <amateurdoedel@gmail.com>
Date: Fri, 15 Sep 2017 22:45:32 +0200
Subject: [PATCH] CMake added *.c* wildcard to compile extern c files; Added
 calculation for absoluteHumidity

---
 RestServer/humidityserver/CMakeLists.txt      |  2 +-
 RestServer/humidityserver/src/calculate.c     | 80 +++++++++++++++++++
 RestServer/humidityserver/src/calculate.h     | 15 ++++
 .../humidityserver/src/humidityserver.cpp     |  4 +-
 4 files changed, 98 insertions(+), 3 deletions(-)
 create mode 100644 RestServer/humidityserver/src/calculate.c
 create mode 100644 RestServer/humidityserver/src/calculate.h

diff --git a/RestServer/humidityserver/CMakeLists.txt b/RestServer/humidityserver/CMakeLists.txt
index 75bcc32..35593f5 100644
--- a/RestServer/humidityserver/CMakeLists.txt
+++ b/RestServer/humidityserver/CMakeLists.txt
@@ -16,7 +16,7 @@ add_custom_command(OUTPUT ${HUMIDITYSERVER_CODEGEN_SOURCES}
     DEPENDS ${HUMIDITYSERVER_HEADERS_PATHS}
 )
 
-file(GLOB HUMIDITYSERVER_SOURCES ${PROJECT_SOURCE_DIR}/*.cpp)
+file(GLOB HUMIDITYSERVER_SOURCES ${PROJECT_SOURCE_DIR}/*.c*)
 
 list(APPEND HUMIDITYSERVER_SOURCES ${HUMIDITYSERVER_CODEGEN_SOURCES})
 
diff --git a/RestServer/humidityserver/src/calculate.c b/RestServer/humidityserver/src/calculate.c
new file mode 100644
index 0000000..24e1d11
--- /dev/null
+++ b/RestServer/humidityserver/src/calculate.c
@@ -0,0 +1,80 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <math.h> /* link against math lib */
+#include "calculate.h"
+
+#define R 8314.3 //J/(kmol*K) (universelle Gaskonstante)
+#define mw 18.016 //kg/kmol (Molekulargewicht des Wasserdampfes)
+
+/*
+Bezeichnungen:
+r = relative Luftfeuchte
+T = Temperatur in °C
+TK = Temperatur in Kelvin (TK = T + 273.15)
+TD = Taupunkttemperatur in °C
+DD = Dampfdruck in hPa
+SDD = Sättigungsdampfdruck in hPa
+
+Parameter:
+a = 7.5, b = 237.3 für T >= 0
+a = 7.6, b = 240.7 für T < 0 über Wasser (Taupunkt)
+a = 9.5, b = 265.5 für T < 0 über Eis (Frostpunkt)
+
+R* = 8314.3 J/(kmol*K) (universelle Gaskonstante)
+mw = 18.016 kg/kmol (Molekulargewicht des Wasserdampfes)
+AF = absolute Feuchte in g Wasserdampf pro m3 Luft
+
+Formeln:
+
+    SDD(T) = 6.1078 * 10^((a*T)/(b+T))
+    DD(r,T) = r/100 * SDD(T)
+    r(T,TD) = 100 * SDD(TD) / SDD(T)
+    TD(r,T) = b*v/(a-v) mit v(r,T) = log10(DD(r,T)/6.1078)
+    AF(r,TK) = 10^5 * mw/R* * DD(r,T)/TK; AF(TD,TK) = 10^5 * mw/R* * SDD(TD)/TK
+*/
+
+static float sdd(float temperature) {
+  //select constant based on input temperature
+  float a = 7.5, b = 237.3;
+  if (temperature >= 0) {
+    a = 7.6;
+    b = 240.7;
+  }
+  return 6.1078 * pow(10, (a * temperature) / (b + temperature));
+}
+
+static float dd(float relativeHumidity, float temperature) {
+  return relativeHumidity / 100 * sdd(temperature);
+}
+
+/* CURRENTLY UNUSED
+
+static float r(float temperature, float dewTemperature) {
+  // This is optional. Necessary with dew point measurements.
+  return 100 * sdd(dewTemperature) / sdd(temperature);
+}
+
+static float v(float relativeHumidity, float temperature) {
+  log10(dd(relativeHumidity, temperature)/6.1078);
+}
+
+static float td(float relativeHumidity, float temperature) {
+  //select constant based on input temperature
+  float a = 7.5, b = 237.3;
+  if (temperature >= 0) {
+    a = 7.6;
+    b = 240.7;
+  }
+  return b * v(relativeHumidity, temperature) / (a - v(relativeHumidity, temperature));
+}
+*/
+static float af(float relativeHumidity, float temperature) {
+    float tk = temperature + 273.15;
+    return pow(10, 5) * mw/R * dd(relativeHumidity, temperature) / tk;
+}
+
+float absoluteHumidityFloat(float temperature, float humidity) {
+    return af(humidity, temperature);
+}
+
+  
diff --git a/RestServer/humidityserver/src/calculate.h b/RestServer/humidityserver/src/calculate.h
new file mode 100644
index 0000000..774cf16
--- /dev/null
+++ b/RestServer/humidityserver/src/calculate.h
@@ -0,0 +1,15 @@
+#ifndef calculate_H
+#define calculate_H
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
+float absoluteHumidityFloat(float temperature, float humidity);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/RestServer/humidityserver/src/humidityserver.cpp b/RestServer/humidityserver/src/humidityserver.cpp
index 890bcf3..83de0f4 100644
--- a/RestServer/humidityserver/src/humidityserver.cpp
+++ b/RestServer/humidityserver/src/humidityserver.cpp
@@ -2,7 +2,7 @@
 // For more information, please visit: https://github.com/loentar/ngrest
 
 #include "humidityserver.h"
-
+#include "calculate.h"
 /*std::string humidityserver::echo(const std::string& text)
 {
     return "Hi, " + text;
@@ -10,5 +10,5 @@
 
 float humidityserver::absolutehumidity(float temperature, float humidity) {
     
-    return temperature + humidity; 
+    return absoluteHumidityFloat(temperature, humidity); 
 }