From 464c3eb0edb2b9b3d31ba8c2ace2038760531a03 Mon Sep 17 00:00:00 2001
From: Sebastian M <sebastian@mobiflight.com>
Date: Mon, 13 Feb 2023 00:10:52 +0100
Subject: [PATCH] Long floats are displayed correctly on 7 segment (#1143)

---
 MobiFlight/MobiFlightLedModule.cs             | 59 ++++++++++++++++++-
 .../MobiFlight/MobiFlightLedModuleTests.cs    | 19 ++++--
 2 files changed, 70 insertions(+), 8 deletions(-)

diff --git a/MobiFlight/MobiFlightLedModule.cs b/MobiFlight/MobiFlightLedModule.cs
index 4e8e8aef9..46ccaeb79 100644
--- a/MobiFlight/MobiFlightLedModule.cs
+++ b/MobiFlight/MobiFlightLedModule.cs
@@ -5,6 +5,7 @@
 using System.Linq;
 using System.Text;
 using System.Text.RegularExpressions;
+using System.Windows.Forms.Design;
 using CommandMessenger;
 using Newtonsoft.Json.Linq;
 using SharpDX.DirectInput;
@@ -114,12 +115,64 @@ private string CalculateCorrectLeadingSpaces(string value)
             return result;
         }
 
+        static public byte CalculatePositionInString(string value, byte mask)
+        {
+            // we have to figure it, how many digits are in use
+            var maskLength = Convert.ToString(mask, 2).Count(c => c == '1');
+
+            // we have to find the n-th character
+            // where "n" is the maskLength
+            // but we have to treat decimal points correctly
+            // because they don't occupy a digit
+            // unless two are following each other
+            // we start with the last character in the value string
+            byte positionInValue = 0;
+
+            // we set the last character to .
+            // so that in case we have the first one being a "."
+            // then we allocate a digit for it correctly
+            var lastCharacter = '.';
+
+            // out inital length is 0, because we start on the left
+            var length = 0;
+
+            for (byte i = 0; i != value.Length; i++)
+            {
+                // in case we see a "." but the last character
+                // was something different,
+                // then we don't have to account for this
+                if (value[i] == '.' && lastCharacter != '.')
+                {
+                    // we store the last character
+                    lastCharacter = value[i];
+                    continue;
+                }
+
+                // in all other cases now we count this
+                // character, length can be different from "i"
+                length++;
+
+                // we store the last character
+                lastCharacter = value[i];
+
+                // once we reach the length
+                // we update the positionInValue
+                if (length == maskLength)
+                {
+                    positionInValue = i;
+                    if (i + 1 < value.Length && value[i + 1] == '.')
+                        positionInValue += 1;
+                    break;
+                }
+            }
+
+            return positionInValue;
+        }
+
         static public byte CalculateCorrectPoints(string value, byte mask)
         {
             byte points = 0;
-            
-            // we start with the last character in the value string
-            int positionInValue = value.Length-1;
+            byte positionInValue = CalculatePositionInString(value, mask);
 
             // we go over all 8 potential digits
             for (byte digit=0; digit<8; digit++)
diff --git a/MobiFlightUnitTests/MobiFlight/MobiFlightLedModuleTests.cs b/MobiFlightUnitTests/MobiFlight/MobiFlightLedModuleTests.cs
index 718c3027c..39ba32997 100644
--- a/MobiFlightUnitTests/MobiFlight/MobiFlightLedModuleTests.cs
+++ b/MobiFlightUnitTests/MobiFlight/MobiFlightLedModuleTests.cs
@@ -171,7 +171,7 @@ public void DisplayTest()
 
             value = "1.234";
             points = 0;
-            mask = 8+4+2+1;
+            mask = 8 + 4 + 2 + 1;
             mockTransport.Clear();
             module.Display(0, value, points, mask);
             WaitForQueueUpdate();
@@ -180,7 +180,7 @@ public void DisplayTest()
 
             value = "1.234";
             points = 0;
-            mask = 128+64+32+16;
+            mask = 128 + 64 + 32 + 16;
             mockTransport.Clear();
             module.Display(0, value, points, mask);
             WaitForQueueUpdate();
@@ -189,7 +189,7 @@ public void DisplayTest()
 
             value = "1.2";
             points = 0;
-            mask = 0+4+0+1;
+            mask = 0 + 4 + 0 + 1;
             mockTransport.Clear();
             module.Display(0, value, points, mask);
             WaitForQueueUpdate();
@@ -205,7 +205,7 @@ public void DisplayTest()
             DataExpected = $"{CommandId},{ModuleIndex},{SubModuleIndex}, 123,8,{mask};";
             Assert.AreEqual(DataExpected, mockTransport.DataWrite, "Decimal point not set correctly");
 
-            
+
             value = "........";
             points = 0;
             mask = 255;
@@ -214,7 +214,7 @@ public void DisplayTest()
             WaitForQueueUpdate();
             DataExpected = $"{CommandId},{ModuleIndex},{SubModuleIndex},        ,255,{mask};";
             Assert.AreEqual(DataExpected, mockTransport.DataWrite, "Decimal point not set correctly");
-            
+
             value = "1..2";
             points = 0;
             mask = 0 + 4 + 2 + 1;
@@ -233,6 +233,15 @@ public void DisplayTest()
             WaitForQueueUpdate();
             DataExpected = $"{CommandId},{ModuleIndex},{SubModuleIndex},12350,4,{mask};";
             Assert.AreEqual(DataExpected, mockTransport.DataWrite, "Decimal point not set correctly");
+
+            value = "118.805000305176";
+            points = 0;
+            mask = 255;
+            mockTransport.Clear();
+            module.Display(0, value, points, mask);
+            WaitForQueueUpdate();
+            DataExpected = $"{CommandId},{ModuleIndex},{SubModuleIndex},11880500,32,{mask};";
+            Assert.AreEqual(DataExpected, mockTransport.DataWrite, "Decimal point not set correctly");
         }
 
         [TestMethod()]