feat: implement WebRTC signaling and UDP-based video streaming and control service

server/cmd/poc-server/main.go

@@ -27,11 +27,13 @@ package main
 import (
 	"bufio"
 	"context"
+	"encoding/hex"
 	"encoding/json"
 	"errors"
 	"flag"
 	"fmt"
 	"log/slog"
+	"math"
 	"net"
 	"net/http"
 	"os"
@@ -685,6 +687,9 @@ func handleInput(c *realtime.Client, e *control.Engine, lobbySvc *lobby.Service,
 	if v, ok := payload["gear"].(float64); ok {
 		in.Gear = int(v)
 	}
+	if v, ok := payload["buttons"].(float64); ok {
+		in.Buttons = uint32(v)
+	}
 	car := e.GetCarByDriver(c.ID)
 	if car == nil {
 		return
@@ -693,21 +698,43 @@ func handleInput(c *realtime.Client, e *control.Engine, lobbySvc *lobby.Service,
 
 	// Forward command transitions to ESP32 physical car if car has a device_id assigned
 	if car.DeviceID != nil {
-		var cmd string
-		if in.Throttle > 0.1 {
-			cmd = "start"
-		} else {
-			cmd = "stop"
-		}
-		if in.Steering < -0.2 {
-			cmd = "left"
-		} else if in.Steering > 0.2 {
-			cmd = "right"
-		}
+		var packet [5]byte
 
-		if cmd != "" && cmd != c.LastUDPCommand {
-			c.LastUDPCommand = cmd
-			_ = videoSvc.SendCommand(uint8(*car.DeviceID), cmd)
+		// 1. Steer: mapping float64 [-1.0, 1.0] to [0..200] (100 is center)
+		steerVal := int(math.Round((in.Steering + 1.0) * 100.0))
+		if steerVal < 0 { steerVal = 0 }
+		if steerVal > 200 { steerVal = 200 }
+		packet[0] = uint8(steerVal)
+
+		// 2. Throttle: mapping float64 [0.0, 1.0] to [0..100]
+		throttleVal := int(math.Round(in.Throttle * 100.0))
+		if throttleVal < 0 { throttleVal = 0 }
+		if throttleVal > 100 { throttleVal = 100 }
+		packet[1] = uint8(throttleVal)
+
+		// 3. Brake: mapping float64 [0.0, 1.0] to [0..100]
+		brakeVal := int(math.Round(in.Brake * 100.0))
+		if brakeVal < 0 { brakeVal = 0 }
+		if brakeVal > 100 { brakeVal = 100 }
+		packet[2] = uint8(brakeVal)
+
+		// 4. Gear: map -1 to 0 (R), 0 to 1 (N), >=1 to 2 (D)
+		gearVal := 1 // Neutral by default
+		if in.Gear < 0 {
+			gearVal = 0 // R
+		} else if in.Gear > 0 {
+			gearVal = 2 // D
+		}
+		packet[3] = uint8(gearVal)
+
+		// 5. Flags: bit 0 (DRS), bit 1 (Pit Limiter)
+		packet[4] = uint8(in.Buttons & 0x03)
+
+		// Deduplicate UDP transmissions
+		hexCmd := hex.EncodeToString(packet[:])
+		if hexCmd != c.LastUDPCommand {
+			c.LastUDPCommand = hexCmd
+			_ = videoSvc.SendControlPacket(uint8(*car.DeviceID), packet)
 		}
 	}