auto register data structs with SimConnect#RegisterDataDefinition

.gitignore

@@ -1,5 +1,6 @@
 .env
 build-vfrmap-upload.sh
 vfrmap.exe
+vfrmap-win64.zip
 request_data.exe
 _vendor

README.md

@@ -0,0 +1,22 @@
+# msfs2020-go
+
+simconnect package [msfs2020-go/simconnect](simconnect/) connects to microsoft flight simulator 2020 using golang.
+
+cross-compiles from macos/linux, no other dependencies required. produces a single binary with no other files or configuration required.
+
+## status
+
+[msfs2020-go/simconnect](simconnect/) package currently only implements enough of the simconnect api for [examples](examples/) and [vfrmap](vfrmap).
+
+## download
+
+program zips are uploaded [here](https://github.com/lian/msfs2020-go/releases)
+
+## tools
+
+* [vfrmap](vfrmap/) web server that shows your current MSFS2020 plane position in google maps inside the browser
+
+## examples
+
+* [examples/request_data](examples/request_data/) port of `MSFS-SDK/Samples/SimConnectSamples/RequestData/RequestData.cpp`
+

examples/request_data/main.go

@@ -12,11 +12,17 @@ import (
 
 type Report struct {
 	simconnect.RecvSimobjectDataByType
-	Title     [256]byte
-	Kohlsman  float64
-	Altitude  float64
-	Latitude  float64
-	Longitude float64
+	Title     [256]byte `name:"TITLE"`
+	Kohlsman  float64   `name:"Kohlsman setting hg" unit:"inHg"`
+	Altitude  float64   `name:"Plane Altitude" unit:"feet"`
+	Latitude  float64   `name:"Plane Latitude" unit:"degrees"`
+	Longitude float64   `name:"Plane Longitude" unit:"degrees"`
+}
+
+func (r *Report) RequestData(s *simconnect.SimConnect) {
+	defineID := s.GetDefineID(r)
+	requestID := defineID
+	s.RequestDataOnSimObjectType(requestID, defineID, 0, simconnect.SIMOBJECT_TYPE_USER)
 }
 
 func main() {
@@ -26,19 +32,15 @@ func main() {
 	}
 	fmt.Println("Connected to Flight Simulator!")
 
-	defineID := simconnect.DWORD(0)
-	s.AddToDataDefinition(defineID, "Title", "", simconnect.DATATYPE_STRING256)
-	s.AddToDataDefinition(defineID, "Kohlsman setting hg", "inHg", simconnect.DATATYPE_FLOAT64)
-	s.AddToDataDefinition(defineID, "Plane Altitude", "feet", simconnect.DATATYPE_FLOAT64)
-	s.AddToDataDefinition(defineID, "Plane Latitude", "degrees", simconnect.DATATYPE_FLOAT64)
-	s.AddToDataDefinition(defineID, "Plane Longitude", "degrees", simconnect.DATATYPE_FLOAT64)
+	report := &Report{}
+	s.RegisterDataDefinition(report)
+	report.RequestData(s)
 
-	fmt.Println("SubscribeToSystemEvent")
-	eventSimStartID := simconnect.DWORD(0)
-	s.SubscribeToSystemEvent(eventSimStartID, "SimStart")
-
-	requestID := simconnect.DWORD(0)
-	s.RequestDataOnSimObjectType(requestID, defineID, 0, simconnect.SIMOBJECT_TYPE_USER)
+	/*
+		fmt.Println("SubscribeToSystemEvent")
+		eventSimStartID := simconnect.DWORD(0)
+		s.SubscribeToSystemEvent(eventSimStartID, "SimStart")
+	*/
 
 	for {
 		ppData, r1, err := s.GetNextDispatch()
@@ -70,8 +72,8 @@ func main() {
 			//spew.Dump(recvEvent)
 
