Release 0.2.0: add high/low arc selection

Author: ujinf74

.gitignore

@@ -49,4 +49,6 @@ Thumbs.db
 # Python
 __pycache__/
 *.py[cod]
-
+**/*.egg-info/
+.venv/
+venv/

CMakeLists.txt

@@ -1,7 +1,7 @@
 cmake_minimum_required(VERSION 3.16)
 
 project(ballistic_solver
-    VERSION 0.1.0
+    VERSION 0.2.0
     LANGUAGES CXX
 )
 
@@ -25,6 +25,8 @@ add_library(ballistic_c SHARED
     src/ballistic_c_api.cpp
 )
 
+target_compile_definitions(ballistic_c PRIVATE BALLISTIC_C_EXPORTS)
+
 target_link_libraries(ballistic_c
     PRIVATE
         ballistic

README.md

@@ -59,6 +59,18 @@ This project instead **simulates the projectile** and **solves the intercept num
 * **Explicit success / failure reporting**
 * **Stable C ABI for multi-language use**
 * **Header-only C++ core**
+* **Low / High arc selection (v0.2.0)**
+
+---
+
+## Arc mode (v0.2.0)
+
+The solver can be guided to converge to either the **low arc** or the **high arc** solution.
+
+C ABI convention:
+
+* `arcMode = 0` → Low
+* `arcMode = 1` → High
 
 ---
 

examples/basic.cpp

@@ -1,24 +1,33 @@
 #include <iostream>
+#include <chrono>
 #include "ballistic/ballistic_solver.hpp"
 
+#ifndef M_PI
+#define M_PI 3.141592653589793238462643383279502884
+#endif
+
 int main()
 {
     // Target state relative to the projectile at t = 0
     Vec3 relPos0 = { 100.0, 30.0, 10.0 };
-    Vec3 relVel  = { 10.0, -30.0, 0.0 };
+    Vec3 relVel  = { 5.0, -10.0, 0.0 };
 
     // Projectile parameters
     double v0 = 80.0;     // initial speed magnitude
     double kDrag = 0.005; // drag coefficient
 
     // Solver configuration
     BallisticParams P;
+    P.arcMode = ArcMode::Low;   // or ArcMode::High
+    P.g = 9.80665;        // gravity
     P.dt = 0.01;          // integration step
     P.tMax = 20.0;        // max simulation time
-    P.tolMiss = 1e-4;     // success tolerance
+    P.tolMiss = 1e-2;     // success tolerance
 
     // Solve launch angles
+    auto t0 = std::chrono::steady_clock::now();
     SolverResult r = solve_launch_angles(relPos0, relVel, v0, kDrag, P);
+    auto t1 = std::chrono::steady_clock::now();
 
     // Output results
     std::cout << "success    : " << r.success << "\n";
@@ -31,5 +40,8 @@ int main()
     std::cout << "message    : " << r.report.message
               << " (status : " << static_cast<int>(r.report.status) << ")\n";
 
+    double ms = std::chrono::duration<double, std::milli>(t1 - t0).count();
+    std::cout << "elapsed    : " << ms << " ms\n";
+
     return 0;
 }

…p/BallisticCSharp/BallisticCSharp.csproj examples/csharp/BallisticCSharp.csprojexamples/csharp/BallisticCSharp/BallisticCSharp.csproj renamed to examples/csharp/BallisticCSharp.csproj examples/csharp/BallisticCSharp/BallisticCSharp.csproj renamed to examples/csharp/BallisticCSharp.csproj

@@ -8,8 +8,10 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <None Include="ballistic_c.dll">
+    <None Include="..\..\build\$(Configuration)\ballistic_c.dll">
+      <Link>ballistic_c.dll</Link>
       <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
     </None>
   </ItemGroup>
-</Project>
+
+</Project>

examples/csharp/BallisticCSharp/Program.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Runtime.InteropServices;
+using System.Text;
 
 [StructLayout(LayoutKind.Sequential, Pack = 8)]
 public struct BallisticInputs
@@ -13,6 +14,9 @@ public struct BallisticInputs
     public double v0;
     public double kDrag;
 
+    public Int32 arcMode;
+    public double g;
+
     public double dt;
     public double tMax;
     public double tolMiss;
@@ -33,19 +37,25 @@ public struct BallisticOutputs
     [MarshalAs(UnmanagedType.ByValArray, SizeConst = 3)]
     public double[] relMissAtStar;
 
-    [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 256)]
-    public string message;
+    [MarshalAs(UnmanagedType.ByValArray, SizeConst = 256)]
+    public byte[] message;
 }
 
 public static class BallisticNative
 {
-    // Windows: ballistic_c.dll must be in the executable directory or PATH
     [DllImport("ballistic_c.dll", CallingConvention = CallingConvention.Cdecl)]
     public static extern Int32 ballistic_solve(ref BallisticInputs input, out BallisticOutputs output);
 }
 
 public class Program
 {
+    private static string CStr(byte[] bytes)
+    {
+        int n = Array.IndexOf(bytes, (byte)0);
+        if (n < 0) { n = bytes.Length; }
+        return Encoding.UTF8.GetString(bytes, 0, n);
+    }
+
     public static void Main()
     {
         var input = new BallisticInputs
@@ -54,6 +64,10 @@ public static void Main()
             relVel  = new double[] { 2.0, -1.0, 0.0 },
             v0 = 90.0,
             kDrag = 0.002,
+
+            arcMode = 0,      // Low
+            g = 9.80665,      // default gravity
+
             dt = 0.01,
             tMax = 30.0,
             tolMiss = 0.5,
@@ -71,6 +85,6 @@ public static void Main()
         Console.WriteLine($"miss={output.miss}");
         Console.WriteLine($"tStar={output.tStar}");
         Console.WriteLine($"relMiss=[{output.relMissAtStar[0]}, {output.relMissAtStar[1]}, {output.relMissAtStar[2]}]");
-        Console.WriteLine($"message={output.message}");
+        Console.WriteLine($"message={CStr(output.message)}");
     }
-}
+}

examples/csharp/Program.cs

@@ -23,6 +23,8 @@ typedef struct BallisticInputs
     double v0;
     double kDrag;
 
+    int32_t arcMode; // 0=Low, 1=High
+    double g;
     double dt;
     double tMax;
     double tolMiss;