add arc and alt

Kconfig

@@ -92,7 +92,7 @@ config METRIC
 	bool "Use metric units"
 	default y
 	help
-	  Show altitudes in meters instead of feet.
+	  Show units in metric instead of aeronautical.
 
 comment "Platform dependent options"
 

src/core/units.hpp

@@ -14,3 +14,9 @@ static inline T knot_to_km(T kt) {
 #else
 #define SPEED_UNIT "knot"
 #endif
+
+#ifdef CONFIG_METRIC
+#define ALTITUDE_UNIT "m"
+#else
+#define ALTITUDE_UNIT "ft"
+#endif

src/hal/draw.hpp

@@ -20,4 +20,5 @@ struct rect_t {
         void circle(const uint16_t x_center, const uint16_t y_center,const uint16_t radius, const color_t color);
         void rhombus(const uint16_t x_center, const uint16_t y_center,const uint16_t radius, const color_t color);
         void line(const uint16_t x1,const uint16_t y1,const uint16_t x2,const uint16_t y2, const color_t color);
+        void arc(uint16_t start_x, uint16_t start_y, float start_angle, float speed /*in pps*/,float angular_speed, uint16_t duration, color_t color);
 }

src/hal/hal_linux.cpp

@@ -25,6 +25,7 @@
 #include <iostream>
 #include <nlohmann/json.hpp>
 #include <nlohmann/json_fwd.hpp>
+#include <numbers>
 #include <tuple>
 
 struct sdl_session {
@@ -221,6 +222,48 @@ void line(const uint16_t x1, const uint16_t y1, const uint16_t x2,
                          0xff);
   SDL_RenderLine(main_sdl_session.renderer, x1, y1, x2, y2);
 }
+
+#ifdef CONFIG_VECTOR_FOLLOW_TRACK_RATE
+void arc(uint16_t start_x, uint16_t start_y, float start_angle_rad, float speed /*in pps*/,float angular_speed_rads, uint16_t duration, color_t color) {
+  SDL_SetRenderDrawColor(main_sdl_session.renderer, color.r, color.g, color.b,
+                         0xff);
+  constexpr float DEG2RAD = std::numbers::pi / 180.0f;
+
+
+    // Handle straight line case
+    if (std::fabs(angular_speed_rads) < 1e-6f) {
+        uint16_t steps = static_cast<int>(speed * duration);
+        for (uint16_t i = 0; i <= steps; ++i) {
+            float t = i / speed;
+            float x = start_x + std::cos(start_angle_rad) * speed * t;
+            float y = start_y + std::sin(start_angle_rad) * speed * t;
+            SDL_RenderPoint(main_sdl_session.renderer,static_cast<int>(std::round(x)), static_cast<int>(std::round(y)));
+        }
+        return;
+    }
+
+    float r = speed / angular_speed_rads;
+
+    // Center of circle: perpendicular to heading
+    float center_x = start_x - r * std::sin(start_angle_rad);
+    float center_y = start_y + r * std::cos(start_angle_rad);
+
+    // Angle from center to start point
+    float radius_angle = std::atan2(start_y - center_y, start_x - center_x);
+
+    // Step size in time — approx 1 pixel arc-length per step
+    float dt = 1.0f / std::max(std::fabs(speed), 1.0f);
+    uint16_t steps = static_cast<int>(duration / dt);
+
+    for (uint16_t i = 0; i <= steps; ++i) {
+        float t = i * dt;
+        float a = radius_angle + angular_speed_rads * t;
+        float x = center_x + std::fabs(r) * std::cos(a);
+        float y = center_y + std::fabs(r) * std::sin(a);
+        SDL_RenderPoint(main_sdl_session.renderer,static_cast<int>(std::round(x)), static_cast<int>(std::round(y)));
+    }
+}
+#endif
 } // namespace draw
 
 namespace net {

src/main.cpp

@@ -111,21 +111,21 @@ int main() {
                                   " aircraft with no alt data detected!\n";
               altitude = 0;
             }
-            #ifndef CONFIG_METRIC
+#ifndef CONFIG_METRIC
             // aircraft ground speed in knots
             float speed_knot;
-            #endif
+#endif
             // aircraft ground speed in km/h
             float speed;
             // aircraft track in degreees
             float track;
             try {
-              #ifdef CONFIG_METRIC
+#ifdef CONFIG_METRIC
               speed = knot_to_km(craft["gs"].get<float>());
-              #else
+#else
-              speed_knot = craft["gs"].get<float>();
+            speed_knot = craft["gs"].get<float>();
-              speed = knot_to_km(speed_knot);
+            speed = knot_to_km(speed_knot);
-              #endif
+#endif
 
               track = craft["track"].get<float>();
             } catch (...) {
@@ -164,11 +164,24 @@ int main() {
               const float track_rad =
                   std::fmod((track - 90), 365.0f) *
                   (static_cast<float>(std::numbers::pi) / 180.0f);
-
+#ifdef CONFIG_VECTOR_FOLLOW_TRACK_RATE
-              draw::line(x_center, y_center,
+{
-                         x_center + (vector_lenght * std::cos(track_rad)),
+              float track_rate_rads;
-                         y_center + (vector_lenght * std::sin(track_rad)),
+              try {
-                         color);
+                track_rate_rads = craft["track_rate"].get<float>() * (static_cast<float>(std::numbers::pi) / 180.0f);
+              } catch (...) {
+                std::clog << YELLOW
+                  "[WARNING]" RESET
+                  " aircraft with no track_rate data detected!\n";
+                  track_rate_rads = 0;
+              }
+                draw::arc(x_center, y_center,track_rad,speed_pph/3600,track_rate_rads,CONFIG_TIME_BASED_VECTOR_LENGHT*60,color);
+              }
+#else
+            draw::line(x_center, y_center,
+                       x_center + (vector_lenght * std::cos(track_rad)),
+                       y_center + (vector_lenght * std::sin(track_rad)), color);
+#endif
               draw::rhombus(x_center, y_center, 8 /*TODO: remove magic*/,
                             color);
 
@@ -182,14 +195,20 @@ int main() {
                   callsign = CONFIG_NO_CALLSIGN_IDENTIFICATION;
                 }
                 // print some info
-                font::puts(callsign, x_center + 10 /*TODO: remove magic*/, y_center, color);
+                font::puts(callsign, x_center + 10 /*TODO: remove magic*/,
+                           y_center, color);
                 font::puts(std::to_string(static_cast<uint16_t>(
-                  #ifdef CONFIG_METRIC
+#ifdef CONFIG_METRIC
-                  speed
+                               speed
-                  #else 
+#else
-                  speed_knot
+                             speed_knot
-                  #endif
+#endif
-                )) + SPEED_UNIT, x_center + 10 /*TODO: remove magic*/, y_center + FONT_HEIGHT +CONFIG_CHARACTER_SPACING, color);
+                               )) +
+                               SPEED_UNIT,
+                           x_center + 10 /*TODO: remove magic*/,
+                           y_center + FONT_HEIGHT + CONFIG_CHARACTER_SPACING,
+                           color);
+                font::puts(std::to_string(altitude) + ALTITUDE_UNIT, x_center + 10 /*TODO: remove magic*/, y_center + (FONT_HEIGHT + CONFIG_CHARACTER_SPACING)*2,color);
               }
             } catch (...) {
               std::clog << YELLOW "[WARNING]" RESET
@@ -197,7 +216,7 @@ int main() {
             }
           }
         } else {
-          // TODO draw vizual error
+          // TODO draw visual error
           std::cerr << RED "[ERROR]" RESET " failed to get aircraft\n";
         }
       }