 			switch recvEvent.EventID {
-			case eventSimStartID:
-				fmt.Println("SimStart Event")
+			//case eventSimStartID:
+			//	fmt.Println("SimStart Event")
 			default:
 				fmt.Println("unknown SIMCONNECT_RECV_ID_EVENT", recvEvent.EventID)
 			}
@@ -81,10 +83,10 @@ func main() {
 			fmt.Println("SIMCONNECT_RECV_SIMOBJECT_DATA_BYTYPE")
 
 			switch recvData.RequestID {
-			case requestID:
-				report := *(*Report)(ppData)
+			case s.DefineMap["Report"]:
+				report := (*Report)(ppData)
 				fmt.Printf("REPORT: %s: GPS: %.6f,%.6f Altitude: %.0f\n", report.Title, report.Latitude, report.Longitude, report.Altitude)
-				s.RequestDataOnSimObjectType(requestID, defineID, 0, simconnect.SIMOBJECT_TYPE_USER)
+				report.RequestData(s)
 			}
 
 		default:

simconnect/defs.go

@@ -1,5 +1,7 @@
 package simconnect
 
+import "fmt"
+
 // MSFS-SDK/SimConnect\ SDK/include/SimConnect.h
 
 const E_FAIL uint32 = 0x80004005
@@ -30,6 +32,36 @@ const (
 	DATATYPE_MAX // enum limit
 )
 
+func derefDataType(fieldType string) (DWORD, error) {
+	var dataType DWORD
+	switch fieldType {
+	case "int32":
+		dataType = DATATYPE_INT32
+	case "int64":
+		dataType = DATATYPE_INT64
+	case "float32":
+		dataType = DATATYPE_FLOAT32
+	case "float64":
+		dataType = DATATYPE_FLOAT64
+	case "[8]byte":
+		dataType = DATATYPE_STRING8
+	case "[32]byte":
+		dataType = DATATYPE_STRING32
+	case "[64]byte":
+		dataType = DATATYPE_STRING64
+	case "[128]byte":
+		dataType = DATATYPE_STRING128
+	case "[256]byte":
+		dataType = DATATYPE_STRING256
+	case "[260]byte":
+		dataType = DATATYPE_STRING260
+	default:
+		return 0, fmt.Errorf("DATATYPE not implemented: %s", fieldType)
+	}
+
+	return dataType, nil
+}
+
 const (
 	RECV_ID_NULL DWORD = iota
 	RECV_ID_EXCEPTION

simconnect/simconnect.go

@@ -10,6 +10,7 @@ import (
 	"io/ioutil"
 	"os"
 	"path/filepath"
+	"reflect"
 	"syscall"
 	"unsafe"
 )
@@ -22,11 +23,14 @@ var proc_SimConnect_GetNextDispatch *syscall.LazyProc
 var proc_SimConnect_RequestDataOnSimObjectType *syscall.LazyProc
 
 type SimConnect struct {
-	handle unsafe.Pointer
+	handle    unsafe.Pointer
+	DefineMap map[string]DWORD
 }
 
 func New(name string) (*SimConnect, error) {
-	s := &SimConnect{}
+	s := &SimConnect{
+		DefineMap: map[string]DWORD{"_last": 0},
+	}
 
 	if proc_SimConnect_Open == nil {
 		exePath, err := os.Executable()
@@ -81,6 +85,49 @@ func New(name string) (*SimConnect, error) {
 	return s, nil
 }
 
+func (s *SimConnect) GetDefineID(a interface{}) DWORD {
+	structName := reflect.TypeOf(a).Elem().Name()
+
+	id, ok := s.DefineMap[structName]
+	if !ok {
+		id = s.DefineMap["_last"]
+		s.DefineMap[structName] = id
+		s.DefineMap["_last"] = id + 1
+	}
+
+	return id
+}
+
+func (s *SimConnect) RegisterDataDefinition(a interface{}) error {
+	defineID := s.GetDefineID(a)
+
+	v := reflect.ValueOf(a).Elem()
+	for j := 1; j < v.NumField(); j++ {
+		fieldName := v.Type().Field(j).Name
+		nameTag, _ := v.Type().Field(j).Tag.Lookup("name")
+		unitTag, _ := v.Type().Field(j).Tag.Lookup("unit")
+
+		fieldType := v.Field(j).Kind().String()
+		if fieldType == "array" {
+			fieldType = fmt.Sprintf("[%d]byte", v.Field(j).Type().Len())
+		}
+
+		if nameTag == "" {
+			return fmt.Errorf("%s name tag not found", fieldName)
+		}
+
+		dataType, err := derefDataType(fieldType)
+		if err != nil {
+			return err
+		}
+
+		s.AddToDataDefinition(defineID, nameTag, unitTag, dataType)
+		//fmt.Printf("fieldName: %s  fieldType: %s  nameTag: %s unitTag: %s\n", fieldName, fieldType, nameTag, unitTag)
+	}
+
+	return nil
+}
+
 func (s *SimConnect) Close() error {
 	// SimConnect_Open(
 	//   HANDLE * phSimConnect,

vfrmap/README.md

@@ -0,0 +1,30 @@
+# msfs2020-go/vfrmap
+
+web server that shows your current MSFS2020 plane position in google maps inside the browser
+
+## install
+
+* download latest release zip [here](https://github.com/lian/msfs2020-go/releases)
+* unzip `vfrmap-win64.zip`
+
+## run
+* run `vfrmap.exe`
+* browse to http://localhost:9000
+
+## arguments
+
+* `-v` show program version
+* `-api-key` use your own gmap api-key
+* `-verbose` verbose output
+
+## change visualisation
+
+if you want to change how the webpage looks then copy and change [index.html](html/index.html) to the same folder as `vfrmap.exe` and relaunch the program.
+
+## compile
+
+`GOOS=windows GOARCH=amd64 go build github.com/lian/msfs2020-go/vfrmap` or see [build-vfrmap.sh](https://github.com/lian/msfs2020-go/blob/master/build-vfrmap.sh)
+
+## screenshots
+
+![screenshot](https://i.imgur.com/YllMEvG.png)

vfrmap/main.go

@@ -22,16 +22,22 @@ import (
 
 type Report struct {
 	simconnect.RecvSimobjectDataByType
-	Title         [256]byte
-	Altitude      float64
-	Latitude      float64
-	Longitude     float64
-	Heading       float64
-	Airspeed      float64
-	VerticalSpeed float64
-	Flaps         float64
-	Trim          float64
-	RudderTrim    float64
+	Title         [256]byte `name:"TITLE"`
+	Altitude      float64   `name:"INDICATED ALTITUDE" unit:"feet"` // PLANE ALTITUDE or PLANE ALT ABOVE GROUND
+	Latitude      float64   `name:"PLANE LATITUDE" unit:"degrees"`
+	Longitude     float64   `name:"PLANE LONGITUDE" unit:"degrees"`
+	Heading       float64   `name:"PLANE HEADING DEGREES TRUE" unit:"degrees"`
+	Airspeed      float64   `name:"AIRSPEED INDICATED" unit:"knot"`
+	VerticalSpeed float64   `name:"VERTICAL SPEED" unit:"ft/min"`
+	Flaps         float64   `name:"TRAILING EDGE FLAPS LEFT ANGLE" unit:"degrees"`
+	Trim          float64   `name:"ELEVATOR TRIM PCT" unit:"percent"`
+	RudderTrim    float64   `name:"RUDDER TRIM PCT" unit:"percent"`
+}
+
+func (r *Report) RequestData(s *simconnect.SimConnect) {
+	defineID := s.GetDefineID(r)
+	requestID := defineID
+	s.RequestDataOnSimObjectType(requestID, defineID, 0, simconnect.SIMOBJECT_TYPE_USER)
 }
 
 var buildVersion string
@@ -46,7 +52,7 @@ var mapApiKey string
 func main() {
 	flag.BoolVar(&showVersion, "v", false, "version")
 	flag.BoolVar(&verbose, "verbose", false, "verbose output")
-	flag.StringVar(&httpListen, "listen", "localhost:9000", "http listen")
+	flag.StringVar(&httpListen, "listen", "0.0.0.0:9000", "http listen")
 	flag.StringVar(&mapApiKey, "api-key", "", "gmap api-key")
 	flag.Parse()
 
@@ -71,29 +77,20 @@ func main() {
 	}
 	fmt.Println("Connected to Flight Simulator!")
 
-	defineID := simconnect.DWORD(0)
-	requestID := simconnect.DWORD(0)
-	s.AddToDataDefinition(defineID, "Title", "", simconnect.DATATYPE_STRING256)
-	s.AddToDataDefinition(defineID, "INDICATED ALTITUDE", "feet", simconnect.DATATYPE_FLOAT64)
-	//s.AddToDataDefinition(defineID, "PLANE ALT ABOVE GROUND", "feet", simconnect.DATATYPE_FLOAT64)
-	//s.AddToDataDefinition(defineID, "PLANE ALTITUDE", "feet", simconnect.DATATYPE_FLOAT64)
-	s.AddToDataDefinition(defineID, "PLANE LATITUDE", "degrees", simconnect.DATATYPE_FLOAT64)
-	s.AddToDataDefinition(defineID, "PLANE LONGITUDE", "degrees", simconnect.DATATYPE_FLOAT64)
-	s.AddToDataDefinition(defineID, "PLANE HEADING DEGREES TRUE", "degrees", simconnect.DATATYPE_FLOAT64)
-	s.AddToDataDefinition(defineID, "AIRSPEED INDICATED", "knot", simconnect.DATATYPE_FLOAT64)
-	s.AddToDataDefinition(defineID, "VERTICAL SPEED", "ft/min", simconnect.DATATYPE_FLOAT64)
-	s.AddToDataDefinition(defineID, "TRAILING EDGE FLAPS LEFT ANGLE", "degrees", simconnect.DATATYPE_FLOAT64)
-	s.AddToDataDefinition(defineID, "ELEVATOR TRIM PCT", "percent", simconnect.DATATYPE_FLOAT64)
-	s.AddToDataDefinition(defineID, "RUDDER TRIM PCT", "percent", simconnect.DATATYPE_FLOAT64)
+	report := &Report{}
+	err = s.RegisterDataDefinition(report)
+	if err != nil {
+		panic(err)
+	}
+
+	report.RequestData(s)
 
 	/*
 		fmt.Println("SubscribeToSystemEvent")
 		eventSimStartID := simconnect.DWORD(0)
 		s.SubscribeToSystemEvent(eventSimStartID, "SimStart")
 	*/
 
-	s.RequestDataOnSimObjectType(requestID, defineID, 0, simconnect.SIMOBJECT_TYPE_USER)
-
 	go func() {
 		for {
 			ppData, r1, err := s.GetNextDispatch()
@@ -136,9 +133,8 @@ func main() {
 				//fmt.Println("SIMCONNECT_RECV_SIMOBJECT_DATA_BYTYPE")
 
 				switch recvData.RequestID {
-				case requestID:
-					report := *(*Report)(ppData)
-					//fmt.Printf("REPORT: %s: GPS: %.6f,%.6f Altitude: %.0f Heading: %.1f\n", report.Title, report.Latitude, report.Longitude, report.Altitude, report.Heading)
+				case s.DefineMap["Report"]:
+					report = (*Report)(ppData)
 
 					if verbose {
 						fmt.Printf("REPORT: %#v\n", report)
@@ -156,7 +152,7 @@ func main() {
 						"rudder_trim":    fmt.Sprintf("%.1f", report.RudderTrim),
 					})
 
-					s.RequestDataOnSimObjectType(requestID, defineID, 0, simconnect.SIMOBJECT_TYPE_USER)
+					report.RequestData(s)
 				}
 
 			default: